bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanical properties of magnetic Fe‐based and Co‐based amorphous wires and microwires
Authors: Chiriac H. , Lupu N. , Dobrea V. , Corodeanu S.
Published: March 2009

In this paper we present measurements of the mechanical properties of magnetically soft Fe‐based and Co‐based conventional amorphous wires (CAW) and glass‐covered amorphous microwires (GCAW) in the as‐quenched state, before and after cold rolling, and after annealing for internal stresses relief. The tensile strength (σ) varies between 2000 MPa and 3400 MPa, strongly depending on CAW diameter and annealing temperature. The Young modulus (E) is following a descendant trend, decreasing with the diameter decrease. The increase of tensile strength (σ) and elongation (ε) values after cold‐rolling and post‐annealing is caused by the release of the internal stresses induced during the preparation. Tensile strengths up to 3900 MPa are achieved for Fe‐based GCAW, depending very strongly on the microwires diameter, but mostly on the glass cover thickness. σ reaches the maximum value of 3150 MPa for a Co‐based microwire having the glass cover of 9 μm and the total diameter of 43 μm, but increases even more after the glass removal (3350 MPa). This behaviour is attributed to the structural disorder and the specific magnetic domains structure in Fe‐based and Co‐based CAW and GCAW. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evidence of type‐II band alignment at the ordered GaInNP to GaAs heterointerface
Authors: Hsu H. P. , Huang Y. N. , Huang Y. S. , Sitarek P. , Tiong K. K. , Tu C. W.
Published: March 2009

Polarized piezoreflectance (PzR) and photoreflectance (PR) are employed to study band alignment in Ga0.46In0.54Ny P1–y /GaAs heterostructures grown by gas‐source molecular‐beam epitaxy. The features near the band edge of Ga0.46In0.54Ny P1–y show strong polarization dependence, indicating the existence of some degree of ordering of these samples. The PR spectra exhibit Franz–Keldysh Oscillations (FKOs) above the band edge of GaAs. The electric fields in the GaAs region are evaluated by analyzing the FKOs and found to decrease with increasing nitrogen content. The type‐II band alignment at the Ga0.46In0.54Ny P1–y /GaAs interface is concluded for the alloys with nitrogen content y larger than 0.5% based on the appearance of additional features below band edge of GaAs. These features are attributed to the spatially indirect type‐II transitions in the vicinity of interface region between Ga0.46In0.54Ny P1–y and GaAs. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Excitonic effects and Franz–Keldysh oscillations in photoreflectance of ultrapure GaAs epilayers
Authors: Komkov O. S. , Glinskii G. F. , Pikhtin A. N. , Ramgolam Y. K.
Published: March 2009

A model based on the exciton theory has been presented for lineshape analysis of photoreflectance (PR) spectra. Experimental PR spectra of high‐quality thick GaAs epilayers of different purity were measured to verify the theoretical results. It has been shown that excitonic effects completely prevail over the one‐electron theory in the formation of photoreflectance spectrum even at high electric fields and room temperature, giving evidence of the existence of Franz–Keldysh oscillations enhanced by excitonic effects. A comparison of PR spectra simulated using the exciton theory and the one‐electron approximation has shown that the semiperiods of the oscillations were practically similar. This demonstrates the validity of using the simple “high‐field” model of Aspnes and Studna to determine surface electric fields. In photoreflectance of thick ultrapure GaAs epilayers an oscillating structure was experimentally observed in the region between the excitonic and the fundamental bandgap. This provides a possibility for contactless characterization not only for doped (N ∼ 1014–1018 cm–3) but also for ultrapure (N ∼ 1011–1013 cm–3) GaAs epilayers as well as other semiconductor materials. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fast measurements of photoreflectance spectra by using multi‐channel detector
Authors: Kudrawiec R. , Khachapuridze A. , Cywinski G. , Suski T. , Misiewicz J.
Published: March 2009

Photoreflectance (PR) measurements were performed on GaAs‐ and GaN‐based structures in the so called ‘bright configuration’ where the sample was illuminated by white light (probing beam) instead of monochromatic light as it takes place in the standard configuration, i.e., so‐called ‘dark configuration’. Within this concept the whole PR spectrum can be measured/processed at the same time using a multi‐channel detector (i.e., CCD camera) instead the phase sensitive lock‐in detection system with the one‐channel detector. In this work PR spectra for Si δ‐doped GaAs structure have been measured using both the CCD detector system as well as the standard lock‐in technique with the one‐channel detector system. GaAs‐related Franz–Keldysh oscillations, which are typical of Si δ‐doped GaAs structure, have been clearly observed in PR spectra measured by using the two detection systems. In addition, the PR system with the CCD detector has been used to measure PR spectra in the UV spectral region for an InGaN/GaN/Al2O3 structure. In this case, PR resonances related to InGaN and GaN band gap absorption have been clearly observed. Using the PR system with CCD detector the time of PR measurements was reduced to few seconds for both GaAs‐ and GaN‐based structures. It shows that the bright configuration of PR set‐up with multi‐channel detection system is very promising and perspective in the fast diagnostic of semiconductor structures. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cardioprotective potential of myricetin in isoproterenol‐induced myocardial infarction in wistar rats
Authors: Tiwari Roshan , Mohan Mahalaxmi , Kasture Sanjay , Maxia Andrea , Ballero Mauro
Published: March 2009

