3,119 research outputs found

    The free encyclopaedia that anyone can edit: the shifting values of Wikipedia editors

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    Wikipedia is often held up as an example of the potential of the internet to foster open, free and non-commercial collaboration. However such discourses often conflate these values without recognising how they play out in reality in a peer-production community. As Wikipedia is evolving, it is an ideal time to examine these discourses and the tensions that exist between its initial ideals and the reality of commercial activity in the encyclopaedia. Through an analysis of three failed proposals to ban paid advocacy editing in the English language Wikipedia, this paper highlights the shift in values from the early editorial community that forked encyclopaedic content over the threat of commercialisation, to one that today values the freedom that allows anyone to edit the encyclopaedia

    An exergy approach to efficiency evaluation of desalination

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    This paper presents an evaluation process efficiency based on the consumption of primary energy for all types of practical desalination methods available hitherto. The conventional performance ratio has, thus far, been defined with respect to the consumption of derived energy, such as the electricity or steam, which are susceptible to the conversion losses of power plants and boilers that burned the input primary fuels. As derived energies are usually expressed by the units, either kWh or Joules, these units cannot differentiate the grade of energy supplied to the processes accurately. In this paper, the specific energy consumption is revisited for the efficacy of all large-scale desalination plants. In today's combined production of electricity and desalinated water, accomplished with advanced cogeneration concept, the input exergy of fuels is utilized optimally and efficiently in a temperature cascaded manner. By discerning the exergy destruction successively in the turbines and desalination processes, the relative contribution of primary energy to the processes can be accurately apportioned to the input primary energy. Although efficiency is not a law of thermodynamics, however, a common platform for expressing the figures of merit explicit to the efficacy of desalination processes can be developed meaningfully that has the thermodynamic rigor up to the ideal or thermodynamic limit of seawater desalination for all scientists and engineers to aspire to

    Response to Corner Brook Pulp & Paper Tire Derived Fuel (TDF) Co-Firing Trial Project Proponent: Corner Brook Pulp & Paper Ltd. (Reg. 1539)

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    While acknowledging potential economic benefits for Corner Brook Pulp and Paper (CBPP) in using tire-derived fuel (TDF), we remain unconvinced of the net public and environmental health benefits of its use and are concerned with the methodology of the proposed test. We hope that this overview of our concerns can help the Department of Environment and Conservation (DEC) make an informed decision regarding the testing of TDF at CBPP. Guiding our submission is the precautionary principle, which has been adopted by all relevant parties, including the Government of Canada, the Government of Newfoundland and Labrador and CBPP. As such and in light of the issues below, it is our position that additional research is required before moving to a test trial. This can be achieved either by conducting a full Environmental Impact Statement, including component studies and additional public hearings, or by rejecting the undertaking outright

    Astrophysical parameters of ten poorly studied open star clusters

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    We present here the fundamental parameters of ten open star clusters, nominated from Kronberger et al. (2006) who presented some new discovered stellar groups on the basis of 2MASS photometry and DSS visual images. Star counts and photometric parameters (radius, membership, distances, color excess, age, luminosity function, mass function, total mass, and the dynamical relaxation time) have been determined for these ten clusters for the first time. In order to calibrate our procedures, the main parameters (distance, age, and color excesses) have been re-estimated for another five clusters, which are studied by Kronberger et al. (2006) as well.Comment: 10 pages, 5 figures, 2 tables; accepted in "Research in Astronomy and Astrophysics Journal

    Numerical studies on added resistance and motions of KVLCC2 in head seas for various ship speeds

