bluuebunny/crossref_metadata_2025 huggingface dataset:
Removal of Arsenic(III) and Arsenic(V) Ions from Aqueous Solutions with Lanthanum(III) Salt and Comparison with Aluminum(III), Calcium(II), and Iron(III) Salts
Authors: Tokunaga S.
Published: August 2006

Interactions of arsenic(III) and arsenic(V) ions with a lanthanum salt were studied with the aim of developing a new precipitation method for removal of arsenic from aqueous solutions. Performance was compared to those of aluminum, polyaluminum chloride (PAC), calcium, and iron(III) salts. Arsenic(III) was removed by iron(III) and lanthanum in a narrow pH range with less than 60% removal. Arsenic(V) was removed more efficiently by aluminum, PAC, iron(III), and lanthanum. Lanthanum was most effective, meeting Japanese effluent and drinking water standards by adding three times as much lanthanum as arsenic(V). The stoichiometry and X‐ray diffraction measurement showed that the precipitation reactions are La3+ + H2AsO4− → LaAsO4 + 2H+ (pH 5) (1) and La3+ + HAsO42− → LaAsO4 + H+ (pH 9) (2) The solubility product of lanthanum arsenate, LaAsO4, was calculated to be 1.07 ± 0.03 × 10−21.
The Application of Electronic Nose Technology to Environmental Monitoring of Water and Wastewater Treatment Activities
Authors: Fenner R.A. , Stuetz R.M.
Published: August 2006

An electronic nose instrument was evaluated for its ability to monitor liquid wastewater samples, wastewater odor, and tainting compounds in water supplies. Current methods for measuring odors are based on human sensory panels (olfactometry) and used to determine 50% detection thresholds. Such methods are time consuming, labor intensive, and subject to large variation between analyses. An electronic nose, consisting of a nonspecific sensor array, could offer a more objective means of measuring odors emanating from water and wastewater. Monitoring of quiescent wastewater liquors from three treatment works over an 8‐month period showed that an electronic nose could distinguish between wastewater samples of different types and origins. Threshold odor numbers obtained from olfactometry analysis were correlated with electronic nose output for wastewater odors from 10 treatment works. Results suggested that no universal relationship exists between these parameters; however, a strong linear relationship can be produced for odor samples that are site or source specific. The electronic nose was also tested for its ability to screen raw and treated water supplies for tainting compounds. This aspect of the work demonstrated that low levels of organic pollutants can be detected by monitoring water samples with the nose.
The effect of processing wavelength and fluence on the microdrilling of 316 L stainless steel with a diode pumped solid state laser
Authors: Tunna L. , Khan A. , O’Neill W. , Sutcliffe C. J.
Published: August 2006

Diode pumped solid state lasers (DPSSs) with multiwavelength capability have become a powerful tool in laser material processing over the last few years. One application of high beam quality DPSS lasers that has received increased attention lately is the drilling of small diameter (<100 μm) holes through industrially important materials. Processing parameters play an important role and limit the precision of the process. A systematic series of experiments was performed to investigate the effect of the high fluence laser-drilling event in ambient air. From this study suitable processing regimes were established.
In-line failure detection and diagnosis of excimer laser-based microvia fabrication using computational intelligence
Authors: Setia Ronald , May Gary S.
Published: August 2006

In this article, two computational intelligent methodologies for run-to-run, in-line excimer laser ablation process failure detection and diagnosis are compared. The techniques used are: (1) a combination of feed-forward neural networks and Dempster-Shafer theory; and (2) adaptive neurofuzzy networks. Both methodologies employ response data originating directly from the laser equipment and characterization of microvias formed by the ablation process, which serves as evidence of equipment malfunctions affecting process parameters. Both neural networks and neurofuzzy models are trained and validated based on this data. Successful failure detection is achieved in 100% of 19 possible failure scenarios using the first technique. Moreover, successful failure diagnosis is also achieved, with only a single false alarm occurring in the 19 failure scenarios. Using adaptive neurofuzzy logic, results indicate a single false alarm in 19 possible failure detection scenarios. For failure diagnosis, a single false alarm and a single missed alarm occur. Neural networks and neuro-fuzzy networks thus achieve approximately 95% and 90% success in diagnosis, respectively.
Optimization of optical density requirements for multiwavelength laser safety
Authors: Hayes Kristy L. , Thomas Robert J. , Pingry Richard E.
Published: August 2006

