bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbon flux to woody tissues in a beech/spruce forest during summer and in response to chronic O3 exposure
Authors: Ritter W. , Andersen C. P. , Matyssek R. , Grams T. E. E.
Published: November 2011

Abstract. The present study compares the dynamics in carbon (C) allocation of adult deciduous beech (Fagus sylvatica) and evergreen spruce (Picea abies) during summer and in response to seven-year-long exposure with twice-ambient ozone (O3) concentrations (2 × O3). Focus was on the respiratory turn-over and translocation of recent photosynthates at various positions along the stems, coarse roots and soils. The hypotheses tested were that (1) 2 × O3 decreases the allocation of recent photosynthates to CO2 efflux of stems and coarse roots of adult trees, and that (2) according to their different O3 sensitivities this effect is stronger in beech than in spruce. Labeling of whole tree canopies was applied by releasing 13C depleted CO2 (δ13C of −46.9‰) using a free-air stable carbon isotope approach. Canopy air δ13C was reduced for about 2.5 weeks by ca. 8‰ in beech and 6‰ in spruce while the increase in CO2 concentration was limited to about 110 μl l−1 and 80 μl l−1, respectively. At the end of the labeling period, δ13C of stem CO2 efflux and phloem sugars was reduced to a similar extend by ca. 3–4‰ (beech) and ca. 2–3‰ (spruce). The fraction of labeled C (fE,new) in stem CO2 efflux amounted to 0.3 to 0.4, indicating slow C turnover of the respiratory supply system in both species. Elevated O3 slightly stimulated the allocation of recently fixed photosynthates to stem and coarse root respiration in spruce (rejection of hypothesis I for spruce), but resulted in a significant reduction in C flux in beech (acceptance of hypotheses I and II). The distinct decrease in C allocation to beech stems indicates the potential of chronic O3 stress to substantially mitigate the C sink strength of trees on the long-term scale.
Colour Doppler and Volume Changes—Anterolateral Thigh Flap: The Sunnybrook Experience
Authors: Eskander Antoine , Enepekides Danny , Higgins Kevin
Published: November 2011

This paper summarizes two recent ALT studies from our institution focusing on the utility of colour flow Doppler's ultrasonography and volumetric changes with radiation. Lastly, we will discuss recommended changes to practice due to the aforementioned studies. Our findings suggest that special care should be made to identify patients at high risk for peripheral arterial disease, and, if the reconstructive surgeon has any concerns, preoperative colour flow Doppler's ultrasonography should be undertaken to better characterize the perforator anatomy and avoid inappropriate flap elevation in patients with silent claudication. Particular detail should be paid to flap thickness especially in patients with increased body habitus. Radiation therapy has on average 20% flap volume-reducing effect, and an overestimation of volume in patients who will be undergoing radiotherapy should lead to the best contour and cosmetic outcomes.
Evaluating a Taxonomy for Mobility Requirements by a Controlled Experiment
Authors: Gopalakrishnan Sundar , Karpati Peter , Sindre Guttorm
Published: November 2011

Requirements taxonomies have been found useful in software requirements elicitation and specification, both for educational purposes and in practical usage, for instance, as checklists to ensure that important categories of requirements are not forgotten, and for guidance on how to write various types of requirements. While mobile information systems are becoming increasingly important, traditional requirements taxonomies do not have any category for mobility requirements. This paper reports on a controlled experiment where two groups of students both got the same excerpts of the well-known Volere requirements taxonomy, but for one treatment group the tutorial material was also extended with additional material on mobility requirements as a requirements category in its own right. Using the provided taxonomy material for guidance, the students were asked to write requirements for a system presented in a natural language case description; afterwards their output was analyzed to score the number and quality of requirements found by each student. The main finding was that the students using the extended taxonomy also found more requirements, but there was no significant difference in the quality of requirements between the two groups.
Development of a Simple Liquid Chromatography-Tandem Mass Spectrometry Method for Multiresidue Determination of Antifungal Drugs in Chicken Tissues
Authors: Yu Ying , Zhang Jing , Shao Bing , Wu Yongning , Duan Hejun , Liu Hongtao
Published: November 2011

A method involving LC coupled with MS/MS (LC/MS/MS) was designed for simultaneous quantification of 10 antifungal drugs (voriconazole, griseofulvin, clotrimazole, bifonazole, econazole, ketoconazole, itraconazole, miconazole, terconazole, and fluconazole) in the liver and muscles of chickens. Homogenized tissue samples were extracted with acetonitrile and subsequently underwent freezing-delipidation. A Waters Acquity Ultra Performance LC BEH C18 column was used to separate the analytes, coupled with MS/MS using an electrospray ionization source. The accuracy of the method was confirmed with a mean recovery of 71–121%, and acceptable coefficients of variation (4–23%, n = 6). The detection capability of these compounds in two different matrixes was 0.50–2.82 μg/kg. This method can be applied for the screening and confirmation of target antifungal drugs in chicken tissues.
Sensitive and Simple Flow Injection Analysis of Formaldehyde Using an Activated Barrel Plating Nickel Electrode
Authors: Chen Pei-Yen , Yang Hsueh-Hui , Zen Jyh-Myng , Shih Ying
Published: November 2011