The study aimed to evaluate the protective role of myricetin obtained from Vitis vinifera (Vitaceae) on heart rate, electrocardiographic (ECG) patterns, vascular reactivity to catecholamines, cardiac marker enzymes, antioxidant enzymes together with morphological and histopathological changes in isoproterenol (ISO) induced myocardial infarction (MI) in male Wistar rats. Rats treated with isoproterenol (85 mg/kg, administered subcutaneously twice at an interval of 24 h) showed a significant increase in heart rate and ST elevation in ECG, and a significant increase in the levels of cardiac marker enzymes – lactate dehydrogenase (LDH), creatine kinase (CK) and aspartate aminotransferase (AST) in serum. Isoproterenol significantly reduced superoxide dismutase (SOD) and catalase (CAT) activity and increased vascular reactivity to various catecholamines. Pretreatment with myricetin (100 mg/kg, p.o. and 300 mg/kg, p.o.) for a period of 21 days significantly inhibited the effects of ISO on heart rate, levels of LDH, CK, AST, SOD, CAT, vascular reactivity changes and ECG patterns. Treatment with myricetin (100 mg/kg and 300 mg/kg) alone did not alter any of the parameters compared with vehicle treated Wistar rats. Myricetin treated animals showed a lesser degree of cellular infiltration in histopathological studies. Thus, myricetin (100 mg/kg and 300 mg/kg) ameliorates the cardiotoxic effects of isoproterenol and may be of value in the treatment of MI. Copyright © 2009 John Wiley & Sons, Ltd.
Large‐scale effect of aerosols on precipitation in the West African Monsoon region
Authors: Huang J. , Zhang C. , Prospero J. M.
Published: March 2009

We used multi‐year satellite observations to study aerosol effects on the large‐scale variability in precipitation of the West African Monsoon (WAM) region, which is often impacted by high concentrations of desert dust and biomass‐burning smoke. We find a statistically significant precipitation reduction associated with high aerosol concentration near the coast of the Gulf of Guinea from late boreal autumn to winter. The largest aerosol‐related precipitation reduction (∼1.5 mm d−1) is about 50% of the climatological mean precipitation in the region and occurs mainly at rain rates in the range of 2–17 mm d−1 off the northern coast of the Gulf of Guinea. This reduction cannot be linearly attributed to known climate and weather factors such as El Niño–Southern Oscillation, North Atlantic Oscillation, Atlantic sea‐surface temperature, or water vapour. The fractional precipitation variance related to aerosol is about 13%, a value comparable to those related to the known climate factors. Based on the spatial pattern and seasonality of the observed precipitation reduction and its dependence on the rain rate, the observed negative correlation cannot be readily attributed to precipitation effects on aerosol by wet deposition or to rain and cloud contamination of satellite aerosol retrievals. We therefore suggest that our results can be taken as observational evidence of aerosol effects on precipitation. The aerosol associated with the observed precipitation reduction can be traced back to various African sources where large quantities of desert dust and biomass‐burning smoke are emitted during much of the year. Given that the emissions of dust and smoke have varied considerably over the past several decades, in part attributable to human activities, our observed rainfall reduction may reflect an anthropogenic impact to some degree. Copyright © 2009 Royal Meteorological Society
Radiosonde humidity bias correction over the West African region for the special AMMA reanalysis at ECMWF
Authors: Agustí‐Panareda Anna , Vasiljevic Drasko , Beljaars Anton , Bock Olivier , Guichard Françoise , Nuret Mathieu , Garcia Mendez Antonio , Andersson Erik , Bechtold Peter , Fink Andreas , Hersbach Hans , Lafore Jean‐Philippe , Ngamini Jean‐Blaise , Parker Douglas J. , Redelsperger Jean‐Luc , Tompkins Adrian M.
Published: March 2009

During the African Monsoon Multidisciplinary Analysis (AMMA) field experiment in 2006 there was a large increase in the number of radiosonde data over West Africa. This has the potential of improving the numerical weather prediction (NWP) analysis/forecast and the water budget studies over that region. However, it is well known that the humidity from radiosondes can have some errors depending on sonde type, relative humidity (RH), temperature and the age of the sensor and can give rise to dry biases that are typically between 5% and 30% for RH. Three main sonde types were used in the AMMA field experiment: Vaisala RS80A, Vaisala RS92 and MODEM. In this article, a new empirical method is presented by using the operational European Centre for Medium‐Range Weather Forecasts (ECMWF) short‐range forecast as an intermediary dataset for computing biases. The validation of the correction method using global positioning system (GPS) total columnar water vapour (TCWV) confirms that the method is able to correct for a large part of the dry biases associated with the different sonde types. Results from analysis experiments show how the correction of humidity is particularly important in the West African region due to its impact on the development of convection in NWP models. The proposed radiosonde humidity bias correction has been applied to the special AMMA reanalysis experiment performed at ECMWF for the 2006 West African wet monsoon season. This is expected to benefit a wide number of AMMA‐related studies that make use of the reanalysis, in particular those focusing on the water cycle. Copyright © 2009 Royal Meteorological Society
Subseasonal extremes of precipitation and active‐break cycles of the Indian summer monsoon in a climate‐change scenario
Authors: Turner A. G. , Slingo J. M.
Published: March 2009

