In the case of desulfurization and spheroization of cast iron using the in-mold method, in which the treated cast iron is poured into the reaction chamber and placed in the casting mold, the mineral raw material of the mold should support these processes. Therefore, it is important to know the physicochemical properties of the materials selected for the production of casting molds and to learn about the phenomena occurring during their pouring. The research presented in this paper was carried out on quartz, magnesite, chromite, and olivine sands.
View Article and Find Full Text PDFPharmaceutical drugs, including antibiotics and hormonal agents, pose a significant threat to environmental and public health due to their persistent presence in aquatic environments. Colistin (KOL), fluoxetine (FLUO), amoxicillin (AMO), and 17-alpha-ethinylestradiol (EST) are pharmaceuticals (PhCs) that frequently exceed regulatory limits in water and wastewater. Current removal methods are mainly ineffective, necessitating the development of more efficient techniques.
View Article and Find Full Text PDFBackground: Erectile dysfunction (ED) is usually underestimated in many developing countries, Nigeria inclusive.
Introduction: ED is associated with stigma and poor health seeking behaviour and is assumed not to be life-threatening. This study was undertaken to determine the prevalence of ED and the pattern among adult males.
Background: The literature is replete with overwhelming evidence that being obese is a predictor of hypertension risk. Obesity can be defined by anthropometric indices, such as Body Mass Index (BMI), Waist Circumference (WC), waist-hip ratio (WHR), and waistheight ratio (WHtR). Despite wide use of BMI as indicator of obesity, it does not reflect central fat distribution, whereas WC, WHR, and WHtR are used as surrogate markers for body fat centralization.
View Article and Find Full Text PDFSteady state and time-resolved luminescence experiments and calorimetric studies, as well as time-dependent density functional theory calculations performed on [ClRe(CO)(3)(Bathocuproinedisulfonate)](2-), show that the photophysical properties of the Re(I) anionic complex are determined by the balance between intraligand ((1)IL) and metal-ligand-to-ligand charge transfer ((3)MLLCT) excited states. In organic solvents, (3)MLLCT states prevail and the usual expected behavior is observed: bathochromic shift of the emission maximum, a reduced luminescence quantum yield and the shortening of the excited-state lifetime upon increasing the polarity of the solvent. In addition, singlet oxygen ((1)O2) is generated with high quantum yields (Φ(Δ) ≈ 0.
View Article and Find Full Text PDFA group of nitrogen heterocyclic aromatic compounds used, among others, as UV-MALDI matrices was studied. By using spectroscopic, luminescence and photoacoustic techniques, as well as time resolved phosphorescence for singlet oxygen production determination, the behaviour of 9-aminoacridine (9AA), 3-aminoquinoline (3AQ), 2-(2-aminoethylamino)-5-nitropyridine (AAN) and 3,4-dihydro-7-methoxy-1-methyl-9H-pyrido[3,4-b] indole (harmaline, HLA) in acetonitrile solutions is described. The results show that for these compounds radiationless processes that release prompt heat to the media are a quite important deactivation mechanism.
View Article and Find Full Text PDFThe effect of molecular oxygen and water on the blue photoluminescence of silicon nanoparticles synthesized by anodic oxidation of silicon wafers and surface functionalized with 2-methyl 2-propenoic acid methyl ester is investigated. The particles of 3 +/- 1 nm diameter and a surface composition of Si(3)O(6)(C(5)O(2)H(8)) exhibit room-temperature luminescence in the wavelength range 300-600 nm upon excitation with 300-400 nm light. The luminescence shows vibronic resolution and high quantum yields in toluene suspensions, while a vibronically unresolved spectrum and lower emission quantum yields are observed in aqueous suspensions.
View Article and Find Full Text PDFThe kinetics of the reaction of sulfate radicals with the IHSS Waskish peat fulvic acid in water was investigated in the temperature range from 289.2 to 305.2 K.
View Article and Find Full Text PDFBy monitoring the decay of SO4*- after flash photolysis of aqueous solutions of S2O82- at different pH values, the kinetics of the reaction of SO4*- radicals with gallic acid and the gallate ion was investigated. The bimolecular rate constants for the reactions of the sulfate radicals with gallic acid and the gallate ion were found to be (6.3 +/- 0.
View Article and Find Full Text PDFTo learn more about the role of the reactive oxygen species (ROS) in the production of bioavailable products of the dissolved organic matter, we investigate here the effect of the photolysis (lambda(exc) > 320 nm) of a soil extract (SE) on the growth of bacteria isolated from the same soil as used for obtaining the extract. Comparative experiments with Aldrich humic acid (AHA) as substrate were performed. The photodegradation of the SE was evaluated with different techniques-UV-visible absorption spectroscopy, fluorescence excitation emission matrices (EEM) and Fourier transform infrared spectroscopy (FTIR).
View Article and Find Full Text PDFReactions of chlorine radicals might play a role in aqueous aerosols where a core of inorganic components containing insulators such as SiO2 and dissolved HUmic-LIke Substances (HULIS) are present. Herein, we report conventional flash photolysis experiments performed to investigate the aqueous phase reactions of silica nanoparticles (NP) and humic acid (HA) with chlorine atoms, Cl*, and dichloride radical anions, Cl2*-. Silica NP and HA may be taken as rough models for the inorganic core and HULIS contained in atmospheric particles, respectively.
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