bluuebunny/crossref_metadata_2025 huggingface dataset:
High efficiency synthesis of octavinylsilsesquioxanes and its high performance hybrids based on bismaleimide‐triazine resin
Authors: Hu Jiang‐tao , Gu Aijuan , Jiang Zhijun , Liang Guozheng , Zhuo Dongxian , Yuan Li , Zhang Beijing , Chen Xiangxiu
Published: August 2011

An improved method is developed to synthesize octavinylsilsesquioxanes (VPOSS) with shorter time and higher yield, and then VPOSS is used to prepare new hybrids based on bismaleimide‐triazine (BD/CE) resin, coded as VPOSS/BD/CE. The effect of the content of VPOSS on the key properties including curing behavior, thermal, mechanical, and dielectric properties as well as water resistance of VPOSS/BD/CE hybrids were systematically discussed. Compared with BD/CE resin, hybrids show similar curing behavior but different chemical structures and thus macro‐performance. These key properties of hybrids are dependent on the content of VPOSS, all hybrids show significantly improved dielectric properties, water resistance, and dimensional stability; moreover, the hybrids with suitable content of VPOSS have bigger impact strengths. Specifically, with the addition of 7 wt% VPOSS to BD/CE resin, the dielectric constant decreases from 3.7 to 3.2, the dielectric loss decreases 55%, and the coefficient of thermal expansion reduces 23%; moreover, the glass transition temperature and initial decomposition temperature increase about 15°C. The attractive integrated properties suggest that VPOSS/BD/CE hybrids have great potential to be used as structural and functional materials for many cutting‐edge fields. Copyright © 2011 John Wiley & Sons, Ltd.
Analysis on interfacial stress in impact of polyphenylene sulfide/CaCO3 composites
Authors: Liang Ji‐Zhao
Published: August 2011

The interfacial stress and its distribution during impact of inorganic particulate‐filled polymer composites were analyzed in the present paper by means of a three‐dimensional (3D) finite element method, and the software used was the ANSYS/LS‐DYNA (ANSYS Inc., Canonsburg, PA, USA). The simulation results showed that the normal stress, the shear stress, and the equivalent stress reached the maximum at the particle equator, and then they reduced quickly toward the direction of the particle pole along the interface between the particle and the matrix and achieved the minimum from about 0.5 to 2.0 µm from the equator. Finally, they tended to gently or somewhat increase. Furthermore, the ways and mechanisms of the major fail or fracture of the polyphenylene sulfide (PPS)/calcium carbonate (CaCO3) composites under impact load were discussed. The mechanism of impact fracture or failure of inorganic particle‐filled PPS composites might be that the matrix around the neighboring inclusions will first yield owing to the stress concentration in the interface between the inclusion and the matrix to induce crazes and extend quickly. Copyright © 2011 John Wiley & Sons, Ltd.
Surface initiated polymerization from integrated poly(dimethylsiloxane) enables crack‐free large area wrinkle formation
Authors: Li Zhong , Zhang Shen , Zhang Pengfei , Yang Dayong , Jin Gang , Ma Hongwei
Published: August 2011

We conducted surface initiated polymerization from stretched poly(dimethylsiloxane) to construct a polymer/PDMS bilayer structure, which formed crack‐free wrinkles over large area (>6 cm2) upon recovery from the stretched state. This system further allowed us to reveal the dynamics and memory effect of wrinkling. Copyright © 2011 John Wiley & Sons, Ltd.
Preparation, characterization, and properties of nanofibers based on poly(vinylidene fluoride) and polyhedral oligomeric silsesquioxane
Authors: Cozza Erika Simona , Monticelli Orietta , Cavalleri Ornella , Marsano Enrico
Published: August 2011

Nanostructered nanofibers based on poly(vinylidene fluoride) (PVDF) and polyhedral oligomeric silsesquioxane (POSS) have been prepared by electrospinning process. The starting solutions were prepared by dissolving both the system components in the mixture N,N‐dimethylacetamide/acetone. The characteristics of the fiber prepared, studied by scanning electron microscopy, atomic force microscopy, and wide angle X‐ray diffraction, have been compared with those of PVDF fibers. Morphological characterization has demonstrated the possibility to obtain defect‐free PVDF/POSS nanofibers by properly choosing the electrospinning conditions, such as voltage, polymer concentration, humidity, etc. Conversely, in the case of fibers based on the neat polymer, it was not possible to attain the complete elimination of beads in the electrospun nanofibers. The different behavior of the two types of solutions has been ascribed to silsesquioxane molecules, which, without influencing the solution viscosity or conductivity, favor the formation of uniform structures by decreasing the system surface tension. Concerning POSS distribution in the fibers, the morphological characterization of the electrospun films has shown a submicrometric dispersion of the silsesquioxane. It is relevant to underline that cast films, prepared by the same solutions, have been found to be characterized by POSS aggregation, thus demonstrating a scarce affinity between the two‐system components. Indeed, the peculiar solvent evaporation of the electrospun solution, which is much faster than that occurring during the cast process, prevents POSS aggregation, thus leading to the formation of nanofibers characterized by a silsesquioxane dispersion similar to that present in solution. Finally, the presence of POSS improves the electrospun film mechanical properties. Copyright © 2011 John Wiley & Sons, Ltd.
Hydrophilic silicone hydrogels with interpenetrating network structure for extended delivery of ophthalmic drugs
Authors: Wang Jingjing , Liu Fang , Wei Jun
Published: August 2011

