bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of LC/MS and ICP/MS for establishing the fingerprint spectrum of the traditional Chinese medicinal preparation Gan‐Lu‐Yin
Authors: Lin I‐Hsin , Lee Ming‐Chung , Chuang Wu‐Chang 
Published: January 2006

AbstractWe developed a method to analyze the fingerprint spectrum qualitatively and quantitatively for the traditional Chinese herbal medicinal preparation Gan‐Lu‐Yin with HPLC combined with photodiode array detection, and MS, and to identify the preparation's 14 main components including baicalin, baicalein, oroxylin A‐7‐O‐glucuronide, wogonin‐7‐O‐glucuronide, wogonin, and oroxylin A in Radix Scutellariae; naringin and neohesperidin in Aurantii fructus; liquiritigenin, liquiritin, and glycyrrhizic acid in Radix Glycyrrhizae. In LC/UV assay, a Cosmosil 5C18‐MS‐II column was used as the stationary phase, and a gradient of potassium dihydrogen phosphate, ACN, and water as the elute solution. The UV detection wavelengths were 250 and 280 nm. In LC/MS assay, a gradient of phosphoric acid, ACN, and water was used as the elute solution, and electrospray positive ion mode ((+)‐ESI) as the analytic mode. In order to explore the distribution of trace metal elements effectively in Gan‐Lu‐Yin, a microwave digestion method was used for sample treatment, and an inductively coupled plasma MS assay was used to analyze fingerprint spectra of the inorganic metals in Gan‐Lu‐Yin. Combined with fingerprint spectra of organic compounds by LC/UV and LC/MS, it was expected to provide effective quality control in the production of Gan‐Lu‐Yin.
A simple and inexpensive “solvent in silicone tube extraction” approach and its evaluation in the gas chromatographic analysis of pesticides in fruits and vegetables
Authors: Jánská Marie , Lehotay Steven J. , Ma�tovská Katerina , Haj�lová Jana , Alon Tal , Amirav Aviv 
Published: January 2006

AbstractA novel, simple, and inexpensive approach to sorptive extraction, which we call solvent in silicone tube extraction (SiSTEx), was applied to pesticide residue analysis and its effectiveness and efficiency were evaluated. In SiSTEx, which is a form of open tubular sorptive extraction, a piece of silicone tubing (4 cm long, 1.47 mm ID, 1.96 mm OD in this study) is attached to the cap of a 20 mL glass vial that contains the aqueous sample. The tubing is plugged at the end dangling in the sample solution, and MeCN (e. g., 40 μL) added by syringe to the inner tube volume through a septum in the cap. A stir‐bar is used to mix the sample for a certain time (e. g., 60 min), which allows chemicals to partition into the tubing where they diffuse across the silicone and partition into the MeCN. The final MeCN extract is then analyzed for the concentrated analytes. In this study, the SiSTEx approach was evaluated for the analysis of organophosphorus (OP) and organochlorine (OC) pesticides in fruits and vegetables using GC/pulsed flame photometric (PFPD) and halogen specific (XSD) detectors for analysis. The produced samples were initially extracted by a rapid MeCN procedure, and 5 mL of the initial extract was diluted four‐fold with water to undergo sorptive extraction for 60 min. The final extract was analyzed by GC/PFPD + XSD for 14 OP and 22 OC pesticides. This simple approach was able to detect 26 of the 36 pesticides at 10 ng/g or less original equivalent sample concentration with average reproducibility of 11 %RSD. For those 26 pesticides, a 44‐fold lower detection limit on average was achieved in matrix extracts using SiSTEx despite the four‐fold dilution with water.
Analysis of lorazepam and its 3O‐glucuronide in human urine by capillary electrophoresis: Evidence for the formation of two distinct diastereoisomeric glucuronides
Authors: Baldacci Andrea , Thormann Wolfgang 
Published: January 2006

