bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and properties of polyurethane networks derived from new soybean oil‐based polyol and a bulky blocked polyisocyanate
Authors: Jalilian Mehrdad , Yeganeh Hamid , Haghighi Mehdi Nekoomanesh 
Published: October 2008

AbstractBACKGROUND: Developing vegetable oil‐based polyols for polyurethane manufacturing is becoming highly desirable for both economic and environmental reasons. Most vegetable oils do not bear hydroxyls naturally. The objective of this work was to prepare a new soybean oil‐based polyol with high functionality of hydroxyl groups and built‐in (preformed) urethane bonds.RESULTS: A facile and improved method was developed for the transformation of epoxidized soybean oil into carbonated soybean oil under ambient pressure of CO2 gas, with tetrabutylammonium bromide/calcium chloride as catalyst/co‐catalyst couple. Ring‐opening reaction of the carbonated oil with ethanolamine led to the desired polyol. A one‐pack polyurethane system was prepared via combination of the polyol and a blocked polyisocyanate. The polyol and final polyurethanes were fully characterized, and their physical, mechanical, viscoelastic and electrical insulating properties were studied.CONCLUSION: The application of this newly developed soybean oil‐based polyol for preparation of electroinsulating casting polyurethanes was examined. The prepared soy‐based polyurethanes offered excellent thermal and electrical insulating properties. Also, tunable physical and chemical properties for the final polyurethanes were achieved by replacing part of the soybean oil‐based polyol with poly(propylene glycol) (Mn = 1000 g mol−1). Copyright © 2008 Society of Chemical Industry
Contrast Effects at Dislocation Networks in Very Thin Polyethylene Single Crystals Observed in the Electron Microscope
Authors: Holland V. F. , Lindenmeyer P. H. , Trivedi R. , Amelinckx S. 
Published: October 2008

AbstractThe contrast effects at dislocations in very thin bi‐layered single crystals of polyethylene are discussed on the basis of the dynamical theory. The crystal thickness is smaller than one extinction distance. In such crystals the dislocation lines can be imaged either as bright or as dark lines in both the bright and the dark field image. In one area of the bright field image one family of dislocations may be observed as bright lines and another family as dark lines. Image “inversion” takes place in the bend contours, i.e., dark lines become bright and vice versa. The dark field images due to the diffraction vectors +g and −g may be either similar or complementary. All these observations can be accounted for by comparing them with profiles computed on the basis of the dynamical theory.Although one would expect the crystals to be thin enough for the kinematical theory to be applicable, it is found that the image profiles, as deduced by Hirsch, Howie, and Whelan[2] on the basis of this theory, cannot account for the observations. It is shown that this is a result of the approximations used in computing the integrals occuring in this theory.The observed dislocation networks are discussed in terms of Burgers vectors. The contrast effects are used to establish this analysis unambigeously. It is found that ribbons of partial dislocations occur in the networks. From the partial separation an estimate is made for the ratio of the stacking fault energy over the shear modulus (γ/μ b).Singularities in the networks are analysed and shown to result from the presence of partial dislocations ending in the foil surfaces.
Mint oil (Mentha spicata Linn.) offers behavioral radioprotection: a radiation‐induced conditioned taste aversion study
Authors: Haksar A. , Sharma A. , Chawla R. , Kumar Raj , Lahiri S. S. , Islam F. , Arora M. P. , Sharma R. K. , Tripathi R. P. , Arora Rajesh 
Published: October 2008

AbstractMentha spicata Linn. (mint), a herb well known for its gastroprotective properties in the traditional system of medicine has been shown to protect against radiation‐induced lethality, and recently its constituents have been found to possess calcium channel antagonizing properties. The present study examined the behavioral radioprotective efficacy of mint oil (obtained from Mentha spicata), particularly in mitigating radiation‐induced conditioned taste aversion (CTA), which has been proposed as a behavioral endpoint that is mediated by the toxic effects of gamma radiation on peripheral systems, primarily the gastrointestinal system in the Sprague‐Dawley rat model. Intraperitoneal administration of Mentha spicata oil 10% (v/v), 1 h before 2 Gy gamma radiation, was found to render significant radioprotection against CTA (p < 0.05), by blocking the saccharin avoidance response within 5 post‐treatment observational days, with the highest saccharin intake being observed on day 5. This finding clearly demonstrates that gastroprotective and calcium channel antagonizing properties of Mentha spicata can be effectively utilized in preventing radiation‐induced behavioral changes. Copyright © 2008 John Wiley & Sons, Ltd.
Estimation of Arctic ozone loss in winter 2004/05 based on assimilation of EOS MLS and SBUV/2 observations
Authors: Jackson D. R. , Orsolini Y. J. 
Published: October 2008