A flow injection analysis coupled with electrochemical detection at an activated barrel plating nickel electrode (Ni-BPE) was developed as a sensitive, simple, and low-cost formaldehyde sensor. The mechanism of Ni-BPE toward the electrocatalytic oxidation of formaldehyde in alkaline medium at ambient temperature was proposed to be based on the electrocatalytic oxidation of formaldehyde by NiIIIO(OH) species. Under the optimized conditions (flow rate = 1.2 mL/min; detection potential = +0.5 V versus Ag/AgCl), a good linearity in the window of 0.037 to 10 μg/mL formaldehyde was observed, and the LOD of 0.23 μg/L was calculated. The RSDs of intraday (n = 10) and interday (n = 6) replicate measurements of 0.185–5 μg/mL formaldehyde ranged from 1.45 to 3.60%, indicating good reproducibility of the proposed method. The proposed method was successfully applied to the determination of formaldehyde in commercial nail polish samples and a drinking water sample.
Solid-Phase Extraction of Some Heavy Metal Ions on a Double-Walled Carbon Nanotube Disk and Determination by Flame Atomic Absorption Spectrometry
Authors: Karatepe Aslihan , Soylak Mustafa , Elçi Latif
Published: November 2011

A new preconcentration method was developed for the determination of trace amounts of Cu(II), Fe(III), Pb(II), Ni(II), and Cd(II) on a double-walled carbon nanotube disk. 4-(2-Thiazolylazo) resorcinol was used as a complexing reagent. The effects of parameters, including pH of the solutions, amounts of complexing reagent, eluent type, sample volume, flow rates of solutions, and matrix ions were examined for quantitative recoveries of the studied analyte ions. The retained metal ions were eluted by 2 M HNO3. The LOD values for the analytes were in the range of 0.7–4.4 μg/mL. Natural water samples and standard reference materials were analyzed by the presented method.
Synthesis of macroporous polymer particles by suspension polymerization using supercritical carbon dioxide as a pressure‐adjustable porogen
Authors: Kamrupi I. R. , Pokhrel B. , Kalita A. , Boruah M. , Dolui S. K. , Boruah R.
Published: October 2011

Reported herein is a green route for the synthesis of macroporous polystyrene particles by suspension polymerization in water in sc‐CO2 medium using polyvinyl alcohol (PVA) as stabilizer, divinylbenzene (DVB) as cross‐linker, and azobisisobutyronitrile (AIBN) as initiator. The solvent properties of sc‐CO2 are adjusted in such a way that it acts as a pressure‐adjustable porogen. All the reactions were carried out at pressures of 70–320 bar and a temperature of 75°C with an agitation speed of 700 rpm. With an increase in pressure (>70 bar), the diameter of the particles increases (8–22 μm), and the surface area of the particles also increases. Similarly, the pore diameter of the particle was observed to be increasing with an increase in pressure and to reach a maximum value (209 nm) at pressure 200 bar. The diameters of the microspheres and the pore size were controlled by varying the pressure of CO2 inside the reactor during the polymerization process. The porous polymer particles were characterized by SEM, TEM, GPC, BET absorption isotherm, and TGA. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 32: 154–162, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20246
Preparation and characterization of nanosilica‐filled color resist
Authors: Lee Chih‐Kang , Hwang Feng‐Hsi , Chen Ching‐Chung , Chang Cheng‐Liang , Cheng Liao‐Ping
Published: October 2011

Nanosilica‐filled red, green, and blue color resists were prepared and their optical, thermal, and mechanical properties were examined. It was found that the International Commission on Illumination color coordinates of the formed resists varied with the concentration of silica in the resist. When the silica content was controlled within 15 phr, the color coordinates fell within the range for TFT–LCD applications. Furthermore, the pencil hardness and the thermal decomposition temperature of the resists increased with increasing silica content, however, at the expense of optical transmittance and resolution. The optimized amount of silica was 10, 15, and 10 phr for red, green, and blue resists, respectively. At these dosages, the synthesized resists had high hardness of 4 H, good thermal stability, and optical performance that met industrial criteria. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 32: 163–171, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20247
Detached eddy simulation on the turbulent flow in a stirred tank
Authors: Gimbun J. , Rielly C. D. , Nagy Z. K. , Derksen J. J.
Published: October 2011

A detached eddy simulation (DES), a large‐eddy simulation (LES), and a k‐ε‐based Reynolds averaged Navier‐Stokes (RANS) calculation on the single phase turbulent flow in a fully baffled stirred tank, agitated by a Rushton turbine is presented. The DES used here is based on the Spalart‐Allmaras turbulence model solved on a grid containing about a million control volumes. The standard k‐ε and LES were considered here for comparison purposes. Predictions of the impeller‐angle‐resolved and time‐averaged turbulent flow have been evaluated and compared with data from laser doppler anemometry measurements. The effects of the turbulence model on the predictions of the mean velocity components and the turbulent kinetic energy are most pronounced in the (highly anisotropic) trailing vortex core region, with specifically DES performing well. The LES—that was performed on the same grid as the DES—appears to lack resolution in the boundary layers on the surface of the impeller. The findings suggest that DES provides a more accurate prediction of the features of the turbulent flows in a stirred tank compared with RANS‐based models and at the same time alleviates resolution requirements of LES close to walls. © 2011 American Institute of Chemical Engineers AIChE J, 58: 3224–3241, 2012
State and specific growth estimation in heterologous protein production by Pichia pastoris
Authors: Barrigón José M. , Ramon Ramon , Rocha Isabel , Valero Francisco , Ferreira Eugénio C. , Montesinos José L.
Published: October 2011

