bluuebunny/crossref_metadata_2025 huggingface dataset:
Correction of chloride threshold concentration and time‐to‐corrosion due to reinforcement presence
Authors: Yu H. , Hartt W. H.
Published: March 2010

Reinforcement presence affecting corrosion threshold concentration, Ct, determination and time‐to‐corrosion, Ti, has been investigated. Elevated Ct and decreased Ti due to reinforcement physical obstruction on the path of chloride ingression into concrete has been examined with finite element modeling. Results indicated that reinforcement with larger size, better corrosion resistance, less cover thickness, or a more flat leading edge causes more pronounced Ti reduction. Experimental results exposed aggregate content discrepancy within reinforced bar vicinity zone. According to this finding, a multi‐shell chloride diffusion model, in which specific chloride ion diffusivity in each shell surrounding bar presents, is proposed. The Ct results of proposed model are discussed along with those acquired from traditional one‐dimensional model, in which chloride diffusion follows Fick's second law without considering reinforcement presence, and two‐dimensional model with the effect of reinforcement physical obstruction regarded.
A New Polymeric pH Sensor Based on Photophysical Property of Gold Nanoparticle and pH Sensitivity of Poly(sulfadimethoxine methacrylate)
Authors: Hong Seok Hwan , Hong Sung Woo , Jo Won Ho
Published: March 2010

A new pH sensor, which consists of a fluorophore and gold nanoparticle (AuNP) attached to each chain end of a pH‐sensitive polysulfonamide, respectively, is synthesized, and its pH sensitivity is investigated in terms of the fluorescent quenching efficiency of AuNP. Since the pH‐sensitive polymeric linker exhibits a pH‐induced coil–globule transition that is rapid enough to show a typical two‐state transition, it shows drastic on‐and‐off quenching efficiency with variation of pH due to the change in the distance between fluorophore and AuNP. This AuNP‐based pH sensor exhibits a well‐defined on‐and‐off behavior at a small change in pH, and therefore can be used for an ideal alarm‐type sensor.

magnified image
Preparation of Polyethylene/Montmorillonite Nanocomposites Through in situ Polymerization Using a Montmorillonite‐Supported Nickel Diimine Catalyst
Authors: Choi Yiyoung , Shin Sang Young A. , Soares João B. P.
Published: March 2010

PE/MMT nanocomposites were prepared through in situ polymerization using a nickel diimine catalyst supported on commercially available MMTs such as Cloisite Na+, Cloisite 30B, and Cloisite 93A. XRD patterns revealed that the layers of Cloisite 30B and Cloisite 93A were intercalated after treatment with TMA and the nickel diimine complex. The catalyst supported on Cloisite 30B showed high yields without additional activator and produced nanocomposites with high melting and decomposition temperatures. The thermal properties and crystallinity could be controlled by varying the clay content in the nanocomposite. The morphologies of the resulting particles and the dispersion of the MMT layers in the polymer matrix were characterized by SEM and TEM.

magnified image
(Co‐)Polyesters Derived from Isosorbide and 1,4‐Cyclohexane Dicarboxylic Acid and Succinic Acid
Authors: Garaleh Mazen , Yashiro Takao , Kricheldorf Hans R. , Simon Peter , Chatti Saber
Published: March 2010

The homopolyester of isosorbide and cis–trans 1,4‐cyclohexane dicarboxylic acid (CHDA) was prepared by three different methods, but only polycondensation of isosorbide and CHDA dichloride yielded a satisfactory molecular weight (corrected $\overline M _{\rm n} $ = 11 000 Da). For the best sample the MALDI‐TOF mass spectrum revealed a high content of cycles. The homopolyester of CHDA and isomannide or isoidide was prepared analogously. For the homopolyesters of CHDA high glass transition temperatures were found (Tg = 146 °C for isosorbide, 133 °C for isomannide, and 115 °C for isoidide), whereas the polyester of isosorbide and succinic acid (SuA) has a Tg around 77 °C. Copolyester of isosorbide and various molar ratios of CHDA and SuA were prepared by two different methods, but only rather low molecular weights were obtained. SEC measurements with and without “universal calibration” revealed that the normal calibration with polystyrene overestimates the real molecular weights by 30–45%.

magnified image
Monodisperse Polystyrene Nanospheres with Ultrahigh Surface Area: Application for Hydrogen Storage
Authors: Liu Qingquan
Published: March 2010

Monodisperse hyper‐crosslinked polystyrene nanospheres with ultrahigh specific surface area were successfully prepared by emulsifier‐free miniemulsion polymerization and post‐crosslinking. The specific surface area and the total pore volume of hyper‐crosslinked nanospheres were increased with increasing the concentration of vinybenzyl chloride in monomer mixture. The hyper‐crosslinked nanospheres exhibited excellent swelling capacity in thermodynamically good and poor solvent. Furthermore, the nanospheres with specific surface area of 1 223 m2 · g−1 adsorbed 2.13 wt.‐% hydrogen at 163 K/1.5 MPa. Overall, the present study provided a simple method to prepare monodisperse microporous hyper‐crosslinked polymer nanospheres.

magnified image
Rheology and Physical Characteristics of Synthetic Biodegradable Aliphatic Polymer Blends Dispersed with MWNTs
Authors: Ko Seung Woo , Gupta Rahul K. , Bhattacharya Sati N. , Choi Hyoung Jin
Published: March 2010