AbstractLorazepam (LOR) is a 3‐hydroxy‐1,4‐benzodiazepine that is chiral and undergoes enantiomerization at room temperature. In humans, about 75% of the administered dose of LOR is excreted in the urine as its 3O‐glucuronide. CE‐MS with negative ESI was used to confirm the presence of LOR‐3O‐glucuronide in urines that stemmed from a healthy individual who ingested 1 or 2 mg LOR, whereas free LOR could be detected in extracts prepared from enzymatically hydrolyzed urines. As the 3O‐glucuronidation reaction occurs at the chiral center of the molecule, two diastereoisomers can theoretically be formed, molecules that can no longer interconvert. The stereoselective formation of LOR glucuronides in humans and in vitro was investigated. MEKC analysis of extracts of the nonhydrolyzed urines suggested the presence of the two different LOR glucuronides in the urine. The formation of the same two diastereoisomers was also observed in vitro employing incubations of LOR with human liver microsomes in the presence of uridine 5′‐diphospho‐glucuronic acid as coenzyme. The absence of other coenzymes excluded the formation of phase I or other phase II metabolites of LOR. Both results revealed a stereoselectivity, one diastereoisomer being formed in a higher amount than the other. After enzymatic hydrolysis using β‐glucuronidase, these peaks could not be detected any more. Instead, LOR was monitored. Analysis of the extracts prepared from enzymatically hydrolyzed urines by MEKC in the presence of 2‐hydroxypropyl‐β‐CD revealed the enantiomerization process of LOR (observation of two peaks of equal magnitude connected with a plateau zone). The data presented provide for the first time the evidence of the stereoselectivity of the LOR glucuronidation in humans.
A study of surface modification and anchoring techniques used in the preparation of monolithic microcolumns in fused silica capillaries
Authors: Courtois Julien , Szumski Michal , Byström Emil , Iwasiewicz Agnieszka , Shchukarev Andrei , Irgum Knut 
Published: January 2006

AbstractBased on a survey of the literature on pretreatment of fused silica capillaries, 3 etching procedures and 11 silanization protocols based on the vinylic silane 3‐((trimethoxysilyl)propyl) methacrylate (γ‐MAPS) were found to be most representative as a means of ensuring attachment of in situ prepared vinylic polymers. These techniques were applied to fused silica capillaries and the success in establishing the intended surface modification was assessed. X‐ray photoelectron spectroscopy (XPS) was used to characterize the chemical state of the surface, providing information regarding presence of the reagent bound to the capillary. Wetting angles were measured and correlated with the XPS results. An adherence test was done by photopolymerization of a 2 mm long plug of 1,6‐butanediol dimethacrylate in the prepared capillaries and evaluation of its ability to withstand applied hydraulic pressure. SEM was also performed in cases where the plug was released or other irregularities were observed. Finally, the roughness of the etched surface, considered to be of importance, was assessed by atomic force microscopy. Alkaline etching at elevated temperature provided a surface roughness promoting adhesion. The commonly used silanization protocols involving water in the silanization or washing steps gave inadequate surface treatment. The best silanization procedure was based on toluene as a solvent.
Reliable assessment of high temperature oxidation resistance by the development of a comprehensive code of practice for thermocycling oxidation testing – European COTEST project –
Authors: Schütze M. , Malessa M. 
Published: January 2006

AbstractThe cyclic oxidation test is the most often used tool in industry to characterise the high temperature oxidation/corrosion resistance of technical materials in the laboratory. In the past, however, there has been the problem of a lack of intercomparability of data from different laboratories and sometimes even from different test runs in the same lab since no general guidelines or standards were existing for this type of test. Being aware of this situation the European COTEST research project was started with 23 participants from 11 countries including representatives from industry, universities, private institutes and national research labs. The present paper reports about the outcome of this project after three years. The project consisted of 8 work packages including literature search on the state‐of‐the‐art at the beginning of the work, experimental investigations supported by a statistics approach in order to quantify the impact of the different test parameters on the test results, a validation testing phase and the development of a comprehensive set of guidelines. The latter is available on the internet and serves as a basis for a future ISO standard for this type of test.
Variation in cyclic oxidation testing practice and data: The European situation before COTEST
Authors: Osgerby S. , Pettersson R. 
Published: January 2006

