Search results for "Alchemy"
showing 10 items of 41 documents
Temperature Dependent Suns-V<inf>oc</inf> of Multicrystalline Silicon Solar Cells from Different Ingot Positions
2018
This paper presents temperature dependent Suns- Voc measurements on multicrystalline silicon cells originating from different ingot positions. The effective lifetime is found to increase for all cells when the temperature is increased from 25°C to 6°C. However, cells from the top of the ingot show a considerably larger increas 40–50% for illumination conditions of 0.1-1 Sun, compared to an increase of 20-30% observed for cells from the bottom. The decrease in Voc with increasing temperature is found to be lower for cells from the top of the ingot compared to cells from the bottom. The temperature coefficient of the Voc is found to vary 5% along the ingot at 1 Sun, highlighting the influence…
Anti-Inflamm-Ageing and/or Anti-Age-Related Disease Emerging Treatments: A Historical Alchemy or Revolutionary Effective Procedures?
2018
The “long-life elixir” has long represented for humans a dream, a vanity’s sin for remaining young and to long survive. Today, because of ageing population phenomenon, the research of antiageing interventions appears to be more important than ever, for preserving health in old age and retarding/or delaying the onset of age-related diseases. A hope is given by experimental data, which evidence the possibility of retarding ageing in animal models. In addition, it has been also demonstrated in animal life-extending studies not only the possibility of increasing longevity but also the ability to retard the onset of age-related diseases. Interestingly, this recent evidence is leading to promise …
Photocrosslinked Dextran-Based Hydrogels as Carrier System for the Cells and Cytokines Induce Bone Regeneration in Critical Size Defects in Mice
2018
Modified biomaterials have for years been the focus of research into establishing new bone substitutes. In our preceding in vitro study employing different cell cultures, we developed chemically and mechanically characterized hydrogels based on photocrosslinkable dextran derivatives and demonstrated their cytocompatibility and their beneficial effects on the proliferation of osteoblasts and endothelial cells. In the present in vivo study, we investigate photocrosslinked dextran-based hydrogels in critical size defects in mice to evaluate their potential as carrier systems for cells or for a specific angiogenesis enhancing cytokine to induce bone formation. We could demonstrate that, with op…
Effectiveness of microwave based digestion procedures for the demineralization of human milk and infant formulas prior to fluorometric determination …
1996
The use of two types of microwave oven, one domestic (A) and the other specially designed for laboratory (B) for microwave-based digestion, to destroy the organic matter in milk and infant formulas prior to fluorometric determination of selenium is studied in order to check their applicability and reliability. In both systems the best results were obtained using the acid mixture HNO3—H2O2, and additional treatment with perchloric acid (60%) in a Thermoblock. The application of two different microwave-based digestion procedures to infant formulas was free of interferences. In the case of human milk, it was necessary to use the standard addition method. Values obtained for detection and quant…
Some observations on the determination of total heavy metals in sewage sludge by atomic absorption spectrophotometry after a pressurized acid digesti…
1990
Abstract An economical and simple method for the flame atomic absorption spectrometric determination of Cd, Pb, Ni, Cu, Fe, and Zn in sewage sludges is described. Samples are treated with concentrated HNO 3 in a thermal oven using Pyrex glass tubes hermetically sealed with Bakelite screw caps. The effect of the digestion parameters, such as digestion time, acid volume, sample mass, and temperature, were studied. The precision and accuracy of this procedure were evaluated by the analysis of two BCR (Community Bureau of Reference, European Communities) certified sewage sludge samples (CRM 146 and 144).
Translation as alchemy: the aesthetics of multilingualism in film
2012
The aim of this paper is to explore the aesthetics of multilingualism in film. We start with a discussion of translation strategy in several films and continue with two case studies based on Azur et Asmar (2006) by Michel Ocelot, on the one hand, and Nostalghia (1983) and Offret (1986) by Andrei Tarkovsky, on the other. Our analysis does not involve a comparison between the original dialogues or monologues and their translations into one or several languages, but, rather, it focuses on the role of translation in film making, considering it independently from any pre-existing oral or written texts. This will lead us to a number of reflections about the possibility and the limits of communica…
Desarrollo histórico y epistemológico de los conceptos elemento químico, sustancia y sustancia simple (Primera parte)
2020
<p>La epistemología de cualquier concepto científico adquiere su pleno significado teniendo en cuenta el problema que hizo posible su conceptualización en un momento histórico dado y su posterior desarrollo. El objetivo de este artículo consistirá en recordar el problema que originó la necesidad epistemológica de introducir la idea de elemento químico a lo largo de la historia y cómo se ha ido desarrollando hasta el siglo XVIII para incidir en la epistemología del concepto de sustancia (pura) y cómo fue cambiando su relación con la del elemento químico. Este manuscrito está dividido en cuatro apartados principales, el primero de ellos titulado “El mundo natural de los filósofos griego…
El frau de l’alquimista en l’infern dantesc de Joan Pasqual i en la tradició medieval
2015
This article presents and analyses chapter XLVI from the Tractat de les penes particulars d’infern by Catalan franciscan friar Joan Pasqual, written soon after 1436. This chapter, “Del cercle de l’alquimia”, includes an exemplum which is doubly significant: on the one hand, it documents the alchemic legend in the Plantagenets’ court during the 14th and 15th centuries; on the other hand, and most importantly, it is a new testimony of two narrative motifs of Eastern origin: the fake alchemist and the king (Thompson, K.111.4; Tubach, 89), and the account-book of mistakes or fools (Thompson,J.1371). After introducing the medieval witnesses of these motifs, the alchemic legend of Ramon Llull and…
The determination of trace element concentrations in fly ash samples using ultrasound-assisted digestion followed with inductively coupled plasma opt…
2009
Abstract A method of ultrasound-assisted digestion followed by inductively coupled plasma optical emission spectrometry (ICP-OES) used for the determination of trace element (chromium, copper, lead, nickel, vanadium and zinc) concentrations in fly ash samples was developed. All the measurements were performed in robust plasma conditions. Ultrasound-assisted digestion procedures using digestion solutions of aqua regia and hydrofluoric acid (HF) resulted in recovery rates of over 80% for all the analyte elements. Ultrasound-assisted two-step digestion with digestion solutions of 6 mL of HNO3 (Step 1) and 3 mL of HNO3 + 3 mL of HF (Step 2) resulted in recovery rates of over 92% for all the ana…
Determination of mineral and trace element concentrations in pine needles by ICP-OES: evaluation of different sample pre-treatment methods
2008
In the present study, the determination of mineral and trace elements (Al, B, Ca, Cu, Fe, K, Mg, Mn, Na, P and Zn) from pine needles using three sample pre-treatment methods followed by inductively coupled plasma optical emission spectrometry, was examined. Sample pre-treatment methods tested were microwave digestion, ultrasound-assisted digestion and dry ashing. The new ultrasound-assisted digestion method was optimised by the analysis of the standard reference material (SRM) 1575a (pine needles) sample. The speed of dry ashing method was significantly increased by ultrasound dissolution after ashing. All the ICP-OES measurements were performed in robust plasma conditions which were tested…