Multiwavelength laser exposures pose unique safety challenges for both laser experts and users of laser systems. We describe two methods of optimizing optical density requirements for multiwavelength laser exposures. The problem is first formulated and solved using standard mathematical programming techniques, and the results are compared to those from a simplified algorithm. The result is a method that can be efficiently integrated into existing laser modeling and hazard analysis software. As an example, overall visible light transmittance is maximized while maintaining eye-safe viewing conditions during a multiwavelength exposure, simultaneously minimizing the total optical density required for sufficient laser eye protection. This optimization formulation helps laser system users determine the proper laser eye protection for safe viewing in multiwavelength laser environments.
Hybrid laser beam welding—Classification, characteristics, and applications
Authors: Mahrle A. , Beyer E.
Published: August 2006

Hybrid laser welding technologies can be defined as the combination of a high quality laser heat source with an additional secondary heat source. Based on such a definition, known hybrid techniques are classified by the type of the heat sources used as well as their arrangement relative to each other. The classification is followed by a discussion of different theoretical aspects occuring during a hybrid laser beam welding process concerning the plasma characteristics and the resultant temperature distribution of the superposed heat sources. Finally, some practical examples demonstrate how the potential of hybrid technologies can be used to extend the application spectrum of the laser beam welding process.
Controlled-fracture of prescored alumina ceramics using simultaneous CO2 lasers
Authors: Brugan P. , Cai G. , Akarapu R. , Segall A. E.
Published: August 2006

While brittle materials such as ceramics will clearly be at the forefront of improved energy efficiency, manufacturing problems related to shaping have proven to be troublesome. Fortunately, the usage of laser machining to shape structural ceramics is increasingly gaining acceptance as an alternative to traditional grinding and cutting methods. Despite the great promise of lasers for a variety of cutting and drilling procedures, premature fractures, poor surface quality, microscale damage, and prohibitively low cutting-speeds are still among the greatest obstacles, especially as the thickness is increased. While many factors contribute to the fractures encountered during laser machining, it is the inevitable and localized increase in temperature and the ensuing thermal stresses that usually cause the damage. As such, the minimization of heat buildup and the resulting thermal stresses often requires the slow and expensive practice of multiple pass or interrupted cutting or drilling. To help control fractures and allow faster machining, a unique method of simultaneously scoring and cutting known as “prescoring” was explored using alumina plates. This concept has now been used to refine the “controlled fracture” approach, where thermal stresses are used to drive a propagating crack along a preordained path using simultaneous CO2 lasers. Using this technique and a systematic design of experiment approach to investigate the effects of various parameters, the use of the dual-beam technique was shown to be capable of predictably controlling fractures in relatively thick alumina plates. In addition to providing a clean fracture surface, this method was also shown to be capable of machining these specimens faster and with less energy input than other laser machining procedures will allow.
Thermal and microstructural aspects of the laser direct metal deposition of waspaloy
Authors: Pinkerton Andrew J. , Karadge Mallikarjun , Ul Haq Syed Waheed , Li Lin
Published: August 2006

A potential problem in applying the laser direct metal deposition (LDMD) technique to the fabrication of superalloys is the possibility of an inconsistent microstructure and gamma-prime constituency throughout a component. Understanding the causes for these inconsistencies is a crucial step towards eliminating it and facilitating widespread application of the technique. This article uses thermocouple and pyrometric thermal monitoring of the LDMD process and optical metallographic, scanning electron microscope, and electron backscattered diffraction analyses of components built from Waspaloy to correlate LDMD process parameters and final part microstructural characteristics. Temperatures in thin wall structures show a good match to classical Rosenthal heat flow models. The Waspaloy grain morphology and orientation are found to be sensitive to LDMD power and powder mass flow rate parameters, with columnar grains forming preferentially at lower powder mass flow rates. Results cannot be explained purely in terms of established maps that relate microstructure to temperature gradient at the solidification front and its velocity. This leads to the conclusion that intra melt pool factors such as local fluctuations in temperature gradients and changes in nucleation density are significant.
Laser welding of zinc coated steels in an edge lap configuration
Authors: Pieters R. R. G. M. , Bakels J. G. , Hermans M. J. M. , den Ouden G.
Published: August 2006

