bluuebunny/crossref_metadata_2025 huggingface dataset:
Environmental Modeling, Technology, and Communication for Land Falling Tropical Cyclone/Hurricane Prediction
Authors: Tuluri Francis , Reddy R. Suseela , Anjaneyulu Y. , Colonias John , Tchounwou Paul
Published: April 2010

Katrina (a tropical cyclone/hurricane) began to strengthen reaching a Category 5 storm on 28th August, 2005 and its winds reached peak intensity of 175 mph and pressure levels as low as 902 mb. Katrina eventually weakened to a category 3 storm and made a landfall in Plaquemines Parish, Louisiana, Gulf of Mexico, south of Buras on 29th August 2005. We investigate the time series intensity change of the hurricane Katrina using environmental modeling and technology tools to develop an early and advanced warning and prediction system. Environmental Mesoscale Model (Weather Research Forecast, WRF) simulations are used for prediction of intensity change and track of the hurricane Katrina. The model is run on a doubly nested domain centered over the central Gulf of Mexico, with grid spacing of 90 km and 30 km for 6 h periods, from August 28th to August 30th. The model results are in good agreement with the observations suggesting that the model is capable of simulating the surface features, intensity change and track and precipitation associated with hurricane Katrina. We computed the maximum vertical velocities (Wmax) using Convective Available Kinetic Energy (CAPE) obtained at the equilibrium level (EL), from atmospheric soundings over the Gulf Coast stations during the hurricane land falling for the period August 21–30, 2005. The large vertical atmospheric motions associated with the land falling hurricane Katrina produced severe weather including thunderstorms and tornadoes 2–3 days before landfall. The environmental modeling simulations in combination with sounding data show that the tools may be used as an advanced prediction and communication system (APCS) for land falling tropical cyclones/hurricanes.
Basic Apoptotic Mechanisms of Lead Toxicity in Human Leukemia (Hl-60) Cells
Authors: Yedjou Clement G. , Milner Jessica N. , Howard Carolyn B. , Tchounwou Paul B.
Published: April 2010

Lead exposure represents a medical and public health emergency, especially in children consuming high amounts of lead-contaminated flake paints. It may also cause hematological effects to people of all ages. Recent studies in our laboratory have indicated that apoptosis may be associated with the lead-induced oxidative stress and DNA damage. However, the mechanisms underlying its effect on lymphocytes are still largely unknown. Therefore, the aim of the present study was to investigate the apoptotic mechanisms of lead nitrate [Pb(NO3)2] using HL-60 cells as a test model. HL-60 cells were treated with different concentrations of Pb(NO3)2 for 24 h prior to cell viability assay and flow cytometry assessment. The results obtained from the trypan blue exclusion test indicated that at very low concentration, Pb(NO3)2 has no effect on the viability of HL-60 cells. A significant (p
The Effects of Arsenic Trioxide on DNA Synthesis and Genotoxicity in Human Colon Cancer Cells
Authors: Stevens Jacqueline J. , Graham Barbara , Walker Alice M. , Tchounwou Paul B. , Rogers Christian
Published: April 2010

Colon cancer is the third leading cause of cancer-related deaths worldwide. Recent studies in our laboratory have demonstrated that arsenic trioxide is cytotoxic in human colon cancer (HT-29), lung (A549) and breast (MCF-7) carcinoma cells. The purpose of the present study is to investigate the effects of arsenic trioxide on DNA synthesis and the possible genotoxic effects on human colon cancer cells. HT-29 cells were cultured according to standard protocol, followed by exposure to various doses (0, 2, 4, 6, 8, 10, and 12 μg/mL) of arsenic trioxide for 24 h. The proliferative response (DNA synthesis) to arsenic trioxide was assessed by [3H]thymidine incorporation. The genotoxic effects of arsenic-induced DNA damage in a human colon cancer cell line was evaluated by the alkaline single cell gel electrophoresis. Results indicated that arsenic trioxide affected DNA synthesis in HT-29 cells in a biphasic manner; showing a slight but not significant increase in cell proliferation at lower levels of exposure (2, 4 and 6 µg/mL) followed by a significant inhibition of cell proliferation at higher doses (i.e., 8 and 10 µg/mL). The study also confirmed that arsenic trioxide exposure caused genotoxicity as revealed by the significant increase in DNA damage, comet tail-lengths, and tail moment when compared to non-exposed cells. Results of the [3H]thymidine incorporation assay and comet assay revealed that exposure to arsenic trioxide affected DNA synthesis and exhibited genotoxic effects in human colon cancer cells.
Biological Activities of Aqueous and Organic Extracts from Tropical Marine Sponges
Authors: Sepčić Kristina , Kauferstein Silke , Mebs Dietrich , Turk Tom
Published: April 2010

