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Selected AbstractsCrystal growth and scintillating properties of (Pr,Si)-doped YAlO3CRYSTAL RESEARCH AND TECHNOLOGY, Issue 12 2007M. Zhuravleva Abstract This paper deals with Pr-doped and Pr, Si-codoped YAlO3 single crystal growth by the micro-pulling-down method and investigation of their spectroscopic and scintillating properties. The Pr3+ 5d -4f radioluminescence intensity is more than 10 times higher than that of Bi4Ge3O12 standard sample, but the Si-codoping decreases it. Absorption spectra of as-grown and air-annealed Si,Pr-codoped YAlO3 samples show along with an onset of 4f -5d transition round 230 nm the induced absorption band at 400 nm which possibly related to a hole center absorption (Pr4+ or O - ). Thermoluminescence measurements above the room temperature were performed in order to monitor deep electron traps. Strong concentration dependence of thermoluminescence was observed for Pr:YAlO3 glow curves. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Essential oil compounds in a historical sample of marjoram (Origanum majorana L., Lamiaceae)FLAVOUR AND FRAGRANCE JOURNAL, Issue 3 2002Johannes Novak Abstract A historical sample of marjoram (Origanum majorana L., Lamiaceae), more than 60 years old, was analysed and its composition compared to standard material from the European herb market. By using a solvent extract of the historical sample, the rearrangements and artefact formation usually occurring during the distillation of marjoram were avoided. The extract contained high amounts of terpinen-4-ol, thus resembling the distilled essential oil more than the solvent extract of the standard sample. So artefact formation in marjoram can also happen in planta in herbs stored for a long time under suboptimal conditions. The high content of carvacrol, normally never present in standard material from cultivation, gave an indication of the heterogeneity of marjoram in former times, and confirmed the opinion that (cultivated) marjoram is a chemovariety selected a long time ago. Copyright © 2002 John Wiley & Sons, Ltd. [source] Rapid and accurate quantitative phase analysis using a fast detectorJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 1 2004A. F. Gualtieri The accuracy of the weight fractions calculated with the Rietveld method for various polycrystalline systems using data collected for very short times (5,45,min) with an RTMS (real-time multiple strip) detector was verified. The weight estimates were compared with those obtained using the same conventional Bragg,Brentano geometry, a gas proportional detector and a 13,h data acquisition. The analysed samples were monophasic and polyphasic mixtures with different degrees of complexity: the standard corundum NIST 676; a sample (labelled 1g) provided as a standard sample for the IUCr CPD Quantitative Phase Analysis Round Robin; a natural pyroclastic rock from Riano (Rome, Italy) containing zeolitic minerals and a glass phase; and a hydraulic lime. The results of the refinements show estimated weights consistent with both those obtained with a gas proportional detector and with the nominal values, indicating a very good accuracy. Only when variable slits are used, the accuracy of the estimated weights slightly decreases. The outcome of this work is a very important step forward towards fast and accurate QPA for production control and quality management, obtained by combining the use of a rapid detector and existing user-friendly software. [source] Rapid quantitative bioassay of osteoinductionJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 3 2000Huston Davis Adkisson We developed a reproducible, relatively rapid bioassay that quantitatively correlates with the osteoinductive capacity of demineralized bone matrix obtained from human long bones. We have found that Saos human osteosarcoma cells proliferate in response to incubation with demineralized bone matrix and that an index of this proliferative activity correlates with demineralized bone matrix-induced osteogenesis in vivo. The bioassay (Saos cell proliferation) had an interassay coefficient of variation of 23 ± 2% and an intra-assay cocfficient of 11 ± 1%. Cell proliferation was normalized to a standard sample of demineralized bone matrix with a clinically high osteoinductive capacity, which was assigned a value of one. The Saos cell proliferation for each sample was related to the standard and assigned a value placing it into thc low (0.00-0.39), intermediate (0.40-0.69). or high (0.70-1.49) osteoinductivc index group. Osteoinduction of human demineralized bone matrix was quantitated by expressing new bone formation as a function of the total bone volume (new bone plus the demineralized bone powder). The demineralized bone matrix was placed in pouches formed in the rectus abdominis muscles of athymic rats, and endochondral bone formation was assessed at 35 days following implantation, when marrow spaces in the ossicles were formed by new bone bridging the spaces between demineralized bone matrix particles. The proliferative index correlated with