Changes to the behaviour of subseasonal precipitation extremes and active‐break cycles of the Indian summer monsoon are assessed in this study using pre‐industrial and 2 × CO2 integrations of the Hadley Centre coupled model HadCM3, which is able to simulate the monsoon seasonal cycle reasonably. At 2 × CO2, mean summer rainfall increases slightly, especially over central and northern India. The mean intensity of daily precipitation during the monsoon is found to increase, consistent with fewer wet days, and there are increases to heavy rain events beyond changes in the mean alone. The chance of reaching particular thresholds of heavy rainfall is found to approximately double over northern India, increasing the likelihood of damaging floods on a seasonal basis. The local distribution of such projections is uncertain, however, given the large spread in mean monsoon rainfall change and associated extremes amongst even the most recent coupled climate models. The measured increase of the heaviest precipitation events over India is found to be broadly in line with the degree of atmospheric warming and associated increases in specific humidity, lending a degree of predictability to changes in rainfall extremes. Active‐break cycles of the Indian summer monsoon, important particularly due to their effect on agricultural output, are shown to be reasonably represented in HadCM3, in particular with some degree of northward propagation. We note an intensification of both active and break events, particularly when measured against the annual cycle, although there is no suggestion of any change to the duration or likelihood of monsoon breaks. Copyright © 2009 Royal Meteorological Society
Modified version of revised Deutsch–Märk model for electron impact K‐shell ionization cross‐sections of atoms at relativistic energies
Authors: Haque A. K. F. , Sarker M. S. I. , Patoary M. A. R. , Shahjahan M. , Hossain M. Ismail , Uddin M. Alfaz , Basak A. K. , Saha B. C.
Published: March 2009

A simple modification of the revised Deutsch–Märk model (RDM) [Deutsch et al., Int J Mass Spectrom 2004, 233, 13] incorporating both the ionic and relativistic corrections is proposed to investigate the K‐shell ionization of 30 atomic targets with atomic numbers Z = 1–92 for incident energies up to 2 GeV. We also revisit our earlier models: modified Bell (MBELL) (Haque et al., Phys Rev A 2006, 73, 012708) and modified Kolbenstvedt (MKLV) (Uddin et al., Eur Phys J D 2006, 37, 361), for the K‐shell ionization cross sections at these ultra‐relativistic energies. The results from the modified version of RDM (MRDM), MBELL, and MKLV models agree well with the available experimental data and quantum mechanical calculations. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Evaluation of recent scaling free methods to predict phenol and phenoxyl radical vibrational properties—Guidelines for more complex models of lignin or protein moieties
Authors: Barsberg Søren
Published: March 2009

Phenol and phenoxyl radical are simple models of neutral or oxidized states of important moieties in biomacromolecules such as lignin or proteins. The evaluation of methods to predict their vibrational properties provides a guideline for predictions based on more complex and adequate model compounds. Fundamental frequencies of phenol and phenoxyl radical are predicted from harmonic frequencies νh obtained from B3LYP calculations, and anharmonic corrections Δνanh from HF, MP2 or B3LYP calculations. The complete basis set limit is estimated for νh and IR intensities. Basis set qualities are evaluated for these properties and for Raman activities. Δνanh values compare well between methods, except that MP2 is for the basis sets used unreliable for out‐of‐plane modes. Correlation effects increase Δνanh(HF) values by an average factor ∼1.1, but the correlated values do not improve predicted fundamental frequencies. The B3LYP functional is inadequate for the phenoxyl radical. Errors of approximately 5–6 cm−1 were obtained for the phenol in‐plane low‐frequency modes. For out‐of‐plane modes basis set dependencies are critical to a degree not previously recognized. The predictions appear mainly limited by the method(s) used to calculate νh and Δνanh, and the basis set dependency of Δνanh. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
The δ point interaction two‐center system
Authors: Hogreve H.
Published: March 2009

Motivated by the behavior of molecules in strong magnetic fields, we study the quantum system consisting of a particle (electron) interacting with two fixed (nuclear) centers by δ‐type point interactions. Spectral properties and resonances of this model as a function of the internuclear separation are investigated qualitatively and quantitatively. We prove analyticity, monotonicity, and other features, compare them with corresponding attributes of related Coulomb systems, and point out the consequences for molecules. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
The reaction of N2O5 with H3O+: A first‐principles direct molecular dynamics study of acid‐catalyzed reactive uptake of N2O5
Authors: Ishikawa Sascha T. , Nakajima Takahito
Published: March 2009

Direct molecular dynamics simulations of N2O5 + H3O+ collision were conducted; (1) to assess the importance of acid‐catalyzed N2O5 decomposition paths expected to play a significant role in the chemistry of stratospheric ozone depletion and (2) for their potential to identify unexpected decomposition paths. A single H3O+‐catalyzed N2O5 decomposition path was observed. Products formed are H2O, NO, HNO3, and complexes of the decomposition products, (H2O)(NO), (H2O)(HNO3), and (HNO3)(NO). All decompositions were barrierless, including complex formations of the products. Reaction exothermicities, which were characterized with a QCISD(T)/6‐311++G(d,p)//MP2/6‐311++G(d,p) model, ranged from 5.9 to 32.0 kcal/mol. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Sequence dependent proton‐transfer reaction in stacked GC pair I: The possibility of proton‐transfer reactions
Authors: Matsui Toru , Sato Takeshi , Shigeta Yasuteru
Published: March 2009