In the current work, hydrophilic silicone hydrogels were prepared for extended drug delivery applications. The preparation method was based on sequential interpenetrating network synthesis. A hydrophilic network was prepared by radical copolymerization of hydrophilic monomers 2‐hydroxyethyl methacrylate and poly(ethylene glycol) diacrylate. A hydrophobic silicone network was obtained by crosslinking polymerization of bifunctional methacrylated polydimethylsiloxanes macromonomer. The morphology of the silicone hydrogels was characterized by transmission electron microscopy. The result showed that the silicone hydrogels exhibited heterogeneous morphology. The properties of the silicone hydrogels such as equilibrium swelling ratio (ESR), mechanical property, oxygen permeability, contact angle, and protein repelling ability were investigated. Finally, the silicone hydrogels were loaded with timolol by pre‐soaking in drug solution to evaluate drug‐loading capacity and in vitro release behavior. The results showed that mechanical strength and oxygen permeability increased, and the ESR decreased with the increase of silicone component in the silicone hydrogels. The result of the contact angle measurement indicated that the silicone hydrogels possessed hydrophilic surfaces. The drug loading and in vitro releases were dependent on the composition of hydrophilic/hydrophobic phase of silicone hydrogels. Copyright © 2011 John Wiley & Sons, Ltd.
Extension‐induced mechanical reinforcement in melt‐spun fibers of polyamide 66/multiwalled carbon nanotube composites
Authors: Mai Fang , Pan Dongdong , Gao Xiang , Yao Meijun , Deng Hua , Wang Ke , Chen Feng , Fu Qiang
Published: August 2011

In this work, polyamide 66 (PA66) and its composites with multiwalled carbon nanotubes (MWNTs) were melt spun into fibers at different draw ratios. PA66 fibers at high draw ratio demonstrate a 40% increase in tensile strength, 66% increase in modulus and a considerable increase in toughness. It is demonstrated that this reinforcement can be mainly attributed to high‐draw‐ratio‐induced good dispersion and orientation of MWNTs, particularly the enhanced interfacial adhesion between MWNT and matrix thanks to interfacial crystallization. Our work provides a simple but efficient method to achieve good dispersion and strong interfacial interaction through melt spinning. Copyright © 2011 Society of Chemical Industry
Photoinitiated precipitation polymerization in liquid CO2: Fast formation of crosslinked poly(acrylic acid‐co‐methoxy polyethylene glycol acrylate) microspheres
Authors: Wu Bo , Tan Jianbo , Yang Jianwen , Zeng Zhaohua
Published: August 2011

Photoinitiated precipitation polymerization of acrylic acid (AA) and methoxy polyethylene glycol acrylate (MPEGA) was carried out in liquid carbon dioxide using ethanol as cosolvent and trimethylol propane triacrylate (TMPTA) as crosslinker. Monodisperse crosslinked microspheres were obtained with size polydispersity index as low as 1.027. The particle yield rose sharply after irradiation and reached to 52% at 5 min, then gently increased to 65% at 60 min, suggesting that most of microspheres were produced in the first 5 min of irradiation. The particle number increased incessantly till very late stage of reaction, which could be attributed to the direct generation of stable nuclei from the fast crosslinking polymerization instead of oligomer aggregation. The effect of ethanol content, feeding ratio of monomers and crosslinker concentration on the morphologies, size, and dispersity of microspheres has been investigated. X‐ray photoelectron spectroscopy showed that the microspheres obtained by this procedure were covered with abundant carbon double bonds. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Effects of thiols, lithium chloride, and ethoxylated monomers on the frontal polymerization of a triacrylate
Authors: Viner Veronika , Pojman John A.
Published: August 2011

Thermal frontal polymerization is a process in which a localized reaction propagates through an unstirred system by the coupling of the thermal diffusion and the Arrhenius kinetics of an exothermic polymerization. With multifunctional acrylates, such as trimethylolpropane triacrylate (TMPTA‐n), front temperatures can reach 250 °C, resulting in smoke from unreacted peroxide. Addition of a thiol lowers the front temperature and the front velocity due the copolymerization between the thiol and the acrylate, with some formulations not sufficiently reactive to sustain frontal polymerization. The effects of molecular weight per thiol and functionality of thiol on front temperature and velocity were studied in the frontal copolymerization of TMPTA‐n/trimethylolpropane ethoxylate triacrylate and different thiols. We also investigated the front temperature and velocity for a system containing triacrylate and dodecyl acrylate. Finally, the effects of lithium chloride in the presence of thiol on the front velocity and front temperature were studied. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Synthesis and self‐assembly of diblock copolymers composed of poly(3‐hexylthiophene) and poly(fluorooctyl methacrylate) segments
Authors: Rashid MD. Harun‐Or , Seo Myungeun , Kim Sang Youl , Gal Yeong‐Soon , Park Jong Myung , Kim Eun Young , Lee Won‐Ki , Lim Kwon Taek
Published: August 2011