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    In this study, numerical simulations for the prediction of added resistance and ship motions at various ship speeds and wave steepnesses for the KVLCC2 are presented. These are calculated using URANS CFD and 3-D potential methods, both in regular head seas. Numerical analysis is focused on the added resistance and the vertical ship motions for a wide range of wave conditions at stationary, operating and design speeds. Firstly, the characteristics of the CFD and the 3-D potential method are presented. Simulations of various wave conditions at design speed are used as a validation study, and then simulations are carried out at stationary and operating speed. Secondly, unsteady wave patterns and time history results of the added resistance and the ship motions are simulated and analysed at each ship speed using the CFD tool. Finally, the relationship between the added resistance and the vertical ship motions is studied in detail and the non-linearity of the added resistance and ship motions with the varying wave steepness are investigated. Systematic studies of the numerical computations at various ship speeds are conducted as well as the grid convergence tests, to show that the numerical results have a reasonable agreement with the available EFD results

    The condensin complexes play distinct roles to ensure normal chromosome morphogenesis during meiotic division in Arabidopsis

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    Meiosis is a specialized cell division essential for sexual reproduction. During meiosis the chromosomes are highly organized, and correct chromosome architecture is required for faithful segregation of chromosomes at anaphase I and II. Condensin is involved in chromosome organization during meiotic and mitotic cell divisions. Three condensin subunits, AtSMC4 and the condensin I and II specific subunits AtCAP-D2 and AtCAP-D3, respectively, have been studied for their role in meiosis. This has revealed that both the condensin I and condensin II complexes are required to maintain normal structural integrity of the meiotic chromosomes during the two nuclear divisions. Their roles appear functionally distinct in that condensin I is required to maintain normal compaction of the centromeric repeats and 45S rDNA, whereas loss of condensin II was associated with extensive interchromosome connections at metaphase I. Depletion of condensin is also associated with a slight reduction in crossover formation, suggesting a role during meiotic prophase I

    Estimation of added resistance and ship speed loss in a seaway

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    The prediction of the added resistance and attainable ship speed under actual weather conditions is essential to evaluate the true ship performance in operating conditions and assess environmental impact. In this study, a reliable methodology is proposed to estimate the ship speed loss of the S175 container ship in specific sea conditions of wind and waves. Firstly, the numerical simulations are performed to predict the added resistance and ship motions in regular head and oblique seas using three different methods; a 2-D and 3-D potential flow method and a Computational Fluid Dynamics (CFD) with an Unsteady Reynolds-Averaged Navier-Stokes (URANS) approach. Simulations of various wave conditions are compared with the available experimental data and these are used in a validation study. Secondly, following the validation study in regular waves, the ship speed loss is estimated using the developed methodology by calculating the resistance in calm water and the added resistance due to wind and irregular waves, taking into account relevant wave parameters and wind speed corresponding to the Beaufort scale, and results are compared with simulation results obtained by other researchers. Finally, the effect of the variation in ship speed and therefore the ship speed loss is investigated. This study shows the capabilities of the 2-D and 3-D potential methods and CFD to calculate the added resistance and ship motions in regular waves in various wave headings. It also demonstrates that the proposed methodology can estimate the impacts on the ship operating speed and the required sea margin in irregular seas

    Ultraviolet-c haematogenous oxidation therapy of lipopolysaccharide-induced endotoxemia in a rabbit model: A biochemical study

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    Systemic inflammatory reaction – due to severe response to toxins of infection associated with immune inhibition – leads to multi-organ dysfunctions and high mortality. Ultraviolet (UV) blood is used for its therapeutic effects when moving across the cells. This study aims to evaluate the impact of UV-c Haematogenous Oxidation Therapy (HOT) in Lipopolysaccharide (LPS)-induced endotoxemia of rabbit model. A total of 40 rabbits randomly divided into four groups, including normal control (NC). LPS and LPS+UV-c HOT groups received 0.1 mg/kg LPS toxin of E. coli, UV-c HOT and LPS+UV-c HOT groups subjected to UV-c HOT treatments once weekly for five times. Blood collected, perfused with oxygen, UV-c directly irradiated into blood, and then auto-transfused. Rabbits were sacrificed after five weeks; blood and serum were collected for analysis. The survival rate, liver, kidney, lipid profile, and blood ions were assessed in treated rabbits. Mortality was 40% in the LPS group, while other groups showed no death. UV-c HOT enhanced critical pH, base deficit, blood gases, hypomagnesemia, hyperlactatemia, and concurrent acidosis. Besides, TNF-α, nitrite, and nitrate were suppressed in response to UV-c HOT. Moreover, UV-c HOT reduced liver and kidney enzymes, improved lipid metabolism, and ameliorated electrolytes homeostasis. Despite that, UV-c HOT performance in ICU for human and animal endotoxemic or septic patients should be evaluated and considered

