Sealed model and computation of hazardous waste landfill high voltage DC leakage detection

According to the structural characteristics of hazardous waste landfill and the leakage current model of high voltage DC Landfill leakage detection, a sealed model is established detail. The detection layer of the hazardous waste landfill is considered as a sealed assumed that the source current flows through the leak entirely. The leak is regard and analyzed in space and it is ed as a positive current resource ＋ I located at the current entrance or a negative resource - I located at the current exit, which depends on the placement of the current supply. The electrical potential of an arbitrary in detection layer satisfies Poisson equation. The boundary condition is regarded as a natural bound- ary condition for the high resistivity of high density polyethylene （HDPE） membrane. Based on which a numerical calculation method is developed. Satisfactory agreement between experimental da- ta and simulated data validates the analysis. Parametric studies show that a larger horizontal distance between the power supply electrode and leak and a smaller distance between the detector electrodes and the detected liner are helpful to leak location. More parametric curves show that parameters leaks can be detected effectively with optimum selection of field survey.

Predictive factors of cardiac rupture in patients with ST-elevation myocardial infarction

Cardiac rupture （CR） is a potentially fatal mechanical complication of ST-elevation myocardial infarction （STEMI）. We aimed to determine the incidence and risk factors of CR in Chinese STEMI patients. A total of 9798 consecutive STEMI patients from four centers in China were retrospectively analyzed, among which 178 patients had CR. STEMI patients without CR were chosen as a control group. Clinical characteristics were compared between STEMI patients with CR and those without CR. The incidence of CR in STEMI patients was 1.82%, and the 30-d mortality was up to 61.2%. CR patients were significantly older, more female, and associated with a longer time from onset of pain to hospital admission than their non-CR counterparts （P〈0.001）. More patients with anterior myocardial infarction （82.1%） were found in the CR group, and CR patients had significantly higher heart rates than the control group （（91±19） bpm vs. （71±16） bpm; P〈0.001）. In multiple-adjusted models, the independent risk factors of CR were advanced age, female gender, anaemia, increased heart rate, anterior myocardial infarction, increased white blood cell （WBC） count, delayed admission, and renal dysfunction. The level of hemoglobin remained a significant deter- minant factor of CR （OR （95% CI）： 0.82 （0.75-0.89）; P〈0.001） after adjusting for various potential confounding factors. Counts of WBC also remained a significant determinant of the CR （OR （95% CI）： 1.08 （1.04-1.12）; P〈0.001）. A number of variables were independently related to CR. This study indicated, for the first time, that both hemoglobin and WBC levels were independently correlated with occurrence of CR.