Color is one of the main problems in wastewater and many techniques can be applied to remove it. In this work, nanofiltration, coagulation–flocculation and their combination were studied to remove ...color from five reactive dyes. Nanofiltration was carried out using an energy saving nanofiltration membrane in a 0.5
L pilot plant at 10
bar. Coagulation–flocculation experiments were performed in a jar test apparatus using an anionic polyelectrolyte flocculant, FeCl
3 as a coagulant agent and two different resins: melamine–urea–formaldehyde and polyamine resin. From the results it was concluded that nanofiltration removed in the order of 40 and 80% of color for the five dyes while coagulation–flocculation reached between 85 and 95% of color removal for four dyes except in the case of polyamine resin for RB5. The combination of these techniques dramatically improved the removals reaching over 98% of color removal for all dyes except for RB5 that achieved a 90%. The combined process also decreases COD values as it implies the use of lower resin concentration than coagulation–flocculation.
Abstract The intraclass correlation coefficient (ICC) is a fundamental parameter of interest in cluster randomized trials as it can greatly affect statistical power. We compare common methods of ...estimating the ICC in cluster randomized trials with binary outcomes, with a specific focus on their application to community-based cancer prevention trials with primary outcome of self-reported cancer screening. Using three real data sets from cancer screening intervention trials with different numbers and types of clusters and cluster sizes, we obtained point estimates and 95% confidence intervals for the ICC using five methods: the analysis of variance estimator, the Fleiss–Cuzick estimator, the Pearson estimator, an estimator based on generalized estimating equations and an estimator from a random intercept logistic regression model. We compared estimates of the ICC for the overall sample and by study condition. Our results show that ICC estimates from different methods can be quite different, although confidence intervals generally overlap. The ICC varied substantially by study condition in two studies, suggesting that the common practice of assuming a common ICC across all clusters in the trial is questionable. A simulation study confirmed pitfalls of erroneously assuming a common ICC. Investigators should consider using sample size and analysis methods that allow the ICC to vary by study condition.
We show the feasibility of a real‐time estimation of waveforms and coseismic displacements, within a few centimeters in accuracy, with a stand‐alone dual‐frequency Global Positioning System (GPS) ...receiver using a so‐called “variometric” approach. The approach is based on time single‐differences of carrier phase observations collected at a high‐rate (1 Hz or more) using a stand‐alone receiver, and on standard GPS broadcast products (orbits and clocks), which are ancillary information routinely available in real time. In the approach, first, the time series of epoch‐by‐epoch displacements are estimated. Then, provided that the collected observations are continuous, they can be summed over the interval (limited to a few minutes) over which an earthquake occurs. Since epoch‐by‐epoch displacements divided by the interval between consecutive epochs are essentially equal to the epoch‐by‐epoch velocities, this is equivalent to saying that we are using the GPS receiver as a velocimeter. Estimation biases, due to the possible mismodeling of various intervening effects (such as multipath, residual clock errors, orbit errors, and atmospheric errors), accumulate over time and display their signature as a trend in coseismic displacements. The trend can be considered linear and easily removed, at least for short intervals. Since the proposed approach (named VADASE (Variometric Approach for Displacements Analysis Stand‐alone Engine)) does not require either additional technological complexity or a centralized data analysis, in principle it can be embedded into GPS receiver firmware, thereby providing a significant contribution to tsunami warning and other hazard assessment systems. After a preliminary test using a simulated example, the effectiveness of this approach was proven using real data. We analyzed the 1 Hz GPS data recorded by the International Global Navigation Satellite Systems Service station BREW during the Denali Fault, Alaska, earthquake (Mw 7.9, 3 November, 2002, 22:12:41 UTC), as well as the 5 Hz data collected by some of the stations of the University NAVSTAR Consortium‐Plate Boundary Observatory network and the California Real Time Network during the Baja California, Mexico, earthquake (Mw 7.2, 4 April, 2010, 22:40:42 UTC). Comparisons of the results obtained using VADASE, as well as other already well‐established approaches, displayed agreement to within a few centimeters.