AbstractIn this paper we present a new technique for the estimation of ozone loss in the stratospheric polar vortex based on the assimilation of Earth Observing System Microwave Limb Sounder (EOS MLS) and Solar Backscatter Ultraviolet radiometer (SBUV/2) ozone observations in the Met Office data assimilation system. We focus on the northern winter of 2004/05, which was exceptionally cold in the Arctic stratosphere, with associated large ozone depletion due to heterogeneous chemistry. Our ozone loss estimate, which was calculated for the 1 February to 10 March 2005 period, peaks at 450 K (approximately 17–18 km), and is 0.6 ppmv at that isentropic level (our loss estimate for the vortex core only was somewhat higher (1.0 ppmv) and indicates uncertainties related to mixing at the vortex edge). This value is similar to or smaller than results from other studies, which estimate ozone loss in this period to be in the 0.6–1.2 ppmv range. When combined with results from other studies that estimate ozone loss occurring outside our assimilation period, we obtain an estimate of 0.8–1.2 ppmv for ozone loss from early January to early March 2005.We find a second maximum in ozone loss for the 1 February–10 March period near 650 K (approximately 25 km) of around 0.4 ppmv. This is a lower figure than found in other studies, but ozone loss is actually much stronger at this level outside the vortex in a low‐ozone pocket in the Aleutian anticyclone, likely due to the NOx catalytic cycle. Our results show that the ozone data assimilation method we have used to estimate ozone loss is very promising, and can lead to potentially more accurate ozone‐loss estimates than other methods. © Royal Meteorological Society and Crown Copyright, 2008.
A large amplitude gravity wave in the lower stratosphere detected by radiosonde
Authors: Shutts G. J. , Kitchen M. , Hoare P. H. 
Published: October 2008

AbstractTemperature profiles in the lower stratosphere commonly show fluctuations (typical peak‐to‐peak amplitude of a few degrees) on a vertical scale of a few kilometres. The routine operational radiosonde launched from Shanwell (56.43°N 2.87°W) at 2318 GMT on 12 December 1986 recorded very large amplitude excursions in temperature (15.9 K change over a vertical distance of 2 km) in the lower stratosphere which were identified as being exceptional by the staff at the radiosonde station. The temperature fluctuations were accompanied by strong shear in the horizontal wind and large variations in the rate of ascent of the balloon.The disturbance is argued to be due to a quasi‐stationary gravity wave with vertical momentum flux about 3 or 4 N m−2 averaged over a horizontal scale of at least 20km. These observations, their meteorological context and their interpretation are described in detail.
Estimating the change point of a normal process mean with a monotonic change
Authors: Noorossana Rassoul , Shadman Alireza 
Published: October 2008

AbstractOne of the essential steps for process improvement is to quickly recognize the starting time or the change point of a process disturbance. In this paper, we describe the behavior model of process mean and then obtain a maximum‐likelihood estimator (MLE) for the change point of the normal process mean without requiring the exact knowledge of the change type. Instead, we assume that the type of change present belongs to a family of monotonic changes. Finally, we study the performance of the proposed change‐point estimator relative to the MLEs for the process mean change point derived under a simple step change and linear trend change assumption. We do this for a number of monotonic change types following a signal from a Shewhart X̄ control chart. Copyright © 2008 John Wiley & Sons, Ltd.
Optimizing tape‐burnishing/wiping process of magnetic recording media through Taguchi method
Authors: Zhao J. M. , Ho S. L. , Piramanayagam S. N. , Shi J. Z. 
Published: October 2008