PLA/PBAT blends and PLA/PBAT/MWNT nanocomposite systems were prepared via a melt mixing process to examine their thermal and rheological properties. To compare the polymer blend/MWNT nanocomposite with a pure polymer/MWNT nanocomposite, PLA/MWNT, PBAT/MWNT, and PLA/PBAT/MWNT nanocomposite systems were prepared. TEM and SEM were used to observe that one phase has better affinity with the MWNT, while the MWNT was found to increase both the thermal properties of the PLA/PBAT blends and rheological properties of the PLA/PBAT/MWNT nanocomposite with distinct shear‐thinning behavior due to the addition of the MWNT. An increase in the storage (G′) and loss (G″) moduli for the PLA/PBT/MWNT nanocomposite was also observed.

magnified image
Monte Carlo Simulations of Metallo‐Supramolecular Micelles
Authors: Wang Shihu , Dormidontova Elena E.
Published: March 2010

Using Monte Carlo simulations we show that the equilibrium properties of metallo‐supramolecular micelles are determined by the competition of 2:1 and 1:1 metal–ligand complexation in the bulk and on the surface as well as steric interactions between the neighboring corona blocks attached to the surface. We predict that by increasing the association energy for the second metal–ligand bond, or decreasing the corona block length one can achieve a larger core surface coverage for metallo‐supramolecular micelles. Compared to covalently bonded block copolymer micelles, we show that metallo‐supramolecular micelles have smaller monomer and end group density, especially in the vicinity of the core, which may lead to experimentally observed aggregation.

magnified image
Vitamin E supplementation and mammalian lifespan
Authors: Banks Ruth , Speakman John R. , Selman Colin
Published: March 2010

Vitamin E refers to a family of several compounds that possess a similar chemical structure comprising a chromanol ring with a 16‐carbon side chain. The degree of saturation of the side chain, and positions and nature of methyl groups designate the compounds as tocopherols or tocotrienols. Vitamin E compounds have antioxidant properties due to a hydroxyl group on the chromanol ring. Recently, it has been suggested that vitamin E may also regulate signal transduction and gene expression. We previously reported that lifelong dietary vitamin E (α‐tocopherol) supplementation significantly increased median lifespan in C57BL/6 mice by 15%. This lifespan extension appeared to be independent of any antioxidant effect. Employing a transcriptional approach, we suggest that this increase in lifespan may reflect an anti‐cancer effect via induction of the P21 signalling pathway, since cancer is the major cause of death in small rodents. We suggest that the role of this pathway in life span extension following supplementation of vitamin E now requires further investigation.
Structure and stereochemistry of novel ecdysteroids from the roots of Serratula wolffii
Authors: Takács Mária , Simon András , Liktor‐Busa Erika , Báthori Mária , Zsila Ferenc , Bikádi Zsolt , Horváth Péter , Veress Gábor , Gergely András , Tóth Gábor
Published: March 2010

Three new natural ecdysteroids viz. 22‐dehydro‐20‐deoxy‐ajugasterone C (1), 1‐hydroxy‐22‐deoxy‐20,21‐didehydro‐ecdysone (2) and 22‐deoxy‐20,21‐didehydro‐ecdysone (3) were isolated from the methanol extract of the roots of Serratula wolffii. The structures of compounds 1–3 were established by various spectroscopic techniques, including one‐ and two‐dimensional NMR, circular dichroism and mass spectroscopic methods. Copyright © 2010 John Wiley & Sons, Ltd.
Beyond taxonomy
Authors: Helm Scott T. , Andersson Fredrik O.
Published: March 2010

Much of the considerable confusion about the definition of social entrepreneurship in academic literature stems from a lack of empirical research on the subject. This article advances social entrepreneurship research beyond conceptualization discussions by developing and validating an instrument that quantifies the incidence of nonprofit entrepreneurial behavior. Information from 145 Kansas City Metropolitan Area nonprofit organizations was collected to validate the underlying constructs represented in the instrument. Behavior differences were depicted between entrepreneurial and nonentrepreneurial nonprofits. Using principal component factor analysis, the research illustrates social entrepreneurship as a unique nonprofit behavior that occurs at the intersection of innovation, proactiveness, and risk taking.
Green matters?
Authors: Dart Raymond , Hill Stephen D.
Published: March 2010

Although the environmental impact of nonprofit organizations is likely significant, those in the sector seem to have largely ignored this fact. We examine a model of environmental performance for corporations and consider its relevance to nonprofit organizations. Our analysis suggests that motivators of environmental performance in nonprofit organizations remain minor, and that countervailing barriers to green behavior by nonprofits remain more significant than those faced by businesses.
Piloting external peer review as a model for performance improvement in third‐sector organizations
Authors: Purcell Martin E. , Hawtin Murray
Published: March 2010

Peer review is used widely in the United Kingdom as a means of engendering performance improvement in the statutory sector and is being used increasingly to address the needs of specific networks of third‐sector organizations. The project on which this article is based sought to develop a peer review model that could be applied by any third‐sector organization to improve performance. The article reviews existing initiatives and details elements of models that the research sought to replicate. It describes the approach taken to develop the model, including details of three pilots, and summarizes the associated guidance. Finally, it incorporates a commentary on some of the opportunities and challenges presented by the model as a means of securing continued performance improvement by third‐sector organizations.
Ectopic expression of the microtubule‐dependent motor protein Eg5 promotes pancreatic tumourigenesis
Authors: Liu Min , Wang Xiuchao , Yang Yunfan , Li Dengwen , Ren He , Zhu Qigang , Chen Qiang , Han Shuyong , Hao Jihui , Zhou Jun
Published: March 2010