AbstractA survey of existing testing practice and pre‐existing data was conducted to provide a starting point for the COTEST project on cyclic oxidation testing. The main parameters within the test that need to be controlled were identified as: control of test environment; temperature stability during hold periods; heating and cooling rates; specimen preparation; and post test evaluation. Existing experimental facilities were surveyed to establish the full range of variability within these parameters.
Designing experiments for maximum information from cyclic oxidation tests and their statistical analysis using half Normal plots
Authors: Coleman S. Y. , Nicholls J. R. 
Published: January 2006

AbstractCyclic oxidation testing at elevated temperatures requires careful experimental design and the adoption of standard procedures to ensure reliable data. This is a major aim of the ‘COTEST’ research programme. Further, as such tests are both time consuming and costly, in terms of human effort, to take measurements over a large number of cycles, it is important to gain maximum information from a minimum number of tests (trials). This search for standardisation of cyclic oxidation conditions leads to a series of tests to determine the relative effects of cyclic parameters on the oxidation process. Following a review of the available literature, databases and the experience of partners to the COTEST project, the most influential parameters, upper dwell temperature (oxidation temperature) and time (hot time), lower dwell time (cold time) and environment, were investigated in partners' laboratories. It was decided to test upper dwell temperature at 3 levels, at and equidistant from a reference temperature; to test upper dwell time at a reference, a higher and a lower time; to test lower dwell time at a reference and a higher time and wet and dry environments. Thus an experiment, consisting of nine trials, was designed according to statistical criteria. The results of the trial were analysed statistically, to test the main linear and quadratic effects of upper dwell temperature and hot time and the main effects of lower dwell time (cold time) and environment. The nine trials are a quarter fraction of the 36 possible combinations of parameter levels that could have been studied. The results have been analysed by half Normal plots as there are only 2 degrees of freedom for the experimental error variance, which is rather low for a standard analysis of variance. Half Normal plots give a visual indication of which factors are statistically significant. In this experiment each trial has 3 replications, and the data are analysed in terms of mean mass change, oxidation kinetics (up to the onset of spall), the onset of spalling, spallation rate and also the variation between the 3 replications. The method is illustrated by cyclic oxidation of alloy 800 undertaken as part of the COTEST project.
Influence of cycling parameter variation on thermal cyclic oxidation testing of high temperature materials (COTEST)
Authors: Niewolak L. , Malessa M. , Coleman S. Y. , Quadakkers W. J. , Schütze M. 
Published: January 2006

AbstractThe effect of cycling parameter variation (i.e. oxidation temperature, upper and lower dwell time, humidity in test gas) of the oxidation/spallation kinetics on four alloys was investigated within the framework of an EC funded research project (COTEST). For this purpose, specimens of AISI 441, Alloy 800H, CM 247 and P91 were subjected to thermocyclic testing in dry or humidified air. It was found that a minimum of 300 h accumulated hot dwell time is required for meaningful test results. Detailed characterisation of the corrosion products was performed using OM, SEM/EDX and XRD. The net weight change curves were evaluated with regards to the characteristic quantitative parameters describing oxide growth rate, time to onset of spallation/breakaway and weight of spalled oxide. Analysis of these values was made by the ANOVA method, which allows assessment of the significance of the roles of different test parameters and parameter variations on the oxidation/spallation kinetics from a limited number of experiments.
Rapid cyclic oxidation tests, using joule heating of wire and foil materials
Authors: Nicholls J. R. , Rose T. , Hojda R. 
Published: January 2006