Key Points
RT GPS‐based coseismic displacements estimation at few cm accuracy is shown
The proposed strategy can be embedded in the GPS receiver firmware
It is useful for RT earthquakes source modeling and tsunami early‐warning system
Previous pooled analyses have reported an association between magnetic fields and childhood leukaemia. We present a pooled analysis based on primary data from studies on residential magnetic fields ...and childhood leukaemia published after 2000.
Seven studies with a total of 10,865 cases and 12,853 controls were included. The main analysis focused on 24-h magnetic field measurements or calculated fields in residences.
In the combined results, risk increased with increase in exposure, but the estimates were imprecise. The odds ratios for exposure categories of 0.1-0.2 μT, 0.2-0.3 μT and ≥0.3 μT, compared with <0.1 μT, were 1.07 (95% CI 0.81-1.41), 1.16 (0.69-1.93) and 1.44 (0.88-2.36), respectively. Without the most influential study from Brazil, the odds ratios increased somewhat. An increasing trend was also suggested by a nonparametric analysis conducted using a generalised additive model.
Our results are in line with previous pooled analyses showing an association between magnetic fields and childhood leukaemia. Overall, the association is weaker in the most recently conducted studies, but these studies are small and lack methodological improvements needed to resolve the apparent association. We conclude that recent studies on magnetic fields and childhood leukaemia do not alter the previous assessment that magnetic fields are possibly carcinogenic.
Advance care planning (ACP) is a process that guarantees the respect of the patient’s values and priorities about his/her future care at the end of life. It consists of multiple conversations with ...the health professional that may lead to the completion of Advance Directives (AD), a set of legal documents helpful to clinicians and family members for making critical decisions on behalf of the patient, whereas he/she might become incapable. Over the past years, ACP has become particularly relevant for the growth of chronic diseases, the increase in life expectancy, and the growing attention paid to the patient’s decisional autonomy. Several nations have introduced specific regulations of ACP and AD. However, their diffusion is accompanied by unforeseen limitations and issues, burdening their complete and systematic adoption. The present article describes several controversial aspects of ACP and some of the most significant challenges in end-of-life care.
Results of recent epidemiologic studies suggest the need to reassess the safe upper limit in drinking water of selenium, a metalloid with both toxicological and nutritional properties. Observational ...and experimental human studies on health effects of organic selenium compounds consumed through diet or supplements, and of inorganic selenium consumed through drinking water, have shown that human toxicity may occur at much lower levels than previously surmised. Evidence indicates that the chemical form of selenium strongly influences its toxicity, and that its biological activity may differ in different species, emphasizing the importance of the few human studies on health effects of the specific selenium compounds found in drinking water. Epidemiologic studies that investigated the effects of selenate, an inorganic selenium species commonly found in drinking water, together with evidence of toxicity of inorganic selenium at low levels in from in vitro and animal studies, indicate that health risks may occur at exposures below the current European Union and World Health Organization upper limit and guideline of 10 and 40μg/l, respectively, and suggest reduction to 1μg/l in order to adequately protect human health. Although few drinking waters are currently known to have selenium concentrations exceeding this level, the public health importance of this issue should not be overlooked, and further epidemiologic research is critically needed in this area.
Freshwater is one the most important renewable water resources of the planet but, due to climate change, surface freshwater available in the form of lakes, rivers, reservoirs, snow, and glaciers is ...becoming significantly threatened. As a result, surface water level monitoring is fundamental for understanding climatic changes and their impact on humans and biodiversity.This study evaluates the accuracy of the Global Ecosystem Dynamics Investigation (GEDI) LiDAR (Light Detection And Ranging) instrument for monitoring inland water levels. Four lakes in northern Italy were selected for comparison with gauge station measurements. To evaluate the accuracy of GEDI altimetric data, two steps of outlier removal are proposed. The first stage employs GEDI metadata to filter out footprints with very low accuracy. Then, a robust version of the standard 3σ test using a 3NMAD (Normalized Median Absolute Deviation) test is iteratively applied.After the outlier removal, which led to the elimination of between 80% to 87% of the data, the remaining footprints show an average standard deviation of 0.36 m, a mean NMAD of 0.38 m, and a Root Mean Square Error (RMSE) of 0.44 m, proving the promising potentialities of GEDI L2A altimetric data for inland water monitoring.
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