Search results for "Arity"
showing 10 items of 2893 documents
Implementation of gradients of organic solvent in micellar liquid chromatography using DryLab®: Separation of basic compounds in urine samples
2014
In micellar liquid chromatography (MLC), chromatographic peaks are more evenly distributed compared to conventional reversed-phase liquid chromatography (RPLC). This is the reason that most procedures are implemented using isocratic elution. However, gradient elution may be still useful in MLC to analyse mixtures of compounds within a wide range of polarities, decreasing the analysis time. Also, it benefits the determination of moderately to low polar compounds in physiological fluids performing direct injection: an initial micellar eluent with a low organic solvent content, or a pure micellar (without surfactant) solution, will provide better protection of the column against the proteins i…
Solvent selection in liquid chromatography
2017
Many solvents and additives are used to prepare mobile phases in liquid chromatography (LC). Also, mixtures of solvents at different ratios are used to modify the mobile-phase properties. This can make solvent selection for method development a puzzling task, unless suitable guidelines are followed. This chapter summarizes the most common strategies used by skilled chromatographers in reversed-phase, normal-phase, and hydrophilic interaction LC. These are based on considerations about the global polarity of solutes, stationary phase, and mobile phase, which determine the elution strength, and on the particular profile of the contributions of intermolecular interactions to the global polarit…
Beiträge zur Extraktion von Drogen. 4. Mitt.: Selektive Extraktionseigenschaften von Lösungsmitteln
1969
Am Beispiel der getrockneten Meerzwiebel wird gezeigt, wie bei der fraktionierten Extraktion mit Losungsmitteln steigender Polaritat die gewunschten Extraktivstoffe bis zu einem gewissen Grad selektiv extrahiert werden konnen. Extraction of Vegetable Drugs With the squill as example it is shown that the components of the extractable matter can be extracted selectively up to a certain point in a fractioned extraction with solvents of increasing polarity.
Quantification of some volatile aromatic compounds of apricot by adding standards
1988
The quantification of twelve volatile aromatic compounds of apricot was realized by adding known amounts of pure compounds directly in the slurry before analysis by vacuum distillation and gas chromatography. This method was compared with the classical technique using an internal standard and was applied to two different apricot cultivars. Large differences were observed between the amounts of volatiles calculated by the two methods. They are due to the differences between the extraction coefficients of the quantified compounds and to the retentions of volatiles on nonvolatile compounds, which may vary according to the polarity.
Circular dichroism of magnetically induced transitions for D 2 lines of alkali atoms
2018
In this letter we study magnetic circular dichroism in alkali atoms exhibiting asymmetric behaviour of magnetically induced transitions. The magnetic field induces transitions between hyperfine levels of alkali atoms and in the range of magnetic field, the intensities of these transitions experience significant enhancement. We have inferred a general rule applicable for the D 2 lines of all alkali atoms, that is the transition intensity enhancement is around four times larger for the case of than for excitation for , whereas it is several hundreds of thousand times larger in the case of than that for polarization for . This asymmetric behaviour results in circular dichroism. For experimenta…
The Sustainability of Reclaimed Asphalt as a Resource for Road Pavement Management through a Circular Economic Model
2019
The transition of the road engineering industry to a circular way of doing business requires more efficient and sustainable resources, energy, and waste management. The rates in which reclaimed asphalt is being recycled or reused in the asphalt mixture production process constitutes a crucial parameter in this transition. This paper aims at establishing a further step towards the combined circularity and sustainability of asphalt pavements, by introducing a framework for quantifying their Material Circularity Index. The framework is based on the methodology proposed by the Ellen MacArthur Foundation and accordingly tailored for the context of asphalt pavements. This study, thus, attempts to…
Comparing the Material Circularity Index of the Italian and Spanish motorways: A case study over the Mediterranean basin
2022
Closely following the attempt of the pavement engineering industry to comply with the principles of Circular Economy (CE) while simultaneously promoting its principles, it can be detected that a significant effort is being made towards the minimization of the energy and raw materials usually utilized. In this regard, Reclaimed Asphalt (RA) is a product that exhibits a tremendous exploitation potential. Knowing that by definition CE is restorative [1], regenerative, and aims to keep products, components, and materials at their highest utility and value at all times [2], i.e. it supports the “re-circulation” of materials and energy within the same or alternative product systems and thus the e…
URBAN RESILIENCE AND WASTE MANAGEMENT: PROPOSALS OF NEW INFRASTRUCTURES FOR URBAN AREAS AND BUILDINGS
2015
La produzione ingente di rifiuti, quale conseguenza di costumi di vita volti allo spreco, rende vulnerabili i sistemi urbani che possono essere sottoposti, in casi emergenziali, a pressioni eccezionali e incontrollate con situazioni prossime al collasso. Un’opportuna e corretta gestione integrata dei rifiuti contribuisce alla resilienza dei sistemi urbani. Perciò si rendono necessarie la pianificazione e la progettazione di nuovi servizi e l’individuazione/integrazione di spazi e dotazioni tecnologiche per incentivare la popolazione a effettuare la raccolta differenziata in modo corretto e costante. Si presentano gli esiti di uno studio svolto in un piccolo centro siciliano. Partendo dalle …
Conversion as Negotiation. Converts as Actors of Civil Society
2020
This article focuses on the religious movement of the Ahmadiyya and its civil society organization, Humanity First, in West-Africa and in Europe. Particular attention is paid to the place of converts within these two institutions. Conversions to an Islamic minority and the actions of this minority are studied through the prism of social commitment. I examine the intersections between religious values, the ideas of solidarity in the societies under scrutiny and, the kaleidoscopic range of Muslim charities. The paper investigates conversion as negotiation in regard to gender, social mobility, and power. Conversion is approached here as a matter of social relations and not personal belief. I a…
Rational Foundations of Democratic Politics
2003
1. Introduction Albert Breton, Gianluigi Galeotti, Pierre Salmon and Ronald Wintrobe Part I. Some Problems with Democratic Institutions and Trends in Their Evolution: 2. Demobilization, demoralization and the loosening bonds of electoral politics Michael C. Munger 3. Turning 'citizens' into 'consumers': economic growth and the level of public discourse Stergios Skaperdas 4. Economic and cultural prerequisites for democracy Roger D. Congleton 5. Civil society and the contemporary social order Frederique Chaumont-Chancelier Part II. Morals in Politics: 6. When does altruism overcome the intransitivity of income redistribution? Donald Wittman 7. Democratic resilience and the necessity of virtu…