This work investigated the washing pre-treatment in order to upgrade a low grade biomass (greenhouse crop residue). Characteristics of biomass and biomass ashes before and after water washing were ...studied and compared. Characterization was carried out using techniques such as elemental analysis, proximate analysis, Inductively Coupled Plasma Optic Emission Spectroscopy (ICP-OES), Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC).The main aim of washing was to decrease the quantity of ashes present in this kind of biomass since inorganics cause operational problems in thermal processes. Water washing process at 80 °C was selected as the best temperature since the higher calorific value (HCV) increased a 7.00%. Moreover, a percentage of 46.16% of ash elimination was achieved at that temperature. Additionally, the quantity of problematic inorganic elements such as Cl, Na, Al, Fe and Si was lowered. Moreover, the ash melting temperature shifted to higher temperatures (1200 °C) after the washing. After carrying out the treatment, HCV was enhanced up to 18.07 MJ/kg and the characteristics for the use of the material as a fuel were improved.
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•Water washing improved fuel properties of greenhouse crop residue.•A treatment at 80 °C showed to be the most effective for ash removal.•A reduction of a 46% in ash content was achieved by water washing.•Fe, Na, Si and Cl were the most affected inorganic compounds.•Ash melting temperature shifted to higher temperatures (1200 °C) after washing.
The objectives of this study were to study the removal mechanism of Cr(VI) by natural olive stone (OS) and to present a sequential-batch process for the removal of total chromium (original Cr(VI) and ...Cr(III) derived from reduction of Cr(VI) during biosorption at acidic conditions). First, experiments were conducted varying pH from 1 to 4, and showed that a combined effect of biosorption and reduction is involved in the Cr(VI) removal. Then, X-ray photoelectron spectroscopy and desorption tests were employed to verify the oxidation state of the chromium bound to OS and to elucidate the removal mechanism of Cr(VI) by this material. The goal of these tests was to confirm that Cr(III) is the species mainly absorbed by OS. Finally, the possibility of total chromium removal by biosorption in a sequential-batch process was analyzed. In the first stage, 96.38% of Cr(VI) is removed by OS and reduced to Cr(III). In the second stage, approximately 31% of the total Cr concentration was removed. However, the Cr(III) released in the first stage is not completely removed, and it could suggest that the Cr(III) could be in a hydrated compound or a complex, which could be more difficult to remove under these conditions.
This work reports the study of the catalytic pyrolysis of rejected plastic fractions collected from municipal solid waste whose mechanical recovery is not plausible due to technical or poor ...conservation issues. The chemical recycling using catalytic pyrolysis was carried out over commercial zeolites formulas, i.e., HY and HZSM-5, in which Ni or Co metals were deposited at two different loadings (1 and 5%, wt.). The presence of these transition metals on the zeolitic supports impacted the total production of compounds existing in the liquid oil. The samples were characterized in terms of structural, chemical, and morphologic properties, and the production of different fuel fractions (gasoline, light cycle oil, and heavy cycle oil) was correlated with a combined parameter defined as a ratio of Acidity/BET area.
The 2020 coronavirus pandemic has involved a series of political and social measures that have been adapted to the spread of the disease. Apart from the severe effects on health sector, the most ...effects of the pandemic have been felt in households and day-to-day life. Consequently, COVID-19 has had a significant impact on the generation of not only medical and health care waste but also of municipal solid waste production and composition. In this context, this work studied the implications of COVID-19 for municipal solid waste generation in Granada, Spain. Granada is a city where the economy is based mainly on the services sector, tourism and the University. Therefore, the impact of COVID-19 pandemic has greatly affected the city and it can be analyzed through the municipal solid waste generation. For the study of the incidence of COVID-19 in the generation of waste a period that goes from March 2019 to February 2021 has been chosen. The results show that, in the global calculation, a decrease in the generation of waste in the city is observed in this last year, reaching − 13.8%. Regarding the organic-rest fraction, the decrease in the COVID year represents − 11.7%. However, bulky waste has shown an increase in the COVID year which may be related to higher home furnishings renovation rates than in other years. Finally, glass is the waste flow that best indicates the effect of COVID in the service sector. In leisure areas, a significant reduction in the collection of glass is observed (− 45%).
Computed tomography (CT) and 18F Fluorodeoxyglucose positron emission tomography (FDG-PET) are considered suitable methods for the noninvasive staging of the mediastinum. Our study was intended to ...estimate the efficacy of contrast-enhanced helical CT (hCT) and FDG-PET, alone and combined, in the diagnosis of lymph node mediastinal metastases.
