Search results for "Geology"
showing 10 items of 6012 documents
New Evidence of the Enhanced Elimination of a Persistent Drug Used as a Lipid Absorption Inhibitor by Advanced Oxidation with UV-A and Nanosized Cata…
2019
This work demonstrates new evidence of the efficient destruction and mineralization of an emergent organic pollutant using UV-A and titanium nanosized catalysts. The target compound considered in this work is the primary metabolite of a lipid regulator drug, clofibrate, identified in many studies as refractory during conventional wastewater treatment. The photocatalytic performance study was carried out in batch mode at laboratory scale, in aqueous suspension. Kinetic data showed that titanium dioxide P25 Aeroxide® exhibits the highest photocatalytic efficiency compared to the other investigated catalysts. Pollutant degradation and mineralization efficiencies strongly increased when decreas…
Guano-related phosphate-rich minerals in European caves
2019
International audience; Guano is a typical deposit found in caves derived from the excretions of bats and in minor cases of birds. These organic deposits decompose and form a series of acid fluids and gases that can interact with the minerals, sediments, and rocks present in the cave. Over sixty phosphates are known and described from caves, but guano decay also often leads to the formation of nitrates and sulfates. In this study twenty-two European caves were investigated for their guano-related secondary minerals. Using various analytical techniques, seventeen phosphates, along with one sulfate (gypsum), were recognized as secondary products of guano decay. Among those minerals, some are …
Unravelling the Photocatalytic Behavior of All-Inorganic Mixed Halide Perovskites: The Role of Surface Chemical States
2019
Within the most mesmerizing materials in the world of optoelectronics, mixed halide perovskites (MHPs) have been distinguished because of the tunability of their optoelectronic properties, balancing both the light-harvesting efficiency and the charge extraction into highly efficient solar devices. This feature has drawn the attention of analogous hot topics as photocatalysis for carrying out more efficiently the degradation of organic compounds. However, the photo-oxidation ability of perovskite depends not only on its excellent light-harvesting properties but also on the surface chemical environment provided during its synthesis. Accordingly, we studied the role of surface chemical states …
Examining how global citizenship education is prefigured in the Scottish Curriculum for Excellence
2021
This study uses the Aristotelian notion of phronesis as a critical lens for examining how global citizenship education is prefigured in the Scottish Curriculum for Excellence. Based on a content analysis of key curriculum documentation, the findings outline the way in which techne and episteme with their associated ways of knowing and acting dominate the curriculum. Nevertheless, the hints of phronesis indicate the potential for developing a more critical form of global citizenship education that prefigures praxis that wisely pursues that which is good for humankind and individual flourishing. This article contributes to the notion of ‘planetary phronesis’ as a critical concept for the furt…
Incorporation mechanism of colloidal TiO2 nanoparticles and their effect on properties of coatings grown on 7075 Al alloy from silicate-based solutio…
2021
Plasma electrolytic oxidation (PEO) was applied using a pulsed unipolar waveform to produce Al2O3-TiO2 composite coatings from sol electrolytic solutions containing colloidal TiO2 nanoparticles. The sol solutions were produced by dissolving 1, 3, and 5 g/L of potassium titanyl oxalate (PTO) in a silicate solution. Scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction, and Raman spectroscopy were applied to characterizing the coatings. Corrosion behavior of the coatings was investigated using polarization and impedance techniques. The results indicated that TiO2 enters the coating through all types of micro-discharging and is doped into the alumina phase. The higher…
Fracture and fatigue of titanium narrow dental implants: New trends in order to improve the mechanical response
2019
Sixty-four fractured commercially pure titanium (cp-Ti) narrow dental implants (NDIs) with similar macrogeometry and connection designs were studied after different implantation times in humans in order to determine their reliability and to evaluate the causes of the fracture. These NDIs were compared with other similar implants, made with alloyed titanium with 15% Zr and with 12% strained titanium. Original implants were tested under static and fatigue conditions, simulating the tri-axial loads in the mouth by means of a Bionix hydraulic test machine. Fractography was studied using field-emission scanning electron microscopy (FSEM). The results showed that cp-Ti NDI exhibits low strength f…
Hydrogeologinen WSN-ympäristömonitorointi : tapaustutkimus Kaitforsin patoalueen pohjavesien korkeusseurannan pilottijärjestelmästä
2017
Tämän pro gradu -tutkielman tavoitteena on selvittää Kaitforsin patoalueelle toteutetun pohjavesien monitorointiin Kokkolan yliopistokeskus Chydeniuksessa kehitetyn pilottijärjestelmän näkökulmasta, millaisin menetelmin vedenkorkeuksien ja veden laadun monitorointia voidaan IoT:n ja langattomien sensoriverkkojen asettamista lähtökohdista automatisoidusti suorittaa. Tämän lisäksi tutkimuksen tavoitteena on selvittää automatisoidun ympäristömonitoroinnin nykytilaa ja siihen kytkeytyviä kehityssuuntauksia. Tutkimuksessa perehdytään myös Kaitforsin patoalueelle asennetun pilottijärjestelmän IEEE 802.15.4 -standardiin perustuvaan langattoman sensoriverkon toimintaan ja siihen kytkeytyneiden sens…
Risk narrations and perceptions in the COVID-19 time. A discourse analysis through the Italian press
2020
This paper explores how the risk related to the pandemic of COVID-19 was managed, narrated and perceived in Italy during the lockdown phase, from February until June 2020. To reach this aim, the study provides a discourse analysis of three main level: the official institutional discourses declaimed by the government and the health authority; the risk narration spread through the diaphragm of the Italian press, and specifically through two of the most-read newspapers in Italy (Repubblica and Corriere della Sera) and their related weeklies (Venerdì di Repubblica and Sette); finally, the diverse reactions and perceptions to the risk coming from the most affected and most vulnerable subjects, c…
Raman Investigations to Identify Corallium rubrum in Iron Age Jewelry and Ornaments
2016
International audience; During the Central European Iron Age, more specifically between 600 and 100 BC, red precious corals (Corallium rubrum) became very popular in many regions, often associated with the so-called (early) Celts. Red corals are ideally suited to investigate several key questions of Iron Age research, like trade patterns or social and economic structures. While it is fairly easy to distinguish modern C. rubrum from bone, ivory or shells, archaeologists are confronted with ancient, hence altered, artifacts. Due to ageing processes, archaeological corals lose their intensive red color and shiny surface and can easily be confused with these other light colored materials. We pr…
Pro-Degradant Activity of Naturally Occurring Compounds on Polyethylene in Accelerate Weathering Conditions
2019
In this work, naturally occurring compounds, such as Vitamin E (VE) and Ferulic Acid (FA), at high concentrations, have been considered as pro-degradant agents for Low Density Polyethylene (PE). However, all obtained results using the naturally occurring molecules as pro-oxidant agents for PE have been compared with the results achieved using a classical pro-oxidant agent, such as calcium stearate (Ca stearate) and with neat PE. The preliminary characterization, through rheological, mechanical and thermal analysis, of the PE-based systems highlights that the used naturally occurring molecules are able to exert a slight plasticizing action on PE and subsequently the PE rigidity and crystalli…