Pancreatic cancer is a highly aggressive disease with a grim prognosis, due to its late diagnosis, propensity to rapidly metastasize, and resistance to therapy. The molecular events underlying this remain poorly defined. Here we report the overexpression and gene copy number gain of the microtubule‐dependent motor protein Eg5 in human pancreatic cancer samples. We also show that Eg5 expression correlates with clinicopathological parameters of pancreatic cancer and promotes anchorage‐independent cell growth and tumour formation in mice. In addition, Eg5 is up‐regulated in pancreatic cancer cell lines and enhances cell proliferation in an ATPase activity‐dependent manner. Our data further reveal that Eg5 overexpression causes the formation of multipolar spindles and multinucleation and induces the accumulation of polyploid cells. These findings demonstrate a role for Eg5 in pancreatic tumourigenesis and indicate a potential for targeting Eg5 in pancreatic cancer treatment. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Clinical presentation and outcome of epidemic Kaposi sarcoma in Ugandan children
Authors: Gantt Soren , Kakuru Abel , Wald Anna , Walusansa Victoria , Corey Lawrence , Casper Corey , Orem Jackson
Published: March 2010

Background

Kaposi sarcoma (KS) is one of the most common pediatric cancers in sub‐Saharan Africa. Few data are available about the clinical presentation or response to treatment of children with epidemic (HIV‐associated) KS.

Methods

Medical records of all children with KS and HIV infection referred to the Uganda Cancer Institute in Kampala, Uganda from October 2004 to June 2007 were reviewed. Charts were abstracted for age, sex, location of KS lesions at presentation, biopsy results, CD4 T‐cell count and percentage, and KS treatment and outcome.

Results

Seventy‐three children with epidemic KS were identified, 37 males and 36 females. The median age was 10.1 years (range 2–18). KS presented with lymph node (LN) involvement in 60% of cases. The median absolute and percentage CD4 T‐cells at presentation were 210 cells/µl and 7.4%, respectively. Those children with lymphadenopathic KS were younger (mean difference 3.7 years; P = 0.01) and had higher CD4 T‐cell counts (mean difference 242 cells/µl; P = 0.03) than those without LN involvement. Of 32 patients for whom outcome data were available, a complete response to chemotherapy and/or antiretroviral therapy was documented in 20 (62.5%) patients.

Conclusions

In comparison to cutaneous involvement, LN involvement of epidemic KS occurs at younger ages and at higher CD4 levels. This clinical presentation may reflect recent infection with human herpesvirus 8 followed by a rapid progression to malignancy. Favorable response to treatment was observed in the majority of cases, but prospective studies are needed to determine optimal management. Pediatr Blood Cancer 2010;54:670–674. © 2010 Wiley‐Liss, Inc.
Synthesis of poly(cyclohexene oxide)‐block‐polystyrene by combination of radical‐promoted cationic polymerization, atom transfer radical polymerization and click chemistry
Authors: Degirmenci Mustafa , Genli Nasrettin
Published: March 2010

The combination of radical‐promoted cationic polymerization, atom transfer radical polymerization (ATRP) and click chemistry was employed for the efficient preparation of poly(cyclohexene oxide)‐block‐polystyrene (PCHO‐b‐PSt). Alkyne end‐functionalized poly(cyclohexene oxide) (PCHO‐alkyne) was prepared by radical‐promoted cationic polymerization of cyclohexene oxide monomer in the presence of 1,2‐diphenyl‐2‐(2‐propynyloxy)‐1‐ethanone (B‐alkyne) and an onium salt, namely 1‐ethoxy‐2‐methylpyridinium hexafluorophosphate, as the initiating system. The B‐alkyne compound was synthesized using benzoin photoinitiator and propargyl bromide. Well‐defined bromine‐terminated polystyrene (PSt‐Br) was prepared by ATRP using 2‐oxo‐1,2‐diphenylethyl‐2‐bromopropanoate as initiator. Subsequently, the bromine chain end of PSt‐Br was converted to an azide group to obtain PSt‐N3 by a simple nucleophilic substitution reaction. Then the coupling reaction between the azide end group in PSt‐N3 and PCHO‐alkyne was performed with Cu(I) catalysis in order to obtain the PCHO‐b‐PSt block copolymer. The structures of all polymers were determined. Copyright © 2010 Society of Chemical Industry
Reinforcing thermosets with crystallizable solvents
Authors: Yordem Onur Sinan , Lesser Alan J.
Published: March 2010

This study demonstrates an approach to generate reinforcement in thermosetting polymers through crystal growth of crystallizable solvents. Emphasis is to identify the reaction conditions, which lead to suitable reinforcement in selected compounds. Crystallization behavior and miscibility of dimethylsulfone (DMS) in diglycidylether of bisphenol‐A epoxy monomer was investigated. Small angle laser scattering and optical microscopy were utilized to monitor phase separation and crystallization of DMS at different isothermal conditions during the cure process. It is shown that DMS crystals grow anisotropically to form faceted geometries and demonstrate possible structures to anchor into the epoxy matrix. The growth mechanism and the agility of crystals are shown to be affected by the cure reaction as well as depth of supercooling. A completely cured sample with 15 wt % DMS shows a broad map of rich morphologies from nanoscale particles to uniformly distributed macroscale, discontinuous fiber‐like crystals generated only by altering the curing conditions. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 840–849, 2010
Polylactide/exfoliated graphite nanocomposites with enhanced thermal stability, mechanical modulus, and electrical conductivity
Authors: Kim Il‐Hwan , Jeong Young Gyu
Published: March 2010