We report on screening tests of 66 extracts obtained from 35 marine sponge species from the Caribbean Sea (Curaçao) and from eight species from the Great Barrier Reef (Lizard Island). Extracts were prepared in aqueous and organic solvents and were tested for hemolytic, hemagglutinating, antibacterial and anti-acetylcholinesterase (AChE) activities, as well as their ability to inhibit or activate cell protein phosphatase 1 (PP1). The most interesting activities were obtained from extracts of Ircinia felix, Pandaros acanthifolium, Topsentia ophiraphidites, Verongula rigida and Neofibularia nolitangere. Aqueous and organic extracts of I. felix and V. rigida showed strong antibacterial activity. Topsentia aqueous and some organic extracts were strongly hemolytic, as were all organic extracts from I. felix. The strongest hemolytic activity was observed in aqueous extracts from P. acanthifolium. Organic extracts of N. nolitangere and I. felix inhibited PP1. The aqueous extract from Myrmekioderma styx possessed the strongest hemagglutinating activity, whilst AChE inhibiting activity was found only in a few sponges and was generally weak, except in the methanolic extract of T. ophiraphidites.
Synthesis of N-(Methoxycarbonylthienylmethyl)thioureas and Evaluation of Their Interaction with Inducible and Neuronal Nitric Oxide Synthase
Authors: Suaifan Ghadeer A.R.Y. , Goodyer Claire L.M. , Threadgill Michael D.
Published: April 2010

Two isomeric N-(methoxycarbonylthienylmethyl)thioureas were synthesised by a sequence of radical bromination of methylthiophenecarboxylic esters, substitution with trifluoroacetamide anion, deprotection, formation of the corresponding isothiocyanates and addition of ammonia. The interaction of these new thiophene-based thioureas with inducible and neuronal nitric oxide synthase was evaluauted. These novel thienylmethylthioureas stimulated the activity of inducible Nitric Oxide Synthase (iNOS).
Development of a Three Dimensional Neural Sensing Device by a Stacking Method
Authors: Chang Chih-Wei , Chiou Jin-Chern
Published: April 2010

This study reports a new stacking method for assembling a 3-D microprobe array. To date, 3-D array structures have usually been assembled with vertical spacers, snap fasteners and a supporting platform. Such methods have achieved 3-D structures but suffer from complex assembly steps, vertical interconnection for 3-D signal transmission, low structure strength and large implantable opening. By applying the proposed stacking method, the previous techniques could be replaced by 2-D wire bonding. In this way, supporting platforms with slots and vertical spacers were no longer needed. Furthermore, ASIC chips can be substituted for the spacers in the stacked arrays to achieve system integration, design flexibility and volume usage efficiency. To avoid overflow of the adhesive fluid during assembly, an anti-overflow design which made use of capillary action force was applied in the stacking method as well. Moreover, presented stacking procedure consumes only 35 minutes in average for a 4 × 4 3-D microprobe array without requiring other specially made assembly tools. To summarize, the advantages of the proposed stacking method for 3-D array assembly include simplified assembly process, high structure strength, smaller opening area and integration ability with active circuits. This stacking assembly technique allows an alternative method to create 3-D structures from planar components.
Desde la dis-capacidad hacia la diversidad funcional. Un ejercicio de dis-normalización
Authors: Rodríguez Díaz Susana , Ferreira Miguel A. V.
Published: April 2010

El colectivo de personas con discapacidad en España ha propuesto el concepto de “diversidad funcional” para reivindicar su derecho a tomar decisiones y a abandonar la marginación a la que tradicionalmente ha sido sometido. el concepto se inscribe en los presupuestos de la “filosofía de vida independiente” y trata de superar las definiciones en negativo (discapacidad, minusvalía), reclamando el derecho al pleno reconocimiento de su dignidad como una expresión más de las muchas diversidades que en la actualidad son reconocidas positivamente en nuestra convivencia colectiva. Sin embargo, el concepto no logra superar, por sí mismo, ciertos presupuestos asociados a la concepción de la discapacidad que tienen que ver con la moderna normalización del cuerpo y de la salud derivados de la hegemonía del discurso de la ciencia médica. En el texto se proponen las líneas de argumentación crítica que, frente a dichos presupuestos, habrá de afrontar la perspectiva de la diversidad funcional.
La pobreza como espacio de indeterminación. Un análisis desde la biopolítica
Authors: Arteaga Botello Nelson , Bacarlett Pérez María Luisa
Published: April 2010

En este artículo se analiza el problema de las políticas que atienden la pobreza como una forma particular de biopolítica de la población, con el fin de resaltar la contradicción que generan al propiciar tanto la inclusión como la exclusión de los sectores considerados como pobres. Dicha contradicción se analiza desde tres ejes: la relación jurídica que se establece con la figura del pobre, como esto define un espacio de indeterminación de la población pobre y, finalmente, las implicaciones que ello tiene en la conformación de una vigilancia específica sobre estos sectores sociales. De esta manera se observa que las políticas de atención a la pobreza se fundan en una estrategia que maximiza las vida de las poblaciones depauperadas al mismo tiempo que tiende a mantenerla en niveles de supervivencia. Aspecto al que habría que prestar mayor atención en los efectos que pudiera tener en la consolidación democrática de la región.
A novel tandem differential mobility analyzer with organic vapor treatment of aerosol particles
Authors: Joutsensaari J. , Vaattovaara P. , Hämeri K. , Laaksonen A.
Published: April 2010