    Ultraviolet-C haematogenous oxidation therapy of lipopolysaccharide-induced endotoxemia in a rabbit model: A biochemical study

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    445-454Systemic inflammatory reaction – due to severe response to toxins of infection associated with immune inhibition – leads to multi-organ dysfunctions and high mortality. Ultraviolet (UV) blood is used for its therapeutic effects when moving across the cells. This study aims to evaluate the impact of UV-C Haematogenous Oxidation Therapy (HOT) in Lipopolysaccharide (LPS)-induced endotoxemia of rabbit model. A total of 40 rabbits randomly divided into four groups, including normal control (NC). LPS and LPS+UV-C HOT groups received 0.1 mg/kg LPS toxin of E. coli, UV-C HOT and LPS+UV-C HOT groups subjected to UV-C HOT treatments once weekly for five times. Blood collected, perfused with oxygen, UV-C directly irradiated into blood, and then auto-transfused. Rabbits were sacrificed after five weeks; blood and serum were collected for analysis. The survival rate, liver, kidney, lipid profile, and blood ions were assessed in treated rabbits. Mortality was 40% in the LPS group, while other groups showed no death. UV-C HOT enhanced critical pH, base deficit, blood gases, hypomagnesemia, hyperlactatemia, and concurrent acidosis. Besides, TNF-α, nitrite, and nitrate were suppressed in response to UV-C HOT. Moreover, UV-C HOT reduced liver and kidney enzymes, improved lipid metabolism, and ameliorated electrolytes homeostasis. Despite that, UV-C HOT performance in ICU for human and animal endotoxemic or septic patients should be evaluated and considered

    Prediction of Undrained Shear Strength by the GMDH-Type Neural Network Using SPT-Value and Soil Physical Properties

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    This study presents a novel method for predicting the undrained shear strength (c(u)) using artificial intelligence technology. The c(u) value is critical in geotechnical applications and difficult to directly determine without laboratory tests. The group method of data handling (GMDH)-type neural network (NN) was utilized for the prediction of c(u). The GMDH-type NN models were designed with various combinations of input parameters. In the prediction, the effective stress (sigma(v)'), standard penetration test result (N-SPT), liquid limit (LL), plastic limit (PL), and plasticity index (PI) were used as input parameters in the design of the prediction models. In addition, the GMDH-type NN models were compared with the most commonly used method (i.e., linear regression) and other regression models such as random forest (RF) and support vector regression (SVR) models as comparative methods. In order to evaluate each model, the correlation coefficient (R-2), mean absolute error (MAE), and root mean square error (RMSE) were calculated for different input parameter combinations. The most effective model, the GMDH-type NN with input parameters (e.g., sigma(v)', N-SPT, LL, PL, PI), had a higher correlation coefficient (R-2 = 0.83) and lower error rates (MAE = 14.64 and RMSE = 22.74) than other methods used in the prediction of c(u) value. Furthermore, the impact of input variables on the model output was investigated using the SHAP (SHApley Additive ExPlanations) technique based on the extreme gradient boosting (XGBoost) ensemble learning algorithm. The results demonstrated that using the GMDH-type NN is an efficient method in obtaining a new empirical mathematical model to provide a reliable prediction of the undrained shear strength of soils.Chungnam National University; National Research Foundation of Korea (NRF) - Korea government (MSIT) [NRF2022R1C1C1011477]This work was supported by research fund of Chungnam National University and National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. NRF2022R1C1C1011477)
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