Estimation of biomass, substrate, and specific growth rate (μ) by two nonlinear observers (nonlinear observer‐based estimator—NLOBE, asymptotic observer with second‐order dynamics tuning—AO‐SODE) and a linear estimator (recursive least squares with variable forgetting factor—RLS‐VFF) is presented. Heterologous protein production in Pichia pastoris PAOX1 (Mut+) and PFLD1‐based systems is closely related to μ and has been addressed due to its high relevance in modern biotechnology and bioprocess engineering. μ was estimated by online gas analyses or substrate measurements, biomass, and substrate considering yield coefficients and mass balances. In simulation studies, NLOBE showed high sensitivity to tuning and initialization variables. Validation experiments demonstrated AO‐SODE performs better than the RLS‐VFF for moderate to rapid changes of μ and model parameters being known. If low changes on μ are presented, for instance, in substrate regulation, RLS‐VFF comes up as the best option, because of its reduced requirements. © 2011 American Institute of Chemical Engineers AIChE J, 58: 2966–2979, 2012
The diagnostic value of biopsy of small peripheral lymph nodes in patients with suspected lymphoma
Authors: Baron Beverly W. , Baron Joseph M.
Published: October 2011

In a patient with suspected lymphoma, it is considered desirable to confirm the diagnosis by excisional biopsy of enlarged lymph nodes. However, sometimes the ideal nodes are positioned internally, requiring a deep invasive procedure for access, or the patient may have underlying medical conditions that make it risky to perform such an invasive procedure. Under a protocol approved by our institution's review board (IRB), we reviewed five patients in whom superficial lymph nodes were biopsied which were smaller than usually considered optimal for diagnosis (=2 cm). In each of these cases, the biopsy yielded diagnostic information upon which treatment could be based, sparing the patient a deep invasive procedure. We suggest that in situations in which large internal lymph nodes are not easily accessible and/or the patient's clinical situation precludes more invasive procedures, including deep core needle biopsy of a large mass, it is worthwhile to consider the removal of smaller, superficial lymph nodes with minimal risk which may suffice for diagnosis. © 2011 Wiley Periodicals, Inc.
A male newborn with VACTERL association and Fanconi anemia with a FANCB deletion detected by array comparative genomic hybridization (aCGH)
Authors: Umaña Luis A. , Magoulas Pilar , Bi Weimin , Bacino Carlos A.
Published: November 2011

We report on a male newborn with multiple congenital abnormalities consistent with the diagnosis of VACTERL association (vertebral, anal, cardiac, tracheo‐esophageal fistula, renal, and limb anomalies), who had Fanconi anemia (complementation group B) recognized by the detection of a deletion in chromosome Xp22.2 using an oligonucleotide array. The diagnosis of Fanconi anemia was confirmed by increased chromosomal breakage abnormalities observed in cultured cells that were treated with cross‐linking agents. This is the first report in the literature of Fanconi anemia complementation group B detected by oligonucleotide array testing postnatally. © 2011 Wiley Periodicals, Inc.
A de novo 3.54 Mb deletion of 17q22‐q23.1 associated with hydrocephalus: A case report and review of literature
Authors: Khattab Mona , Xu Fang , Li Peining , Bhandari Vineet
Published: November 2011

We describe a female newborn with a de novo 3.54 megabase (Mb) deletion of 17q22‐q23.1 (chr17:53,072,536–56,612,662, hg18) including genes from MSI2 to BCAS3 detected by oligonucleotide array comparative genomic hybridization (aCGH). Prenatal ultrasound examination noted oligohydramnios and ventriculomegaly in the fetus. Postnatal examination found hypotonia, macrocephaly, arachnodactyly of fingers and toes, dysmorphic features, bilateral hearing loss and heart defect. Review of reported cases with genomic findings noted one case with proximal deletion involving the NOG gene and a case series with distal recurrent microdeletions involving the TBX2 and TBX4 genes. Our case presented a unique deletion partially overlapped with the above deletions but not including the NOG, TBX2, and TBX4 genes. A genomic map for deletions in this 17q22‐q23.1 region was constructed to further define the common deletion intervals for potential haplo‐insufficient genes. © 2011 Wiley Periodicals, Inc.
A novel Xp22.11 deletion causing a syndrome of craniosynostosis and periventricular nodular heterotopia
Authors: van Kogelenberg Margriet , Lerone Margherita , De Toni Teresa , Divizia Maria T. , de Brouwer Arjan P.M. , Veltman Joris A. , van Bokhoven Hans , Robertson Stephen P.
Published: November 2011

We report on a follow‐up evaluation of a male with a phenotype including craniosynostosis, periventricular nodular heterotopia, and neurodevelopmental delay. He was initially assigned a clinical diagnosis of Fontaine–Farriaux syndrome (FFS) as an infant although now, with improved delineation of this entity, it is evident that this diagnosis is not applicable to this individual. Array comparative genomic hybridization has demonstrated a 300 kb interstitial deletion on Xp22.11 affecting all or part of three annotated genes, ZFX, PDK3, and PCYT1B in this subject. The deletion was inherited from the phenotypically normal mother who also exhibited markedly skewed X‐inactivation. These findings implicate hemizygosity for one or all three of these genes as the cause of this phenotype. © 2011 Wiley Periodicals, Inc.
Objective assessment of nasality in flemish adults with neurofibromatosis type 1
Authors: Cosyns Marjan , Mortier Geert , Janssens Sandra , Claes Kathleen , Van Borsel John
Published: November 2011