Abstract. A novel method to characterize the organic composition of aerosol particles has been developed. The method is based on organic vapor interaction with aerosol particles and it has been named an Organic Tandem Differential Mobility Analyzer (OTDMA). The OTDMA method has been tested for inorganic (sodium chloride and ammonium sulfate) and organic (citric acid and adipic acid) particles. Growth curves of the particles have been measured in ethanol vapor and as a comparison in water vapor as a function of saturation ratio. Measurements in water vapor show that sodium chloride and ammonium sulfate as well as citric acid particles grow at water saturation ratios (S) of 0.8 and above, whereas adipic acid particles do not grow at S<0.96. For sodium chloride and ammonium sulfate particles, a deliquescence point is observed at S=0.75 and S=0.79, respectively. Citric acid particles grow monotonously with increasing saturation ratios already at low saturation ratios and no clear deliquescence point is found. For inorganic sodium chloride and ammonium sulfate particles, no growth can be seen in ethanol vapor at saturation ratios below 0.9. In contrast, for organic adipic acid particles, the deliquescence takes place at around S=0.95 in the ethanol vapor. Citric acid particles grow in ethanol vapor similarly as in water vapor; the particles grow monotonously with increasing saturation ratios and no stepwise deliquescence is observed. The results show that the working principles of the OTDMA are operational and the OTDMA method can be used to determine an organic composition of the aerosol particles. Operation of OTDMA and hygroscopicity TDMA together allows making a rough categorization of different substances found in atmospheric aerosol particles based on their growth in pure ethanol and pure water vapor.
GOCE SGG and SST quick-look gravity field analysis
Authors: Pail R. , Wermut M.
Published: April 2010

Abstract. The purpose of quick-look analysis in the framework of the GOCE data processing architecture is to analyse partial data sets of satellite gravity gradiometry (SGG) and satellite-to-satellite tracking in high-low mode (hl-SST), in order to derive a diagnosis of the system performance. The semi-analytic (SA) method for gravity field recovery from GOCE observations, which is based on Fast Fourier Transform, is used. From a theoretical point of view, a number of requirements (circular, exact repeat orbit, uninterrupted measurement time series) have to be fulfilled. However, in the present paper it is demonstrated, that the SA approach can also be applied in the practical case of non-circular, nonrepeat orbits, and data gaps in the GOCE measurement time series. The performance of this approach is assessed in 5 case studies on the basis of a realistic closed-loop simulation.Key words. GOCE – semi-analytic approach – colored noise – data gaps – repeat orbit
Editorial
Authors: Richter A. K.
Published: April 2010

Abstract. This is the first issue of a new scientific publication of the European Geophysical Society, which will serve as the official organ of the Section on Nonlinear Processes in Geophysics. At the General Assembly in Strasbourg, 1987, this Section started with a special Joint Symposium on "Computer Simulations in Fluid Dynamics - Earth, Atmosphere and Space Plasmas" with 8 contributions. This was followed, a year later in Bologna, by a Joint Symposium entitled "Chaos and Turbulence in Geophysics" with 20 contributions. Since then the group of "nonlinear" scientists within the EGS has grown rapidly in size and in the quality of its contributions presented at the General Assemblies of the Society. Nowadays the programme of this Section normally includes 10 or more independent sessions with a total of some 250-300 papers. This development encouraged the officers and the members of the Section to search for a journal of their own, rather than to distribute their papers in the "classical" journals ranging from solid Earth geophysics to planetary and space sciences. Originally, the Society was asked to join an already existing publication in the field of nonlinear sciences. After almost two years of negotiations with the editors and the publishers of the most accepted journals in the field, the Section members decided differently; namely to launch their own journal, preferentially with a well known European publisher. However, in view of the general decrease in financial support for science and the generally increasing overheads of the publishers, it was decided that the new journal should be published by the Society itself, as an independent publication owned and run only by the EGS. The Society and the editors of this new journal are pleased to offer a modern, international, interdisciplinary and refereed publication to a young and growing generation of geophysicists with no page charges and fast publication on a "first come - first published" basis. The subscription rates are modest both for libraries and for members of the Society. We hope that scientists from other disciplines will also enjoy reading this journal and that publishing in it will be rewarding for the authors. With best wishes, Dr. Arne K. Richter Executive Secretary
Lifetime trajectory of physical activity according to energy expenditure and joint force
Authors: Ratzlaff Charles R. , Doerfling Paul , Steininger Gavin , Koehoorn Mieke , Cibere Jolanda , Liang Matt , Wilson David R. , Esdaile John , Kopec Jacek
Published: April 2010

Objective

To develop and demonstrate the feasibility of a method for estimating lifetime hip and knee cumulative joint force using survey data on physical activity, and to construct and describe lifetime trajectories of energy expenditure and hip and knee joint force.

Methods

Exposure data on lifetime physical activity, including type (occupational, household, and recreation) and dose (frequency, intensity, and duration), were collected from a Canada‐wide population study of adults ages ≥45 years. Subjects were ranked in 2 ways: in terms of physical activity–related energy expenditure and in terms of a cumulative peak force index (CPFI) for the hip and knee, which is a measure of lifetime exposure and is a time/joint force product involving years of force and subject bodyweight. A relative joint loading index was calculated as the ratio of joint force (CPFI score) to energy expenditure.

Results

A total of 4,269 subjects completed the baseline measurements. Lifetime energy expenditure and hip and knee CPFI scores were higher for occupational and household activity than sport. The mean lifetime energy expenditure from total physical activity in the study sample was 119.1 metabolic equivalent‐hours/week. Women had slightly higher total lifetime energy expenditure and CPFI scores than men. The relative joint loading index was highest for male household and sport activity and lowest for female occupational activity.