We explored the possibilities of proton‐transfer reactions between guanines (G) and cytosines (C) in stacking two GC pairs by means of density functional methods. There are two combinations of sequences, GC/GC (5′‐dGpG‐3′) and CG/GC (5′‐dCpG‐3′). We found that the simultaneous single proton transfer (SPT) in two base pairs, two independent double proton transfer (DPT), and continuous double SPT reactions strongly depend on the sequence of the DNA, because the SPT reaction occurs in specific sequences including CG/GC and the latter DPTs occur in those including GC/GC. The properties of the DPT products, such as effective charges, are almost the same as the original GC/GC, whereas the effective charges on G and C in the simultaneous SPT product become negative and positive in comparison with those in the original GC/GC. Coulomb attraction caused by the charge separation mainly contributes to the stability of the SPT product. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Accelerating convergence in iterative solution for large‐scale complete active space self‐consistent‐field calculations
Authors: Yanai Takeshi , Kurashige Yuki , Ghosh Debashree , Chan Garnet Kin‐Lic
Published: March 2009

An algorithm that accelerates the convergence of the iterative optimization of the complete active space self‐consistent field (CASSCF) wavefunction so as to find a optimum solution in fewer macroiterations is described. The algorithm is oriented to large‐scale CASSCF problems that are to be solved with a combination of density matrix renormalization group (DMRG) method for the configuration interaction (CI) process. The algorithm is based on the alternating (or two‐step) CASSCF optimization in which the CI and molecular orbital (MO) parameters are optimized separately. Convergence ratio is improved by finding further optimized MOs from a linear extrapolation of the MO sets of the iteration history. The acceleration results in fewer diagonalizations in a total CASSCF calculation to save a considerable computational cost. The convergence performance is examined in a couple of realistic applications on SiC3 and poly(phenyl)carbenes. For poly(phenyl)carbenes, the large‐size CASSCF calculations with CAS(30e,30o) that entails full π valence space as well as sp2 orbital space of carbenes are performed by using the practical implementation of DMRG‐CASSCF in conjunction with the acceleration technique. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Theoretical study of acetonitrile‐exchange reactions on hexasolvated divalent cations in the first transition series elements
Authors: Wasada Hiroaki , Wasada‐Tsutsui Yuko , Hashimoto Tomohiro , Funahashi Shigenobu
Published: March 2009

Penta‐, hexa‐, and heptaacetonitrile complexes of divalent cations of the first transition series are studied by ab initio molecular orbital calculations. The factors that determine the structural stability and the reaction mechanism of solvent‐exchange reactions are discussed. All the penta‐ and hexaacetonitrile species are at local minima, whereas the geometrical stability of the heptacoordinated species depends on the 3d electron configurations. The structural stability of heptaacetonitrile species is intermediate between those of hydrogen cyanide complexes and hydrates. Acetonitrile exchange reactions have more dissociative character than hydrogen cyanide exchange reactions because the inductive effect of the methyl group in CH3CN destabilizes the heptacoordinated structures. The successive binding energies show that associative mechanisms are favorable for acetonitrile exchange with earlier members of the first transition series, whereas dissociative mechanisms become favorable for later members. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Accurate torsional potentials for monohalo and fluorohalo keto‐enolate compounds
Authors: Vongachariya Arthit , Tantiwattanakul Sutheera , Parasuk Vudhichai
Published: March 2009

Accurate torsional potentials upon two rotatable carbon–carbon bonds for monohalo and fluorohalo keto‐enolate compounds were constructed using CCSD(T)/CBS level of theory. Stable conformers of monohalo and fluorohalo keto‐enolates can be determined from the steric repulsion between moieties around these carbon–carbon bonds. The repulsion between fluorine and halogen atoms is the strongest and stronger than that between oxygen and halogen, followed by that between oxygen and oxygen. The maximum of the torsional potentials corresponds to the conformation where both or one of the two rotatable bonds align perpendicular to the molecular plane, suggesting the strong double bond character between these two carbon–carbon bonds. Thus, the π‐bond conjugation and steric repulsion control the torsional potentials of monohalo and fluorohalo keto‐enolate compounds. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
The NHN+ hydrogen bridge between 4,5‐dihydro‐1H‐imidazole and various amines
Authors: Lankau Timm , Yu Chin‐Hui
Published: March 2009

The B3LYP/D95+(p,p) analysis of the NHN+ bridge between 4,5‐dihydro‐1H‐imidazole and 23 amines covering a proton affinity range from 213 to 257 kcal/mol reveals a continues transition between different types of hydrogen bonding, Van der Waals bond, standard hydrogen bond, double well hydrogen bond, and low barrier hydrogen bond. The mismatch in the proton affinities ΔPA of 9 kcal/mol for an intrinsic low barrier hydrogen bond (LBHB) shows that the chemical environments of the bridge head nitrogen atoms differ significantly and that heteromolecular NHN+ bridges have properties similar to heteronuclear OHN+ LBHBs. The analysis further showed that the properties of NHN+ LBHBs are similar to those observed in other hydrogen bonds and that the reliable classification of hydrogen bonds requires the careful analysis of all available data. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Fast liquid chromatography/multiple‐stage mass spectrometry of coccidiostats
Authors: Martínez‐Villalba Anna , Moyano Encarnación , Galceran Maria T.
Published: March 2009