We have prepared a series of polylactide/exfoliated graphite (PLA/EG) nanocomposites by melt‐compounding and investigated their morphology, structures, thermal stability, mechanical, and electrical properties. For PLA/EG nanocomposites, EG was prepared by the acid treatment and following rapid thermal expansion of micron‐sized crystalline natural graphite (NG), and it was characterized to be composed of disordered graphite nanoplatelets. It was revealed that graphite nanoplatelets of PLA/EG nanocomposites were dispersed homogeneously in the PLA matrix without forming the crystalline aggregates, unlike PLA/NG composites. Thermal degradation temperatures of PLA/EG nanocomposites increased substantially with the increment of EG content up to ∼3 wt %, whereas those of PLA/NG composites remained constant regardless of the NG content. For instance, thermal degradation temperature of PLA/EG nanocomposite with only 0.5 wt % EG was improved by ∼10 K over PLA homopolymer. Young's moduli of PLA/EG nanocomposites increased noticeably with the increment of EG content up to ∼3 wt %, compared with PLA/NG composites. The percolation threshold for electrical conduction of PLA/EG nanocomposites was found to be at 3–5 wt % EG, which is far lower graphite content than that (10–15 wt % NG) of PLA/NG composites. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 850–858, 2010
Acid/Base Gas/Liquid Adsorption Properties of Carbon Black Modified in NH3/O2 RF Glow Discharges
Authors: De Vietro Nicoletta , Favia Pietro , Fracassi Francesco , d'Agostino Riccardo
Published: March 2010

Carbon Black granules were modified in a rotating RF (13.56 MHz) plasma reactor fed with NH3/O2 gas mixtures, in order to graft acid (O‐containing) and/or basic (N‐containing) chemical groups and tune their surface acid/base character. X‐rays photoelectron spectroscopy was used to evaluate the surface chemical composition of the modified carbon surface. Boehm titrations, in OH−/H+ water solutions, and NH3/HCl vapour adsorption tests were performed on plasma treated Carbon Black, with the aim to check its capability of adsorbing acid and basic compounds from solution and in gas/vapour phase, respectively.

magnified image
Post‐infectious bronchiolitis obliterans: Can CT scan findings at early age anticipate lung function?
Authors: Mattiello Rita , Sarria Edgar E. , Mallol Javier , Fischer Gilberto B. , Mocelin Helena , Bello Rodrigo , Flores Jose A.M. , Irion Klaus , Jones Yvonne
Published: March 2010

Background

The image findings of post‐infectious bronchiolitis obliterans (PIBO) have been described, however, we do not know if such findings can predict lung function (LF) deterioration with increasing patient age. Aim: To assess whether computed tomography (CT) abnormalities detected at an early stage of the disease can anticipate abnormal LF a decade later in children with PIBO.

Methods

We compared CT scans of 21 children with PIBO, done within their first 3 years of life, and their actual LF. To evaluate CT scans we used a modified Bhalla score and, for LF, FEV1 as percentage of predicted values. We calculated prevalence ratios (PRs) by comparing the proportion of patients with worst CT score and worst LF, with the proportion of those with best CT score and worst LF.

Results

PR was 1.17 (CI 1.02; 1.34, P = 0.02).

Conclusions

The CT finding early in the life of children with PIBO, when assessed by the Bhalla, score seem to anticipate future LF status. Pediatr Pulmonol. 2010; 45:315–319. © 2010 Wiley‐Liss, Inc.
Inhomogeneities and cosmological expansion
Authors: Tetradis N.
Published: March 2010

I review work on the influence of inhomogeneities in the matter distribution on the determination of the luminosity distance of faraway sources, and the connection to the perceived cosmological acceleration.
Basics of F‐theory from the Type IIB perspective
Authors: Blumenhagen R.
Published: March 2010

These short lecture notes provide an introduction to some basic notions of F‐theory with some special emphasis on its relation to Type IIB orientifolds with O7/O3‐planes.
Insecticidal efficacy of fipronil against four stored‐product insect pests: influence of commodity, dose, exposure interval, relative humidity and temperature
Authors: Kavallieratos Nickolas G , Athanassiou Christos G , Vayias Basileios J , Betsi Petri Christina C
Published: March 2010

BACKROUND: Fipronil is an insecticidal pyrazole that is commonly used as an insecticide in field crops, urban pesticide and veterinary medicine, but there are no reports of its evaluation against stored‐product insects. Three series of laboratory bioassays were conducted to assess fipronil as a potential grain protectant against adults of Sitophilus oryzae (L.), Tribolium confusum Jacquelin du Val, Rhyzopertha dominica (F.) and Prostephanus truncatus (Horn). Factors such as dose (0.01, 0.1, 1 and 10 mg fipronil kg−1 grain), exposure interval (24 h, 48 h, 7 days and 14 days), temperature (20, 25 and 30 °C), relative humidity (RH; 55 and 65%) and commodity (wheat, maize, barley and paddy rice) were evaluated with regard to their impact on the insecticidal activity of fipronil. Progeny production was assessed after 64 days of exposure.