Conclusion

Lifetime cumulative hip/knee joint force trajectories were successfully constructed from survey data and followed expected trends. Comparing energy expenditure with joint force revealed variation by age, sex, and activity type, indicating these measures may help distinguish the numerous benefits of physical activity from possible risks.
Validity of the disease activity score in undifferentiated arthritis
Authors: Fransen Jaap , Visser Karen , van Dongen Henrike , Huizinga Tom , van Riel Piet L. C. M. , van der Heijde Désirée M.
Published: April 2010

Objective

To study whether the Disease Activity Score (DAS) is a valid measure of disease activity in undifferentiated arthritis (UA).

Methods

Data from a randomized, double‐blind, placebo‐controlled trial of methotrexate (MTX) and placebo involving 110 patients with UA were used. Data included baseline and 3, 6, 9, and 12 months, as well as diagnosis at 18 months. Validity of the DAS was analyzed using factor analysis, correlations with disease activity variables, correlations with changes in disability and joint damage, differences in DAS between diagnoses, and detecting the difference between placebo and MTX.

Results

Three disease activity factors were retrieved from the disease activity variables: patient reported outcomes, tender and swollen joints, and acute phase reactants. The DAS had its highest correlations (r > 0.77) with tender joint counts, followed by swollen joint counts (r > 0.63) and patient reported outcomes (r > 0.30), but the DAS correlated less with C‐reactive protein levels (r = 0.32). Over time, the DAS was related to the Health Assessment Questionnaire response with an odds ratio of 4.1 (95% confidence interval 2.1–8.0), but not with change in joint damage. At 18 months, the mean DAS was 2.6 for rheumatoid arthritis patients, 2.2 for UA patients, and 1.9 for patients in remission (P = 0.001). The DAS discriminated better than all single variables between MTX and placebo, with a Guyatt's effect size of 0.89.

Conclusion

The DAS appears to be a reasonably valid measure of disease activity for use in UA clinical trials.
An Environmentally Benign, Highly Efficient Catalytic Reduction of p‐Nitrophenol using a Nano‐Sized Nickel Catalyst Supported on Silica‐Alumina
Authors: El Maksod Islam Hamdy Abd , Hegazy Eman. Z. , Kenawy Sayed. H. , Saleh Tamer S.
Published: April 2010

A green and effective method is reported for the reduction of p‐nitrophenol to p‐aminophenol using a nano‐sized nickel catalyst supported on silica‐alumina in the presence of hydrazine hydrate as an alternative source of hydrogen. It was found that nickel loaded on a silica‐alumina support is a very effective catalyst in the hydrogenation of p‐nitrophenol to p‐aminophenol. Thus it attained 100% conversion in only 69 seconds instead of 260 seconds for commercial Raney nickel. In addition, the possibility to reuse it more than one time with great efficiency gives it another advantage over commercial Rainey nickel which cannot be used more than once. This economical and environmentally friendly method provides a potentially new approach for the synthesis of the intermediate product of paracetamol in industry, which overcomes the drawbacks of the known reduction methods. The prepared catalysts were fully characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X‐ray (EDX), and electron spin resonance (ESR) tehniques.
(η6‐Arene)ruthenium(N‐heterocyclic carbene) Complexes for the Chelation‐Assisted Arylation and Deuteration of Arylpyridines: Catalytic Studies and Mechanistic Insights
Authors: Prades Amparo , Poyatos Macarena , Peris Eduardo
Published: April 2010

A series of (η6‐arene)ruthenium complexes have been tested in the arylation of arylpyridines. One (η6‐p‐cymene)ruthenium(N‐heterocyclic carbene) complex (labelled as 1 in the text) was found to be the most effective, being capable of arylating a wide set of substantially different arylpyridines. Complex 1 is also able to promote the regioselective deuteration of a series of arylated N‐heterocycles, via a nitrogen‐directed mechanism. Two of the deuterated amines were used to measure the kinetic isotope effect (KIE) in the arylation process. The detection of an inverse KIE, together with the observation that the CH activation process does not require the addition of a base, suggest that the rate‐limiting step in the arylation process may be different to that of previously reported studies.
Development of a dual‐color, double fusion FISH assay to detect RPN1/EVI1 gene fusion associated with inv(3), t(3;3), and ins(3;3) in patients with myelodysplasia and acute myeloid leukemia
Authors: Shearer Brandon M. , Sukov William R. , Flynn Heather C. , Knudson Ryan A. , Ketterling Rhett P.
Published: April 2010

Approximately 2–3% of adult patients with acute myeloid leukemia harbor a rearrangement of RPN1 (at 3q21) and EVI1 (at 3q26.2) as inv(3)(q21q26.2), t(3;3)(q21;q26.2), or ins(3;3)(q26.2;q21q26.2). The most recent World Health Organization (WHO) classification has designated AML with inv(3) or t(3;3) and associated RPN1/EVI1 fusion, as a distinct AML subgroup associated with an unfavorable prognosis. We have created a dual color, double fusion fluorescence in situ hybridization (D‐FISH) assay to detect fusion of the RPN1 and EVI1 genes. A blinded investigation was performed using 30 normal bone marrow samples and 51 bone marrow samples from 17 patients with inv(3)(q21q26.2), 11 patients with t(3;3)(q21;q26.2), and one patient with ins(3;3)(q26.2;q21q26.2) previously defined by chromosome analysis. The unblinded results indicated abnormal RPN1/EVI1 fusion results in 30 (97%) of 31 samples from the inv(3)(q21q26.2) group including seven bone marrow samples for which chromosome analysis was unsuccessful or failed to detect an inv(3)(q21q26.2). Abnormal FISH results were detected in 14 (88%) of 16 samples with t(3;3)(q21;q26.2) and in the sole sample with an ins(3;3)(q26.2;q21q26.2). All 30 negative controls were normal and were used to establish a normal cutoff of 0.6% for the typical abnormal D‐FISH signal pattern. Overall, this D‐FISH assay was more accurate than chromosome analysis and based on the normal cutoff of 0.6%, this assay can be used for minimal residual disease detection and disease monitoring in patients with RPN1/EVI1 fusion. Am. J. Hematol., 2010. © 2010 Wiley‐Liss, Inc.
Thermally induced phase separation in liquid crystalline polymer/polycarbonate blends
Authors: Lee Kam‐Wa D. , Chan Philip K. , Kamal Musa R.
Published: April 2010

