scholarly journals Gasification of RDF and Its Components with Tire Pyrolysis Char as Tar-Cracking Catalyst

2020 ◽  
Vol 12 (16) ◽  
pp. 6647
Author(s):  
Patrik Šuhaj ◽  
Jakub Husár ◽  
Juma Haydary
Keyword(s):  
Oxygen Demand ◽  
Co2 Concentration ◽  
Gas Composition ◽  
Hydrocarbon Gases ◽  
Two Stage ◽  
Promising Alternative ◽  
Product Gas ◽  
Tar Reduction ◽  
Tar Cracking ◽  
The Impact

The composition of gas produced by the gasification of refuse-derived fuel (RDF) can be affected by the content of individual components of RDF and their mutual interactions. In this work, plastics, paper, wood, textile and RDF were gasified in a two-stage gasification system and the obtained tar yields and product gas quality were compared. The two-stage reactor consisted of an air-blown gasifier and a catalytic reactor filled with carbonized tire pyrolysis char as the tar-cracking catalyst. Tire pyrolysis char is a promising alternative to expensive catalysts. The impact of temperature and catalyst amount on the tar yield and gas composition was investigated. Theoretical oxygen demand for all material classes was calculated and its effect on gas composition and tar yield is discussed. The results indicate that the gasification of plastics produces the highest amount of tar and hydrocarbon gases, while the CO2 content of the product gas remains the lowest compared to all other materials. On the other hand, the paper fraction produced hydrogen-rich gas with low tar content. The gasification of RDF at 700 °C provided the lowest tar yield compared to all other materials, indicating positive synergic effects of lignocellulosic biomass and plastics in tar reduction. The significance of these interactions was suppressed at the highest temperature of 900 °C, as the thermal cracking of tar became dominant. For CO2 content, a negative synergic effect (higher CO2 concentration) was observed.

Considering the impact of intermittent discharges when modelling overflows

1998 ◽  
Vol 38 (10) ◽  
pp. 23-30
Author(s):  
Sarah Jubb ◽  
Philip Hulme ◽  
Ian Guymer ◽  
John Martin
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Preliminary Investigation ◽  
Oxygen Demand ◽  
Sediment Oxygen Demand ◽  
Combined Sewer Overflows ◽  
River Hydraulics ◽  
Combined Sewer ◽  
The Impact ◽  
Curve Equation

This paper describes a preliminary investigation that identified factors important in the prediction of river water quality, especially regarding dissolved oxygen (DO) concentration. Intermittent discharges from combined sewer overflows (CSOs) within the sewerage, and overflows at water reclamation works (WRW) cause dynamic conditions with respect to both river hydraulics and water quality. The impact of such discharges has been investigated under both wet and dry weather flow conditions. Data collected from the River Maun, UK, has shown that an immediate, transient oxygen demand exists downstream of an outfall during storm conditions. The presence of a delayed oxygen demand has also been identified. With regard to modelling, initial investigations used a simplified channel and the Streeter-Phelps (1925) dissolved oxygen sag curve equation. Later, a model taking into account hydrodynamic, transport and dispersion processes was used. This suggested that processes other than water phase degradation of organic matter significantly affect the dissolved oxygen concentration downstream of the location of an intermittent discharge. It is proposed that the dynamic rate of reaeration and the sediment oxygen demand should be the focus of further investigation.

scholarly journals Robust Inferences from a Before-and-After Study with Multiple Unaffected Control Groups

2013 ◽  
Vol 1 (2) ◽  
pp. 209-234 ◽  
Author(s):  
Pengyuan Wang ◽  
Mikhail Traskin ◽  
Dylan S. Small
Keyword(s):  
Sensitivity Analysis ◽  
Control Groups ◽  
Two Stage ◽  
Time Effects ◽  
Unaffected Control ◽  
Group Time ◽  
Before And After ◽  
Group Variation ◽  
The Impact ◽  
Before And After Study