RESULTS: At doses of < 1 mg fipronil kg−1 grain, efficacy of fipronil was enhanced by an increase in temperature from 20 to 25 °C against S. oryzae or R. dominica for exposures of > 48 h and against T. confusum or P. truncatus for exposures of > 24 h. A further increase in temperature from 25 to 30 °C, although it enhanced efficacy at doses of < 1 mg fipronil kg−1 grain against S. oryzae at all exposure intervals and against T. confusum after 7 days of exposure, it was negatively associated with efficacy against R. dominica or P. truncatus for exposures of > 24 h. By contrast, increase in RH did not have a significant impact on efficacy of fipronil. Although the performance of fipronil among the tested commodities was species dependent, this substance appeared to be less effective in paddy rice than in barley, maize and wheat. Regardless of the treated commodity, progeny production of all the tested species was almost suppressed with doses higher than 0.1 mg fipronil kg−1 grain.

CONCLUSIONS: Fipronil appeared to be a very effective alternative to the existing substances in stored‐grain protection at doses equal to or higher than 1 mg fipronil kg−1 grain, and thus these doses require further evaluation in terms of safety for the consumer and residues on stored products. Copyright © 2010 Society of Chemical Industry
Autosomal inheritance of deltamethrin resistance in field populations of Triatoma infestans (Heteroptera: Reduviidae) from Argentina
Authors: Germano Mónica D , Vassena Claudia V , Picollo María I
Published: March 2010

BACKGROUND: Triatoma infestans (Klug) is the major Chagas disease vector in the Southern Cone area of South America, and its chemical control is based on the use of pyrethroid insecticides. Resistance to deltamethrin in Salta Province, Argentina, has been detected in field populations since 2002, causing the failure of vector control campaigns in this disease‐endemic area. The inheritance of deltamethrin resistance in T. infestans was evaluated through reciprocal crosses conducted between resistant and susceptible insects.

RESULTS: The response of the reciprocally mated insects' progeny to deltamethrin was intermediate between the highly resistant and the susceptible parent colonies. Lack of significant differences between the LD50 and resistance ratios of the reciprocally mated insects indicated no sex linkage on this trait.

CONCLUSION: Bioassay results, in addition to degree of dominance calculations, suggest that the resistance to deltamethrin in T. infestans is controlled by semi‐dominant, autosomally inherited factors. Copyright © 2010 Society of Chemical Industry
Contact toxicity of insecticides for attract‐and‐kill applications against adult Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae)
Authors: Campos Manuel , Phillips Thomas W
Published: March 2010

BACKGROUND: The Indian meal moth (IMM), Plodia interpunctella (Hübner), is an important pest of stored food products. Contact toxicities of 13 insecticides applied to different surfaces were evaluated at registered label and a higher dose for killing adult males. The ultimate objective was to develop attract‐and‐kill technologies for P. interpunctella. Two‐day‐old adult males were exposed to treated surfaces for 2.0 s and then paired with virgin females for mating and oviposition over a 24 h period.

RESULTS: Permethrins and pyrethrins (organic pyrethrin and pyrethrin plus a synergist) caused over 70% mortality to males. Oviposition was impacted by these insecticides, while egg hatch was not. A second experiment tested the 8 week residual toxicity of cyfluthrin, permethrin and pyrethrin at label and at a higher dose of 20 g AI L−1 on five surfaces: plastic‐coated paper, metal, painted plastic, unpainted plastic and wood. Permethrin at 20 g AI L−1 suppressed males at over 80% for up to 8 weeks and retained activity on surfaces made with plastic‐coated paper, metal or plastic. Oviposition was variable among treatments. Egg hatch was generally unaffected by treatment.

CONCLUSION: Effective attract‐and‐kill surfaces can be developed for killing IMM males and thereby potentially lead to reduced reproduction and, ultimately, population suppression. Copyright © 2010 Society of Chemical Industry
Fe‐catalysed synthesis of C nanotubes by i‐C4H10 decomposition: Advantages and problems deriving from H2 addition to the growth ambient
Authors: Santangelo Saveria , Milone Candida , Lanza Maurizio , Messina Giacomo
Published: March 2010

This work is a continuation and a completion of our previous studies on the synthesis of multi‐walled carbon nanotubes (MWCNTs) by i‐C4H10 decomposition at moderate temperature (600 °C). It intends to show the existence of well‐defined relationships between the variations of the reaction parameters and the changes of yield and graphitization degree of the grown MWCNTs. For this purpose, MWCNTs prepared by catalysed chemical vapour deposition (CCVD) in i‐C4H10–H2–He environment over Fe/Al2O3 catalysts (metal load: 29%; reduction temperature: 500 or 700 °C) are considered. The results of scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy (RS) and thermo‐gravimetry (TG) analyses, performed on purified MWCNTs, evidence the changes in morphology, crystalline arrangement, purity and thermal stability produced by the use of different i‐C4H10 and H2 partial pressures (0.25–0.75 atm) and catalyst amount (0.25–2.00 g). The empirical correlations established, by fitting the data, between issue of reactions, in terms of yield and MWCNT graphitization degree, and relative (to catalyst) carbon‐ and hydrogen‐supply rates allow highlighting, on a quantitative basis, benefits and problems deriving from H2 addition to the growth atmosphere, topic on which, as in our knowledge, only qualitative information is available in literature.
Structural evolution optimization at p/i interface and in the bulk intrinsic‐layer for high efficiency microcrystalline silicon solar cells
Authors: Hou Guofu , Han Xiaoyan , Geng Xinhua , Zhang Xiaodan , Wei Changchun , Sun Jian , Chen Xinliang , Zhang Jianjun , Zhao Ying
Published: March 2010