the area of new bone formation in histological sections ol the newly formed ossicles. When the proliferative index (the osteoinductive index) was divided into low, intermediate. and high groups, the correlation between it and new bone formation (osteoinduction) was 0.850 (p < 0.0005) in 25 samples of demineralized bone matrix. There was no overlap in the osteoinduction stimulated between the samples with low and high osteoinductive indices. We conclude that the proliferation assay is useful for the routine screening of bone allograft donors for osteoinductivc potential. Furthermore, the two-dimensional area of new bone formation. as it relates to total new bone area, is a quantitative measure of osteoinduction. [source] Colorant formulation based on new two-constant theoryCOLORATION TECHNOLOGY, Issue 4 2007Guoxing He A new two-constant theory for colour matching has been developed based on the Kubelka,Munk theory. Colorant formulations and algorithms for matching tristimulus, K/S and reflectance values of a standard are presented based on the new theory. The algorithms are suitable for a single-constant theory as well as a two-constant theory. The experimental data show that the recipes predicted by the new two-constant theory are closer to the actual recipes of the standard sample than the recipes predicted by the single-constant theory, and also show smaller colour difference values for some disperse dyes. The results show that the scattering of some disperse dyes cannot be negligible, and that the recipes that match to textiles coloured by these disperse dyes should be predicted using the new two-constant theory. [source] Temperature field design, process analysis and control of SAPMAC method for the growth of large size sapphire crystalsCRYSTAL RESEARCH AND TECHNOLOGY, Issue 8 2007C. H. Xu Abstract In this paper, the relationship between quality of sapphire crystal and growing parameters of SAPMAC (Sapphire growth technique with micro-pulling and shoulder-expanding at cooled center) method was discussed. Optimized temperature distribution and technique control were proposed by theoretical analysis, numerical simulation computation and experimental validation to obtain large size sapphire crystals. For a-axis crystallized direction, with 1.0-5.0mm/h growth velocity and 10-30K/h temperature decreasing speed, large sapphire single crystal (,240mm×210mm, 27.5kg) having high optical quality was successfully grown. The absorption spectrum of standard samples was measured as well. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Development of an Antibody Hapten-Chip System for Detecting the Residues of Multiple Antibiotic Drugs,JOURNAL OF FORENSIC SCIENCES, Issue 4 2009Ailiang Chen M.Sc. Abstract:, The abuse of antibiotic drugs during animal production remains a worldwide problem and the subsequent detection of the residues of various drugs present at low concentrations in complex biological matrices poses significant analytical challenges. The present study outlines a practical biochip assay system to identify antibiotic residues in different animal tissue extracts. The system uses a simple but efficient multiresidue sample extraction procedure to isolate the antibiotic residues which were then identified directly using high-affinity monoclonal antibodies presented in a competitive immunoassay with conjugated antibiotic hapten-chips. The hapten-chip can analyze six samples each for eight antibiotics on a single chip within 3 h. The analytical results with both artificial positive standard samples and the incurred samples show that the antibody hapten-chip system has a comparable accuracy and a similar sensitivity to a standard ultra performance liquid chromatography,mass spectrometry (MS)/MS assay. In conclusion, an effective analytical screening system based on antibody hapten-chip was developed for detecting multiple antibiotic residues from multiple samples. [source] Image-based hysteresis modeling and compensation for an AFM piezo-scanner,ASIAN JOURNAL OF CONTROL, Issue 2 2009Yudong Zhang Abstract As an important component of Atomic Force Microscopes (AFM), a piezo-scanner exhibits some undesired nonlinear characteristics, among which the inherent hysteresis largely decreases positioning accuracy during scanning and nano-manipulation process. To alleviate this problem, an image-based approach is proposed in this paper to model and then compensate for the hysteresis behavior of the piezo-scanner. Specifically, some scanning images over standard samples are utilized to identify the parameters of the classical Preisach model (CPM) of hysteresis. On the basis of the obtained model, an inversion-based technique is adopted to design a compensator for the hysteresis of the piezo-scanner. The proposed algorithm presents such advantages as low cost and little complexity since no nanoscale position sensor is required to collect identification data. Some scanning and nano-imprinting results are included to demonstrate the performance of the proposed strategy. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source] | ||||||||||