Search results for "quantitative analysis"

An Inquiry-Based Approach to a Pedagogical Laboratory for Primary School Teacher Education

2017

In questo articolo vengono presentati e di- scussi alcuni risultati relativi alla sperimen- tazione di due esperienze di didattica laboratoriale della fisica, una basata su me- todi di indagine scientifica e l’altra su meto- dologie didattiche più “tradizionali”, svolte durante l’A.A. 2014-15 con studenti del CdL in Scienze della Formazione Primaria del- l’Università di Palermo. I dati, analizzati tra- mite metodi quantitativi, sono stati ricavati dalla somministrazione prima, durante e do- po le attività laboratoriali, di un questionario finalizzato a comprendere gli stili di insegna- mento preferiti dagli studenti, la motivazio- ne di questi all’apprendimento/insegna- mento delle scienze …

Methods of research Textual analysis

2014

Electoral opportunism and water pricing with incomplete transfer of control rights

2020

One of the forms of intervention in public services that lie beyond market forces is price control. While such regulation is justified by the need to achieve social goals, empirical evidence has sh...

Political patterning of urban namescapes and post-socialist toponymic change: A quantitative analysis of three Romanian cities

2020

Abstract Critical scholars of place-name studies have compellingly demonstrated that significant transformations in a society's namescape follow suit major power shifts and regime changes. However, despite the wealth of particular case studies existing in the literature, scarce efforts have been made to examine street name changes in a comparative framework using statistical modeling techniques of multivariate analysis. This paper aims to overcome these shortcomings by developing a comparative approach to analyzing post-socialist street-naming transformations in three Romanian cities from Transylvania (Brașov, Cluj-Napoca, and Sibiu). Based on comprehensive data collected from multiple sour…

Retention of carbaryl by polyether type polyurethane foam: a critical study

2000

This paper reports the retention of carbaryl by polyether type polyurethane foam in a dynamic mode. Several parameters that can influence the extraction of carbaryl from water samples were investigated such as concentration of carbaryl, mass of sorbent in the column, sample pH, saline concentration, solvent washing and sample flow rate. Results show that it is possible to achieve quantitative extractions when the sample flow rate is maintained up to 2.4 mL min−1, a mass of foam of 300 mg and a sample volume of 30 mL in 0.5 NaCl are employed. They also indicate that there is an ether-like solvent extraction mechanism controlling the sorption of the substance by the foam. Some recovery tests …

Identification and quantification of phosphatidylcholines containing very-long-chain polyunsaturated fatty acid in bovine and human retina using liqu…

2010

The retina is one of the vertebrate tissues with the highest content in polyunsaturated fatty acids (PUFA). A large proportion of retinal phospholipids, especially those found in photoreceptor membranes, are dipolyunsaturated molecular species. Among them, dipolyunsaturated phosphatidylcholine (PC) molecular species are known to contain very-long-chain polyunsaturated fatty acids (VLC-PUFA) from the n-3 and n-6 series having 24-36 carbon atoms (C24-C36) and four to six double bonds. Recent interest in the role played by VLC-PUFA arose from the findings that a protein called elongation of very-long-chain fatty acids 4 (ELOVL4) is involved in their biosynthesis and that mutations in the ELOVL…

Quantitative analysis of chromite ores using glass discs in moderate dilutions of lithium tetraborate by x-ray fluorescence spectrometry

2006

A method for the quantitative analysis of chromite ores by x-ray fluorescence spectrometry using beads is proposed. The work concerned the serious problems caused by the refractory nature of these materials which prevents the use of glass discs in x-ray fluorescence. An in-depth study was done to optimise the variables which influence the glass disc formation process. Sufficiently homogeneous glass discs were obtained under the following experimental conditions: lithium tetraborate as flux with moderate sample dilution (1:40), with the addition of one or two drops of LiBr solution(250 g l−1), at a temperature of 1200 °C for 30 min. The qualitative and semiquantitative results for the chromi…

Recurrence Plots in Nonlinear Time Series Analysis: Free Software

2002

Recurrence plots are graphical devices specially suited to detect hidden dynamical patterns and nonlinearities in data. However, there are few programs available to apply such a mehodology. This paper reviews one of the best free programs to apply nonlinear time series analysis: Visual Recurrence Analysis (VRA). This program is targeted to recurrence analysis and the so-called Recurrence Quantitative Analysis (RQA, the quantitative counterpart of recurrence plots), although it includes many procedures in a friendly visual environment. Comparisons with alternative programs are performed.

Structure and evolution of a European Parliament via a network and correlation analysis

2016

We present a study of the network of relationships among elected members of the Finnish parliament, based on a quantitative analysis of initiative co-signatures, and its evolution over 16 years. To understand the structure of the parliament, we constructed a statistically validated network of members, based on the similarity between the patterns of initiatives they signed. We looked for communities within the network and characterized them in terms of members' attributes, such as electoral district and party. To gain insight on the nested structure of communities, we constructed a hierarchical tree of members from the correlation matrix. Afterwards, we studied parliament dynamics yearly, wi…

Antibacterial Activity of Flavonoids Against Methicillin-resistant Staphylococcus aureus strains

2000

An experimental and theoretical study was performed on the anti-staphylococcal activity of 18 natural and synthetic flavonoids against methicillin-resistant Staphylococcus aureus strains. The analysed flavonoids belong to three well-differentiated structural patterns: chalcones, flavanones and flavones. The quantitative analysis of the anti-staphylococcal activity of the compounds was carried out by determining their percent inhibition degree. The hierarchical cluster analysis method was used to analyse the anti-MRSA activity of the compounds. With this methodology, the flavonoids were classified into four groups according to their anti-staphylococcal activity (high, sufficient, intermediat…