The structural evolution in high‐rate deposited hydrogenated microcrystalline silicon (μc‐Si:H) films and solar cells has been investigated. In order to reduce the incubation layer thickness, a high‐quality initial seed layer at p/i interface has been developed by lowering silane concentration and very high frequency (VHF) power simultaneously. This initial seed layer not only acts as a seed layer for the high‐rate deposited i ‐layer, but also it can reduce the ion bombardment on the p/i interface. Then, a novel VHF power profiling technique, which is designed by dynamically decreasing the VHF power step by step during the deposition of μc‐Si:H, has been developed to control the structural evolution along the growth direction in the bulk i ‐layer. Another advantage of this VHF power profiling technique is the reduced ion bombardments on growth surface because of decreasing the VHF power. At last, a high conversion efficiency of 9.4% has been obtained for a single junction μc‐Si:H p‐i‐n solar cell with i ‐layer deposited at average deposition rate over 10 Å/s (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Enhanced blue‐orange‐red light emission from nc‐Si:H/SiO2 pillar arrays using nanosphere lithography
Authors: Ma Z. Y. , Liu G. Y. , Yan M. Y. , Xia G. Y. , Jiang X. F. , Ling T. , Sun H. C. , Wang D. Q. , Dong H. P. , Xu L. , Li W. , Chen K. J. , Xu J. , Feng D.
Published: March 2010

Hydrogen passivated nanocrystalline Si/SiO2 (nc‐Si:H/SiO2) pillar arrays were fabricated by using nanosphere lithography combination with hydrogen plasma annealing (HPA). Enhanced blue‐orange‐red photoluminescence (PL) could be observed by the naked eye in the bright room from the samples. By controlling the size of nc‐Si:H from 3.8 to 1.8 nm, the PL peak blueshifts from 757 to 435 nm. It is found that the nanopillar structure can drastically enhance the light‐absorbing properties of the samples and hydrogenation of nc‐Si embedded in pillars is benefit to the increase of photoluminescence (PL) intensity. Combined with the analysis of atomic force microscope (AFM), transmission electron microscopy (TEM), Fourier Transform Infrared (FTIR) spectroscopy and absorption spectra, the blue photoluminescence (PL) peak are ascribed to the quantum size effect of the nc‐Si passivated by hydrogen, and the orange and red ones to both the localized surface states and quantum confinement effects of nc‐Si:H. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Excess noise in amorphous selenium p‐i‐n devices
Authors: Majid Shaikh Hasibul , Johanson Robert E.
Published: March 2010

We report on 1/f noise measurements in amorphous selenium p‐i‐n devices, where the p‐ and n‐layers are trapping layers for electrons and holes respectively. Under forward bias, the normalized 1/f noise power is 5 × 104 times less than that of a single i‐layer device. At frequencies above 100 Hz, a region of white noise is observed that we attribute to partial shot noise.

We propose that the reduction in 1/f noise and the region of shot noise are a result of the trapping layers acting as reservoirs of charge carriers. The traps randomize the charge carriers producing the observed white noise and act as the source of the device current. Sourcing the current in this way suppresses the very noisy charge injection from the metal electrodes which controls the current in single i‐layer devices (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Novel morphology of chemical vapor deposited diamond films
Authors: Tang C. J. , Fernandes A. J. S. , Abe I. , Grácio J. , Buijnsters J. G. , Pinto J. L.
Published: March 2010

We have obtained simultaneously nanocrystalline and {100} faceted large‐grained polycrystalline diamond films not only on different substrates but also on the same substrate in only one deposition run using a novel approach for substrate arrangement. Furthermore, interesting unusual morphologies and microstructures composed by non‐faceted nanostructures and terminated with large smooth {100} facet‐like belt are found near the edges of the top square sample. The morphology variation is likely caused by the so called edge effect, where a strong variation in temperature is also present. We have modelled the temperature distribution on the substrates by computer simulations using the finite element method. The novel feature, namely the coexistence of oval non‐faceted nanocrystalline diamond grains and large smooth {100} facet‐like belt in one diamond grain, is in the transition from {100} faceted polycrystalline diamond to cauliflower‐like nanocrystalline diamond. The formation mechanism is discussed based on the temperature analysis and other simulation results described in the literature. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Amorphous silicon‐based multilayers for photovoltaic applications
Authors: Zeman M. , Isabella O. , Tichelaar F. D. , Luxembourg S. L.
Published: March 2010

Multilayer (ML) structures were fabricated by alternating deposition of hydrogenated amorphous silicon (a‐Si:H) and amorphous silicon nitride (a‐SiNx:H) using plasma enhanced chemical vapour deposition. The ML structures were grown with and without hydrogen dilution of the source gas mixture. A blue shift of the absorption spectra was observed upon reduction of the a‐Si:H thickness below 5 nm. Hydrogen dilution was found to improve the abruptness of the interfaces between subsequent a‐Si:H and a‐SiNx:H layers to below 1 nm. In order to investigate the potential of a‐Si:H based ML structures as absorbers in solar cells and to study transport perpendicular to the interfaces, we have incorporated ML absorbers in a single junction p‐i‐n solar cell. We have determined the J‐V characteristics and the external quantum efficiency of solar cells with a 60 period ML absorber, composed of 5 nm thick a‐Si:H and 1 nm thick a‐SiNx:H layers. The solar cell with ML absorber operated at efficiency of 1.8% (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Combined thermal and zero‐valent iron In Situ soil mixing remediation technology
Authors: La Mori Phillip , Kirkland Elgin , Faircloth Harlan , Bogert Robert , Kershner Mark
Published: March 2010