AbstractFor the ever‐increasing recording density in hard disk drives, ultra‐low gliding height media are required. It is an immense challenge for the tape‐burnishing/wiping process of media to reduce the asperities effectively and efficiently while no scratches occur. The purpose of this paper is to characterize and then optimize the tape‐burnishing/wiping process as so to minimize the asperities without leaving any scratches on the media surface. A Taguchi experiment design method is adopted to analyze the data and acquire an optimal level combination of process parameters. The resulting optimal combination is practically implemented in tape‐burnishing/wiping the several magnetic recording media, which reveals that the average pass ratio of 5 nm glide avalanche testing increases nearly doubly to a level of 96%. Copyright © 2008 John Wiley & Sons, Ltd.
Robust optimization of an airplane component taking into account the uncertainty of the design parameters
Authors: Steenackers Gunther , Guillaume Patrick , Vanlanduit Steve 
Published: October 2008

AbstractA slat track, structural component of an aircraft wing that transfers the aerodynamical loads, excited by operational forces can result in excessive displacement levels if not properly designed. The design parameter values are not always precisely known but can contain a level of uncertainty to some extent due to, for example dimensional variation. During the different optimization approaches, the slat track geometry is optimized in order to limit the maximum vertical displacement, taking into account the variability of the design parameters. Application and comparison of different optimal, robust and generalized optimization approaches is presented and applied on the slat track finite element model, making use of mean and variance response functions to model the uncertainty on the finite element displacement values. Next to validating different objective function statements, a comparison is also made on the level of accuracy and practicability concerning the different response function models, based on regression techniques and Monte Carlo simulations, optimization and transmissibilities and regressive techniques and vibration reduction over a frequency range. Copyright © 2008 John Wiley & Sons, Ltd.
The use of reliability‐oriented field feedback information for product design improvement: a case study
Authors: Magniez Clément , Brombacher Aarnout C. , Schouten Jeu 
Published: October 2008

AbstractIn the innovative industry, four major trends are found to influence product quality and reliability: the increase in product complexity, the strong pressure on time to market, the increasing global economy, and the decreasing tolerance for quality problems. Thus, it becomes more difficult to anticipate all potential failures during the product development process. In this context, an efficient field feedback process should be in place to react to the unanticipated deviations in product performance. Based on a case study made in an innovative company, this paper shows that the problem is not so much in the information collection as in the inherent quality of the information and in the manner the information is processed. Therefore, a new method, presented in this paper, was developed to classify and prioritize field data and to upgrade it into information that can be used for design improvement according to the dominant classes of failures using the four‐phase roller coaster model. Although this newly generated information is richer than raw field data it is not yet detailed enough to allow direct design optimization. Therefore, a second upgrading stage, based on design of experiments, was developed. It uses a method that combines physics‐of‐failure (bottom‐up) and field information (top‐down). As traditional DoE mainly deals with largely time‐independent quality data obtained during the manufacturing process the approach had to be modified to deal with time‐dependent reliability data. Case study results show that it is a promising approach for characterizing and resolving failure mechanisms also in innovative companies. Copyright © 2008 John Wiley & Sons, Ltd.
Characterization of impurities in sisomicin and netilmicin by liquid chromatography/mass spectrometry
Authors: Li Bo , Van Schepdael Ann , Hoogmartens Jos , Adams Erwin 
Published: October 2008

AbstractThe characterization of unknown impurities present in netilmicin and sisomicin by liquid chromatography (LC) coupled with mass spectrometry (MS) is described. The volatile ion‐pairing agent trifluoroacetic acid (TFA) was used for the retention of the main compounds and their impurities on a reversed‐phase (RP) C18 column, because they are highly hydrophilic and basic compounds. The method showed good separation between netilmicin and its four potential related substances prescribed in the European Pharmacopoeia, which were identified by comparison of their retention times with those of the reference substances. Furthermore, in total 16 unknown impurities in a netilmicin sample and six in a sisomicin sample with unknown identity were detected. The structures of the unknown compounds were deduced based on comparison of fragmentation patterns with those of the reference substances investigated in LC/MSn experiments by the use of electrospray ion trap mass spectrometry. Copyright © 2008 John Wiley & Sons, Ltd.
Rapid comprehensive amino acid analysis by liquid chromatography/tandem mass spectrometry: comparison to cation exchange with post‐column ninhydrin detection
Authors: Dietzen Dennis J. , Weindel Annette L. , Carayannopoulos Mary O , Landt Michael , Normansell Ellen T. , Reimschisel Tyler E. , Smith Carl H. 
Published: October 2008