Regioregular poly(3‐hexylthiophene)‐b‐poly(1H,1H‐dihydro perfluorooctyl methacrylate) (P3HT‐b‐PFOMA) diblock copolymers were synthesized by atom transfer radical polymerization of fluorooctyl methacrylate using bromoester terminated poly(3‐hexylthiophene) macroinitiators in order to investigate their morphological properties. The P3HT macroinitiator was previously prepared by chemical modification of hydroxy terminated P3HT. The block copolymers were well characterized by 1H NMR spectroscopy and gel permeation chromatography. Transmission electron microscopy was used to investigate the nanostructured morphology of the diblock copolymers. The block copolymers are able to undergo microphase separation and self‐assemble into well‐defined and organized nanofibrillar‐like micellar morphology. The development of the morphology of P3HT‐b‐PFOMA block copolymers was investigated after annealing in solvent vapor and also in supercritical CO2. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Electroactuation of solvated triblock copolymer dielectric elastomers: Decoupling the roles of mechanical prestrain and specimen thickness
Authors: Krishnan Arjun S. , Vargantwar Pruthesh H. , Ghosh Tushar K. , Spontak Richard J.
Published: August 2011

Dielectric elastomers (DEs) constitute a class of electroactive polymers that are becoming increasingly important as lightweight and mechanically robust replacements for conventional transducers and actuators. Because of their inherent cycling resilience, they also show tremendous promise as energy‐harvesting media, as well as smart sensors and microfluidic devices. Recent studies have demonstrated that DEs composed of midblock‐solvated triblock copolymers exhibit attractive electromechanical attributes such as giant electroactuation strains at relatively low electric fields at high conversion efficiency. Moreover, the properties of these readily processable systems are highly composition‐tunable, thereby making them ideal candidates for a detailed study of the coupling between initial specimen thickness and mechanical prestrain, which is frequently used to reduce specimen thickness before actuation to lower the voltage required to achieve electroactuation. Conventional wisdom based on the notion of an ideal DE indicates that electroactuation should only depend on pre‐actuation specimen thickness, but we report results that unequivocally indicate a more detailed material/process description is required. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 49: 1569–1582, 2011
The burden of depression in prostate cancer
Authors: Jayadevappa Ravishankar , Malkowicz S. Bruce , Chhatre Sumedha , Johnson Jerry C. , Gallo Joseph J.
Published: August 2011

Objective

We sought to analyze the prevalence and incremental burden of depression among elderly with prostate cancer.

Methods

We adopted a retrospective cohort design using the Surveillance, Epidemiology and End Results‐Medicare linked database between 1995 and 2003. Patients with prostate cancer diagnosed between 1995 and 1998 were identified and followed retrospectively for 1 year pre‐diagnosis and up to 8 years post diagnosis. In this cohort of patients with prostate cancer, depression during treatment phase (1 year after diagnosis of prostate cancer) or in the follow‐up phase was identified using the International Classification of Diseases‐Ninth Revision depression‐related codes. Poisson, general linear (log‐link) and Cox regression models were used to determine the association between depression status during treatment and follow‐up phases and outcomes–health resource utilization, cost and mortality.

Results

Of the 50,147 patients newly diagnosed with prostate cancer, 4285 (8.54%) had a diagnosis of depression. A diagnosis of depression during treatment phase was associated with higher odds of emergency room visits (odds ratio (OR) = 4.45, 95% CI = 4.13, 4.80), hospitalizations (OR = 3.22, CI = 3.08, 3.37), outpatient visits (OR = 1.71, CI = 1.67, 1.75) and excess risk of death over the course of the follow‐up interval (hazard ratio = 2.82, CI = 2.60, 3.06). Health care costs associated with depression remained elevated compared with costs for men without depression, over the course of the follow‐up.

Conclusions

Depression during the treatment phase was associated with significant health resource utilization, costs and mortality among men with prostate cancer. These findings emphasize the need to effectively identify and treat depression in the setting of prostate cancer. Copyright © 2011 John Wiley & Sons, Ltd.
Crystal structure of N‐domain of FKBP22 from Shewanella sp. SIB1: Dimer dissociation by disruption of Val‐Leu knot
Authors: Budiman Cahyo , Angkawidjaja Clement , Motoike Hideki , Koga Yuichi , Takano Kazufumi , Kanaya Shigenori
Published: August 2011

FK506‐binding protein 22 (FKBP22) from the psychrotophic bacterium Shewanella sp. SIB1 (SIB1 FKBP22) is a homodimeric protein with peptidyl prolyl cis‐trans isomerase (PPIase) activity. Each monomer consists of the N‐terminal domain responsible for dimerization and C‐terminal catalytic domain. To reveal interactions at the dimer interface of SIB1 FKBP22, the crystal structure of the N‐domain of SIB1 FKBP22 (SN‐FKBP22, residues 1‐68) was determined at 1.9 Å resolution. SN‐FKBP22 forms a dimer, in which each monomer consists of three helices (α1, α2, and α3N). In the dimer, two monomers have head‐to‐head interactions, in which residues 8–64 of one monomer form tight interface with the corresponding residues of the other. The interface is featured by the presence of a Val‐Leu knot, in which Val37 and Leu41 of one monomer interact with Val41 and Leu37 of the other, respectively. To examine whether SIB1 FKBP22 is dissociated into the monomers by disruption of this knot, the mutant protein V37R/L41R‐FKBP22, in which Val37 and Leu41 of SIB1 FKBP22 are simultaneously replaced by Arg, was constructed and biochemically characterized. This mutant protein was indistinguishable from the SIB1 FKBP22 derivative lacking the N‐domain in oligomeric state, far‐UV CD spectrum, thermal denaturation curve, PPIase activity, and binding ability to a folding intermediate of protein, suggesting that the N‐domain of V37R/L41R‐FKBP22 is disordered. We propose that a Val‐Leu knot at the dimer interface of SIB1 FKBP22 is important for dimerization and dimerization is required for folding of the N‐domain.
Systemic nematicidal activity of fluensulfone against the root‐knot nematode Meloidogyne incognita on pepper
Authors: Oka Yuji , Shuker Shimshon , Tkachi Nadia
Published: August 2011

BACKGROUND: Fluensulfone, a new nematicide of the fluoroalkenyl group, has proved to be very effective in controlling root‐knot nematodes, Meloidogyne spp., by soil application. The systemic activity of this compound against M. incognita on peppers via soil drenching and foliar spray was evaluated.