AbstractAs part of a programme to establish a thermal cyclic oxidation test standard for metallic materials at elevated temperatures (COTEST) a programme of work has been undertaken on the rapid cyclic oxidation of wire and foil materials, using Joule heating.By way of introduction, alternative technologies for rapid thermal cyclic tests are reviewed. Following this the benefits of adopting a modified existing ASTM standard is discussed. The aims of the project were, first, to define a suitable test matrix to evaluate the effect of critical material parameters, to undertake the test to a prescribe standard and then evaluate the performance of materials under rapid thermal cycling, using Joule heating. The performance of the testing methodology is assessed using two materials, Kanthal A1 (reference temperature 1250°C) and Alloy 800 (reference temperature 1000°C). In this paper tests on Kanthal A1 at 1200, 1250 and 1300°C are reported. These tests have been undertaken in laboratory air. Other parameters include the upper dwell time (2, 5 and 10 min), the lower dwell time (constant at 2 min) and specimen geometry. Kanthal A1 material was available as 0.4 mm diameter wire, 0.7 mm diameter wire and 70 μm × 1.25 mm ribbon.The results of these tests were analysed statistically using a 3 × 3 × 3 test matrix with triplicate repeat specimens. The lifetime of the wire or foil samples could be measured using either of two parameters: 1) the number of cycles to failure or the accumulated hot time to failure (accumulated upper dwell time). The cyclic lifetime was critically dependent on temperature, hot dwell time and sample geometry.For these rapid cycle tests on Kanthal A1 wire and foil cycle life decreased with increase in temperature and increase in hot dwell time. The wire/foil endurance (accumulated hot time to failure) decreased slightly with increase in temperature, but increased with hot dwell time (fewer cycles). The endurance of foil samples was shorter than wire samples. Thus for wire/foil endurance only hot dwell time was a statistically significant parameter, over the temperature range studied.
Thermo‐mechanical fatigue – the route to standardisation (“TMF‐Standard” project)
Authors: Beck T. , Hähner P. , Kühn H.‐J. , Rae C. , Affeldt E. E. , Andersson H. , Köster A. , Marchionni M. 
Published: January 2006

AbstractThermo‐mechanical fatigue (TMF) data are needed for dimensioning of safety‐critical parts, e.g. in power generation and in transportation by air, rail and road, and for designing of components, which operate at higher levels of efficiency and safety for longer periods of time. However, the current lack of a validated international standard for TMF leads to non‐reproducibility of TMF data with negative implications on the design and economy of operation of many components. While a preliminary draft TMF standard has been written under the auspices of the International Standards Organisation (ISO), the “TMF‐STANDARD” project addresses this issue at the European level, within the GROWTH programme of Framework Programme 5 funded by the European Commission.The R&D work in the TMF‐Standard project has been started with the preparation of an inventory of institutions in the EU and the pre‐accession states that perform TMF testing, and the testing methods and procedures which they apply. Afterwards, extensive pre‐normative testing work has been carried out, the results of which have been considered in the drafting of a preliminary Code‐of‐Practice (CoP) that forms the base for the current validation round robin testing. The results of the validation tests are going to be subjected to statistical analysis, in order to substantiate the formulation of a validated CoP on strain‐controlled TMF testing. The present paper summarizes the main objectives and achievements obtained so far within the TMF‐Standard project, and gives an outlook on the further activities of the project.
Evaluation of high‐temperature corrosion life using temperature gradient corrosion test with thermal cycle component in waste combustion environments
Authors: Kawahara Y. 
Published: January 2006

AbstractIn energy conversion facilities such as boilers and pyrolysis reactors that burn waste, fossil fuel, biomass and other materials, many corrosion factors, such as gas temperature and fluctuations in gas temperature, the condition of deposits, and gas composition, influence the high‐temperature corrosion rate of materials in a complex manner. In order to evaluate the corrosion behavior and corrosion life time of materials rapidly and accurately, a temperature gradient corrosion test (TGT) was developed and applied to waste incineration environments.The TGT with thermal cycle was carried out without corrosive deposits in order to investigate the basic effect of gas temperature and fluctuation on corrosion behavior, especially in terms of the stability of protective oxide layers. As a result, it was clarified that gas temperature enhances the environmental factors such as the deposition rate of ash and penetration of corrosive species, while thermal cycle mainly enhances material factors such as the breakdown of protective scales.Furthermore, three application case studies of TGTs for corrosion life estimation were carried out with a comparison between TGT and field corrosion data. From these studies, a good correspondence of corrosion rates between TGTs and field tests was obtained. This correspondence of corrosion rate was explained by the breakdown of the protective oxide layer and the penetration of corrosive species in a corrosion front.The reproducibility and applicability of TGTs in the evaluation of the corrosion life time of materials were clarified based on the consideration of various corrosion mechanisms.
Accelerated cyclic oxidation testing protocols for thermal barrier coatings and alumina‐forming alloys and coatings
Authors: Stiger M. J. , Meier G. H. , Pettit F. S. , Ma Q. , Beuth J. L. , Lance M. J. 
Published: January 2006