When characterizing the speech of a patient with neurofibromatosis type 1 (NF1), hypernasality is often mentioned. As few studies applied technically assisted evaluations of nasality in NF1 patients, the aim of the present study was to document the nasal resonance of adults with NF1 using nasometry. The nasometric data obtained from the NF1 patients were compared with the nasalance scores of a healthy control group and with normative data. The final study group consisted of 24 adult NF1 patients and 16 controls, all living in the East Flemish part of Belgium. Nasalance scores were obtained while the participants sustained three vowels (/a:/, /i./, and /u./) and one consonant (/m/) and read three standard nasalance passages. Despite the inter‐ and intra‐subject variability, we observed that NF1 patients as a group exhibited higher mean nasalance scores than controls. This finding was especially clear in males. Potential genotype–phenotype correlations between NF1 mutation type and hypernasality were examined but could not be demonstrated. Conversely, comparison of the nasometric data obtained from the NF1 patients with magnetic resonance imaging findings showed some degree of interesting correlation. We conclude that, notwithstanding the small sample size for some analyses, nasality is an area of interest in the NF1 population. As altered nasality influences speech intelligibility, nasality requires attention during follow‐up visits, particularly when it concerns a male NF1 patient. © 2011 Wiley Periodicals, Inc.
Severe neonatal‐onset panniculitis in a female infant with Prader–Willi syndrome
Authors: Sakthivel Muthukumar , Hughes Stephen M. , Riley Phil , Arkwright Peter D. , Mukherjee Anindya , Ramsden Simon , Urquhart Jill , Crow Yanick J.
Published: November 2011

The panniculitides are a group of heterogeneous inflammatory diseases involving the subcutaneous fat, the pathogenesis of which is poorly understood. Here, we report on a female infant with Prader–Willi syndrome who developed a systemic inflammatory disorder in the neonatal period demonstrating recurrent panniculitis as a prominent feature. This is the second report of an association between Prader–Willi syndrome and panniculitis. Such an association might be explained by the unmasking of a recessive allele as a consequence of hemizygosity, in the case of a 15q11 deletion, or homozygosity, in the case of maternal isodisomy. © 2011 Wiley Periodicals, Inc.
Compound heterozygous mutations in PYCR1 further expand the phenotypic spectrum of De Barsy syndrome
Authors: Lin Dar‐Shong , Chang Jui‐Hsing , Liu Hsuan‐Liang , Wei Chin‐Hung , Yeung Chun‐Yan , Ho Che‐Sheng , Shu Chyong‐Hsin , Chiang Ming‐Fu , Chuang Chih‐Kuang , Huang Yu‐Wen , Wu Tsu‐Yen , Jian Yuan‐Ren , Huang Zon‐Darr , Lin Shuan‐Pei
Published: November 2011

De Barsy syndrome (DBS) is characterized by progeroid features, ophthalmological abnormalities, intrauterine growth retardation, and cutis laxa. Recently, PYCR1 mutations were identified in cutis laxa with progeroid features. Herein, we report on a DBS patient born to a nonconsanguineous Chinese family. The exceptional observation of congenital glaucoma, aortic root dilatation, and idiopathic hypertrophic pyloric stenosis in this patient widened the range of symptoms that have been noted in DBS. Mutation analysis of PYCR1 revealed compound heterozygous PYCR1 mutations, including a p.P115fsX7 null mutation allele and a second allele with two missense mutations in cis: p.G248E and p.G297R. The effect of mutation results in a reduction of PYCR1 mRNA expression and PYCR1 protein expression in skin fibroblasts from the patient. The findings presented here suggest a mutation screening of PYCR1 and cardiovascular survey in patients with DBS. © 2011 Wiley Periodicals, Inc.
Soft PVC foams: Study of the gelation, fusion and foaming processes. III. Mixed phthalate ester plasticizers
Authors: Zoller Agnes , Marcilla Antonio
Published: November 2011

The foaming of PVC (poly(vinyl chloride)) plastisols is a complex combination of simultaneous processes, involving the curing and structural changes of the plastisol, the gas generation and the foam formation. Our comprehensive study of such processes and of the influence of plasticizer on the foam quality has shown that all the processes involved have to be adequately synchronized to obtain foams of the required quality. A series of plastisols prepared by mixing a high and a low compatible phthalate ester plasticizer in several proportions (100/0, 75/25, 50/50, 25/75, 0/100 ratios) has been studied and characterized (by means of rheology, calorimetry, thermal stability, thermomechanical properties, density, and foam morphology), to study the influence of the plasticizer in such processes with changing compatibility. We found expectable rheological and calorimetric behavior regarding the plastisols without curing; however we experienced nonlinear (unexpected) behaviors in cases of foams and plastisols being cured. To confirm such behavior and our hypothesis regarding the possible plasticizer evaporation, the thermal stability of the plastisols, precured samples and foams have been studied by themorgravimetric analysis (TGA). According to our results it can be deduced that the plasticizer loss occurring in some cases during the production of the foams or the specimens being characterized, plays an important role in the foaming process and also influences the foam quality. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Structure and properties of amine‐hardened epoxy/benzoxazine hybrids: Effect of epoxy resin functionality
Authors: Grishchuk S. , Schmitt S. , Vorster O. C. , Karger‐Kocsis J.
Published: November 2011