RESULTS: Root application of fluensulfone via soil drenching showed slight and no nematode control activity when applied 4 and 10 days, respectively, after inoculation. A single foliar spray of peppers with a fluensulfone solution at 3.0 g L−1 prior to inoculation reduced the galling index by 80% and the number of nematode eggs by 73–82% of controls. The reduction in these parameters by fluensulfone was much higher than that obtained with oxamyl or fenamiphos at the same concentration. This activity was also observed when the plants were sprayed 21 days before inoculation. A series of experiments suggested that foliar spray with fluensulfone prior to inoculation reduces nematode invasion. However, foliar spray after inoculation did not inhibit nematode development inside roots.

CONCLUSION: Fluensulfone showed relatively high nematode control activity when sprayed on the foliage before inoculation. Fluensulfone may be used as a foliar application, in addition to soil application, for root‐knot nematode control. Copyright © 2011 Society of Chemical Industry
Developmental studies of transgenic maize expressing Cry1Ab on the African stem borer, Busseola fusca; effects on midgut cellular structure
Authors: George Derick M , Rind F Claire , Bendall Mark W , Taylor Mark A , Gatehouse Angharad MR
Published: August 2011

BACKGROUND: Busseola fusca is a major pest of maize in Africa but unfortunately is difficult to control using chemical insecticides. Insect‐resistant transgenic crops may provide an alternative viable strategy to control this pest.

RESULTS: Recombinant Cry1Ab (1%) reduced larval weight by 60% over the trial period, while larval weight in the control group increased by 25%; no effects on mortality were observed. Insect survival, developmental rate and pupal and adult weight were significantly reduced (P < 0.05) on maize expressing Cry1Ab (MON810) compared with the non‐transformed parental line. These differences were more pronounced with second‐instar larvae than with third‐instar larvae. Leaf area consumed by Bacillus thuringiensis (Bt)‐fed larvae was significantly lower (0.5 cm2 larva−1 day−1) compared with the area consumed by control‐fed insects (3.3 cm2 larva−1 day−1). EM studies revealed that consumption of Bt maize deleteriously affected gut integrity. Effects were observed in columnar cells of the midgut epithelium, with the cytoplasm becoming highly vacuolated; the microvilli were disorganised, the mitochondria were abnormal and there was an increase in the number of lysosomal bodies. The rough endoplasmic reticulum had also become dilated.

CONCLUSION: This study confirms the potential for Bt maize, when used as part of an IPM programme, for control of B. fusca. Copyright © 2011 Society of Chemical Industry
What have the mechanisms of resistance to glyphosate taught us?
Authors: Shaner Dale L , Lindenmeyer Richard Bradley , Ostlie Michael H
Published: August 2011

The intensive use of glyphosate alone to manage weeds has selected populations that are glyphosate resistant. The three mechanisms of glyphosate resistance that have been elucidated are (1) target‐site mutations, (2) gene amplification and (3) altered translocation due to sequestration. What have we learned from the selection of these mechanisms, and how can we apply those lessons to future herbicide‐resistant crops and new mechanisms of action? First, the diversity of glyphosate resistance mechanisms has helped further our understanding of the mechanism of action of glyphosate and advanced our knowledge of plant physiology. Second, the relatively rapid evolution of glyphosate‐resistant weed populations provides further evidence that no herbicide is invulnerable to resistance. Third, as new herbicide‐resistant crops are developed and new mechanisms of action are discovered, the weed science community needs to ensure that we apply the lessons we have learned on resistance management from the experience with glyphosate. Every new weed management system must be evaluated during development for its potential to select for resistance, and stewardship programs should be in place when the new program is introduced. Copyright © 2011 Society of Chemical Industry
The effect of PCBM doping on the electroluminescent performance of organic light‐emitting diodes
Authors: Yan Guang , Zhao Suling , Xu Zheng , Zhang Fujun , Kong Chao , Liu Xiaodong , Gong Wei , Xu Xurong
Published: August 2011

In this paper, the devices with and without electron‐injecting layer (EIL) are fabricated. The effect of [6,6]‐Phenyl C61 butyric acid methyl ester (PCBM) doping in the hole transport layer poly(9‐vinylcarbazole)(PVK) on the electroluminescent performance of organic light‐emitting diodes is investigated by changing the PCBM content from 0 to 3%. A simple and efficient method is presented to improve the hole‐mobility of organic light emitting devices by doping PCBM into PVK which facilitates the hole injection and transport, and leads to a low driving voltage with a high luminance in both series of devices. The higher the PCBM concentration is, the higher the efficiency of the doped devices with EIL over the entire investigated PCBM concentration is. However, in the devices without EIL an appropriate concentration (1%) results in a higher efficiency. The balanced carrier in the doped devices with EIL is better than that in other devices. This leads to the improvement in the luminance and current efficiency.
Luminescence properties of engineered nitrogen vacancy centers in a close surface proximity
Authors: Petráková Vladimíra , Nesládek Miloš , Taylor Andrew , Fendrych František , Cígler Petr , Ledvina Miroslav , Vacík Jiří , Štursa Jan , Kučka Jan
Published: August 2011

