2,867 research outputs found

    Test data from pullout experiments on vetiver grass (Vetiveria zizanioides) grown in semi-arid climate

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    The data set presented in this article includes the results of pullout tests carried out on vetiver grass (Vetiveria zizanioides) growing on an abandoned terrace slopes in Spain. The results comprise tables showing the resistance of each tested vetiver plant to pullout forces applied to it at various angles. The dataset also contains the measurements of the displacement at each pullout force increment. The dataset also includes the plots of the pullout resistance of each vetiver plant against the measured displacement

    Jitter in DLL-Based Clock Multipliers caused by Delay Cell Mismatch

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    This paper describes the jitter problem in\ud DLL-based clock multipliers that arises due to stochastic\ud mismatch in the delay cells that are used in the Voltage Controlled\ud Delay Line of the DLL [1]. An analysis is presented\ud that relates the stochastic spread of the delay of the cells to\ud the output jitter of the clock multiplier. This analysis shows\ud that relative time deviations are highest in the middle of the\ud Delay Line and proportional to the square root of the frequency\ud multiplication factor of the structure. A circuit design\ud technique, called Impedance Level Scaling, is presented\ud that allows the designer to optimize the noise and mismatch\ud behavior of a circuit independent of other specifications such\ud as speed and linearity. Applying this technique on delay cell\ud design yields a direct trade-off between noise induced jitter\ud and power usage, and between stochastic mismatch induced\ud jitter and power usage

    Operation of a concentrated mode dual-alkali scrubber plant at the Lonmin smelter

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    Lonmin Platinum installed a concentrated mode dual-alkali scrubber at the smelter in Marikana in 2002. The dual-alkali scrubber was the technology of choice at that time as a sulphur fixation plant, due to the perceived benefits of handling both the high SO2 concentrations of converter off-gas and the swings in SO2 concentration that are linked to Peirce-Smith operation. Owing to current and impending legislative requirements for air quality and waste, Lonmin is currently considering additions to the dual-alkali plant, but is also evaluating alternative technologies for sulphur fixation. This paper reviews the decision of Lonmin to install a concentrated mode dual-alkali scrubber and presents plant performance achieved. It also describes the important control variables and sensitivities of the plant, and the final product that is produced by the operation of the plant. The legislative requirement that drives the Lonmin technology evaluation is also discussed

    Macrophage migration inhibitory factor, infection, the brain, and corticosteroids

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    Bacterial meningitis is a complex disorder in which injury is caused, in part, by the causative organism and, in part, by the host's own inflammatory response. Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine and a neuro-endocrine mediator that might play a role in pneumococcal meningitis. Here, we discuss the role of MIF in infection, the brain, and corticosteroids and conclude that experimental meningitis studies have to determine whether MIF is a potential target for adjunctive therapy in pneumococcal meningitis

    Attenuated cerebrospinal fluid leukocyte count and sepsis in adults with pneumococcal meningitis: a prospective cohort study

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    BACKGROUND: A low cerebrospinal fluid (CSF) white-blood cell count (WBC) has been identified as an independent risk factor for adverse outcome in adults with bacterial meningitis. Whereas a low CSF WBC indicates the presence of sepsis with early meningitis in patients with meningococcal infections, the relation between CSF WBC and outcome in patients with pneumococcal meningitis is not understood. METHODS: We examined the relation between CSF WBC, bacteraemia and sepsis in a prospective cohort study that included 352 episodes of pneumococcal meningitis, confirmed by CSF culture, occurring in patients aged >16 years. RESULTS: CSF WBC was recorded in 320 of 352 episodes (91%). Median CSF WBC was 2530 per mm(3 )(interquartile range 531–6983 per mm(3)) and 104 patients (33%) had a CSF WBC <1000/mm(3). Patients with a CSF WBC <1000/mm(3 )were more likely to have an unfavourable outcome (defined as a Glasgow Outcome Scale score of 1–4) than those with a higher WBC (74 of 104 [71%] vs. 87 of 216 [43%]; P < 0.001). CSF WBC was significantly associated with blood WBC (Spearman's test 0.29), CSF protein level (0.20), thrombocyte count (0.21), erythrocyte sedimentation rate (-0.15), and C-reactive protein levels (-0.18). Patients with a CSF WBC <1000/mm(3 )more often had a positive blood culture (72 of 84 [86%] vs. 138 of 196 [70%]; P = 0.01) and more often developed systemic complications (cardiorespiratory failure, sepsis) than those with a higher WBC (53 of 104 [51%] vs. 69 of 216 [32%]; P = 0.001). In a multivariate analysis, advanced age (Odds ratio per 10-year increments 1.22, 95%CI 1.02–1.45), a positive blood culture (Odds ratio 2.46, 95%CI 1.17–5.14), and a low thrombocyte count on admission (Odds ratio per 100,000/mm(3 )increments 0.67, 95% CI 0.47–0.97) were associated with a CSF WBC <1000/mm(3). CONCLUSION: A low CSF WBC in adults with pneumococcal meningitis is related to the presence of signs of sepsis and systemic complications. Invasive pneumococcal infections should possibly be regarded as a continuum from meningitis to sepsis
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