scholarly journals The Electrochemical Degradation of Poly(3,4-ethylenedioxythiophene) Films Electrodeposited from Aqueous Solutions

2016 ◽  
Vol 230 (9) ◽  
Author(s):  
Gyözö G. Láng ◽  
Mária Ujvári ◽  
Soma Vesztergom ◽  
Veniamin Kondratiev ◽  
Jenö Gubicza ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Structural Changes ◽  
Morphological Changes ◽  
Aqueous Media ◽  
Degradation Process ◽  
Electrochemical Stability ◽  
Experimental Techniques ◽  
Electrochemical Degradation ◽  
Degradation Properties

AbstractIn this review, results of recent studies on the electrochemical stability and degradation properties of poly(3,4-ethylenedioxythiophene) films are summarized, with particular emphasis on the structural changes induced by overoxidation and electrochemical degradation. The most important electrodeposition methods for the preparation of PEDOT films in surfactant free aqueous media have also been summarized, and several experimental techniques suitable for monitoring the degradation process have been discussed. Morphological changes in PEDOT films during overoxidation have been analyzed. Overoxidation mechanisms proposed in the literature have been surveyed.

scholarly journals Application of Photocatalytic Falling Film Reactor to Elucidate the Degradation Pathways of Pharmaceutical Diclofenac and Ibuprofen in Aqueous Solutions

Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 465 ◽  
Author(s):  
Kosar Hikmat Hama Aziz ◽  
Khalid M. Omer ◽  
Ali Mahyar ◽  
Hans Miessner ◽  
Siegfried Mueller ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Degradation Kinetics ◽  
Aqueous Media ◽  
Degradation Process ◽  
Transformation Products ◽  
Photocatalytic Decomposition ◽  
Gas Chromatography Mass Spectrometry ◽  
Falling Film ◽  
Pharmaceutical Residues ◽  
Film Reactor

Diclofenac (DCF) and ibuprofen (IBP) are common pharmaceutical residues that have been detected in the aquatic system. Their presence in the aquatic environment has become an emerging contaminant problem, which has implications for public health. The degradation pathway and identification of transformation products of pharmaceutical residues are crucial to elucidate the environmental fate of photocatalytic decomposition of these pollutants in aqueous media. The degradation process might lead to creation of other possible emerging contaminates. In this study, the degradation of DCF and IBP in aqueous solutions was investigated. To this end, coated TiO2 on a Pilkington Active glass was used as a photocatalyst under UVA illumination, in a planar falling film reactor. Pilkington ActivTM glass was used as a photocatalyst and a falling liquid film generator. Degradation kinetics of both pharmaceuticals followed a pseudo-first-order model. The transformation products of both diclofenac and ibuprofen during the degradation process were detected and identified with gas chromatography–mass spectrometry (GC–MS) and ion chromatography. The results showed that the mineralization rate of both pharmaceuticals through photocatalysis was very low. Low chain carboxylic acids, such as formic, acetic, oxalic, malonic, and succinic acids were the main by-products. A pathway of DCF and IBP degradation was proposed.

Structural changes in uterine tissues after uterine artery embolization in patients with leiomyoma complicated by uterine bleeding

GYNECOLOGY ◽  
2018 ◽  
Vol 20 (1) ◽  
pp. 78-82
Author(s):  
G P Titova ◽  
M M Damirov ◽  
L S Kokov ◽  
O N Oleynikova ◽  
G E Belozerov
Keyword(s):  
Uterine Artery Embolization ◽  
Uterine Artery ◽  
Structural Changes ◽  
Morphological Changes ◽  
Uterine Bleeding ◽  
Small Scale ◽  
Artery Embolization ◽  
Vessel Occlusion ◽  
Uterine Arteries ◽  
Uterine Tumors

Uterine leiomyoma (UL) is often complicated by the development of uterine bleeding. In urgent gynecology for the implementation of endovascular hemostasis, uterine artery embolization (UAE) is used. Performing UAE allows to stop and/or significantly reduce the intensity of bleeding and prepare a patient for surgical intervention. At the same time, the morphological changes that occur in uterine tissues in operated UL patients after performing the UAE are not studied. The aim was to study the peculiarities of pathomorphological changes in uterine tumors and tissues in operated UL patients complicated by uterine bleeding after performing UAE. Material and methods. The results of morphological changes appearing in tumors and tissues of the uterus in 39 operated UL patients, who were used for stopping uterine bleeding, were analyzed. Results. After applying different types of embolizing agents in macroscopic study of the uterus, signs of ischemia of its tissues were revealed, and the most pronounced disorders were detected in the UL nodes. Morphologically it was established that UAE microemboli resulted in vessel occlusion with increasing thrombosis in their distal sections. UAE was not accompanied by occlusal occlusion of the arteries and resulted in small-scale necrosis of the tumor with complete regeneration of the endometrium. Conclusions. The results of the morphological study showed that after the UAE was performed, the myomatous nodes underwent dystrophic, necrobiotic and necrotic changes. Depending on the nature of occlusion of the uterine arteries, various variants of necrosis (scale and completeness of the process) developed in the tumor tissue, which was aseptic in nature.