Drugs that are used as medicines and also as growth promoters in veterinary care are considered as emerging environmental contaminants and in recent years concern about their potential risk to ecosystems and human health has risen. In this paper we used a method based on liquid chromatography/electrospray tandem mass spectrometry to analyze eight coccidiostatic compounds: diclazuril, dinitrocarbanilide (the main metabolite of nicarbazin), robenidine, lasalocid, monensin, salinomycin, maduramicin and nasarin. Multiple‐stage mass spectrometry (MSn) based on the precursor ions [M+Na]+ (polyether ionophores), [M+H]+ (robenidine) and [M–H]− (diclazuril and dinitrocarbanilide) was used to study the fragmentation of these compounds. MSn data and genealogical relationships were used to propose a tentative assignment of the different fragment ions. Loss of water, decarboxylations, ketone β‐cleavages and rearrangement of cyclic ethers and amide groups were some of the fragmentations observed for these compounds. Liquid chromatography with a sub‐2 µm particle size column was coupled to tandem mass spectrometry (LC/MS/MS) allowing the separation of these compounds in less than 7 min. Method detection limits ranging from 11 to 71 ng L−1 and run‐to‐run values in terms of relative standard deviation (RSD) (up to 12%) were obtained. Copyright © 2009 John Wiley & Sons, Ltd.
In situ chemical oxidation of residual LNAPL and dissolved‐phase fuel hydrocarbons and chlorinated alkenes in groundwater using activated persulfate
Authors: Siegal Joan , Rees Assaf A. , Eggers Karl W. , Hobbs Rebecca L.
Published: March 2009

A treatablity study (TS) was conducted to evaluate the efficacy of in situ chemical oxidation (ISCO) using activated persulfate, alone and in combination with air sparging (AS), for treating a source area contaminated with residual light nonaqueous‐phase liquid (LNAPL), dissolved‐phase fuel hydrocarbons (HCs), and dissolved‐phase chlorinated alkenes at Edwards Air Force Base (AFB), California. The TS was implemented in two phases. Phase I included injecting a solution of sodium persulfate and sodium hydroxide (NaOH) into groundwater via an existing well where residual LNAPL and dissolved‐phase contaminants were present. Because the results of Phase I indicated a limited distribution of the activated persulfate, Phase II was performed to assess whether AS could enhance the distribution of the sodium persulfate. Each phase was followed by groundwater monitoring and sampling at the injection well and at three monitoring wells, located 20 to 44 feet from the injection well. Results from Phases I and II of the TS indicated that (1) alkaline‐activated persulfate was effective in promoting the dissolution of LNAPL and the degradation of dissolved‐phase contaminants, but only at the injection well; (2) the addition of AS was effective in enhancing the radius of persulfate distribution from less than 20 feet to greater than 44 feet, and (3) persulfate alone (i.e., not in an activated state) was effective in reducing the concentrations of dissolved‐phase fuel HC and chlorinated alkenes. © 2009 Wiley Periodicals, Inc.
Successful unsaturated zone treatment of PCE with sodium permanganate
Authors: Hesemann John R. , Hildebrandt Martha
Published: March 2009

In situ chemical oxidation (ISCO) with permanganate has been widely used for soil and groundwater treatment in the saturated zone. Due to the challenges associated with achieving effective distribution and retention in the unsaturated zone, there is a great interest in developing alternative injection technologies that increase the success of vadose‐zone treatment.

The subject site is an active dry cleaner located in Topeka, Kansas. A relatively small area of residual contamination adjacent to the active facility building has been identified as the source of a large sitewide groundwater contamination plume with off‐site receptors. The Kansas Department of Health and Environment (KDHE) currently manages site remedial efforts and chose to pilot‐test ISCO with permanganate for the reduction of perchloroethene (PCE) soil concentrations within the source area. KDHE subsequently contracted Burns & McDonnell to design and implement an ISCO pilot test.

A treatability study was performed by Carus Corporation to determine permanganate‐soil‐oxidant‐demand (PSOD) and the required oxidant dosing for the site. The pilot‐test design included an ISCO injection approach that consisted of injecting aqueous sodium permanganate using direct‐push technology with a sealed borehole.

During the pilot test, approximately 12,500 pounds of sodium permanganate were injected at a concentration of approximately 3 percent (by weight) using the methods described above. Confirmation soil sampling conducted after the injection event indicated PCE reductions ranging from approximately 79 to more than 99 percent. A follow‐up treatment, consisting of the injection of an additional 6,200 pounds of sodium permanganate, was implemented to address residual soil impacts remaining in the soil source zone. Confirmation soil sampling conducted after the treatment indicated a PCE reduction of greater than 90 percent at the most heavily impacted sample location and additional reductions in four of the six samples collected. © 2009 Wiley Periodicals, Inc.
Managing environmental problems during transitions: The department of energy as a case study
Authors: Burger Joanna , Gochfeld Michael , Powers Charles W. , Kosson David , Greenberg Michael , Toffler Barbara Ley
Published: March 2009