Thermally induced phase separation in liquid crystalline polymer (LCP)/polycarbonate (PC) blends was investigated in this study. The LCP used is a main‐chain type copolyester comprised of p‐hydroxybenoic acid and 6‐hydroxy‐2‐naphthoic acid. Specimens for microscopic observation were prepared by melt blending. The specimens were heated to a preselected temperature, at which they were held for isothermal phase separation. The preselected temperatures used in this study were 265, 290, and 300°C. The LCP contents used were 10, 20, and 50 wt %. These parameters corresponded to different positions on the phase diagram of the blends. The development of the phase‐separated morphology in the blends was monitored in real time and space. It was observed that an initial rapid phase separation was followed by the coarsening of the dispersed domains. The blends developed into various types of phase‐separated morphology, depending on the concentration and temperature at which phase separation occurred. The following coarsening mechanisms of the phase‐separated domains were observed in the late stages of the phase separation in these blends: (i) diffusion and coalescence of the LCP‐rich droplets; (ii) vanishing of the PC‐rich domains following the evaporation‐condensation mechanism; and (iii) breakage and shrinkage of the LCP‐rich domains. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Reactive grafting of glycidyl methacrylate onto polypropylene
Authors: Burton Emma‐Louise , Woodhead Mike , Coates Phil , Gough Tim
Published: April 2010

This work explored the melt‐phase grafting of glycidyl methacrylate (GMA) onto polypropylene on a closely intermeshing corotating twin‐screw extruder (16‐mm screws, 40 : 1 length/diameter ratio). The modification of the base polypropylene to produce GMA‐grafted polypropylene was achieved via peroxide‐induced hydrogen abstraction from the polypropylene followed by the grafting of the GMA monomer or by the grafting of styrene followed by copolymerization with the GMA. In this study, both the position and order of the reactant addition were investigated as a route to improving graft yields and reducing side reactions (degradation). For the peroxide–GMA system, adding GMA to the melt before the peroxide resulted in significant improvements in the graft levels because of the improved dispersion of GMA in the melt. The addition of a comonomer (styrene) was explored as a second route to improving the graft yield. Although the addition of the comonomer led to a considerable rise in the level of grafted GMA, altering the order of the reactant addition was not found to contribute to an increase in the grafted GMA levels. However, variable levels of grafted styrene were achieved, and this may play an important role in the development of grafted polymers to suit specific needs. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Compatibilizing effect of starch‐grafted‐poly(L‐lactide) on the poly(ε‐caprolactone)/starch composites
Authors: Chen Li , Zhang Zhe , Zhuang Xiuli , Chen Xuesi , Jing Xiabin
Published: April 2010

The poly(ε‐caprolactone) (PCL)/starch blends were prepared with a coextruder by using the starch grafted PLLA copolymer (St‐g‐PLLA) as compatibilizers. The thermal, mechanical, thermo‐mechanical, and morphological characterizations were performed to show the better performance of these blends compared with the virgin PCL/starch blend without the compatibilizer. Interfacial adhesion between PCL matrix and starch dispersion phases dominated by the compatibilizing effects of the St‐g‐PLLA copolymers was significantly improved. Mechanical and other physical properties were correlated with the compatibilizing effect of the St‐g‐PLLA copolymer. With the addition of starch acted as rigid filler, the Young's modulus of the PCL/starch blends with or without compatibilizer all increased, and the strength and elongation were decreased compared with pure PCL. Whereas when St‐g‐PLLA added into the blend, starch and PCL, the properties of the blends were improved markedly. The 50/50 composite of PCL/starch compatibilized by 10% St‐g‐PLLA gave a tensile strength of 16.6 MPa and Young's modulus of 996 MPa, respectively, vs. 8.0 MPa and 597 MPa, respectively, for the simple 50/50 blend of PCL/starch. At the same time, the storage modulus of compatibilized blends improved to 2940 MPa. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Macroporous poly(vinyl alcohol) foam crosslinked with epichlorohydrin for microorganism immobilization
Authors: Bai Xue , Ye Zhengfang , Li Yanfeng , Ma Yingxia
Published: April 2010