Thermal characterization of ABS-Graphene blended three dimensional printed functional prototypes for electro chemical energy storage

2018 ◽  
Vol 1 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Kamaljit Singh Boparai ◽  
Rupinder Singh
Keyword(s):  
Energy Storage ◽  
Structural Changes ◽  
Fused Deposition Modeling ◽  
Morphological Changes ◽  
Three Dimensional ◽  
Thermal Characterization ◽  
Chemical Energy ◽  
Flow Index ◽  
Fused Deposition

This study highlights the thermal characterization of ABS-Graphene blended three dimensional (3D) printed functional prototypes by fused deposition modeling (FDM) process. These functional prototypes have some applications as electro-chemical energy storage devices (EESD). Initially, the suitability of ABS-Graphene composite material for FDM applications has been examined by melt flow index (MFI) test. After establishing MFI, the feedstock filament for FDM has been prepared by an extrusion process. The fabricated filament has been used for printing 3D functional prototypes for printing of in-house EESD. The differential scanning calorimeter (DSC) analysis was conducted to understand the effect on glass transition temperature with the inclusion of Graphene (Gr) particles. It has been observed that the reinforced Gr particles act as a thermal reservoir (sink) and enhances its thermal/electrical conductivity. Also, FT-IR spectra realized the structural changes with the inclusion of Gr in ABS matrix. The results are supported by scanning electron microscopy (SEM) based micrographs for understanding the morphological changes.

Roughened gold electrode for in situ SERS analysis of structural changes accompanying the doping process of polyaniline in acidic aqueous media

2021 ◽  
Vol 882 ◽  
pp. 115034
Author(s):  
A. El Guerraf ◽  
M. Bouabdallaoui ◽  
Z. Aouzal ◽  
S. Ben Jadi ◽  
N.K. Bakirhan ◽  
...  
Keyword(s):  
Gold Electrode ◽  
Structural Changes ◽  
Aqueous Media

scholarly journals Yttrium doped phosphate-based glasses: structural and degradation analyses

2020 ◽  
Vol 6 (1) ◽  
pp. 34-49
Author(s):  
Abul Arafat ◽  
Sabrin A. Samad ◽  
Jeremy J. Titman ◽  
Andrew L. Lewis ◽  
Emma R. Barney ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Structural Changes ◽  
Xrd Analysis ◽  
Calcium Pyrophosphate ◽  
Ion Release ◽  
Subsequent Increase ◽  
Structural Characterisation ◽  
Release Studies ◽  
Degradation Properties

AbstractThis study investigates the role of yttrium in phosphate-based glasses in the system 45(P2O5)–25(CaO)– (30-x)(Na2O)–x(Y2O3) (0≤x≤5) prepared via melt quenching and focuses on their structural characterisation and degradation properties. The structural analyses were performed using a combination of solid-state nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). 31P NMR analysis showed that depolymerisation of the phosphate network occurred which increased with Y2O3 content as metaphosphate units (Q2) decreased with subsequent increase in pyrophosphate species (Q1). The NMR results correlated well with structural changes observed via FTIR and XPS analyses. XRD analysis of crystallised glass samples revealed the presence of calcium pyrophosphate (Ca2P2O7) and sodium metaphosphate (NaPO3) phases for all the glass formulations explored. Yttrium-containing phases were found for the formulations containing 3 and 5 mol% Y2O3. Degradation analyses performed in Phosphate buffer saline (PBS) and Milli-Q water revealed significantly reduced rates with addition of Y2O3 content. This decrease was attributed to the formation of Y-O-P bonds where the octahedral structure of yttrium (YO6) cross-linked phosphate chains, subsequently leading to an increase in chemical durability of the glasses. The ion release studies also showed good correlation with the degradation profiles.

Characterization of Structural Changes of Poly(vinyl methyl ether) γ-Irradiated in Diluted Aqueous Solutions

Langmuir ◽  
2004 ◽  
Vol 20 (7) ◽  
pp. 2883-2889 ◽  
Author(s):  
Claudia Querner ◽  
Thomas Schmidt ◽  
Karl-Friedrich Arndt
Keyword(s):  
Aqueous Solutions ◽  
Methyl Ether ◽  
Structural Changes ◽  
Vinyl Methyl ◽  
Vinyl Methyl Ether

Ouricuri (Syagrus coronata) fiber: a novel biosorbent to remove methylene blue from aqueous solutions

2016 ◽  
Vol 75 (1) ◽  
pp. 106-114 ◽  
Author(s):  
Lucas Meili ◽  
Társila Santos da Silva ◽  
Daniely Carlos Henrique ◽  
João Inácio Soletti ◽  
Sandra Helena Vieira de Carvalho ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Experimental Design ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Adsorption Process ◽  
Fiber Diameter ◽  
Aqueous Media ◽  
Process Efficiency ◽  
Maximum Adsorption Capacity ◽  
Equilibrium Studies

In this work, the potential of ouricuri (Syagrus coronata) fiber as a novel biosorbent to remove methylene blue (MB) from aqueous solutions was investigated. The fiber was prepared and characterized according to the fundamental features for adsorption. A 23 experimental design was used to evaluate the effects of adsorbent dosage (M), fiber diameter (D) and agitation (A) on the adsorption capacity. In the more adequate conditions, kinetic and equilibrium studies were performed. The experimental design results showed that M = 10 g L−1), D = 0.595 mm and A = 200 rpm were the more adequate conditions for MB adsorption. Based on the kinetic study, it was found that the adsorption process was fast, being the equilibrium was attained at about 5 min, with 90% of color removal. The isotherm was properly represented by the Sips model, and the maximum adsorption capacity was 31.7 mg g−1. In brief, it was demonstrated that ouricuri fiber is an alternative biosorbent to remove MB from aqueous media, taking into account the process efficiency and economic viewpoint.