Thermal remediation of contaminated soils and groundwater by injection of hot air and steam using large‐diameter auger in situ soil mixing effectively remediates volatile and semivolatile organic compounds. This technology removes large amounts of contamination during the early treatment stages, but extended treatment times are needed to achieve high removal percentages. Combining thermal treatment with another technology that can be injected and mixed into the soil, and that continues to operate after removal of the drilling equipment, improves removal efficiency, and reduces cost. Using field‐determined pseudo first‐order removal rates, the cost of the combined remediation of chlorinated volatile organic compounds (CVOCs) by thermal treatment followed by reductive dechlorination by iron powder has been estimated as 57 percent of the cost of thermal treatment alone. This analysis was applied to a case‐study remediation of 48,455 cubic yards, which confirmed the cost estimate of the combined approach and showed over 99.8 percent removal of trichloroethene and other chlorinated VOCs. © 2010 Wiley Periodicals, Inc.
Variability of mesohabitat characteristics in riffle‐pool reaches: Testing an integrative evaluation concept (FGC) for MEM‐application
Authors: Hauer Christoph , Unfer Günther , Tritthart Michael , Formann Erik , Habersack Helmut
Published: March 2010

This paper investigates the variability of mesohabitat characteristics in various riffle‐pool reaches. The tested river sections (n = 13) feature clear variation in slope (0.0004–0.0132) and low flow discharge (0.05–915 m3s−1) in different river types (straight to meandering). Mesohabitat characteristics (water depth, flow velocity, bottom shear stress) were calibrated according to the MEM‐concept (MEM—Mesohabitat Evaluation Model). Statistical analysis clearly revealed significant differences (p < 0.001) for the same mesohabitats (e.g. riffles) in different rivers concerning the tested abiotic habitat parameters. A comparative analysis of hydromorphological parameters (width‐depth variance, Froude number) showed no correlation to mesohabitat variability based on 2D/3D numerical modelling related to a range of flows (n = 10) (low flow to annual flood). Only an increasing hydraulic radius (Rhy) was correlated to an increase in fast run and a decrease in run habitats. In a case study, a Fish Guild Concept (FGC) is presented which links mesohabitats to the rheophilic fish guild (12 fish species grouped) at the Sulm River. Mesohabitat suitability (preferred, useable and avoided) for the FGC was determined for spawning, juveniles (0+, 1+), sub‐adult and adult stages based on meso‐unit and point abundance electro‐fishing. Copyright © 2010 John Wiley & Sons, Ltd.

This article was published online on March 3, 2010. An error was subsequently identified in Figure 1. This notice is included in the online and print versions to indicate that both have been corrected [March 10, 2010].
Micromechanics and Advanced Designs for Curved Photodetector Arrays in Hemispherical Electronic‐Eye Cameras
Authors: Shin Gunchul , Jung Inhwa , Malyarchuk Viktor , Song Jizhou , Wang Shuodao , Ko Heung Cho , Huang Yonggang , Ha Jeong Sook , Rogers John A.
Published: March 2010

The fabrication of a hemispherical electronic‐eye camera with optimized designs based upon micromechanical analysis is reported. The photodetector arrays combine layouts with multidevice tiles and extended, non‐coplanar interconnects to improve the fill factor and deformability, respectively. Quantitative comparison to micromechanics analysis reveals the key features of these designs. Color images collected with working cameras demonstrate the utility of these approaches.
Becoming a leader in university budgeting
Authors: Varlotta Lori E.
Published: March 2010

This chapter presents information to help senior student affairs officers first establish themselves as experts in division‐level budgeting and then go on to become leaders in university‐wide budgeting.
Alternate budgetary sources during budget rescissions
Authors: Keppler Kurt
Published: March 2010

This chapter describes revenue‐generating and cost‐saving strategies that student affairs divisions may consider during periods of budget rescissions and categorizes them according to the decision‐making entities involved in each. The chapter also explains why particular examples are well suited to individual institutions.
Communicating with stakeholders
Authors: Eldridge Jonathan , Mason Tisa
Published: March 2010

Understanding the institutional context of financial issues and related communication enhances the effectiveness of student affairs administrators within their areas of responsibility and as leaders of change on campus. This chapter focuses on key aspects of developing a comprehensive communication strategy.
13–14‐week fetal anatomy scan: a 5‐year prospective study
Authors: Ebrashy A. , El Kateb A. , Momtaz M. , El Sheikhah A. , Aboulghar M. M. , Ibrahim M. , Saad M.
Published: March 2010

Objectives

To assess the potential value of an early (first‐trimester) ultrasound examination in depicting fetal anomalies by transabdominal (TAS) and transvaginal (TVS) sonography, to compare it with the traditional mid‐trimester anomaly ultrasound examination and to evaluate the degree of patient acceptance of early sonography by the transvaginal route.

Methods

In this prospective study over a 5‐year period (January 2002 to January 2007) 2876 pregnant women underwent a 13–14‐week ultrasound examination. The scan was performed by TAS at first and then, if a full fetal anatomical survey was not achieved, by TVS. A mid‐trimester fetal anatomy scan was then performed in patients who had not dropped out, miscarried or undergone pregnancy termination (n = 2834).