Ever increasing amounts of zinc coated sheet steel are being applied in the automotive industry. At present, the main joining method used for this application is resistance spot welding. In many automotive applications there are opportunities for replacing this technique by laser welding. During the assembly of these sheets major problems arise when welding in overlap configuration as result of the low boiling temperature of zinc in comparison to the melting temperature of steel. This results in pores and/or blowholes in the weld due to instabilities during welding. In this article research is presented which shows the possibilities of welding these zinc coated steel sheets in an edge lap configuration without present gap. In this configuration the zinc vapor between the sheets has an alternative escape route other than through the weld pool and it is shown that the amount of spatter can be controlled when using such a joint configuration.
Recombinant human soluble tumor necrosis factor receptor fusion protein as treatment for steroid refractory graft‐versus‐host disease following allogeneic hematopoietic stem cell transplantation
Authors: Busca Alessandro , Locatelli Franco , Marmont Filippo , Ceretto Cristina , Falda Michele
Published: August 2006

Etanercept is a recombinant human soluble tumor necrosis factor (TNF‐α) receptor fusion protein that inhibits TNF‐α, a major mediator in the pathogenesis of graft‐versus‐host disease (GVHD). The purpose of our study was to evaluate the safety and efficacy of etanercept therapy in 21 patients with steroid‐refractory acute GVHD (aGVHD) (n = 13) and chronic GVHD (cGVHD) (n = 8). Etanercept 25 mg was given subcutaneously twice weekly for 4 weeks followed by 25 mg weekly for 4 weeks. At the time of initiation of etanercept, 14 patients had skin, 13 had gastro‐intestinal, 5 had liver, 5 had pulmonary, and 4 had oral involvement. Twelve patients (57%) completed 12 doses of therapy. Overall, 11 of 21 patients (52%) responded to the treatment with etanercept, including 6 patients (46%) with aGVHD [n = 4 complete response (CR), n = 2 partial response (PR)] and 5 patients (62%) with cGVHD (n = 1 CR, n = 4 PR). Clinical responses were most commonly seen in patients with refractory gut aGVHD with 55% of the patients having a CR and 9% having a PR. CMV reactivation occurred in 48% of patients, bacterial infections in 14% of patients, and fungal infections in 19% of patients. Fourteen patients (67%) were alive after a median follow‐up of 429 days (range 71–1007 days) since initiation of etanercept. Seven patients died, 3 of infections, 2 of refractory aGVHD, and 2 of disease progression. In conclusion, our preliminary data indicate that etanercept is well tolerated and can induce a high response rate in patients with steroid‐refractory aGVHD and cGVHD, particularly in the setting of GI involvement. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.
A kinetic study of lipase‐catalyzed reversible kinetic resolution involving verification at miniplant‐scale
Authors: Berendsen W.R. , Gendrot G. , Freund A. , Reuss M.
Published: August 2006

Lipase‐catalyzed kinetic resolution of racemates is a popular method for synthesis of chiral synthons. Most of these resolutions are reversible equilibrium limited reactions. For the first time, an extensive kinetic model is proposed for kinetic resolution reactions, which takes into account the full reversibility of the reaction, substrate inhibition by an acyl donor and an acyl acceptor as well as alternative substrate inhibition by each enantiomer. For this purpose, the reversible enantioselective transesterification of (R/S)‐1‐methoxy‐2‐propanol with ethyl acetate catalyzed by Candida antarctica lipase B (CAL‐B) is investigated. The detailed model presented here is valid for a wide range of substrate and product concentrations. Following model discrimination and the application of Haldane equations to reduce the degree of freedom in parameter estimation, the 11 free parameters are successfully identified. All parameters are fitted to the complete data set simultaneously. Six types of independent initial rate studies provide a solid data basis for the model. The effect of changes in substrate and product concentration on reaction kinetics is discussed. The developed model is used for simulations to study the behavior of reaction kinetics in a fixed bed reactor. The typical plot of enantiomeric excess versus conversion of substrate and product is evaluated at various initial substrate mixtures. The model is validated by comparison with experimental results obtained with a fixed bed reactor, which is part of a fully automated state‐of‐the‐art miniplant. © 2006 Wiley Periodicals, Inc.
The use of an oil absorber as a strategy to overcome starvation periods in degrading 1,2‐dichloroethane in waste gas
Authors: Koutinas Michalis , Baptista Inês I.R. , Peeva Ludmila G. , Ferreira Jorge Ruben M. , Livingston Andrew G.
Published: August 2006