Many federal, state, and private agencies deal with long‐term environmental problems within a transition framework where political administrations, funds, regulators, regulatory requirements, environmental conditions, and tribal and stakeholder concerns change. In this article, we examine the types of transitions, as well as important stabilities, that agencies face, the interactions with stakeholders that are vulnerable to disruption or failure, and some of the problems that develop as a result of these conditions, using the U.S. Department of Energy (US DOE's) Office of Environmental Management (EM) as a case study. Transitions, or instabilities, include changes in administrations at the federal, state, and local level; public perceptions and concerns; political climate; available funds; environmental conditions (e.g., global climate change, global contaminant transport, local and regional contamination); international and national business conditions; and site conditions (physical, chemical, biological). Governmental agencies operate under several different kinds of uncertainties, including scientific, fiscal‐year economic, technological, and societal. Not all information can be known, and the outcomes from scientific issues or technologies cannot always be predicted. The authors believe that transitions from one set of conditions to another can be more effectively integrated with the long‐term stability of environmental laws and regulations, and with the stability of the treaty rights and concerns of tribal nations, as well as the shorter‐term stability of career personnel and established programs. A sense of stability for government agencies allowing maintenance of ongoing environmental management programs can also be achieved through processes and programs, such as establishing long‐term contracts (for remediation or restoration work), schedule and scope documents, future land‐use documents, National Environmental Research Parks (which obligate lands to study and conservation), and other programs that set the direction of work and activities for many years. Further, two other factors are essential for success within any agency facing transitions: (1) expectations should be both forward‐looking and realistic, and (2) there must be flexibility in both programs and processes. The authors conclude that several features are essential to addressing some of the problems created by transitions, including information, integration, iteration, interaction, and inclusion. © 2009 Wiley Periodicals, Inc.
Use of Fenton's Reagent as a Disinfectant
Authors: Selvakumar Ariamalar , Tuccillo Mary Ellen , Muthukrishnan Swarna , Ray Asim B.
Published: March 2009

Several compositions of Fenton's Reagent and hydrogen peroxide alone were used to disinfect combined sewage samples from a wastewater treatment facility. The presettled samples contained suspended solids (SS) and dissolved organic carbon (DOC) at concentrations of 28 and 290 mg/L, respectively. Disinfection with Fenton's Reagent was carried out at a pH between 5.90 and 6.0 and at a temperature of 25°C. All disinfected samples contained residual oxidants. Under all reaction conditions studied, complete inactivation of E. coli was achieved within one minute of the addition of Fenton's Reagent. Disinfection with hydrogen peroxide alone under similar conditions is incomplete even under much longer contact times. © 2009 Wiley Periodicals, Inc.
Transmission line maintenance robots capable of crossing obstacles: State‐of‐the‐art review and challenges ahead
Authors: Toussaint Kristopher , Pouliot Nicolas , Montambault Serge
Published: March 2009

Power line inspection and maintenance already benefit from developments in mobile robotics. This paper presents a comprehensive review of the state of the art. It focuses on mobile robots designed to cross obstacles found on a typical transmission line while using the conductor as support for traveling. Promising areas of research and development as well as challenges that remain to be solved are discussed with a view to developing fully autonomous technologies. Maintenance tasks, including inspection and repairs, are identified as high‐value applications in transmission live‐line work. Conclusions are drawn from experience, and the future of mobile robotics applied to transmission line maintenance is discussed. © 2009 Wiley Periodicals, Inc.
Changes in biomass and structure after a fire in Spartina densiflora Brong marshes on the floodplain of the Paraná River, Argentina
Authors: Vicari Ricardo , Fischer Sylvia , Madanes Nora , Bonaventura Stella M.
Published: March 2009

We examined the responses of a Spartina densiflora (Poaceae) marsh to an accidental summer fire taking place in the Otamendi Natural Reserve (Argentina). Green, standing dead, reproductive and litter fractions of S. densiflora, as well as forbs biomass were determined before and after burning using randomly selected quadrates. Fire reduced most of the aboveground biomass of the green, standing dead and litter fractions of S. densiflora. Green biomass attained higher values before the fire as compared to those from the first year after burning during the spring, while the second year spring attained intermediate values. The standing dead material represented the main fraction of S. densiflora biomass in the pre‐fire period, and after burning, this fraction reappeared in autumn, 4 months after the fire. The litter showed zero values throughout the first 16 months after the fire, and reappeared at end of the second winter. The flower biomass was exclusively recorded on late summer and showed relatively low values. Seedling recruitment of S. densiflora was not observed throughout the study period. Forbs biomass showed large fluctuations both before and after fire and highest forbs biomass values were observed during the spring before fire, and at end of summer 1 year after the fire. Although the results of the present study showed a tendency towards the original structure, most of the biomass fractions did not reach values similar to those before the fire after 2 years of post‐fire growing, suggesting that a longer recovering time is expected. Copyright © 2009 John Wiley & Sons, Ltd.
Entrepreneur behaviors, opportunity recognition, and the origins of innovative ventures
Authors: Dyer Jeffrey H. , Gregersen Hal B , Christensen Clayton
Published: March 2009

This study traces the origins of innovative strategies by examining the attributes of ‘innovative entrepreneurs.’ In an inductive grounded theory study of innovative entrepreneurs, we develop a theory that innovative entrepreneurs differ from executives on four behavioral patterns through which they acquire information: (1) questioning; (2) observing; (3) experimenting; and (4) idea networking. We develop operational measures of each of these behaviors and find significant differences between innovative entrepreneurs and executives in a large sample survey of 72 successful and unsuccessful innovative entrepreneurs and 310 executives. Drawing on network theory, we develop a theory of entrepreneurial opportunity recognition that explains why these behaviors increase the probability of generating an idea for an innovative venture. We contend that one's ability to generate novel ideas for innovative new businesses is a function of one's behaviors that trigger cognitive processes to produce novel business ideas. We also posit that innovative entrepreneurs are less susceptible to the status quo bias and engage in these information‐seeking behaviors with a motivation to change the status quo. Copyright © 2009 Strategic Management Society.
Opportunities as attributions: Categorizing strategic issues from an attributional perspective
Authors: Gartner William B. , Shaver Kelly G. , Liao Jianwen (Jon)
Published: March 2009