Results

In the early scan, analyzable data for 2876 TAS and 1357 TVS examinations showed that TVS was significantly better in visualizing the cranium, spine, stomach, kidneys, bladder and upper and lower limbs (P < 0.001). Complete fetal anatomical surveys were achieved by TAS in 64% of cases versus 82% of the cases in which it was attempted by TVS (P < 0.001). Patient body mass index significantly affected the ability of the sonographer to achieve a complete anatomical survey by both TAS and TVS (P < 0.001 and P = 0.004, respectively). The duration of the scan was significantly longer using TVS. The heart and kidneys were not properly visualized in 42% and 27% of cases, respectively, at the 13‐week scan compared with 1.6% and 0% at the mid‐trimester scan. The total number of cases in which anomalies were detected was 31. At the first‐trimester scan, anomalies were detected in 21 fetuses and in 14 of these cases the parents chose pregnancy termination. At the second‐trimester scan, anomalies were detected in 17 fetuses: 10 new anomalous cases along with seven cases already detected in the first‐trimester scan.

Conclusion

Besides its importance in screening for chromosomal abnormalities, the early scan has great potential in visualizing with precision fetal anatomy. TVS can be used to compliment difficult TAS examinations; however, patients do not always agree to undergo TVS. The mid‐trimester scan remains crucial for detailed fetal anatomical survey. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
Reproducibility of regional placental vascularity/perfusion measurement using 3D power Doppler
Authors: Lai P. K. , Wang Y. A. , Welsh A. W.
Published: March 2010

Objectives

To assess reproducibility and regional variability of placental perfusion measurement using three‐dimensional (3D) power Doppler VOCAL™ (Virtual Organ Computer‐aided AnaLysis).

Methods

Twenty pregnant women at 26–34 weeks' gestation with normally grown, biophysically normal, singleton pregnancies with anterior placentae had placental power Doppler mapping data stored digitally from each of the four placental quadrants. Each was imaged by two investigators, with two datasets stored per investigator per quadrant. 5760 data values from the 320 datasets were evaluated by the same two investigators. Power Doppler imaging of the placental cord insertion was performed to generate a value for standardization as ‘fractional moving blood volume’ if appropriate. The vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were calculated from spherical regions‐of‐interest to assess reproducibility within and between quadrants and between investigators for both acquisition and analysis.

Results

We found extensive variability for all readings. For repeated measurements within the same dataset the intra‐analyzer intraclass correlation coefficient (ICC) range was: 0.24–0.57 for VI, 0.33–0.78 for FI and 0.12–0.48 for VFI. The corresponding interanalyzer ICC range was: 0.38–0.92 for VI, 0.40–0.85 for FI and 0.10–0.92 for VFI. The intra‐acquirer variability (paired t‐test) mean differences range was: − 3.91 to 4.71 for VI, − 2.68 to 3.31 for FI and − 2.23 to 2.78 for VFI; the corresponding interacquirer variability (paired t‐test) range was: − 1.92 to 5.18 for VI, − 3.06 to 2.04 for FI and − 1.69 to 2.60 for VFI. The regional variability range (coefficient of variation) was: 6.28–126.34% for VI, 2.26–49.01% for FI and 6.09–151.55% for VFI. For all analyzed data, FI showed least variability and cord values for VI were consistently 100% (mean VFI, 98.4 and 98.8 between observers).

Conclusions

There is insufficient evidence to support the meaning, reliability or reproducibility of VOCAL (VI, FI or VFI) as a tool to quantify placental perfusion, despite its use in multiple publications and journal submissions. There is poor reproducibility at the most fundamental level. Further investigation into the reproducibility of placental perfusion and quantification using VOCAL is required before development and application as a clinically useful tool. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
Comparison of inter‐ and intraobserver agreement and reliability between three different types of placental volume measurement technique (XI VOCAL™, VOCAL™ and multiplanar) and validity in the in‐vitro setting
Authors: Cheong K. B. , Leung K. Y. , Li T. K. T. , Chan H. Y. , Lee Y. P. , Tang M. H. Y.
Published: March 2010

Objectives

To compare XI VOCAL™ (eXtended Imaging Virtual Organ Computer‐aided AnaLysis) for three‐dimensional (3D) ultrasound volumetry of the placenta and of phantom objects with a rotational method using VOCAL™ and with the multiplanar method.

Methods

We acquired 3D volume datasets from 32 fetuses at 11–14 weeks' gestation. Placental volume was calculated twice by each of two observers using XI VOCAL (with 5, 10, 15 and 20 slices), multiplanar (1‐mm interval) and VOCAL (with 12°, 18° and 30° rotation) methods. In addition, validity was assessed using the in‐vitro setting with three phantom objects of known volume.

Results

Both inter‐ and intraobserver reliabilities were very high for all three methods. There was no systematic bias between any two methods except between XI VOCAL (10 slices) and the multiplanar (1‐mm interval) method, with a smaller volume using the former method. The limits of agreement were wide between any two of the three methods. In the in‐vitro setting, there was a trend towards less valid measurements with the XI VOCAL technique and fewer slices. With the same number of steps, measurements made with VOCAL (12° and 18°) were more valid than were those made with XI VOCAL (15 and 10 slices, respectively).

Conclusion

XI VOCAL cannot be used interchangeably with VOCAL or multiplanar techniques in measuring placental volume at 11–14 weeks' gestation. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.