Bifunctional, trifunctional, and tetrafunctional epoxy resins (EP) were hardened with stoichiometric amount of 4,4′‐diaminodiphenyl methane in presence and absence of benzoxazine (BOX). The EP/BOX ratio of the hybrid systems was 100/0, 75/25, 50/50, and 25/75 wt %, respectively. Information on the structure of the hybrid systems was received from differential scanning calorimetry, dynamic‐mechanical thermal analysis, atomic force microscopy, and fractographic studies. The flexural and fracture mechanical properties of the EP/BOX hybrids were determined and compared to those of the reference EPs. The thermal degradation and fire resistance of the hybrids were also studied. It was found that the polymerized BOX was built in the network in from of nanoscale inclusions and acted as antiplasticizer. Incorporation of BOX enhanced the flexural modulus and strength and reduced the glass transition temperature of the parent EP. The fracture toughness and energy were practically not improved by hybridization with BOX. The charring and flame resistance were improved with increasing amount of BOX in the EP/BOX hybrids. The relative improvement in the latter was most prominent for the bifunctional EP/BOX systems. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Low‐temperature synthesis of nano‐to‐submicron size organo‐zinc oxide and its effect on properties of polybutadiene rubber
Authors: Maiti Madhuchhanda , Vaghasia Avani , Jasra Raksh Vir
Published: November 2011

Nano‐to‐submicron sized particles of zinc oxide (ZnO) were synthesized by low temperature hydrolysis method. Organo‐ZnO was also synthesized by the aforementioned method in presence of polyethylene glycol (PEG‐2000). The synthesized ZnO particles were characterized by infra‐red spectroscopy, X‐ray diffraction, BET surface area, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). FTIR showed that PEG was present on the ZnO surface. Organo‐ZnO exhibited floral‐shape morphology consisting of concentric nanorods. The average diameter of the nanorods was ∼ 250 nm as evident from SEM. TEM showed that the nanorods were made of ∼ 50 nm sized small particles. UV‐absorbance property of ZnO was unaltered even after organic coating. Curing, physico‐mechanical and thermal properties of polybutadiene rubber compounded with organo‐ZnO were compared with those of standard commercial rubber grade ZnO and nano‐ZnO prepared by high and low temperature methods. The cure‐characteristics were studied with the help of moving die rheometer as well as differential scanning calorimetry (DSC). Crosslink‐density measurement along the DSC vulcanization exotherm showed better cure efficiency of organo‐ZnO. Organo‐ZnO containing compound exhibited better mechanical and thermal properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Recovery of alcohols from water using polydimethylsiloxane–silica nanocomposite membranes: Characterization and pervaporation performance
Authors: Shirazi Yaser , Ghadimi Ali , Mohammadi Toraj
Published: November 2011

Different polydimethylsiloxane (PDMS) nanocomposite membranes were synthesized by incorporating various contents of nanosized silica particles to improve the PDMS pervaporation (PV) performance. A uniform dispersion of silica nanoparticles in the PDMS membranes was obtained. The nanocomposite membranes were characterized morphologically by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results showed that surface roughness increases by incorporating silica, and this decreases absorption of penetrants on the membrane. Swelling studies showed that the presence of silica nanoparticles into the PDMS membranes decreases degree of swelling, which can be attributed to rigidification of the PDMS matrix. Additionally, the results revealed that helium permeability decreases through the nanocomposite membranes, due to the more polymer chains packing. Effects of silica on recovery of isopropanol (IPA) from water mixtures were also investigated. Based on the results, incorporating silica nanoparticles promotes significantly the PDMS membrane selectivity because the polymer chains are rigidified and also the polymer free volume decreases. However, permeation flux decreases as diffusion of the penetrants reduces in the presence of silica nanoparticles within the PDMS membranes. As PV performance depends on operating conditions, effects of feed composition, and temperature were also studied. Moreover, recoveries of IPA, ethanol, and methanol from water mixtures were compared using the PDMS‐silica nanocomposite membranes. The results demonstrated that polarity and solubility of alcohols affect permeation flux and selectivity resulting in the higher permeation flux and selectivity for IPA. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Emulsion polymerization using NaPSS‐b‐PS as a cosurfactant
Authors: Chu Hou‐Hsein , Liou Ling‐Shih , Chuang Kuang Sein
Published: November 2011

A NaPSS‐b‐PS was prepared via a two‐stage stable free‐radical polymerization using a mixture of ethylene glycol and water as the medium. Styrene emulsion polymerization was conducted using a mixture of NaPSS‐b‐PS and SDS. Results showed that there is little aggregation among particles. Two other NaPSSs with different sulfonation fractions were also compared. Comparisons were made using relationships, such as
$ {\overline n} $
versus Dv, chain growing time versus SDS content, and Dv versus SDS content. Characteristic behaviors of various NaPSSs on entry were revealed. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Electrical resistance measurement methods and electrical characterization of poly(3,4‐ethylenedioxythiophene)‐coated conductive fibers
Authors: Bashir Tariq , Fast Lars , Skrifvars Mikael , Persson Nils‐Krister
Published: November 2011