Fluorescent cellular biomarkers play an essential role in biology and medicine for in vitro and in vivo imaging in living cells. Recently, we have demonstrated that photoluminescence (PL) can be driven chemically by changing the occupation of NV− and NV0 states by H‐ or O‐termination. In the presented work we study, how the luminescence of NV centers at controlled depth from the surface changes upon different surface treatment. We compare NV luminescence of hydrogen (H) and oxygen (O) terminated surfaces in single crystal diamond (SCD) containing shallow‐implanted NV centers (3–10 nm) with similarly treated nanodiamond particles (ND) of various size distributions. The H‐termination leads to reduction of NV− related luminescence in both, ND and SCD. The effect is much stronger in ND in comparison with SCD. We mathematically model both situations and discuss parameters influencing the effect, including implantation energy and different contents of nitrogen in the diamond crystal lattice.
Residual strain around grown‐in defects in CVD diamond single crystals: A 2D and 3D Raman imaging study
Authors: Crisci Alexandre , Baillet Francis , Mermoux Michel , Bogdan Ganna , Nesládek Milos , Haenen Ken
Published: August 2011

Single crystal diamond grown by chemical vapor deposition (CVD) sometimes exhibits strain induced birefringence arising from bundles of dislocations lying almost parallel to the [001] growth axis. Some of these specific birefringence patterns consist of four or eight bright petals, depending of the observation conditions. The present study reports results of a Raman imaging investigation of such defects. A specific homoepitaxial film still attached to its substrate, which contained a few of these defects, has been studied. Point by point mapping was used to visualize structural features at certain depths inside the crystals to produce either 2D or 3D tomographic images. These defects were easily detected in the Raman images, with specific line intensity, frequency, and width contrasts. Systematically, dislocations were found to nucleate at the epitaxial interface. In each case, dislocation nucleation was caused by particulate (carbon) contamination. High compressive strain was evidenced in the vicinity of the carbon particles, which was found to decrease in magnitude as the film grew in thickness. Dislocation walls were revealed by the width images. In most cases, 4‐arm patterns lying along 〈110〉 directions were evidenced, but sometimes, more complex features were observed. Finally, polarized Raman measurements gave intensity contrasts that were rather similar to those seen in the birefringence images.
Influence of laser energy on the crystallization of Ge2Sb2Te5 thin film prepared by pulsed laser deposition
Authors: Hu D. Z. , Pan F. M. , Lu X. M. , Zhu J. S.
Published: August 2011

Four Ge2Sb2Te5 thin films were prepared by pulsed laser deposition (PLD) at 58, 100, 140, and 190 mJ/pulse laser energy, respectively. The influence of laser energy on the crystallization of Ge2Sb2Te5 was investigated. The result shows that laser energy has evident effect on the crystallization of Ge2Sb2Te5, including crystallization temperature, incubation time, Avrami coefficient, and grain size. The sample prepared at 140 mJ/pulse laser energy has the lowest crystallization temperature, the shortest incubation time, the largest Avrami coefficient, and the maximum mean grain size. The result of X‐ray diffraction indicates that there are impurity‐phase peaks in the pattern of the sample prepared at 190 mJ/pulse laser energy. A possible reason was given for these phenomenons.
Piezoelectric MEMS generator based on the bulk PZT/silicon wafer bonding technique
Authors: Tang Gang , Liu Jing‐quan , Liu He‐sheng , Li Yi‐gui , Yang Chun‐sheng , He Dan‐nong , DzungDao Viet , Tanaka Katsuhiko , Sugiyama Susumu
Published: August 2011

A MEMS‐based piezoelectric energy harvester was fabricated by bonding a piezoelectric ceramic Pb (Zr,Ti)O3 (PZT) plate to silicon wafer. The generator structure of a trapezoidal shape composite cantilever beam with nickel metal mass was designed. The novel fabrication techniques to obtain PZT thick film with excellent piezoelectric properties, including a low‐temperature PZT—Si bonding using epoxy resin as the intermediate adhesive layer and thinning of the bulk PZT ceramics by mechanical lapping and polishing method, were carried out. A piezoelectric MEMS power generator array was successfully fabricated and the measurement results for a microgenerator with typical dimension were also presented. The test result shows that this novel technique has great potential to fabricate high‐performance piezoelectric MEMS energy harvester.
Comparison of boron diffusion in silicon during shallow p+/n junction formation by non‐melt excimer and green laser annealing
Authors: Aid Siti Rahmah , Matsumoto Satoru , Fuse Genshu , Sakuragi Susumu
Published: August 2011

The combination of Ge pre‐amorphization implantation, low‐energy boron implantation, and non‐melt laser annealing is a promising method for forming ultrashallow p+/n junctions in silicon. In this study, shallow p+/n junctions were formed by non‐melt annealing implanted samples using a green laser (visible laser). The dopant diffusion, activation, and recrystallization of an amorphous silicon layer were compared with those obtained in our previous study in which non‐melt annealing was performed using a KrF excimer laser (UV laser). The experimental results reveal that only slight diffusion of boron in the tail region occurred in green‐laser‐annealed samples. In contrast, remarkable boron diffusion occurred in KrF‐laser‐annealed samples for very short annealing times. Recrystallization of the amorphous silicon layer was slower in green‐laser‐annealed samples than in KrF‐laser‐annealed samples. We consider the penetration depth and the pulse duration are important factors that may affect boron diffusion.
Thermal annealing behavior of fluorescence of Pr3+‐doped lead tungstate single crystal
Authors: Xiong F. B. , Huang Y. D. , Zhu W. Z.
Published: August 2011