AbstractThe oxide spallation resistance of oxide scales and ceramic thermal barrier coatings is a key design factor for developing high‐temperature alloy systems.Determination of the lifetimes of such alloy and coating systems is highly desirable. However, as improved systems are developed, lifetimes become so long that the time required to test a system to failure becomes prohibitive. Therefore, reliable protocols for accelerated testing and lifetime prediction are needed. This paper describes two attempts at developing such protocols. The first involves modification of the NASA COSP model to predict cyclic oxidation behavior of alloys and metallic coatings and the incorporation of acoustic emission data into this model. The second involves use of an indentation technique to induce spalling of thermal barrier coatings (TBCs) after short‐term thermal exposures.The first effort involves using the COSP Model, developed at NASA, as the basis for the prediction of oxide spallation. Acoustic emission measurements are used in an attempt to obtain critical parameters in the model from short‐time experiments for a variety of alloys and coatings which rely on alumina scales for oxidation resistance. The model is then used to predict the lives of these alloys and coatings when subjected to cyclic oxidation at 1100°C.A principal concern with ceramic thermal barrier coatings (TBCs) used in gas turbines is their loss of adhesion during service, leading to coating spallation. In this paper, an overview is given of an indentation test for brittle coatings on ductile substrates which is used to quantify decreases in interfacial toughness of TBC systems due to cyclic high‐temperature exposures. The indentation test involves penetration of the TBC and the oxide layer below it, inducing plastic straining in the underlying metal bond coat and superalloy substrate. The indentation strains cause an axisymmetric delamination of the TBC and oxide layers. Measurement of the extent of the delamination, coupled with finite‐element modeling, provides a measure of the adherence of the coating. Test results are presented tracking the loss of interfacial toughness for EBPVD TBC systems cyclically exposed at 1100°C.
Reactive Blending of Aromatic Polyesters: Thermal Behaviour of Co‐precipitated Mixtures PTT/PET
Authors: Castellano Maila , Turturro Antonio , Valenti Barbara , Avagliano Alessandra , Costa Giovanna 
Published: January 2006

AbstractSummary: Due to its unique combination of properties, PTT is a promising material for textile fibre and engineering thermoplastic applications, both as neat polymer and in formulated products. To bring down the cost yet keeping some of its advantageous properties it seems interesting to apply PTT in blends and particularly with PET. We consider here the effect of composition and reaction time on co‐precipitated mixtures PTT/PET, in terms of melting and crystallization behaviour, solution properties and morphology. Blends of various compositions were prepared from mixed solutions, kept in the DSC at 280 °C for different times (0–120 min) and analysed during a successive cooling‐heating cycle. A single Tg was detected for each composition, indicative of miscibility in the glassy state. Melting temperatures, at fixed composition, decrease with increasing treatment time. Mixtures rich in one component show a single Tm, whereas two distinct peaks were observed for the 50/50 blend; on increasing the treatment time some transesterification takes place, evidenced by the melting peak broadening and merging together. The overall crystallinity developed when transesterification plays a role strongly depends on composition: it is inhibited for the 50/50 mixture on cooling, though it can be induced to some extent by reheating or holding during cooling, whereas in one component‐rich blends the main effect is a reduction of the crystallization temperature. Isothermal crystallizations were also carried out as a function of the composition and of the residence time in the molten state; crystallization rate decreases with increasing holding time in the melt. Morphology of PTT and PTT‐rich mixtures under the adopted crystallization conditions exhibits typical banded spherulites, whose growth rate and band spacing vary with melt holding time; moreover, less regular concentric circles develop on increasing residence time at 280 °C.Spherulitic texture developed at 198 °C after 60 min storage at 280 °C by a PTT/PET 90/10 mixture.magnified imageSpherulitic texture developed at 198 °C after 60 min storage at 280 °C by a PTT/PET 90/10 mixture.