Textile fibers and yarns of high conductivity, and their integration into wearable textiles for different electronic applications, have become an important research field for many research groups throughout the world. We have produced novel electrically conductive textile yarns by vapor‐phase polymerization (VPP) of a conjugated polymer, poly(3,4‐ethylenedioxythiophene) (PEDOT), on the surface of commercially available textile yarns (viscose). In this article, we have presented a novel setup for electrical resistance measurements, which can be used not only for fibrous structures but also for woven structures of specific dimensions. We have reported a two‐point resistance‐measuring method using an already manufactured setup and also a comparison with the conventionally used method (so‐called crocodile clip method). We found that the electrical properties of PEDOT‐coated viscose fibers strongly depend on the concentration of oxidant (FeCl3) and the doping (oxidation) process of PEDOT. To evaluate the results, we used mass specific resistance values of PEDOT‐coated viscose yarns instead of normal surface resistance values. The voltage–current (V–I) characteristics support the ohmic behavior of coated fibers to some extent. Monitoring of the charging effect of the flow of current through conductive fibers for prolonged periods of time showed that conductivity remains constant. The change in electrical resistance values with increase in the length of coated fibers was also reported. The resistance‐measuring setup employed could also be used for continuous measurement of resistance in the production of conductive fibers, as well as for four‐point resistance measurement. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
An investigation of scratch testing of silicone elastomer coatings with a thickness gradient
Authors: Kohl James G. , Randall Nicholas X. , Schwarzer Norbert , Ngo Truc T. , Michael Shockley J. , Nair Rahul P.
Published: November 2011

Silicone elastomer coatings are currently being investigated as foul release coatings on ships hulls. Previous tests on silicone duplex elastomer coatings used a progressive load scratch test. It has been shown that the durability of uniform silicone duplex elastomer coatings is a function of thickness, indentation modulus, and stylus and that the failure mechanism depended on coating thickness and stylus. When applying silicone coatings to a ship's hull, there are regions on the ship where the coating is not uniform. This article investigates the effect of a thickness gradient on the durability of a single layer silicone elastomer coating. In these tests, a constant normal load was used as the stylus moved transversely to the surface. It was found that when the scratch test started in the silicone coating and proceeded in the direction of decreasing coating thickness (“Elastomer to Metal”), there was first a scratch tract followed by the initiation of detachment of the coating, then by gross detachment of the coating. When the scratch started on the exposed aluminum surface and proceeded into the silicone in the direction of increasing coating thickness (“Metal to Elastomer”), there was first gross detachment of the coating, followed by recovery (i.e., silicone coating is intact) and a scratch tract into the silicone. It was also found that the coefficient of friction was much higher in the silicone when the scratch test was going in the direction of decreasing coating thickness as opposed to the scratch test going in the opposite direction. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Isothermal crystallization and melting behaviors of bionanocomposites from poly(lactic acid) and TiO2 nanowires
Authors: Li Yonghui , Chen Caihong , Li Jun , Sun Xiuzhi Susan
Published: November 2011

Two representative poly(lactic acid) (PLA) nanocomposites with 1% TiO2 nanowires were prepared through in situ melt polycondensation and easy solution‐mixing approaches, respectively. The former was denoted as ISPLANC, and the latter as SMPLANC. The isothermal crystallization kinetics and melting behaviors of pure PLA, ISPLANC, and SMPLANC were comparatively investigated by differential scanning calorimetry in the temperature range of 80–115°C. Maximum crystallization growth rate (Gexp) was observed at 100°C for all three samples. The well dispersed TiO2 nanowires acted as effective nucleation agents in ISPLANC, which exhibited much higher Gexp in compared to pure PLA and SMPLANC below 110°C. However, much smaller crystallization enthalpy of ISPLANC was obtained because of its restricted chain mobility in forming crystalline lamellar. The crystallization behavior of all three samples fit the Avrami equation quite well, with most of the R2 values larger than 0.9990. Double‐melting behaviors were observed after heating the samples after isothermal crystallization at various temperatures, which was explained by the melt recrystallization of the smaller and imperfect crystals formed at lower isothermal crystallization temperatures. We also obtained the equilibrium melting temperatures of the three samples by carrying out Hoffman–Weeks plots. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
The role of dry and wet isothermal annealing treatment on the structure and the mechanical properties of isotactic polypropylene fibers
Authors: Karacan Ismail , Benli Hüseyin
Published: November 2011

Dry and wet annealing of isotactic polypropylene fibers was carried out under constant length at 120°C in air and in glycerine environments with annealing times ranging from 1 to 30 h. A detailed analysis of the infrared spectrum of samples annealed, especially in air, showed clear evidence of the surface oxidation as indicated by the appearance of oxygen containing functional groups. Annealing was found to lead to an improved structural organization as indicated by the crystallinity, crystallite size, and orientation measurements using X‐ray diffraction and infrared spectroscopy methods. Analysis of the X‐ray diffraction measurements showed a gradual transformation of metastable smectic phase to a more stable α‐monoclinic phase with increasing annealing time. Crystallinity, crystallite size, and orientation measurements performed for the samples annealed in air and in glycerine environments showed no distinct difference. Mechanical properties of the annealed samples were influenced by the annealing environment. Annealing in an air environment resulted in a continuous loss of tensile strength up to the annealing time of 12 h due to an oxidation related chain scission mechanism. On the other hand, annealing in glycerine environment resulted in a continuous and gradual increase of tensile strength without loss of physical form up to the annealing time of 30 h. It is suggested that wet annealing in glycerine environment should be used to obtain improved tensile strength values. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Evaluation of physico‐mechanical properties and in vitro biocompatibility of compression molded HDPE based biocomposites with HA/Al2O3 ceramic fillers and titanate coupling agents
Authors: Tripathi Garima , Dubey Ashutosh Kumar , Basu Bikramjit
Published: November 2011