The effects of thermal annealing treatment on the spectroscopic properties of Pr3+‐doped PbWO4 crystals were discussed in detail. The polarized absorption spectra, polarized fluorescence spectra, and fluorescence decay curves of main emission manifolds of the as‐grown and annealed Pr3+‐doped PbWO4 crystals were measured at room temperature and analyzed. Thermal annealing treatment can diminish most defect centers related to oxygen vacancies and thermal stress. The results demonstrate that thermal annealing treatment can exert a distinct influence on the spectroscopic properties of Pr3+: PbWO4 crystals as promising phosphors and laser materials.
Optical properties of Dy3+ ions in La3Ga5SiO14 crystal
Authors: Wang Zengmei , Sun Wei
Published: August 2011

The absorption and fluorescence spectra of Dy3+‐doped La3Ga5SiO14 (LGS) crystals were measured and analyzed according to the Judd–Ofelt theory. When applied, the following spectral parameters have been obtained: phenomenological intensity parameters Ωt, Ω2 = 2.64 × 10−20 cm2, Ω4 = 1.39 × 10−20 cm2 and Ω6 = 0.63 × 10−20 cm2. These intensity parameters were used to predict radiative properties that included electronic line strengths, radiative transition probabilities AJ″,J′, the radiative lifetime τrad, the fluorescence branching ratios βJ″,J′. The value of absorption section σabs(λ), and the integrated emission cross sections σem(λ) were also calculated. The emission transition 4F9/2 → 6H13/2 provides potential applications of LGS:Dy crystal as a laser material.
Transparent indium tin oxide as inkjet‐printed thin film electrodes for organic field‐effect transistors
Authors: Hoffmann Rudolf C. , Dilfer Stefan , Schneider Jörg J.
Published: August 2011

Indium tin oxide (ITO) thin films can be manufactured by spincoating or inkjet printing of a solution containing indium and tin oximato precursor complexes. After sintering at 600 °C and annealing in reducing atmosphere, resistivities as low as 2.34 × 10−3 Ω cm were observed, with a transparency of more than 95% in the visible region. The employment of an amorphous hafnia interlayer on top of a silicon dioxide dielectric was found to improve the wetting behaviour significantly. Thus source–drain structures could be obtained by inkjet‐printing and field‐effect transistors were constructed using poly(3‐hexylthiophene) (P3HT) as organic semiconductor.

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Evaluation of the statistical cloud scheme in the ECHAM5 model using satellite data
Authors: Weber T. , Quaas J. , Räisänen P.
Published: August 2011

An evaluation of a statistical cloud scheme taking into account subgrid‐scale variability for water vapour and cloud condensate in the ECHAM5 general circulation model of the atmosphere is presented. Three‐dimensional modelled water vapour, cloud liquid water and cloud ice were distributed stochastically into subcolumns of each grid box and vertically integrated to total water path (TWP). Thus the lower atmosphere is emphasized in the evaluation of TWP due to its exponential profile. The edited model dataset was compared with the globally analyzed distribution of TWP measured by the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite instrument. The results show that the mean TWP and mean cloud cover are on average relatively well simulated. However, large deficiencies are revealed by the evaluation of both variance and skewness of the probability density function (PDF). Systematically negative deviations of variance are found for almost all regions of the globe. Skewness of the TWP is overestimated in the Tropics and underestimated at high latitudes. Moreover, sensitivity experiments were performed to reveal the deficiencies in the parametrization leading to the observed deviations of variance and skewness of TWP. It was found that the positive bias in skewness in the Tropics can be reduced by modifying the influence of convection on the PDF. Copyright © 2011 Royal Meteorological Society
Performance of different forecast systems in an exceptional storm in the Western Mediterranean Sea
Authors: Bertotti L. , Bidlot J.‐R. , Bunney C. , Cavaleri L. , Delli Passeri L. , Gomez M. , Lefèvre J.‐M. , Paccagnella T. , Torrisi L. , Valentini A. , Vocino A.
Published: August 2011

We consider an exceptional storm—‘Klaus’ (January 2009)—its evolution on the Western Mediterranean Sea, and how the associated wind and wave conditions were modelled by seven of the major systems presently operational in this area. We intercompare the model results and then verify them and the related model ensemble versus the available measured data.

Working with short‐term forecasts (24 h) only, as expected, each model correctly anticipates the incoming of an exceptional storm. However, even at such limited range, we have found substantial differences among the results of the different models. The differences concern the time the storm should have entered the Western Mediterranean Sea, the peak values of wind speed and significant wave height, the general distribution of the fields, and the locations where the maxima were achieved.

We have compared the model results versus the available measured data, wind from scatterometer, waves from altimeter, plus a few buoy data. We have found some inconsistencies in the results, model wind data being on average larger than the measured one, while the opposite was true for wave heights. However, the limited amount of data available and its different times and positions, at and off the centre of the storm, impede the drawing of any definite conclusion in this respect.

