Search results for "SPD"
showing 10 items of 22 documents
Welding abilities of UFG metals
2018
Ultrafine Grained (UFG) metals are characterized by an average grain size of <1 μm and mostly high angle grain boundaries. These materials exhibit exceptional improvements in strength, superplastic behaviour and in some cases enhanced biocompatibility. UFG metals barstock can be fabricated effectively by means of Severe Plastic Deformation (SPD) methods. However, the obtained welded joints with similar properties to the base of UFG material are crucial for the production of finished engineering components. Conventional welding methods based on local melting of the joined edges cannot be used due to the UFG microstructure degradation caused by the heat occurrence in the heat affected zone…
Application of an HPLC-MS/MS method for mycotoxin analysis in commercial baby foods
2012
Abstract This article describes the validation of an analytical method for the detection of 21 mycotoxins in baby food. The analytical method is based on the simultaneous extraction of selected mycotoxins by matrix solid-phase dispersion (MSPD) followed by liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) using a hybrid triple quadrupole-linear ion trap mass spectrometer (QTRAP®). Information Dependent Acquisition (IDA), an extra confirmation tool for samples that contain the selected mycotoxins, was used. The matrix effects were evaluated, and the corrections for the matrix effects were performed using two calibration approaches: external matrix-matched calibration and…
Sag, wie hältst Du's mit Grün-Rot? Die grün-rote Landesregierung im Urteil der Wähler 2011 bis 2015
2016
In unserem Beitrag analysieren wir, wie die Burgerinnen und Burger den Regierungswechsel und die Ubernahme der Regierungsgeschafte durch die neue grun-rote Regierung wahrgenommen, wie sich die Regierungs- und Parteienzufriedenheit (ausgedruckt durch die hypothetische Wahlentscheidung) im Zeitverlauf entwickelt haben und was die Determinanten der Zufriedenheit sind. Unsere Analysen basieren dabei auf insgesamt sechs reprasentativen telefonischen Befragungen im Zeitraum von November 2011 bis Oktober 2015. Wir konnen zeigen, dass im Laufe der Legislaturperiode die vor der Wahl stattgefundenen Ereignisse mehr und mehr an Bedeutung fur die Bewertung der Regierungsleistung verlieren. Die Landesre…
Indoor artificial lighting: Prediction of the circadian effects of different spectral power distributions.
2014
The study presented in this paper aims to evaluate if and how the environment affects the circadian impact of a light source by predicting circadian stimulus (CS) resulting from the exposure to different light scenes, using equations reported in studies by Rea et al. The main findings are: (1) Above 600 lx at eye level the increase of CS is little; (2) Between 50 lx and 200 lx at the eye level an increase of only 50 lx determines a significant increase of CS; (3) Light sources with correlated colour temperatures between 2900 K and 4200 K have similar impacts on the circadian system according to the calculation method used; (4) Even an almost neutral environment affects the circadian impact…
Occurrence of fourteen mycotoxins in tiger-nuts
2012
Abstract A previous developed matrix solid-phase dispersion (MSPD) extraction method was applied for the routine analysis of aflatoxins (AFs), ochratoxin A (OTA), fumonisins (FB 1 and FB 2 ), beauvericin (BEA), nivalenol (NIV), deoxynivalenol (DON), the toxin T-2 (T-2), toxin HT-2 (HT-2), diacetoxyscirpenol (DAS) and zearalenone (ZEN) in tiger-nuts by liquid chromatography–triple-quadrupole linear ion trap (HPLC–QTRAP ® ). The extraction solid support used was C 18 , while the elution solvent was acetonitrile/methanol (50/50, v/v) 1 mM ammonium formate. Using matrix-matched calibration, recoveries and repeatabilities were in the range 67–89% and 2–11% relative standard deviation (RSD), resp…
Evaluation of matrix solid-phase dispersion (MSPD) extraction for multi-mycotoxin determination in different flours using LC-MS/MS
2011
An existing matrix solid-phase dispersion (MSPD) method for aflatoxins (AFs) and ochratoxin A (OTA) extraction was extended by further 14 mycotoxins. After it careful optimization, this method was applied to determine the occurrence of these mycotoxins on commercial flour samples (with different cereals composition) collected from local markets. In a total of 49 samples investigated, 9 mycotoxins were identified. Nivalenol (NIV) and Beauvericin (BEA) were the mycotoxins found most frequently. The samples that presented major contamination were wheat flours and bakery preparations. Despite of the great number of positives finding, only one wheat flour sample exceeded the maximum limits (ML) …
Severe plastic deformation (SPD) processes for metals
2008
Abstract Processes of severe plastic deformation (SPD) are defined as metal forming processes in which a very large plastic strain is imposed on a bulk process in order to make an ultra-fine grained metal. The objective of the SPD processes for creating ultra-fine grained metal is to produce lightweight parts by using high strength metal for the safety and reliability of micro-parts and for environmental harmony. In this keynote paper, the fabrication process of equal channel angular pressing (ECAP), accumulative roll-bonding (ARB), high pressure torsion (HPT), and others are introduced, and the properties of metals processed by the SPD processes are shown. Moreover, the combined processes …
Analysis of mycotoxins in barley using ultra high liquid chromatography high resolution mass spectrometry: comparison of efficiency and efficacy of d…
2012
The effectiveness of four extraction methods (modified QuEChERS, matrix solid-phase dispersion (MSPD), solid-liquid extraction (SLE) and solid-phase extraction (SPE) clean-up) were evaluated for simultaneous determination of 32 mycotoxins produced by the genus Fusarium, Claviceps, Aspergillus, Penicillium and Alternaria in barley by ultra high pressure liquid chromatography coupled to ultra-high resolution mass spectrometry (UHPLC-Orbitrap(®) MS). The efficiency and efficacy of extraction methods were evaluated and compared in number of extracted mycotoxins and obtained recoveries. From the one point of view, QuEChERS procedure was fast and easy, as well as it was able to successfully extra…
Effects Of Variation Of The Color Characteristics Of Lighting Sources By The Environmental Context
2012
Over recent years the importance of using daylight in indoor environments to achieve reductions of energy consumption was largely discussed, but the use of daylight is even more important because of its effects on human beings. Daylight has a more uniform spectral distribution than the artificial sources (especially discharge lamps) and consequently it allows a better color perception; moreover it changes during the day both in intensity and spectral power distribution (SPD). For all these reasons, daylight ensures a high comfort in carrying out all the human activities and is also important to the circadian rhythm regulation; therefore it results necessary to evaluate the entrance of natur…
Subjective responses to different light sources. A study on light preferences and comparison of standard light measures with human individual estimat…
2013
The experimental research here described investigates how people perceive different light sources that have same CCTs and illuminance values on a visual task. The results show that photometric quantities like illuminances and CCTs fail to guarantee users comfort, because parameters like SPD of the light source and its technology heavily influence people's perception of an environment.