Search results for "Quality Control"
showing 10 items of 180 documents
Determination of abamectin in citrus fruits by liquid chromatography-electrospray ionization mass spectrometry.
2000
Liquid chromatography coupled to electrospray mass spectrometry (LC-ES-MS) with positive ion detection was used to determine abamectin in oranges. MS conditions were optimized to achieve maximum sensitivity. The main ion for abamectin was [M+Na]+ at a fragmentor voltage of 180 V. Abundant structural information can be obtained at different fragmentor voltages. The detection limit for the standard solution was 12 pg injected, and good linearity and reproducibility were observed. Abamectin residues were extracted using matrix solid-phase dispersion. Orange samples were homogenized with C18 bonded silica placed onto a glass column and eluted with dichloromethane. Recoveries of the abamectin fr…
Simultaneous determinations of zirconium, hafnium, yttrium and lanthanides in seawater according to a co-precipitation technique onto iron-hydroxide.
2013
Very low concentrations (pg mL(-1) or sub-pg mL(-1) level) along with the high salinity are the main problems in determining trace metal contents in seawater. This problem is mainly considered for investigations of naturally occurring YLOID (Y and Lanthanides) and Zr and Hf in order to provide precise and accurate results. The inductively coupled plasma mass spectrometry (ICP-MS), both in high and low resolution, offers many advantages including simultaneous analyses of all elements and their quantitative determination with detection limits of the order of pg mL(-1). However in the analysis of YLOID in seawater, a better determination needs an efficient combination of ICP-MS measurement wit…
Quality control for exposure assessment in epidemiological studies
2010
In the framework of an epidemiological study, dosemeters were used for the assessment of radio frequency electromagnetic field exposure. To check the correct dosemeter's performance in terms of consistency of recorded field values over the entire study period, a quality control strategy was developed. In this paper, the concept of quality control and its results is described. From the 20 dosemeters used, 19 were very stable and reproducible, with deviations of a maximum of +/- 1 dB compared with their initial state. One device was found to be faulty and its measurement data had to be excluded from the analysis. As a result of continuous quality control procedures, the confidence in the meas…
A methodology for sequencing batch reactor identification with artificial neural networks: A case study
2009
This paper presents a systematic methodology based on the application of artificial neural networks for sequencing batch reactor (SBR) identification. The SBR is a fill-and-draw biological wastewater technology, which is specially suited for nutrient removal. The proposed approach makes optimal use of the available data during the training stage and it is aimed at achieving high generalization ability. For this purpose, a wide range of experimental conditions, including different solids retention times and influent characteristics, has been used. The methodology is successfully applied to develop a soft-sensor for monitoring a laboratory-scale SBR operated for enhanced biological phosphorus…
Proposal of geographic information systems methodology for quality control procedures of data obtained in naturalistic driving studies
2015
The primary goal of naturalistic driving studies is to provide a comprehensive observation of the driver's behaviour under real-life conditions by measureing a great number of parameters at high temporal frequencies. Achieving this goal, however, is a complex endeavor that faces many challenges such as the complexity of the vehicle instrumentation during the phase of data collection, and the difficult handling of large data volumes during the phase of data analysis. These drawbacks often cause episodes of data losses. Improving the technical aspects of the collection of naturalistic data is of paramount importance to increase the return of the investment made in it. An aspect to consider is…
QUALITY SYSTEM FOR PRODUCTION SOFTWARE (QSPS): AN INNOVATIVE APPROACH TO IMPROVE THE QUALITY OF PRODUCTION SOFTWARE
2013
A quality system for production software should be part of the quality management system of an organization and can be expressed as objectives in the form of processes, procedures, tools and responsibilities, designed and developed to fulfil the quality requirements. These usually are addressing the customers (external or internal), compliance with standards (effectiveness) waste reduction and better use of resources (efficiency) for continual improvement. Such systems are designed according to the requirements of the standards for quality management, software engineering and information security. Quality systems themselves could not provide all necessary means for driving the organization…
Bibliometric analysis through methodological quality indicators of Spanish education journals indexed in JCR during the three year period 2014-2016
2019
This study carries out a bibliometric evaluation through methodological quality indicators of the scientific production published during the triennium of 2014 to 2016 in the seven Spanish journals of education indexed in the Journal Citation Reports (JCR): Revista de Psicodidáctica; Comunicar; Revista de Educación; Educación XX1; Enseñanza de las Ciencias, Revista Española de Pedagogía; y Porta Linguarum. Through a bibliometric-descriptive methodology, a sample of articles that totals 479 and selected through a non-probabilistic sampling of deliberate type. Overall, the results obtained indicate that the journals evaluated have achieved levels of compliance with the proposed methodological …
FTIR approaches for diuron determination in commercial pesticide formulations.
2005
Two strategies have been developed for Diuron determination by FTIR spectrometry, an off-line extraction and stopped-flow determination and a fully mechanized procedure, based on the on-line extraction of Diuron and FIA-FTIR measurement of the extracts. The aforementioned procedures have been compared with a reference chromatographic method. The off-line FTIR spectra were obtained at a nominal resolution of 4 cm(-1) from 4000 to 900 cm(-1) by accumulating 25 scans. Diuron was determined using peak height measurements at 1582 cm(-1) corrected using a baseline defined between 1562 and 1614 cm(-1). The waste generation of the off-line procedure was 3.4 mL chloroform for each sample, and the me…
National economy: Quality Research of Products and Goods
1993
This edition is to reflect research results with modern analytical methodology including measurements and examinations with spectrophotometric appliances in combination with modern nondestructive testing methods which are employed in farming products' analysis and in merchandise quality control as well as relative advantages in terms of methodology.
A method for detecting malfunctions in PV solar panels based on electricity production monitoring
2017
In this paper a new method is developed for automatically detecting outliers or faults in the solar energy production of identical sets (sister arrays) of photovoltaic (PV) solar panels. The method involves a two-stage unsupervised approach. In the first stage, "in control" energy production data are created by using outlier detection methods and functional principal component analysis in order to remove global and local outliers from the data set. In the second stage, control charts for the "in control" data are constructed using both a parametric method and three non-parametric methods. The control charts can be used to detect outliers or faults in the production data in real-time or at t…