On the whole we feel that our results, although related to a single storm, cast doubts on the reliability of a single forecast system to provide sufficiently reliable and accurate forecasts in case of an incoming exceptional storm. The results, both for wind and waves, have improved using an ensemble of the seven considered models. This suggests that there is no relevant systematic error in the used models except, as possibly suggested by our results, in the case of wave generation under very strong wind and very young sea conditions. Copyright © 2011 Royal Meteorological Society and British Crown Copyright, the Met Office
Initiation of daytime local convection in a semi‐arid region analysed with high‐resolution simulations and AMMA observations
Authors: Couvreux F. , Rio C. , Guichard F. , Lothon M. , Canut G. , Bouniol D. , Gounou A.
Published: August 2011

A modelling case study designed from observations from the African Monsoon Multidisciplinary Analysis (AMMA) is presented and discussed. It aims at investigating the issue of initiation of convection in a semi‐arid environment. This case corresponds to the development of local daytime convection mainly controlled by boundary layer characteristics rather than by atmospheric synoptic scales. A high‐resolution three‐dimensional simulation is presented and extensively evaluated against the numerous observations available for 10 July 2006 from the AMMA campaign. The simulation, run over a domain of 100 × 100 km, is able to represent main boundary layer structures and processes leading to deep convection initiation as well as the formation of density currents. Sensitivity tests point to the key role of the sensible heat flux, the humidity of low to mid levels, the lapse rate at low levels and of a mesoscale ascent to initiate deep convection in those semi‐arid conditions, while evaporation of precipitation is shown to play a minor role. This study thus provides a case to investigate the ability of parametrizations to handle the initiation of convection in a semi‐arid environment. Copyright © 2011 Royal Meteorological Society
Robust decentralized adaptive fuzzy control for a class of large‐scale MIMO nonlinear systems
Authors: Huang Yi‐Shao
Published: August 2011

In this paper, a novel decentralized robust adaptive fuzzy control scheme is proposed for a class of large‐scale multiple‐input multiple‐output uncertain nonlinear systems. By virtue of fuzzy logic systems and the regularized inverse matrix, the decentralized robust indirect adaptive fuzzy controller is developed such that the controller singularity problem is addressed under a united design framework; no a priori knowledge of the bounds on lumped uncertainties are being required. The closed‐loop large‐scale system is proved to be asymptotically stable. Simulation results confirmed the validity of the approach presented. Copyright © 2011 John Wiley & Sons, Ltd.
Nonlinear adaptive stabilizing control of an anaerobic digestion model with unknown kinetics
Authors: Dimitrova Neli , Krastanov Mikhail
Published: August 2011

In this paper, we consider a nonlinear model of a biological wastewater treatment process, on the basis of two microbial populations and two substrates. The model, described by a four‐dimensional dynamic system, is known to be practically validated and reliable. We propose a feedback control law for asymptotic stabilization of the closed‐loop system towards a previously chosen operating point. A numerical extremum seeking algorithm is applied to stabilize the dynamics towards an equilibrium point with maximal methane flow rate. Computer simulations are reported to illustrate the theoretical results. Copyright © 2011 John Wiley & Sons, Ltd.
MicroMAIS: executing and orchestrating Web services on constrained mobile devices
Authors: Plebani Pierluigi , Cappiello Cinzia , Comuzzi Marco , Pernici Barbara , Yadav Sandeep
Published: August 2011

Mobile devices with their more and more powerful resources allow the development of mobile information systems in which services are not only provided by traditional systems but also autonomously executed and controlled in the mobile devices themselves. Services distributed on autonomous mobile devices allow both the development of cooperative applications without a back‐end infrastructure and the development of applications blending distributed and centralized services. In this paper, we propose MicroMAIS: an integrated platform for supporting the execution of Web service‐based applications natively on a mobile device. The MicroMAIS platform is composed of mAS and μ‐BPEL. The former allows the execution of a single Web service, whereas the latter permits the orchestration of several Web services according to the WS‐BPEL standard. Copyright © 2011 John Wiley & Sons, Ltd.
HYPE: Hybrid modelling by composition of flows
Authors: Galpin Vashti , Bortolussi Luca , Hillston Jane
Published: August 2011

Hybrid systems are manifest in both the natural and the engineered world, and their complex nature, mixing discrete control and continuous evolution, make it difficult to predict their behaviour. In recent years several process algebras for modelling hybrid systems have appeared in the literature, aimed at addressing this problem. These all assume that continuous variables in the system are modelled monolithically, often with differential equations embedded explicitly in the syntax of the process algebra expression. In HYPE an alternative approach is taken which offers finer-grained modelling with each flow or influence affecting a variable modelled separately. The overall behaviour then emerges as the composition of flows. In this paper we give a detailed account of the HYPE process algebra, its semantics, and its use for verification of systems. We establish both syntactic conditions (well-definedness) and operational restrictions (well-behavedness) to ensure reasonable behaviour in HYPE models. Furthermore we consider how the equivalence relation defined for HYPE relates to other relations previously proposed in the literature, demonstrating that our fine-grained approach leads to a more discriminating notion of equivalence. We present the HYPE model of a standard hybrid system example, both establishing that our approach can reproduce the previously obtained results and demonstrating how our compositional approach supports variations of the problem in a straightforward and flexible way.
“Changing the Text”: Modeling Council Capacity to Produce Institutionalized Change
Authors: Allen Nicole E. , Javdani Shabnam , Lehrner Amy L. , Walden Angela L.
Published: August 2011