Macroporous poly(vinyl alcohol) foam with epichlorohydrin as a crosslinking agent was investigated. The average molecular weight between crosslinks, crosslinking density, and mesh size were determined through the equilibrium swelling theory. The characterization of foams with different crosslinking ratios was also investigated through the testing of the thermal properties, specific surface areas, and diffusion coefficients. The biomass densities and activity yields were measured by detection of the protein concentration and oxygen uptake rate. Thermogravimetry and differential scanning calorimetry tests showed an increase in the thermal stability and a decrease in the polymeric crystallinity with increasing crosslinking ratio. The biomass densities increased with increasing crosslinking ratio, with the highest value shown at 0.0638 ± 0.0093 g of volatile suspended solid (VSS)/g of carrier. However, the activity yields decreased with increasing crosslinking ratio, with the highest value at 69.38%. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Micromechanical behavior related to the nanostructure of biodegradable polyesters
Authors: Cagiao M. E. , Buzin P. , Kricheldorf H. R. , Funari S. S. , Calleja F. J. Baltá
Published: April 2010

The microhardness of a series of biodegradable polyesters was determined. The nanostructural features of these materials were studied by wide‐angle X‐ray scattering (WAXS), small‐angle X‐ray scattering (SAXS), and differential scanning calorimetry. Analysis of the SAXS and WAXS patterns allowed direct derivation of the degree of crystallinity and crystal thickness values, and correlations of the micromechanical properties are presented. The differences in the thermal and mechanical properties exhibited by the studied systems and the ones found in other aromatic polyesters are explained as due to the different chemical natures of the monomeric units. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Influence of aliphatic amine epoxy hardener on the adhesive properties of blends of mono‐carboxyl‐terminated poly(2‐ethylhexyl acrylate‐co‐methyl methacrylate) with epoxy resin
Authors: González Garcia Filiberto , Soares Bluma Guenther , Leyva Maria Elena , Simões Alexandre Zirpoli
Published: April 2010

The adhesive properties have been investigated in blends of mono‐carboxyl‐terminated poly(2‐ethylhexyl acrylate‐co‐methyl methacrylate) with diglycidyl ether of bisphenol A and three different aliphatic amine epoxy hardener. The adhesives properties are evaluated in steel alloy substrate using single‐lap shear test. The copolymers are initially miscible in the stoichiometric blends of epoxy resin and hardener at room temperature. Phase separation is noted in the course of the polymerization reaction. Different morphologies are obtained according to the amine epoxy hardener. The most effective adhesive for steel–steel joints in single‐lap shear test is the blends using 1‐(2‐aminoethyl)piperazine (AEP) as hardener. This system shows the biggest lap shear strength. However, the modified adhesives show a reduction in the mechanical resistance. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Effect of the preparation conditions on the permeation of ultrahigh‐molecular‐weight polyethylene/silicon dioxide hybrid membranes
Authors: Li Nana , Xiao Changfa
Published: April 2010

Porous ultrahigh‐molecular‐weight polyethylene/SiO2 membranes were prepared by thermally induced phase separation (TIPS) with white mineral oil as the diluent and SiO2 as an additive. Influential factors, including extraction method, SiO2 content, and cooling rate, were investigated. The results suggest that the both porosity and pure water flux of the membranes by extraction of the solvent naphtha in the tension state with alcohol were the best among our research. With increasing SiO2 content, the porosity, pure water flux, and pore diameter increased. However, with excessive SiO2 content, defects formed easily. Moreover, SiO2 improved the pressure resistance of the membranes. The cooling rate directly effected the crystal structure. A slow cooling rate was good for crystal growth and the integration of the diluent. Therefore, the porosity, pure water flux, and bubble‐point pore diameter increased with decreasing cooling rate. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Surface modification of vulcanized rubber by radiation grafting, part 1: Improvement in friction behavior
Authors: Mizote N. , Katakai A. , Tamada M. , Matsuoka H.
Published: April 2010

Hydrophilic monomer, 2‐hydroxyethyl methacrylate (HEMA), and hydrophobic monomer, 3‐(methacryloyloxy)propyltris(trimethylsiloxy)silane (MPTS) were grafted on vulcanized rubber surface with simultaneous electron beam irradiation. Degree of graft polymerization was evaluated by composition ratio of imparted graft chain against trunk rubber. The composition ratio could be controlled by the monomer concentration and the irradiation dose. Grafted rubbers were evaluated by surface roughness and contact angle. Graft polymerization of HEMA decreased the contact angle from 93 to ∼ 70° without considerable change of the surface roughness. In the case of MPTS, the contact angle increased approximately to 108°. The relationship between the contact angle of water on the modified surface and the friction at the moment of semi‐dry was investigated as an application of the resulting rubber to wiper blade. The increase of the contact angle owing to the grafting of hydrophobic MPTS led to the decrease of Δμ (deference between semi‐dry state and dry friction). Instead, the decrease of the contact angle by grafting of hydrophilic HEMA resulted in the increase of Δμ. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Prepared hydrogenated nitrile rubber (HNBR)/organo–montmorillonite nanocomposites by the melt intercalation method
Authors: Zhang R. L. , Liu L. , Huang Y. D. , Tang Y. R. , Zhang T. C. , Zhan S. Z.
Published: April 2010

The polymer, Hydrogenated Nitrile‐Butadiene Rubber (HNBR) was melt compounded with organophilic montmorillonite (OMMT). The dispersion of the OMMT in the HNBR matrix was characterized by X‐ray diffraction (XRD), which indicated that at the temperature of 100°C, the organoclay belong to the exfoliated and interlayer structure. The effect of sulfur on the dispersion of OMMT in the polymer matrix was also studied. The vulcanization changed the dispersion of OMMT in polymer matrix greatly and the basal spacing of clay layers is decreased after vulcanization. The mechanical properties, Akron abrasion and the crude oil medium aging‐resistant of HNBR nanocomposites were examined as a function of the OMMT content in the matrix of polymer. The results of the test show remarkable improvement in tensile strength, tear strength, aging‐resistant, and hardness of HNBR nanocomposites than that of unfilled HNBR. It is obvious that the 10 phr of OMMT filled nanocomposites have the best mechanical properties. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Surfactant assisted processing of carbon nanotube/polypropylene composites: Impact of surfactants on the matrix polymer
Authors: Rausch Julius , Zhuang Rong‐Chuan , Mäder Edith
Published: April 2010