AbstractIon‐exchange chromatography with ninhydrin detection remains the gold standard for detecting inborn errors of amino acid catabolism and transport. Disadvantages of such analysis include long chromatography times and interference from other ninhydrin‐positive compounds. The aim of this project was to develop a more rapid and specific technique using liquid chromatography/tandem mass spectrometry (LC/MS/MS). Optimal fragmentation patterns for 32 amino acids were determined on a triple quadrupole mass spectrometer following butylation. Chromatographic characteristics of each of the amino acids were determined using C8 reversed‐phase chromatography with 20% acetonitrile/0.1% formic acid as isocratic mobile phase. Quantitation using eleven deuterated internal standards was compared to cation exchange and ninhydrin detection on a Beckman 7300 system. Following methanol extraction and butylation, determination of 32 amino acids required 20 min. The dynamic range of each amino acid was generally 1–1000 µmol/L. Imprecision ranged from 7 to 23% (CV) over 6 months and recovery ranged from 88–125%. Deming regression with the Beckman 7300 yielded slopes from 0.4–1.2, intercepts from −21 to 65 µmol/L, correlation coefficients from 0.84–0.99 and Syx from 2–125 µmol/L. Isobaric amino acids were separated by chromatography (e.g. leucine, isoleucine) or by unique fragmentation (e.g., alanine, β‐alanine). LC/MS/MS is comparable to traditional LC‐ninhydrin detection. Mass spectral detection shortens analysis times and reduces potential for interference in detecting inborn metabolic errors. Copyright © 2008 John Wiley & Sons, Ltd.
High‐resolution liquid chromatography/electrospray ionization time‐of‐flight mass spectrometry combined with liquid chromatography/electrospray ionization tandem mass spectrometry to identify polyphenols from grape antioxidant dietary fiber
Authors: Touriño Sonia , Fuguet Elisabet , Jáuregui Olga , Saura‐Calixto Fulgencio , Cascante Marta , Torres Josep Lluís 
Published: October 2008

AbstractGrape antioxidant dietary fiber (GADF) is a dietary supplement that combines the benefits of both fiber and antioxidants that help prevent cancer and cardiovascular diseases. The antioxidant polyphenolic components in GADF probably help prevent cancer in the digestive tract, where they are bioavailable. Mass spectrometry coupled to liquid chromatography is a powerful tool for the analysis of complex plant derivatives such as GADF. We use a combination of MS techniques, namely liquid chromatography/electrospray ionization time‐of‐flight mass spectrometry (LC/ESI‐TOF‐MS) and liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI‐MS/MS) on a triple quadrupole, for the identification of the polyphenolic constituents of the soluble fraction of GADF. First, we separated the mixture into four fractions which were tested for phenolic constituents using the TOF system in the full scan mode. The high sensitivity and resolution of the TOF detector over the triple quadrupole facilitate the preliminary characterization of the fractions. Then we used LC/ESI‐MS/MS to identify the individual phenols through MS/MS experiments (product ion scan, neutral loss scan, precursor ion scan). Finally, most of the identities were unequivocally confirmed by accurate mass measurements on the TOF spectrometer. LC/ESI‐TOF‐MS combined with MS/MS correctly identifies the bioactive polyphenolic components from the soluble fraction of GADF. High‐resolution TOF‐MS is particularly useful for identifying the structure of compounds with the same LC/ESI‐MS/MS fragmentation patterns. Copyright © 2008 John Wiley & Sons, Ltd.
A new method for the identification and the structural characterisation of carotenoid esters in freshwater microorganisms by liquid chromatography/electrospray ionisation tandem mass spectrometry
Authors: Frassanito Rita , Cantonati Marco , Flaim Giovanna , Mancini Ines , Guella Graziano 
Published: October 2008