Collaboration is a ubiquitous approach to change, but is notoriously difficult and not definitively linked to desirable outcomes. Not surprisingly, the collaboration literature is replete with numerous facilitators and barriers to collaborative efforts. The current study aimed to develop a parsimonious model of factors influencing the success of collaborative efforts both internal and external to the council, including, (a) features of the council environment, (b) intermediate outcomes including the empowerment of members in the council context and the degree to which councils have generated social capital and (c) the extent to which collaborative efforts are occurring in a community context supportive of their aims. In particular, this study examines whether these factors affect the extent to which councils are positioned to achieve institutionalized change, or changes “in the text” that govern front line providers’ (e.g., police, advocates) practices in the community response to intimate partner violence. Results suggest that perceived member empowerment, generation of social capital, and supportive community context are the most important predictors of the extent to which councils foster shifts in institutionalized change. Features of the council environment are only indirectly related to the degree to which institutionalized change is ultimately fostered as mediated by the generation of social capital. This suggests that the ability of members to act as change agents and the extent to which those in power support council efforts figure more prominently to facilitate or constrain council efforts than council functioning itself.
Barriers to and Motivations for Physician Referral of Patients to Cancer Genetics Clinics
Authors: Prochniak Carrie F. , Martin Lisa J. , Miller Erin M. , Knapke Sara C.
Published: August 2011

Although it is well known that under‐referral of colon cancer patients to cancer genetics clinics is a chronic problem, no study has yet examined why physicians may be ordering testing independently rather than referring patients to cancer genetics clinics. The current study explored variables which may impact a physician's preference for ordering testing independently or referring patients to outside cancer genetics experts. An online questionnaire, distributed to the membership of the American College of Gastroenterology and the American Society of Colorectal Surgeons, yielded responses from 298 physicians. Motivations to refer to cancer genetics clinics rather than order testing independently included fear of genetic discrimination and a belief that patients benefit from genetic counseling about the risks, benefits and consequences of testing. These results suggest that in order to increase referrals, genetic counselors must educate physicians about the unique benefits patients receive from participating in genetic counseling.
Physicochemical Properties of Soy Protein Adhesives Obtained by In Situ Sodium Bisulfite Modification During Acid Precipitation
Authors: Qi Guangyan , Li Ningbo , Wang Donghai , Sun Xiuzhi Susan
Published: August 2011

Successful industrial applications of soy protein adhesives require high adhesion strength and low viscosity at high solid protein concentration. This study examined the effects of β‐conglycinin (7S) and glycinin (11S) ratios on the physicochemical properties of soy protein adhesives. Soy protein adhesives with various 7S/11S ratios were extracted from soy flour slurry modified with sodium bisulfite using the acid precipitation method, which is based on the different solubilities of 7S and 11S globulins. Seven glycinin‐rich soy protein fractions and six β‐conglycinin‐rich soy protein fractions were obtained. The external morphology of the samples changed from the viscous cohesive phase to the clay‐like phase without cohesiveness. The viscous cohesive samples had good flowability and good water resistance with a wet adhesion strength of 2.0–2.8 MPa. They were stable for up to several months without phase separation at room temperature. Based on the results, we suggest that proper protein–protein interaction, hydration capacity (glycinin‐rich soy protein fractions), and certain ratios of 7S and 11S (β‐conglycinin rich soy protein fractions) in the soy protein sample are crucial to continuous protein phase formation. Hydrogen bonding, electrostatic forces, and hydrophobic interactions are involved in maintaining the protein viscous cohesive network, whereas disulfide bonds do not exert significant effects. This study describes a new way to investigate viscous cohesive soy protein systems with high solid protein content, thus alleviating the disadvantages of traditional methods for studying the adhesive properties of soy protein isolates, which tend to have poor water resistance, low solid contents, and short storage life.
Product Selectivity and Optimization of Lipase‐Catalyzed 1,3‐Propylene Glycol Esters by Mixture Design and RSM
Authors: Chen Hsiao‐Ching , Kuo Chia‐Hung , Tsai Wei‐Chuan , Chung Yi‐Lin , Chiang Wen‐Dee , Chang Chieh‐Ming J. , Liu Yung‐Chuan , Shieh Chwen‐Jen
Published: August 2011

Propylene glycol mono‐ (PGM) and diesters (PGD) are widely used as emulsifiers in food and pharmaceutical industry. Solvent engineering was applied to determine the optimum solvent mixtures for the lipase‐catalyzed synthesis of 1,3‐PGM and 1,3‐PGD. After 24 h reaction, the results showed that the molar production of 1,3‐PGM was 75% under pure 2M2B (2‐methyl‐2‐butanol) system, whereas 1,3‐PGD was preferred to produce in binary mixture system (n‐hexane: octane 1:1) with 55% of molar production. Furthermore, the reaction parameters that affect esterification of 1,3‐PGD using oleic acid as acyl donor in optimum cosolvent environment were evaluated by response surface methodology (RSM). The reaction temperature and reaction time were the most important parameters. Based on a ridge max analysis, the optimum conditions for 1,3‐PGD synthesis were predicted to consist of a reaction time of 40.6 min, a temperature of 59 °C, an enzyme amount of 70.4%, a substrate molar ratio (1,3‐propylene glycol/oleic acid) of 1:2.7 and an enzyme pretreatment pH of 6.4 on percentage of molar production of 1,3‐PGD of 43.3 ± 4.2%.