Search results for " DEGRADATION"
showing 10 items of 510 documents
Elimination of pesticide atrazine by photoelectrocatalysis using a photoanode based on WO3 nanosheets
2018
[EN] The photoelectrocatalytic (PEC) degradation of a persistent and toxic herbicide, atrazine, has been investigated by using a novel and high-performance WO3 nanostructure in the form of nanosheets/nanorods as photoanode. The nanostructure has been synthesized by anodization in acidic media in the presence of a very small amount (0.05 M) of H2O2, and its morphology, as well as its electrochemical and photoelectrochemical properties have been characterized. Atrazine was completely degraded after similar to 180 min of reaction following pseudo-first order kinetics, and 2-hydroxyatrazine was identified as the main intermediate species. Moreover, the s-triazine ring in cyanuric acid (the fina…
Synthesis of WO3 nanorods through anodization in the presence of citric acid: Formation mechanism, properties and photoelectrocatalytic performance
2021
[EN] In this study, WO3 nanomds have been fabricated by simple anodization in the presence of different amounts of citric acid and at different anodization times. A comprehensive morphological, structural, electrochemical and photoelectrochemical characterization of different samples has been carried out. Moreover, a formation mechanism for WO3 nanorods has been proposed. Finally, these nanostructures have been proven to be excellent visible-light photoelectrocatalysts to remove persistent organic pollutants present in wastewaters, such as fenamiphos. Almost the 80% of this molecule was eliminated from the test solution after 180 min of irradiation, indicating the great potential of these W…
DOMESTIC MATERIAL CONSUMPTION INDICATOR AND NATURAL RESOURCES: A EUROPEAN ANALYSIS OF THE ENVIRONMENTAL KUZNETS CURVE
2014
The study investigates the relation between per capita Domestic Material Consumption indicator (DMC) and per capita income. Economic literature focuses mainly on air, water and land pollution while we consider as environmental degradation the consumption on natural resources extracted from the environment. Using a cross– European panel of countries over the period 2000-2011, our results confirm the absence of an Environmental Kuznets Curve (EKC) between per capita DMC and per capita GDP both for EU-27 vs. 30 European countries and for Western vs. Eastern European countries. The turning points are so high that it is present a monotonic increasing relation between DMC indicator and GDP.
Assessment of threat status and management effectiveness in Kakamega Forest, Kenya
2006
To counteract an increasing biodiversity decline, parks and protected areas have been established worldwide. However, many parks lack adequate management to address environmental degradation. To improve management strategies simple tools are needed for an assessment of human impact and management effectiveness of protected areas. This study quantifies the current threats in the heavily fragmented and degraded tropical rainforest of Kakamega, western Kenya. We recorded seven disturbance parameters at 22 sites in differently managed and protected areas of Kakamega Forest. Our data indicate a high level of human impact throughout the forest with illegal logging being most widespread. Furthermo…
Protein Aggregation in Muscle Fibers and Respective Neuromuscular Disorders
2007
Protein aggregation in muscle fibers may be a nonspecific phenomenon such as occurring in cores or ragged red fibers. However, it may also be a disease-specific and disease-significant phenomenon constituting protein aggregate myopathies (PAMs). These may be divided into two classes: The first one is marked by impaired extralysosomal degradation of proteins, catabolic PAM, encompassing desmin-related myopathies. Mutant proteins, that is, desmin, myotilin, or α-B crystallin, defy protein degradation, aggregate and associate with other proteins within muscle fibers, hence marking desminopathies, myotilinopathies, and α-B crystallinopathies. A second class of PAM encompasses those apparently a…
Heavy-Ion Microbeam Studies of Single-Event Leakage Current Mechanism in SiC VD-MOSFETs
2020
Heavy-ion microbeams are employed for probing the radiation-sensitive regions in commercial silicon carbide (SiC) vertical double-diffused power (VD)-MOSFETs with micrometer accuracy. By scanning the beam spot over the die, a spatial periodicity was observed in the leakage current degradation, reflecting the striped structure of the power MOSFET investigated. Two different mechanisms were observed for degradation. At low drain bias (gate and source grounded), only the gate-oxide (at the JFET or neck region) is contributing in the ion-induced leakage current. For exposures at drain–source bias voltages higher than a specific threshold, additional higher drain leakage current is observed in t…
Isotopic Enriched and Natural SiC Junction Barrier Schottky Diodes Under Heavy Ion Irradiation
2022
The radiation tolerance of isotopic enriched and natural silicon carbide junction barrier Schottky diodes are compared under heavy ion irradiation. Both types of devices experience leakage current degradation as well as single-event burnout events. The results were comparable, although the data may indicate a marginally lower thresholds for the isotopic enriched devices at lower linear energy transfer (LET). Slightly higher reverse bias threshold values for leakage current degradation were also observed compared to previously published work.
Ochratoxin A removal in synthetic media by living and heat-inactivated cells of Oenococcus oeni isolated from wines
2010
The capacity of Oenococcus oeni to eliminate ochratoxin A (OTA) from synthetic media in different conditions was studied. Ten tested O. oeni strains removed OTA from the medium but with significant differences depending on the strain, incubation period, and initial OTA level in the medium. Mycotoxin reductions higher than 60% were recorded in 14-day cultures spiked with 2 mu g OTA/l. Toxin removal was independent of bacterial viability and culture medium composition. This is the first study carried out to study OTA removal dynamics by living and heat-inactivated cells of O. oeni. The results aim that this bacterium may be a very useful tool to control OTA in food and beverages. (C) 2009 Els…
Biomarkers for Prognosis and Treatment Response in COVID-19 Patients
2021
During a severe infection such as coronavirus disease 2019 (COVID-19), the level of almost all analytes can change, presenting a correlation with disease severity and survival; however, a biomarker cannot be translated into clinical practice for treatment guidance until it is proven to have a significant impact. Several studies have documented the association between COVID-19 severity and circulating levels of C-reactive protein (CRP) and interleukin-6, and the accuracy of the CRP level in predicting treatment responses has been evaluated. Moreover, promising findings on prothrombin and D-dimer have been reported. However, the clinical usefulness of these biomarkers in COVID-19 is far from …
Synthesis, characterization and thermal degradation of 8-hydroxyquinoline–guanidine–formaldehyde terpolymer
2007
Abstract Terpolymer (8-HQGF) has been synthesized using the monomers 8-hydroxyquinoline, guanidine, formaldehyde in 1:1:2 molar proportions. The structure of 8-HQGF terpolymer has been elucidated on the basis of elemental analysis and various physicochemical techniques, i.e. UV–Visible, FTIR–ATR and 1 H NMR spectroscopy. Detailed thermal degradation study of the new terpolymer has been carried out to ascertain its thermal stability. Thermal degradation curve is discussed which shows two decomposition steps (265–475 °C and 540–715 °C). Sharp–Wentworth and Freeman–Carroll methods have been used to calculate activation energies and thermal stability. The activation energy ( E a ) calculated by…