Multiwalled carbon nanotubes (MWCNT) were dispersed in presence of various surfactants and introduced into isotactic polypropylene (PP) via melt blending. The effect of the surfactants on the crystallization and mechanical properties was studied on the injection molded specimens by isothermal differential scanning calorimetry and tensile tests, respectively. The results reveal that the presence of surfactants affects the mechanical and thermal properties of the nanocomposite. This information is supported by thermogravimetric analysis of the surfactants to examine their behavior at temperatures relevant for the processing of PP. In addition, they have to be taken into account as a third phase between the MWCNT and polymeric matrix, affecting the crystallization and failure behavior of PP or causing the formation of pores at elevated temperatures. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Impact of curing condition on pH and alkalinity/acidity of structural wood adhesives
Authors: Zhang Yaolin , Wang Xiang‐Ming , Casilla Romulo , Cooper Paul , Huang Zeen , Wang Xiaodong
Published: April 2010

Nine formulations were selected for evaluating the effect of different curing methods on pH and alkalinity or acidity of various structural wood adhesives. These included four phenol–formaldehyde (PF) resins with high pH, one phenol–resorcinol–formaldehyde (PRF) resin with intermediate pH, two melamine–urea–formaldehyde (MUF) resins, and two melamine–formaldehyde (MF) resins with low pH. The four curing methods used in the study were: (1) curing at 102–105°C for 1 h (based on CSA O112.6‐1977), (2) four‐hour curing at 66°C followed by 1‐hour curing at 150°C (based on ASTM D1583‐01), (3) curing at room temperature overnight (based on ASTM D 1583‐01), and (4) cured adhesive squeezed out from glue lines of bonded shear block samples. The effect of the different methods on pH and alkalinity/acidity of the cured adhesive depended strongly on the individual adhesives. For the PF, the alkalinity was different for the different formulations in the liquid form, while in the cured form, the difference in the alkalinity depended on the curing method used. The MF and the MUF were the adhesives most affected by the method used. In particular, the MUF showed much higher cured film pH values when cured by method 2 compared to the other three methods, while both the cured MF and MUF exhibited quite variable acidity values when cured with the different methods. The PRF showed reasonably uniform cured film pH but varying acidity values when cured with the different methods. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Thermal properties of new bismaleimide resins containing hydrogen silsesquioxane and diallyl bisphenol A
Authors: Huang Fuwei , Huang Farong , Zhou Yan , Du Lei
Published: April 2010

Bismaleimide (BMI) resins modified with hydrogen silsesquioxane (HSQ) and diallyl bisphenol A (DABPA) (BMI‐HSQ‐DABPA resins) were prepared. DSC, FTIR, and TGA were used to characterize the curing behaviors, structures, and thermal properties of the BMI‐HSQ‐DABPA resins, respectively. The results showed that the glass transition temperatures and thermal stabilities of the cured BMI‐HSQ‐DABPA resins increased with the rise of the contents of HSQ. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
A novel route for preparation of PVC sheets with high UV irradiation resistance
Authors: Ye Xianke , Pi Hong , Guo Shaoyun
Published: April 2010

A novel acrylonitrile acrylate copolymer coating was proposed to improve the UV irradiation resistance of poly(vinyl chloride) (PVC) sheets. Its effect on the photoageing properties of the sheets was evaluated by means of Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), yellowness index test, and the oxygen permeability coefficient and mechanical properties measurement. The experimental results show that the novel acrylonitrile acrylate copolymer coating significantly improves the UV irradiation resistance of PVC sheets. Compared with the PVC sheets without coating, the coated PVC sheets show better mechanical properties, lower yellowness index, and smaller oxygen permeability coefficient after UV irradiation. The analysis on the SEM images of the PVC sheets indicates that the coating acts as a film to prevent the PVC sheets from UV energy and oxygen that can accelerate the photochemical reactions of PVC. The FTIR analysis confirms that the coating can slow down the microstructures development of the PVC sheets, also indicating that the coating impeded the photochemical reactions of PVC. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Terpolymerization and performance of 2‐acrylamide‐2‐methyl propane sulfonic acid / itaconic acid / N‐vinyl‐2‐pyrrolidone
Authors: Zhang Liang , Zhuang Jia , Liu Hanbin , Li Huan Ming , Zhao Zhangping
Published: April 2010