This study was a prospective and blind comparison of the efficacy of hCT and FDG-PET with two alternative reference standards, mediastinoscopy, and mediastinoscopy plus thoracotomy plus a 6-month follow-up to diagnose lymph node mediastinal metastases in 132 consecutive patients with potentially resectable non-small-cell lung cancer (NSCLC). The metastatic disease was assessed histopathologically. Further clinical information was obtained postoperatively after a median follow-up of 42 months.
The prevalence of cN2,3 is 0.28. For hCT the sensitivity and specificity are 0.86 (95% CI, 0.70 to 0.93) and 0.67 (95% CI, 0.56 to 0.75), for PET 0.94 (95% CI, 0.81 to 0.98) and 0.59 (95% CI, 0.49 to 0.68), and for hCT and PET combined in-parallel 0.97 (95% CI, 0.84 to 0.99) and 0.44 (95% CI, 0.34 to 0.53), which translate into a negative predicted probability of 0.98 (95% CI, 0.88 to 1.00). The crude diagnostic odds ratio of PET in the total sample studied is 13.1, in the subgroup hCT+ 11.04 (3.0 to 40 0.1), and in the hCT- 3.5 (0.5 to 21.5). Similar results were obtained for hCT stratified by PET.
hCT and PET perform similarly in the mediastinal staging of NSCLC, both tests are conditionally dependent and provide complementary information, and their diagnostic value mainly resides on the negative results.
This study assesses cognitive abilities through video games for entertainment (Blek, Edge, and Unpossible) that were programmed from scratch to record players' behavior and the levels achieved in a ...sample without emotional problems and in one with emotional problems. The non-emotional-problem sample was recruited from three universities and two bachelor's degree programs. The emotional-problem sample was recruited from two outpatient centers. The participants in the emotional-problem sample completed reduced versions of the ability tests and video games, as required by their emotional problems. Three subtests of the Differential Aptitude Test that assessed abstract reasoning, visuospatial reasoning, and perceptual speed were selected as ability tests. All participants were required to complete a mental health questionnaire (PROMIS) and a brief questionnaire on their gaming habits and previous experience with the video games used. The results that were obtained showed good convergent validity of the video games as measures of cognitive abilities, and they showed that the behavior of players in the sample without emotional problems while playing predicted the level achieved in the Blek and Unpossible game fragments, but this was only true for Unpossible in the emotional-problem sample; finally, shorter versions of the Blek and Edge game fragments can be used because they maintain their good psychometric properties.
Using a science mapping approach, we analyzed the exponential increase in the number of scientific documents about the negative environmental impacts produced by waste from personal protective ...equipment (PPE), especially face masks, used to reduce SARS-CoV-2 transmission worldwide. Our results revealed that India, China, and Canada are leaders in this research field, which is clearly related to environmental issues, but also the solutions developed from an engineering point of view. Our analysis of the most-relevant documents in the field uncovered the considerable negative effects of PPE waste in aquatic media, its contribution to greenhouse gas emissions, effects on wildlife, etc. To reduce the negative environmental impacts of PPE waste, we need to implement innovative ecodesign strategies for their green production, including their re-use as and the use of recycling materials, but also a collaboration with the population to reduce PPE waste at its source. Both action lines could be materialized by establishing a collective, extended producer responsibility system for PPE to ensure their sustainable production and consumption. These well-implemented strategies will contribute to maintaining progress towards achieving sustainable development goals.
Chronic obstructive pulmonary disease (COPD) patients constitute a heterogeneous population in terms of treatment response. Our objective was to identify possible predictive factors of response to ...treatment with single bronchodilation monotherapy in patients diagnosed with COPD. The Time-based Register and Analysis of COPD Endpoints (TRACE; clinicaltrials.gov NCT03485690) is a prospective cohort of COPD patients who have been attending annual visits since 2012. Patients who were kept on a single bronchodilator during the first year of follow-up were selected. The responders were defined according to all of the following variables: any improvement in morning post-dose forced expiratory volume in 1 s or deterioration <100 mL, no change or improvement in dyspnea score, and no occurrence of exacerbations. Significant and plausible variables were analyzed using a proportional hazard Cox regression for single bronchodilator responders. We analyzed 764 cases, of whom 128 (16.8%) were receiving monotherapy with one bronchodilator. Of these, 85 patients (66.4%) were responders. Factors affecting responder status were: female gender (hazard ratio (HR) 0.276; 95% confidence interval (CI) 0.089-0.858), dyslipidemia (HR 0.436; 95%CI 0.202-0.939), not performing regular exercise (HR 0.523; 95%CI 0.254-1.076), active smoking (HR 0.413; 95%CI 0.186-0.920), and treatment adherence (HR 2.527; 95%CI 1.271-5.027). The factors associated with a single bronchodilation response are mainly non-pharmacological interventions and comorbidities.
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