This work investigates the use of an oil absorber as an operational strategy in vapor phase bioreactors exposed to starvation periods, during the treatment of inhibitory pollutants. After being exposed to 1,2‐dichloroethane (DCE) starvation periods, the response and stability of a combined oil‐absorber‐bioscrubber (OAB) system was compared to that of a bioscrubber only (BO) system. In the BO system, after a 5.2 days starvation period, the DCE removal efficiency was reduced to 12%, and 6 days were needed to recover the initial removal efficiency when the DCE feed resumed. The total organic discharged (TODDCE) was 16,500 gDCE m after the DCE starvation. Biomass analysis performed using fluorescence in situ hybridisation (FISH) showed that the microbial activity was significantly reduced during the starvation period and that 5 days were needed to recover the initial activity, after the re‐introduction of DCE. In contrast, the performance of the OAB system was stable during 5.2 days of DCE starvation. The DCE removal efficiency was not affected when the DCE feed resumed and the TODDCE was significantly reduced to 2,850 gDCE m. During starvation, the activity of the microbial culture in the OAB system showed a substantially lower decrease than in the BO system and recovered almost immediately the initial activity after the re‐introduction of DCE. Additionally, a mathematical model describing the performance of the OAB system was developed. The results of this study show that the OAB system can effectively sustain the biological treatment of waste gas during starvation periods of inhibitory pollutants. Biotechnol. Bioeng. 2007;96:673–686. © 2006 Wiley Periodicals, Inc.
Intracellular protein binding to asbestos induces aneuploidy in human lung fibroblasts
Authors: MacCorkle R. A. , Slattery S. D. , Nash D. R. , Brinkley B. R.
Published: August 2006

Exposure to the natural mineral fiber asbestos causes severe lung‐damaging fibrosis and cancer, yet it continues to be used as an industrial insulating material throughout the world. When cultured human lung cells are exposed to asbestos, individual fibers are engulfed into the cytoplasm where they induce significant mitotic aberrations leading to chromosomal instability and aneuploidy. The mechanisms of how asbestosis ultimately leads to lung cancer remain unclear. However, our experiments indicate that intracellular asbestos fibers induce aneuploidy and chromosome instability by binding to a subset of proteins that include regulators of the cell cycle, cytoskeleton, and mitotic process. Moreover, precoating of fibers with protein complexes efficiently blocked asbestos‐induced aneuploidy in human lung cells without affecting their uptake by cells. These results provide new evidence that asbestos fibers can contribute to significant spindle damage and chromosomal instability by binding to proteins needed for the assembly and regulation of the cytoskeleton or the cell cycle. Cell Motil. Cytoskeleton, 2006. © 2006 Wiley‐Liss, Inc.
Dual roles of tropomyosin as an F‐actin stabilizer and a regulator of muscle contraction in Caenorhabditis elegans body wall muscle
Authors: Yu Robinson , Ono Shoichiro
Published: August 2006

Tropomyosin is a well‐characterized regulator of muscle contraction. It also stabilizes actin filaments in a variety of muscle and non‐muscle cells. Although these two functions of tropomyosin could have different impacts on actin cytoskeletal organization, their functional relationship has not been studied in the same experimental system. Here, we investigated how tropomyosin stabilizes actin filaments and how this function is influenced by muscle contraction in Caenorhabditis elegans body wall muscle. We confirmed the antagonistic role of tropomyosin against UNC‐60B, a muscle‐specific ADF/cofilin isoform, in actin filament organization using multiple UNC‐60B mutant alleles. Tropomyosin was also antagonistic to UNC‐78 (AIP1) in vivo and protected actin filaments from disassembly by UNC‐60B and UNC‐78 in vitro, suggesting that tropomyosin protects actin filaments from the ADF/cofilin‐AIP1 actin disassembly system in muscle cells. A mutation in the myosin heavy chain caused greater reduction in contractility than tropomyosin depletion. However, the myosin mutation showed much weaker suppression of the phenotypes of ADF/cofilin or AIP1 mutants than tropomyosin depletion. These results suggest that muscle contraction has only minor influence on the tropomyosin's protective role against ADF/cofilin and AIP1, and that the two functions of tropomyosin in actin stability and muscle contraction are independent of each other. Cell Motil. Cytoskeleton 2006. © 2006 Wiley‐Liss, Inc.
From faculty to administrator: Like going to a new planet
Authors: Foster Brian L.
Published: August 2006

The transition from faculty to administration is a cultural as well as organizational shift.
Efficient visualization of high‐order finite elements
Authors: Remacle Jean‐François , Chevaugeon Nicolas , Marchandise Émilie , Geuzaine Christophe
Published: August 2006