The present article demonstrates how the stiffness, hardness as well as the cellular response of bioinert high‐density polyethylene (HDPE) can be significantly improved with combined addition of both bioinert and bioactive ceramic fillers. For this purpose, different amounts of hydroxyapatite and alumina, limited to a total of 40 wt %, have been incorporated in HDPE matrix. An important step in composite fabrication was to select appropriate solvent and optimal addition of coupling agent (CA). In case of chemically coupled composites, 2% Titanium IV, 2‐propanolato, tris iso‐octadecanoato‐O was used as a CA. All the hybrid composites, except monolithic HDPE, were fabricated under optimized compression molding condition (140°C, 0.75 h, 10 MPa pressure). The compression molded composites were characterized, using X‐ray diffraction, Fourier transformed infrared spectroscopy, and scanning electron microscopy. Importantly, in vitro cell culture and cell viability study (MTT) using L929 fibroblast and SaOS2 osteoblast‐like cells confirmed good cytocompatibility properties of the developed hybrid composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effects of liquid‐type silane additives and organoclay on the morphology and thermal conductivity of rigid polyisocyanurate‐polyurethane foams
Authors: Kim Youn Hee , Kang Min Jung , Park Gun Pyo , Park Sang Do , Kim Sang Bum , Kim Woo Nyon
Published: November 2011

This article investigates the effects of liquid‐type silane additives and organoclay as a solid‐type additive on the morphological, mechanical and thermal insulating properties of polyisocyanurate‐polyurethane (PIR‐PUR) foams. The organoclay likely acted as nucleating agents during the formation of PIR‐PUR foams. When the liquid silane additives and organoclay were added, the cell size and thermal conductivity of the PIR‐PUR foams appeared to be decreased. However, organoclay did not contribute to reduce the cell size distribution of the foam. PIR‐PUR foams synthesized with tetramethylsilane as a liquid‐type additive showed a smaller average cell size and lower thermal conductivity than that of PIR‐PUR foams synthesized with the other silane additives or with organoclay as a solid‐type additive. For the PIR‐PUR foam with organoclay/TEMS (1.5/1.5 php) mixture, cell size and thermal conductivity of the foam showed similar to the foam with TEMS. These results suggest that smaller cell size appears to be one of the major factors in the improvement of thermal insulation properties of the PIR‐PUR foams. Silane additives did not seem to have a strong effect on the flammability of the PIR‐PUR foams. However, heat resistance was more dominant for the foam with the organoclay at the higher temperature. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effect of adding feldspar on free volume properties of crosslinked polyester studied by positron annihilation lifetime spectroscopy
Authors: Gomaa E. , N. Asaad J.
Published: November 2011

Positron annihilation lifetime spectroscopy (PAL) was applied to study the feldspar effect on the free volume properties of crosslinked polyester based on neopentyl glycol, succinic acid, phthalic anhydride, and maleic anhydride. The measurements have been carried on the polyester resin samples cured with three crosslinking agents namely styrene (SS) or styrene/methyl methacrylate (SM) or styrene/acrylonitrile (SA) comonomers mixtures in the ratios of 2 : 1 and loaded with different concentrations of feldspar in the range from 0 to 80 wt %. The free volume parameters (size and fractions of holes) depend on type of the crosslinking agent as well as the feldspar content added to the polyester. The results are supported by a significant variation in the nanoscale free volume hole size distributions. Moreover, the correlation between positron annihilation parameters and electrical parameters was discussed. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
A study of factors that affect the information‐seeking behavior of academic scientists
Authors: Niu Xi , Hemminger Bradley M.
Published: October 2011

In an effort to understand how academic scientists seek information relevant to their research in today's environment of ubiquitous electronic access, a correlation framework is built and regression analysis is applied to the survey results from 2,063 academic researchers in natural science, engineering, and medical science at five research universities in the United States. Previous work has reported descriptive statistics about these scientists' information‐seeking behavior. This study extends that work to examine relationships between scientists' information‐seeking behaviors and their personal and environmental factors. Several regression models, including the Poisson model, the logit model, and the ordered logit model, are built to interpret the correlation among scientists' behaviors. In addition, exploratory factor analysis is used for data reduction. Overall, many factors were found to affect the specific information‐seeking behaviors of scientists, including demographic, psychological, role‐related, and environmental factors. Of the factors having an effect, academic position was the most important determinant of information behavior.
Anionic peroxidase production byArnebia euchromacallus
Authors: Farhadi Sahar , Haghbeen Kamahldin , Marefatjo Mohammad‐Javad , Hoor Marjan Ghiyami , Zahiri Hossein Shahbani , Rahimi Karim
Published: October 2011

Arnebia euchromacallus, obtained from the root cell culture of an Iranian native specimen, has gained a doubling time of 63 H after regular subculturing on Linsmaier–Skoog (LS) medium containing sugar (50 g/L), 2,4‐dichlorophenoxyacetic acid (10−6M), and kinetin (10−5M) under darkness at 25°C. Despite the observed somaclonal variations, peroxidase production by theA. euchromacalli has been stable over 4 years under the aforementioned conditions. Isoelectric focusing experiments revealed that the partially purifiedA. euchromaperoxidases (AePoxs) are mainly anionic with pI values of about 5.5 and 6.6. AePox reaches its optimal activity at 55°C and pH 7.5. Results of the various kinetic studies suggest that AePox belongs to the type III plant peroxidases with no activity for the oxidation of 3‐indoleacetic acid, but seems to play a role in the lignin biosynthesis and H2O2regulation during the proliferation of theA. euchromacells on LS medium. Comparing the biochemical properties of AePox with horseradish peroxidase and in view of the ease of solid cell culture, theA. euchromacallus could be considered as a source of plant peroxidase for some biotechnological applications.
Straßenbrücken zwischen aktuellem und zukünftigem Verkehr – Straßenverkehrslasten nach DIN EN 1991‐2/NA
Authors: Freundt Ursula , Böning Sebastian , Kaschner Rolf
Published: November 2011