AbstractThe before-and-after study with multiple unaffected control groups is widely applied to study treatment effects. The current methods usually assume that the control groups’ differences between the before and after periods, i.e. the group time effects, follow a normal distribution. However, there is usually no strong a priori evidence for the normality assumption, and there are not enough control groups to check the assumption. We propose to use a flexible skew-t distribution family to model group time effects, and consider a range of plausible skew-t distributions. Based on the skew-t distribution assumption, we propose a robust-t method to guarantee nominal significance level under a wide range of skew-t distributions, and hence make the inference robust to misspecification of the distribution of group time effects. We also propose a two-stage approach, which has lower power compared to the robust-t method, but provides an opportunity to conduct sensitivity analysis. Hence, the overall method of analysis is to use the robust-t method to test for the overall hypothesized range of shapes of group variation; if the test fails to reject, use the two-stage method to conduct a sensitivity analysis to see if there is a subset of group variation parameters for which we can be confident that there is a treatment effect. We apply the proposed methods to two datasets. One dataset is from the Current Population Survey (CPS) to study the impact of the Mariel Boatlift on Miami unemployment rates between 1979 and 1982.The other dataset contains the student enrollment and grade repeating data in West Germany in the 1960s with which we study the impact of the short school year in 1966–1967 on grade repeating rates.

scholarly journals Consumption of Enriched Yogurt with PAF Inhibitors from Olive Pomace Affects the Major Enzymes of PAF Metabolism: A Randomized, Double Blind, Three Arm Trial

Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 801
Author(s):  
Maria Detopoulou ◽  
Agathi Ntzouvani ◽  
Filio Petsini ◽  
Labrini Gavriil ◽  
Εlizabeth Fragopoulou ◽  
...  
Keyword(s):  
Platelet Activating Factor ◽  
Lipid Mediator ◽  
Olive Pomace ◽  
Double Blind ◽  
Promising Alternative ◽  
Catabolic Enzymes ◽  
Platelet Activating Factor Acetylhydrolase ◽  
The Impact ◽  
By Products ◽  
Apparently Healthy

Platelet-activating factor (PAF), a proinflammatory lipid mediator, plays a crucial role in the formation of the atherosclerotic plaque. Therefore, the inhibition of endothelium inflammation by nutraceuticals, such as PAF inhibitors, is a promising alternative for preventing cardiovascular diseases. The aim of the present study was to evaluate the impact of a new functional yogurt enriched with PAF inhibitors of natural origin from olive oil by-products on PAF metabolism. Ninety-two apparently healthy, but mainly overweight volunteers (35–65 years) were randomly allocated into three groups by block-randomization. The activities of PAF’s biosynthetic and catabolic enzymes were measured, specifically two isoforms of acetyl-CoA:lyso-PAF acetyltransferase (LPCATs), cytidine 5′-diphospho-choline:1-alkyl-2-acetyl-sn-glycerol cholinephosphotransferase (PAF-CPT) and two isoforms of platelet activating factor acetylhydrolase in leucocytes (PAF-AH) and plasma (lipoprotein associated phospholipase-A2, LpPLA2). The intake of the enriched yogurt resulted in reduced PAF-CPT and LpPLA2 activities. No difference was observed in the activities of the two isoforms of lyso PAF-AT. In conclusion, intake of yogurt enriched in PAF inhibitors could favorably modulate PAF biosynthetic and catabolic pathways.

scholarly journals Effect of biomass fuel ash and bed material on the product gas composition in DFB steam gasification

Energy ◽  
2021 ◽  
Vol 219 ◽  
pp. 119650
Author(s):  
K. Fürsatz ◽  
J. Fuchs ◽  
F. Benedikt ◽  
M. Kuba ◽  
H. Hofbauer
Keyword(s):  
Steam Gasification ◽  
Biomass Fuel ◽  
Gas Composition ◽  
Product Gas ◽  
Fuel Ash ◽  
Bed Material

scholarly journals Baicalin Represses Type Three Secretion System of Pseudomonas aeruginosa through PQS System

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1497
Author(s):  
Pansong Zhang ◽  
Qiao Guo ◽  
Zhihua Wei ◽  
Qin Yang ◽  
Zisheng Guo ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Virulence Factors ◽  
Mammalian Cells ◽  
Secretion System ◽  
Chinese Herbs ◽  
Infection Model ◽  
Lung Pathology ◽  
Promising Alternative ◽  
The Impact

Therapeutics that target the virulence of pathogens rather than their viability offer a promising alternative for treating infectious diseases and circumventing antibiotic resistance. In this study, we searched for anti-virulence compounds against Pseudomonas aeruginosa from Chinese herbs and investigated baicalin from Scutellariae radix as such an active anti-virulence compound. The effect of baicalin on a range of important virulence factors in P. aeruginosa was assessed using luxCDABE-based reporters and by phenotypical assays. The molecular mechanism of the virulence inhibition by baicalin was investigated using genetic approaches. The impact of baicalin on P. aeruginosa pathogenicity was evaluated by both in vitro assays and in vivo animal models. The results show that baicalin diminished a plenty of important virulence factors in P. aeruginosa, including the Type III secretion system (T3SS). Baicalin treatment reduced the cellular toxicity of P. aeruginosa on the mammalian cells and attenuated in vivo pathogenicity in a Drosophila melanogaster infection model. In a rat pulmonary infection model, baicalin significantly reduced the severity of lung pathology and accelerated lung bacterial clearance. The PqsR of the Pseudomonas quinolone signal (PQS) system was found to be required for baicalin’s impact on T3SS. These findings indicate that baicalin is a promising therapeutic candidate for treating P. aeruginosa infections.