A general method for the post‐processing treatment of high‐order finite element fields is presented. The method applies to general polynomial fields, including discontinuous finite element fields. The technique uses error estimation and h‐refinement to provide an optimal visualization grid. Some filtering is added to the algorithm in order to focus the refinement on a visualization plane or on the computation of one single iso‐zero surface. 2D and 3D examples are provided that illustrate the power of the technique. In addition, schemes and algorithms that are discussed in the paper are readily available as part of an open source project that is developed by the authors, namely Gmsh. Copyright © 2006 John Wiley & Sons, Ltd.
Block diagonalization of Laplacian matrices of symmetric graphs via group theory
Authors: Kaveh A. , Nikbakht M.
Published: August 2006

In this article, group theory is employed for block diagonalization of Laplacian matrices of symmetric graphs. The inter‐relation between group diagonalization methods and algebraic‐graph methods developed in recent years are established. Efficient methods are presented for calculating the eigenvalues and eigenvectors of matrices having canonical patterns. This is achieved by using concepts from group theory, linear algebra, and graph theory. These methods, which can be viewed as extensions to the previously developed approaches, are illustrated by applying to the eigensolution of the Laplacian matrices of symmetric graphs. The methods of this paper can be applied to combinatorial optimization problems such as nodal and element ordering and graph partitioning by calculating the second eigenvalue for the Laplacian matrices of the models and the formation of their Fiedler vectors. Considering the graphs as the topological models of skeletal structures, the present methods become applicable to the calculation of the buckling loads and the natural frequencies and natural modes of skeletal structures. Copyright © 2006 John Wiley & Sons, Ltd.
Direct correlation between proteins' folding rates and their amino acid compositions: An ab initio folding rate prediction
Authors: Ma Bin‐Guang , Guo Jian‐Xiu , Zhang Hong‐Yu
Published: August 2006

Discovering the mechanism of protein folding, in molecular biology, is a great challenge. A key step to this end is to find factors that correlate with protein folding rates. Over the past few years, many empirical parameters, such as contact order, long‐range order, total contact distance, secondary structure contents, have been developed to reflect the correlation between folding rates and protein tertiary or secondary structures. However, the correlation between proteins' folding rates and their amino acid compositions has not been explored. In the present work, we examined systematically the correlation between proteins' folding rates and their amino acid compositions for two‐state and multistate folders and found that different amino acids contributed differently to the folding progress. The relation between the amino acids' molecular weight and degeneracy and the folding rates was examined, and the role of hydrophobicity in the protein folding process was also inspected. As a consequence, a new indicator called composition index was derived, which takes no structure factors into account and is merely determined by the amino acid composition of a protein. Such an indicator is found to be highly correlated with the protein's folding rate (r > 0.7). From the results of this work, three points of concluding remarks are evident. (1) Two‐state folders and multistate folders have different rate‐determining amino acids. (2) The main determining information of a protein's folding rate is largely reflected in its amino acid composition. (3) Composition index may be the best predictor for an ab initio protein folding rate prediction directly from protein sequence from the standpoint of practical application. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Acoustic phonons in InSb probed by time‐resolved X‐ray diffraction
Authors: Morak A. , Kämpfer T. , Uschmann I. , Lübcke A. , Förster E. , Sauerbrey R.
Published: August 2006

Acoustical phonons in InSb were induced with femtosecond light pulses and probed by diffraction of ultrashort X‐ray pulses in the crystal lattice. The time dependent transient X‐ray diffraction signal due to elastic lattice deformation was measured with subpicosecond resolution. The elastic lattice deformation depends on the temporal evolution of the energy transfer from excited electrons in the semiconductor into the lattice. As already shown in previous investigation a conventional thermoelastic model is not sufficient to describe this coupling process. Here a complex simulation including a two temperature model of the electron and lattice as well as the microscopic behavior of the electron plasma is applied to explain important effects like thermal carrier diffusion and band gap deformation found in the lattice deformation experiments. When this model is used, with realistic values for both pump laser fluences and bulk material constants, excellent agreement between the experimentally observed time dependent lattice deformation and calculated values is obtained throughout the observation period. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Band‐edge photoluminescence in CdTe
Authors: Horodyský P. , Grill R. , Hlídek P.
Published: August 2006