Staphylococcal infection and pathomurfological characteristic of the pituitary-adrenal-thyroid system

2020 ◽  
Vol 03 (04) ◽  
pp. 69-73
Author(s):  
Samira Mammadhasan Yagubova ◽  
◽  
Elchin Chingiz Akbarov ◽  
Tarana Nadir Mirzayeva ◽  
◽  
...  
Keyword(s):  
Structural Changes ◽  
Adrenal Glands ◽  
Early Stage ◽  
Morphological Changes ◽  
Endocrine System ◽  
Staphylococcal Infection ◽  
The Body ◽  
Glandular Cells ◽  
Exogenous Factors ◽  
Specific Symptoms

During the staphylococcal infection, changes in the interaction of glandular cells, dystrophic and disorganizing pathologies in tissues, especially acute structural and hemodynamic changes in the stroma of the glands in the pituitary-adrenal-thyroid system, develop from the first day of the experiment. At the end of the experiment, on the background of a decrease in exudative processes, fibroplastic reactions are significantly activated, resulting in signs of incomplete regeneration – mainly sclerotic processes and cystic-atrophic changes in the parenchyma. Structural changes in tissues in the early stages of staphylococcal infection and the dynamics of development are characterized by specific symptoms in each of the glands. Since the pituitary gland is exposed to endogenous and exogenous factors earlier and more often than the adrenal glands, and the adrenal glands are earlier than the thyroid gland, dystrophic and destructive changes in the pituitary and adrenal glands are more pronounced at the early stage of the experiment. These morphological changes can change the hormonal status of the body and lead to dysfunction of the endocrine system as a whole – a decrease in the functional activity of the glands to some extent, and even inhibition of adenohypophyseal cells. Key words: staphylococcal infection, peritonitis, pituitary, adrenal and thyroid glands

scholarly journals Multi-Component Adsorption of Benzene, Toluene, Ethylbenzene, and Xylene from Aqueous Solutions by Montmorillonite Modified with Tetradecyl Trimethyl Ammonium Bromide

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
H. Nourmoradi ◽  
Mehdi Khiadani ◽  
M. Nikaeen
Keyword(s):  
Experimental Data ◽  
Aqueous Solutions ◽  
Structural Changes ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Ammonium Bromide ◽  
Order Kinetic ◽  
Multicomponent Adsorption ◽  
Benzene Toluene ◽  
Kinetic And Isotherm Models

Multicomponent adsorption of benzene, toluene, ethylbenzene, and xylene (BTEX) was assessed in aqueous solutions by montmorillonite modified with tetradecyl trimethyl ammonium bromide (TTAB-Mt). Batch experiments were conducted to determine the influences of parameters including loading rates of surfactant, contact time, pH, adsorbate concentration, and temperature on the adsorption efficiency. Scanning electron microscope (SEM) and X-ray diffractometer (XRD) were used to determine the adsorbent properties. Results showed that the modification of the adsorbent via the surfactant causes structural changes of the adsorbent. It was found that the optimum adsorption condition achieves with the surfactant loading rate of 200% of the cation exchange capacity (CEC) of the adsorbent for a period of 24 h. The sorption of BTEX by TTAB-Mt was in the order ofB<T<E<X. The experimental data were fitted by many kinetic and isotherm models. The results also showed that the pseudo-second-order kinetic model and Freundlich isotherm model could, respectively, be fitted to the experimental data better than other available kinetic and isotherm models. The thermodynamic study indicated that the sorption of BTEX with TTAB-Mt was achieved spontaneously and the adsorption process was endothermic as well as physical in nature. The regeneration results of the adsorbent also showed that the adsorption capacity of adsorbent after one use was 51% to 70% of original TTAB-Mt.

scholarly journals Recyclable glucose-derived palladium(0) nanoparticles as in situ-formed catalysts for cross-coupling reactions in aqueous media

RSC Advances ◽  
2016 ◽  
Vol 6 (20) ◽  
pp. 16115-16121 ◽  
Author(s):  
Jason E. Camp ◽  
Jay J. Dunsford ◽  
Oliver S. G. Dacosta ◽  
Rebecca K. Blundell ◽  
James Adams ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Aqueous Media ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Cross Coupling Reactions

Renewable sugar-derived palladium(0) nanoparticles (PdNPs) are effective as in situ formed catalysts for cross-coupling reactions in aqueous solutions.

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