scholarly journals Effects of Climatic Conditions, Season and Environmental Factors on CO2 Concentrations in Naturally Ventilated Primary Schools in Chile

2021 ◽  
Vol 13 (8) ◽  
pp. 4139
Author(s):  
Muriel Diaz ◽  
Mario Cools ◽  
Maureen Trebilcock ◽  
Beatriz Piderit-Moreno ◽  
Shady Attia
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Primary Schools ◽  
Co2 Concentration ◽  
Building Design ◽  
Climatic Conditions ◽  
Indoor Environmental Quality ◽  
Co2 Concentrations ◽  
The Impact

Between the ages of 6 and 18, children spend between 30 and 42 h a week at school, mostly indoors, where indoor environmental quality is usually deficient and does not favor learning. The difficulty of delivering indoor air quality (IAQ) in learning facilities is related to high occupancy rates and low interaction levels with windows. In non-industrialized countries, as in the cases presented, most classrooms have no mechanical ventilation, due to energy poverty and lack of normative requirements. This fact heavily impacts the indoor air quality and students’ learning outcomes. The aim of the paper is to identify the factors that determine acceptable CO2 concentrations. Therefore, it studies air quality in free-running and naturally ventilated primary schools in Chile, aiming to identify the impact of contextual, occupant, and building design factors, using CO2 concentration as a proxy for IAQ. The monitoring of CO2, temperature, and humidity revealed that indoor air CO2 concentration is above 1400 ppm most of the time, with peaks of 5000 ppm during the day, especially in winter. The statistical analysis indicates that CO2 is dependent on climate, seasonality, and indoor temperature, while it is independent of outside temperature in heated classrooms. The odds of having acceptable concentrations of CO2 are bigger when indoor temperatures are high, and there is a need to ventilate for cooling.

scholarly journals Histological, Biomechanical, and Biological Properties of Genipin-Crosslinked Decellularized Peripheral Nerves

2021 ◽  
Vol 22 (2) ◽  
pp. 674
Author(s):  
Óscar Darío García-García ◽  
Marwa El Soury ◽  
David González-Quevedo ◽  
David Sánchez-Porras ◽  
Jesús Chato-Astrain ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Nerve Repair ◽  
Wistar Rat ◽  
Biomechanical Properties ◽  
Biological Properties ◽  
Suitable Alternative ◽  
Promising Alternative ◽  
Histological Pattern ◽  
The Impact

Acellular nerve allografts (ANGs) represent a promising alternative in nerve repair. Our aim is to improve the structural and biomechanical properties of biocompatible Sondell (SD) and Roosens (RS) based ANGs using genipin (GP) as a crosslinker agent ex vivo. The impact of two concentrations of GP (0.10% and 0.25%) on Wistar rat sciatic nerve-derived ANGs was assessed at the histological, biomechanical, and biocompatibility levels. Histology confirmed the differences between SD and RS procedures, but not remarkable changes were induced by GP, which helped to preserve the nerve histological pattern. Tensile test revealed that GP enhanced the biomechanical properties of SD and RS ANGs, being the crosslinked RS ANGs more comparable to the native nerves used as control. The evaluation of the ANGs biocompatibility conducted with adipose-derived mesenchymal stem cells cultured within the ANGs confirmed a high degree of biocompatibility in all ANGs, especially in RS and RS-GP 0.10% ANGs. Finally, this study demonstrates that the use of GP could be an efficient alternative to improve the biomechanical properties of ANGs with a slight impact on the biocompatibility and histological pattern. For these reasons, we hypothesize that our novel crosslinked ANGs could be a suitable alternative for future in vivo preclinical studies.

scholarly journals Predicting the Future Distribution of Ara rubrogenys, an Endemic Endangered Bird Species of the Andes, Taking into Account Trophic Interactions

Diversity ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 94
Author(s):  
Alain Hambuckers ◽  
Simon de Harenne ◽  
Eberth Rocha Ledezma ◽  
Lilian Zúñiga Zeballos ◽  
Louis François
Keyword(s):  
Food Resource ◽  
Bird Species ◽  
Co2 Concentration ◽  
Distribution Models ◽  
Plant Resources ◽  
Term Survival ◽  
The Andes ◽  
Vegetation Models ◽  
Fertilizing Effect ◽  
The Impact