This study explores the label ‘opportunity’ in the strategic issue literature as a point of departure for offering an attributional framework for categorizing opportunities entrepreneurs offer as they undertake efforts to start businesses. The strategic issue literature broadly labels opportunities as being positive and controllable and involving potential gain. We demonstrate that this is similar to an attribution theory approach. In preparing this article, the authors analyzed open‐ended questions from the Panel Study of Entrepreneurial Dynamics (PSED). Entrepreneurs were more likely to offer attributions about their opportunities that can be categorized as dependent on their abilities (internal and stable attributions) and efforts (internal and variable attributions). Copyright © 2009 Strategic Management Society.
Antitumor Activity and Prolonged Survival by Carbon‐Nanotube‐Mediated Therapeutic siRNA Silencing in a Human Lung Xenograft Model
Authors: Podesta Jennifer E. , Al‐Jamal Khuloud T. , Herrero M. Antonia , Tian Bowen , Ali‐Boucetta Hanene , Hegde Vikas , Bianco Alberto , Prato Maurizio , Kostarelos Kostas
Published: March 2009

Carbon nanotubes are novel nanomaterials that are thought to offer potential benefits to a variety of biomedical and clinical applications. In this study, the treatment of a human lung carcinoma model in vivo using siRNA sequences leading to cytotoxicity and cell death is carried out using either cationic liposomes (DOTAP:cholesterol) or amino‐functionalized multi‐walled carbon nanotubes (${\rm MWNT - NH}_3^ +$). Validation for the most cytotoxic siRNA sequence using a panel of human carcinoma and murine cells reveals that the proprietary siTOX sequence is human specific and can lead to significant cytotoxic activities delivered both by liposome or ${\rm MWNT - NH}_3^ +$ in vitro. A comparative study using both types of vector indicates that only ${\rm MWNT - NH}_3^ +$:siRNA complexes administered intratumorally can elicit delayed tumor growth and increased survival of xenograft‐bearing animals. siTOX delivery via the cationic ${\rm MWNT - NH}_3^ +$ is biologically active in vivo by triggering an apoptotic cascade, leading to extensive necrosis of the human tumor mass. This suggests that carbon‐nanotube‐mediated delivery of siRNA by intratumoral administration leads to successful and statistically significant suppression of tumor volume, followed by a concomitant prolongation of survival of human lung tumor‐bearing animals. The direct comparison between carbon nanotubes and liposomes demonstrates the potential advantages offered by carbon nanotubes for the intracellular delivery of therapeutic agents in vivo. The present work may act as the impetus for further studies to explore the therapeutic capacity of chemically functionalized carbon nanotubes to deliver siRNA directly into the cytoplasm of target cells and achieve effective therapeutic silencing in various disease indications where local delivery is feasible or desirable.
Controlled Growth of Platinum Nanoparticles on Strontium Titanate Nanocubes by Atomic Layer Deposition
Authors: Christensen Steven T. , Elam Jeffrey W. , Rabuffetti Federico A. , Ma Qing , Weigand Steven J. , Lee Byeongdu , Seifert Soenke , Stair Peter C. , Poeppelmeier Kenneth R. , Hersam Mark C. , Bedzyk Michael J.
Published: March 2009

With an eye toward using surface morphology to enhance heterogeneous catalysis, Pt nanoparticles are grown by atomic layer deposition (ALD) on the surfaces of SrTiO3 nanocubes. The size, dispersion, and chemical state of the Pt nanoparticles are controlled by the number of ALD growth cycles. The SrTiO3 nanocubes average 60 nm on a side with {001} faces. The Pt loading increases linearly with Pt ALD cycles to a value of 1.1 × 10−6 g cm−2 after five cycles. Scanning electron microscopy images reveal discrete, well‐dispersed Pt nanoparticles. Small‐ and wide‐angle X‐ray scattering show that the Pt nanoparticle spacing and size increase as the number of ALD cycles increases. X‐ray absorption spectroscopy shows a progression from platinum(II) oxide to metallic platinum and a decrease in PtO bonding with an increase in PtPt bonding as the number of ALD cycles increases.
Examination of the secondary palate on stored 3D ultrasound volumes of the fetal face
Authors: Wong H. S. , Tait J. , Pringle K. C.
Published: March 2009

Objectives

To examine the use of oblique planes from stored three‐dimensional (3D) ultrasound volumes of the fetal face for viewing the secondary palate at various gestational ages.

Methods

3D ultrasound volumes of the fetal face acquired with surface rendering at 15–35 weeks' gestation in 31 fetuses with confirmed normal secondary palates were reviewed. The secondary palate was viewed in three oblique planes targeted at the uvula: the oblique axial, the oblique sagittal and the reverse face view. The detection and appearance of the secondary palate, including the soft palate, with these views at various gestational ages were compared.

Results

The various surfaces of the secondary palate could be viewed in all 31 fetuses in the oblique axial and the reverse face views, and in all except two fetuses in the oblique sagittal view. Both of these were < 19 weeks' gestation, at which age the uvula could not be identified clearly in this plane.