AbstractLiquid chromatography/electrospray ionisation mass spectrometry (LC/ESI‐MS) has been employed to identify carotenoid esters present in raw organic extracts of pigmented freshwater microalgae and to gain structural information on these compounds. In particular, acyl carotenoid derivatives of Haematococcus pluvialis and Euglena sanguinea have been characterised by tandem mass spectrometry (MS/MS) in a quadrupole ion trap. ESI‐MS/MS allows recognition of the presence of carotenoid esters in complicated mixtures without any initial chromatographic work‐up and without the need to use UV‐Vis photo‐diode array (PDA) detectors. Product ion scans of the [M + Na]+ ion lead to known neutral losses of the C7H8 and C8H10 residues from the conjugated polyene moiety of the carotenoid unit, that permit the unambiguous identification of the carotenoid itself. These structurally relevant ions are not observed in positive or negative ion APCI (atmospheric pressure chemical ionisation) mass spectra. Moreover, the several product ions observed in positive and/or negative ion ESI‐MS/MS not only are a diagnostic signature of the main structural features of the acyl chains such as length, position and unsaturation, but also display the nominal mass of the parent xanthophyll. Our methodology has been validated (i) by using esters of astaxanthin obtained from off‐line purification of the H. pluvialis extracts and structurally elucidated through proton nuclear magnetic resonance (1H‐NMR) spectroscopy and (ii) by product analysis of esters by alkaline hydrolysis. The characterisation of the unknown carotenoid esters of E. sanguinea is a demonstration of the capabilities of this methodology. Copyright © 2008 John Wiley & Sons, Ltd.
An exploration of spirituality, spiritual beliefs and paediatric rehabilitation
Authors: Baldwin Patricia J. , McDougall Janette , Evans Jan 
Published: October 2008

AbstractThis paper presents key concepts related to spirituality that are meaningful to a community‐based paediatric rehabilitation centre in Ontario, Canada, for the provision of holistic care for children and youth with disabilities and their families. These key concepts were identified through an extensive review of quantitative and qualitative studies from relevant areas of research. Discussions around the concepts then took place with service providers from multiple disciplines, administrators, advisory board members, childhood disability researchers and parents of children and youth with disabilities. Practice implications from the literature and from the discussions resulted in six recommendations related to implementation of holistic care to address the spiritual needs of children and youth with disabilities and their families within the context of paediatric rehabilitation. Copyright © 2008 John Wiley & Sons, Ltd.
Early clinical and radiological outcomes after double osteotomy in patients with late presentation Legg-Calvé-Perthes disease
Authors: Sarassa Carlos A. , Herrera Ana Milena , Carvajal Jaime , Gomez Luisa F. , Lopez Camilo A. , Rojas Andres F. 
Published: October 2008

Purpose Legg-Calvé-Perthes disease is an idiopathic avascular necrosis of the femoral head. Although many surgical approaches to treat the late presentation of this pathology have been proposed, there are few reports about the early results of the double osteotomy procedure (femoral varus osteotomy combined with Salter innominate osteotomy). The purpose of this study was to describe the early results obtained with the double osteotomy in patients with late presentation of Legg-Calvé-Perthes disease. Methods Cross-sectional evaluation of ten patients intervened with double osteotomy. There were seven males and three females with a mean age of 9.2 ± 1.7 years [standard deviation (SD)]. The average post-surgical time of evaluation was of 46.5 ± 26.2 months. Results Of the ten evaluated patients, four had a Catterall III and six had a Catterall IV disease. According to Herring classification, three patients were Herring B and seven were Herring C. The epiphyseal extrusion average before and after the surgical procedure was 19.3 ± 12.4 and 12.1 ± 14.9%, respectively. In accordance with the Ratliff classification and Lloyd Roberts radiological results, the following were the postoperative clinical results: four good, five fair and one poor. Based on the Stulberg classification, there was one patient in class I, five in class II, three in class III and one in class IV. Conclusion The surgical treatment for late Perthes disease with the best expected outcome is still a challenge. According to the resultsreported here, the double osteotomy could be considered as an alternative to treat this entity.