Die Auswirkungen des aktuellen Schwerverkehrsaufkommens im deutschen Straßennetz und dessen prognostizierte Entwicklung auf die Beanspruchung der Straßenbrücken werden untersucht. Im Schwerpunkt stehen dabei die Einwirkungen auf den Neubau von Brücken. Es werden aber auch Untersuchungen für den Bauwerksbestand vorgestellt. Diese finden in der Nachrechnungsrichtlinie ihren Niederschlag.

Road bridges between actual and future heavy load traffic – Road traffic loads according to DIN EN 1991‐2/NA

The effects of the actual heavy load traffic on the Germen road network and the predicted future development of this traffic to the actions on road bridges are analysed. The main focus are the loads for the design of new road bridges. Analyses for the load on existing bridges are given too. Those are part of the guideline for recalculation of bridges.
Wildbrücke Völkermarkt – vorgespanntes Bogentragwerk aus UHFB‐Segmentfertigteilen
Authors: Reichel Michael , Sparowitz Lutz , Freytag Bernhard
Published: November 2011

In unserer wachsenden Infrastruktur werden die Forderungen nach wartungsarmen und langlebigen Bauwerken, die zugleich den Forderungen der Nachhaltigkeit entsprechen, immer größer. Dass Ultrahochfester Beton – nachfolgend UHFB genannt – ein solch hohes Potenzial in Bezug auf seine Festigkeits‐ und Dauerhaftigkeitseigenschaften aufweist, zeigten bereits Forschungsergebnisse vor mehr als 20 Jahren, die aktuelle Untersuchungen inzwischen bestätigen. Berücksichtigt man die enormen Stärken dieses Baustoffes konsequent bei der Umsetzung in einem materialgerechten Entwurf, lassen sich wirtschaftliche, dauerhafte und nachhaltige Bauwerke mit eminentem Nutzen für unsere Volkswirtschaft errichten. Die Fertigteilsegmentbögen des Pilotprojektes Wildbrücke Völkermarkt vereinigen das hohe Potenzial von UHFB mit einer materialgerechten Tragwerksausbildung, mit einem effizienten und schnellen Bauverfahren und einer einfachen und schnellen aber auch robusten und dauerhaften Fügetechnik.

Bridge WILD Völkermarkt – prestressed arched structure made of precast UHPC‐segments. Part 1 – Design and detailing

Our steadily expanding infrastructure requires long‐lasting buildings which can be maintained with low effort. At the same time they should meet the comprehensive demands of sustainability. Ultra high performance concrete (UHFB) is a building material which is, due to its particular properties, predestined for the application in such buildings. It is strong, tough and durable. Its high potential for application in this field was already recognised twenty years ago. Since then this was confirmed by means of manifold research. It is very important to keep in mind that normal strength concrete cannot simply be replaced by UHFB. It is a new material the properties of which must be considered carefully and consistently when designing structures. This is how the beneficial material properties can be utilised in buildings, which consequently will result in a great economic exploitation. The pilot project WILD‐bridge follows these basic principles. The development of the bridge led to a pre‐cast segmental arch which is slender and therefore very light. Thus, it can quickly be assembled and erected. Not only do the pre‐cast elements meet the demands of sustainability but also the joints. They are realised simple and robust by means of high precision dry joints. Part 1 of the paper deals with form finding, structural detailing and the structural analysis of the WILD‐bridge.
Development and validation of an LC‐MS/MS‐ESI method for the determination of lorglumide, a CCK‐1 antagonist in mouse plasma: application to a pharmacokinetic study
Authors: Sharma Kuldeep , Police Anitha , Kumar Avinash , Pawar Gopal V. , Giri Sanjeev , Rajagopal Sriram , Mullangi Ramesh
Published: November 2011

A highly sensitive, rapid assay method was developed and validated for the estimation of lorglumide in mouse plasma using liquid chromatography coupled to tandem mass spectrometry with electrospray ionization in positive‐ion mode. The assay procedure involves extraction of lorglumide and phenacetin (internal standard, IS) from mouse plasma with simple protein precipitation. Chromatographic separation was achieved using an isocratic mobile (0.2% formic acid solution–acetonitrile, 20:80, v/v) at a flow‐rate of 0.5 mL/min on an Atlantis dC18 column maintained at 40 °C with a total run time of 4.0 min. The MS/MS ion transitions monitored were 459.2 → 158.4 for lorglumide and 180.1 → 110.1 for IS. Method validation was performed as per FDA guidelines and the results met the acceptance criteria. The lower limit of quantitation achieved was 0.42 ng/mL and the linearity range extended from 0.42 to 500 ng/mL. The intra‐ and inter‐day precisions were in the ranges of 1.47–10.9 and 3.56–7.53, respectively. Copyright © 2011 John Wiley & Sons, Ltd.