Conclusions

The oblique axial, the oblique sagittal and the reverse face view targeted at the uvula allow visualization of the various aspects of the fetal secondary palate on 3D ultrasound in the second and third trimesters of pregnancy. The uvula could be used as a landmark for viewing the soft palate, but was not always easily identifiable before 19 weeks' gestation. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Medians and correction factors for biochemical and ultrasound markers in Chinese women undergoing first‐trimester screening for trisomy 21
Authors: Sahota D. S. , Leung T. Y. , Fung T. Y. , Chan L. W. , Law L. W. , Lau T. K.
Published: March 2009

Objective

To establish normative values and distribution parameters of first‐trimester maternal serum free β‐human chorionic gonadotropin (β‐hCG), pregnancy‐associated plasma protein‐A (PAPP‐A) and fetal nuchal translucency (NT) thickness in Chinese women and to examine the effects of covariates on their levels.

Methods

Maternal serum free β‐hCG, PAPP‐A and fetal NT were measured in 9762 women presenting for first‐trimester combined screening for Down syndrome at 11 to 14 weeks of gestation. Individuals' markers were converted to multiples of the median (MoM) using expected medians estimated by performing a weighted regression analysis. Multivariate regression analysis was performed to assess the influence of maternal weight, parity, ethnicity, chorionicity in twin pregnancies, smoking, insulin‐dependent diabetes and mode of conception on individual marker MoM levels.

Results

Both free β‐hCG and PAPP‐A median values demonstrated an exponential relationship with gestational age in days. Multivariate regression analysis indicated that free β‐hCG MoM was statistically significantly dependent on maternal weight (P < 0.0001) and chorionicity in twin pregnancy (both monochorionic and dichorionic P < 0.0001), that PAPP‐A MoM was dependent on maternal weight (P < 0.0001), parity (P < 0.0001), chorionicity in twin pregnancy (both monochorionic and dichorionic P < 0.0001) and mode of conception (P = 0.002), and that fetal NT‐MoM was dependent on maternal weight (P = 0.0006) and mode of conception (P = 0.012).

Conclusion

Normative values have been generated to allow conversion of NT, free β‐hCG and PAPP‐A to their MoM equivalents and correction factors have been determined to adjust for maternal and pregnancy characteristics for use in ethnic Chinese women undergoing first‐trimester screening for aneuploidy. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Amniotic fluid ‘sludge’ detected in patients with subchorionic hematoma: a report of two cases
Authors: Tskitishvili E. , Tomimatsu T. , Kanagawa T. , Sawada K. , Kinugasa Y. , Mimura K. , Kimura T.
Published: March 2009

Amniotic fluid ‘sludge’ is defined as the presence of dense aggregates of particulate matter in close proximity to the internal cervical os. It is of clinical significance in asymptomatic patients at high risk for spontaneous delivery, and in patients with preterm labor and intact membranes. Subchorionic hematoma is another ultrasound finding that is associated with a higher incidence of threatened miscarriage and preterm delivery. We report two cases of occurrence of amniotic fluid sludge in patients with previously detected large subchorionic hematoma. In the first case subchorionic hematoma and amniotic fluid sludge were detected by ultrasonography at 13 + 1 and 18 + 6 weeks' gestation, respectively, followed by preterm premature rupture of membranes, placental abruption and emergency Cesarean section. In the second case subchorionic hematoma and amniotic fluid sludge were detected by ultrasound at 11 + 3 and 15 + 5 weeks' gestation, respectively, followed by miscarriage with histological chorioamnionitis. The coincidence of subchorionic hematoma and amniotic fluid sludge in these cases points to a possible connection between these two significant ultrasound findings. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Development of a micro‐focus x‐ray fluorescence spectrometer using multiple target anode monochromatic x‐ray sources
Authors: Maeo S. , Krämer M. , Utaka T. , Taniguchi K.
Published: March 2009

A micro‐focus x‐ray fluorescence spectrometer using an x‐ray tube with multiple excitation sources and a doubly curved crystal (DCC) has been developed in this study. The excited target of the x‐ray tube can be selected from among Cr, W, and Rh. The focal spot size for the conditions of 30 kV and 0.5 mA was estimated to be about 10 µm in diameter. The doubly curved crystal has von Hámos geometry in the vertical direction and Johann geometry in the horizontal direction. Thin Si(111) was selected as the crystal material. It can focus the W‐Lβ x‐rays into an area of 165.6 µm × 132.9 µm as the full width at half maximum for the sample position. The spectrometer combining the present x‐ray tube and DCCs was demonstrated to be able to measure an Ni particle 5 µm in diameter on an Si wafer by W‐Lβ excitation. The lower limit of detection was estimated to be 7.29 pg, or equivalent to a particle 0.58 µm in diameter. Copyright © 2009 John Wiley & Sons, Ltd.
Two Coordination Networks Built from p‐Sulfonatothiacalix[4]arene Tetranuclear Clusters
Authors: Chen Baiquan , Yuan Daqiang , Wu Mingyan , Jiang Feilong , Hong Maochun
Published: March 2009

Two coordination compounds based on p‐sulfonatothiacalix[4]arene (TCAS) were synthesized by hydrothermal reactions of TCAS with M2+ cations (M = Cu for 1, M = Co for 2) in the presence of [PhCH2N(CH3)3]+. Single‐crystal X‐ray analyses revealed that both compounds, 1 and 2, are isomorphous and crystallize in the same space group $P{\bar 1}$. The tetranuclear cluster units are connected into layer networks through complicated hydrogen‐bonding and π–π interactions. The results of thermogravimetric measurements demonstrate that 1 and 2 have the high thermal stabilities.