Using 2‐acrylamide‐2‐methyl propane sulfonic acid (AMPS), itaconic acid (IA), and N‐vinyl‐2‐pyrrolidone (NVP) as monomers, a new retader terpolymer AMPS/IA/NVP (PAIN) was synthesized by free radical aqueous solution copolymerization and characterized by FTIR and H‐NMR. Through the orthogonal experiment, the optimum reaction conditions of copolymerization were obtained: NVP 7.5 wt (mass fraction) %; regulator V 4%; reaction temperature 60°C; initiator 1 wt %. The intrinsic viscosity number of PAIN synthesized with different amount of regulator (isopropanol) was determined, finding that the regulator can change the molecular weight and distribution of PAIN. Through the thickening experiment in high temperature and high pressure, it was found that PAIN had an excellent retardation property in high temperature, and the thickening times of the cement slurries with 1% (BOWC) PAIN were up to 256 min at 110°C and 234 min at 130°C, respectively. The PAIN was even stable when the temperature below 350°C proved by TG‐SDTA analysis. Moreover, the retarding mechanism of PAIN was analyzed and discussed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
The role of temperature on the Egyptian drilling mud performance in the presence of cationic polyethylene imine and anionic polyacrylamide
Authors: Mostafa Bassem A. , Assaad Faiz F. , Rashad Mohamed A. , El‐Niklawy Ahmed S.
Published: April 2010

The flow properties of Egyptian bentonite suspensions were determined in the presence of cationic polyethylene imine followed by anionic polyacrylamide at different clay/water ratios. This sequence of addition was examined at four different temperatures (20, 40, 60, and 80°C). The aging time was kept constant after 24 h. The data showed that there is an inverse relation between temperature and plastic viscosity of the bentonite suspension. Contrary to that, apparent viscosity, yield point, gel strength, and consistency index are increased as temperature increases. The zeta potential of bentonite suspension in the presence of 50 mg/L cationic polyethylene imine followed by 10 mg/L anionic polyacrylamide were investigated at different temperature. The results showed that there is a direct relation between temperature and ζ potential. Potential energy profiles were constructed to investigate the relation between rheological and electrical properties. Potential energy profile at different bentonite suspensions gave a high‐repulsion potential energy between clay surfaces by increasing temperature, which means that the suspension stability improved. From the above results, it might be possible to say that the Egyptian clay suspension can give desired drilling mud properties using 6% clay suspension concentration treated with 50 mg/L polyethylene imine followed by 10 mg/L polyacrylamide at 80°C up to 24‐h aging time. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Morphology and properties of the PA66/PC/silicone rubber composites
Authors: Chen Jun , Wu Wei , You Yi , Fan Wei , Chen Yujie
Published: April 2010

The research focused on the PA66/PC/silicone rubber composites. By adding silicone rubber as a toughener, the composites were prepared via dynamic vulcanization. The morphology and properties of the composites were characterized by FTIR, TEM, SEM, XRD, etc. The FTIR spectrum of the composites presented an increase of the 1730, 1240, and 1450 cm−1 that can be due to the CO interaction and the presence of the OCOO group, and this fact can mean the formation of the PA66–PC copolymer. The crosslinking of silicone rubber in the PA66/PC matrix formed the net‐like structure like semi‐IPN, which is propitious to enhance the interaction between PA66 matrix and PC and in further makes the PC particles embed in PA66 matrix closely. Novel composites are gained with outstanding mechanical properties and high temperature resistance, so the combine toughening by silicone rubber and PC is an ideal toughening system owing to the synergistic effect. In addition, the PA66/PC/silicone rubber/OMMT composite exhibits better flexile strength and flexile modulus without weakening other mechanical properties. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Optimizing preparation of NaCS–chitosan complex to form a potential material for the colon‐specific drug delivery system
Authors: Wang Ming‐Jun , Xie Yu‐Liang , Chen Zheng‐Jie , Yao Shan‐Jing
Published: April 2010

A novel polyelectrolyte complex (PEC) formed by sodium cellulose sulfate (NaCS) and chitosan was prepared as a candidate material for colon‐specific drug delivery system. It was found in experiments that the properties of two raw materials and the process parameters, such as the degree of substitution (DS) and concentration of NaCS, the viscosity and concentration of chitosan, were very important factors on the properties of the final product—NaCS–chitosan‐PEC. The preparation of NaCS–chitosan complex was optimized by using response surface methodology to evaluate the effects of these parameters on the degradation properties of NaCS–chitosan in the simulated colonic fluid (SCF). The DS of NaCS was in the range from 0.2 to 0.6, the concentration of NaCS from 2 to 4% (w/v), the viscosity of chitosan from 50 to 550 mPa s, and the concentration of chitosan from 0.5 to 1.5% (w/v). A mathematical model was developed to describe the effect of these parameters and their interactions on the degradation of NaCS–chitosan complex. The optimum operation conditions for preparing NaCS–chitosan complex were determined to DS of NaCS of 0.2, the concentration of NaCS of 4.0% (w/v), chitosan viscosity of 327 mPa s, and the concentration of chitosan 0.5% (w/v), respectively. Validation of experiments with 5 confirmatory runs indicated the high degree of prognostic ability of response surface methodology. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Simultaneous algorithm for trajectory planning
Authors: Rubio Francisco J. , Valero Francisco J. , Suñer Jose Luis , Mata Vicente
Published: April 2010

This paper addresses the solution of smooth trajectory planning for industrial robots in environments with obstacles using a direct method, creating the trajectory gradually as the robot moves. The presented method deals with the uncertainties associated with the lack of knowledge of kinematic properties of intermediate via‐points since they are generated as the algorithm evolves looking for the solution. Several cost functions are also proposed, which use the time that has been calculated to guide the robot motion. The method has been applied successfully to a PUMA 560 robot and four operational parameters (execution time, computational time, distance travelled and number of configurations) have been computed to study the properties and influence of each cost function on the trajectory obtained.

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