Species distribution models (SDMs) are commonly used with climate only to predict animal distribution changes. This approach however neglects the evolution of other components of the niche, like food resource availability. SDMs are also commonly used with plants. This also suffers limitations, notably an inability to capture the fertilizing effect of the rising CO2 concentration strengthening resilience to water stress. Alternatively, process-based dynamic vegetation models (DVMs) respond to CO2 concentration. To test the impact of the plant modelling method to model plant resources of animals, we studied the distribution of a Bolivian macaw, assuming that, under future climate, DVMs produce more conservative results than SDMs. We modelled the bird with an SDM driven by climate. For the plant, we used SDMs or a DVM. Under future climates, the macaw SDM showed increased probabilities of presence over the area of distribution and connected range extensions. For plants, SDMs did not forecast overall response. By contrast, the DVM produced increases of productivity, occupancy and diversity, also towards higher altitudes. The results offered positive perspectives for the macaw, more optimistic with the DVM than with the SDMs, than initially assumed. Nevertheless, major common threats remain, challenging the short-term survival of the macaw.

scholarly journals Impact of the municipal merger on watershed management: a study of Lake Kasumigaura, Japan

2021 ◽  
Author(s):  
Takeshi Mizunoya ◽  
Noriko Nozaki ◽  
Rajeev Kumar Singh
Keyword(s):  
Watershed Management ◽  
Large Scale ◽  
Environmental Changes ◽  
Water Environment ◽  
Reduction Rate ◽  
Oxygen Demand ◽  
Policy Implications ◽  
Pollution Reduction ◽  
Lake Kasumigaura ◽  
The Impact

AbstractIn the early 2000s, Japan instituted the Great Heisei Consolidation, a national strategy to promote large-scale municipal mergers. This study analyzes the impact that this strategy could have on watershed management. We select the Lake Kasumigaura Basin, the second largest lake in Japan, for the case study and construct a dynamic expanded input–output model to simulate the ecological system around the Lake, the socio-environmental changes over the period, and their mutual dependency for the period 2012–2020. In the model, we regulate and control the following water pollutants: total nitrogen, total phosphorus, and chemical oxygen demand. The results show that a trade-off between economic activity and the environment can be avoided within a specific range of pollution reduction, given that the prefectural government implements optimal water environment policies, assuming that other factors constraining economic growth exist. Additionally, municipal mergers are found to significantly reduce the budget required to improve the water environment, but merger budget efficiency varies nonlinearly with the reduction rate. Furthermore, despite the increase in financial efficiency from the merger, the efficiency of installing domestic wastewater treatment systems decreases drastically beyond a certain pollution reduction level and eventually reaches a limit. Further reductions require direct regulatory instruments in addition to economic policies, along with limiting the output of each industry. Most studies on municipal mergers apply a political, administrative, or financial perspective; few evaluate the quantitative impact of municipal mergers on the environment and environmental policy implications. This study addresses these gaps.

scholarly journals A Two-Stage Joint Model for Nonlinear Longitudinal Response and a Time-to-Event with Application in Transplantation Studies

2012 ◽  
Vol 2012 ◽  
pp. 1-18 ◽  
Author(s):  
Magdalena Murawska ◽  
Dimitris Rizopoulos ◽  
Emmanuel Lesaffre
Keyword(s):  
Empirical Bayes ◽  
Cox Model ◽  
Data Sets ◽  
Two Stage ◽  
Nonlinear Mixed Effects Model ◽  
Resistance Evolution ◽  
Longitudinal Response ◽  
Longitudinal Measurements ◽  
Subject Specific ◽  
The Impact

In transplantation studies, often longitudinal measurements are collected for important markers prior to the actual transplantation. Using only the last available measurement as a baseline covariate in a survival model for the time to graft failure discards the whole longitudinal evolution. We propose a two-stage approach to handle this type of data sets using all available information. At the first stage, we summarize the longitudinal information with nonlinear mixed-effects model, and at the second stage, we include the Empirical Bayes estimates of the subject-specific parameters as predictors in the Cox model for the time to allograft failure. To take into account that the estimated subject-specific parameters are included in the model, we use a Monte Carlo approach and sample from the posterior distribution of the random effects given the observed data. Our proposal is exemplified on a study of the impact of renal resistance evolution on the graft survival.

Sign in / Sign up

Export Citation Format

Share Document