Near band‐gap photoluminescence (PL) and absorption of bulk crystals of CdTe were measured over a wide range of temperatures (4–500 K). It is demonstrated that the high‐temperature (above 150 K) PL intensity correlates with a lower quality of the samples and quasiparticle localization induced by the crystal potential fluctuations. The influence of the high absorption coefficient at the free‐exciton resonance energy on the PL spectra is analytically studied by solving the diffusion‐recombination equation. We show that the reabsorption of the radiation by the free‐exciton states creates two illusory PL maxima. No dead surface layer is needed to explain reabsorption effects. The room‐temperature PL maximum matches neither the free‐exciton resonance nor the band‐gap energy. The high temperature PL is explained by the recombination of electrons and holes localized on potential fluctuations. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theory of the cubic‐tetragonal phase transition in PbTiO3
Authors: El‐frikhe Es‐saïd , Toumanari Ahmed , Khatib Driss
Published: August 2006

The phase transition in PbTiO3 is discussed quantitatively from the microscopic free energy based upon the mean field approximation, where the Ti ions shift is considered as the order parameter in the lattice having the spontaneous deformation. From our calculation of the microscopic free energy, the ionic shift of the Ti ion and the coefficient of the expanded free energy, we concluded that the transition temperature and the order of cubic‐tetragonal transition are well explained by this model. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Application of neutron diffraction on the spinel system with long and short range order
Authors: Hamedoun M. , Talbi F. , Masrour R. , Bouslykhane K. , Hourmatallah A. , Benzakour N.
Published: August 2006

The diluted spinels systems ZnCr2x Al2–2x S4 have been studied by means of neutron diffraction in the concentration range0.3 ≤ x ≤ 1. For this compound, several powders samples with different heat treatment and a single crystal were studied. A helical structure with, wave vector k1 = [0, 0, 0.79] and mk1 ⊥ [001] is built up in a second‐order phase transition. At T 0 = 12 K, a first order transition takes place and the helical structure begins to transform into two collinear structure corresponding to k2 = [${1 \over 2}$, ${1 \over 2}$, 0], mk2//[1$ \bar 1 $0] and k3 = [1, ${1 \over 2}$, 0] mk3//[001]. For x ≤ 0.8, no long‐range magnetic ordering was detected, reflecting the presence of a spin glass state (SG). By using the high‐temperature series expansions (HTSE), we have deduced the magnetic phase diagrams. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The effects of magnetic field on the removal of organic compounds and metals by coagulation and flocculation
Authors: Duangduen C. , Nathaporn A. , Kitiphatmontree M.
Published: August 2006

The effects of magnetic field (MF) were studied using surface water from the Pra Ram IX reservoir. Dissolved organic carbon (DOC) removal was improved by exposure of untreated water to MF for up to 5 hours duration. MF was found to alter the physico‐chemical properties of some involved substances. Optimum DOC removal (15‐20%) was observed after 30‐40 minutes of exposure. Flocculation was also improved in the presence of MF. The removal of DOC, iron, heavy metals (As, Zn) was the best with an optimum ferric chloride dosage of 50 mg/L and exposure to 0.35Tesla magnetic field for 30 min. However, Ca removal was not affected by this treatment. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Decoherence effects due to exciton‐phonon interaction in CdSe quantum dots: Contribution of the piezoelectricity and deformation potential couplings
Authors: Sellami Karim , Jaziri Sihem
Published: August 2006

We analyse decoherence effects of an exciton in II‐VI semiconductor quantum dot. We calculate the scattering rate of excitons by acoustic phonons laying a foundation for work on understanding carrier relaxation in quantum dots providing then a basis for studying decoherence phenomena in these systems. We considered two exciton‐acoustic phonons scattering mechanisms the standard deformation potential coupling and the piezoelectric coupling. The latter was found to be relatively important in large dots. We discuss the influence of an external applied magnetic field and the dot size on the scattering rate. We show that it depends strongly on the quantum dot size, then using a modulated external magnetic field the interaction of the exciton and acoustic phonon modes can be modified in a wide range. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetic properties of the electrolytic super alloys Ni‐Fe
Authors: Bouhouch L. , Fadel M. , Hilali E.
Published: August 2006

This paper will be devoted to the study of the magnetic properties of the layers of Ni100–xFex alloys, obtained by electrolytic deposit. The chemical composition of these alloys varies, according to the content of both constituents nickel and iron, from 50 at% to 90 at% of nickel, for a layer thickness of about 10 μm. We have started a systematic study in order to determine the influence of the atomic composition of nickel on specific magnetization to saturation and the hysteresis loops, as well as the thermomagnetic effects. During our investigations, we noted that, firstly specific magnetization to saturation grows almost linearly with the content of iron of alloy. Secondly, the hysteresis loops present all a low coercitive force and a strong susceptibility. Finally we underlined that the effect of the heat treatment is very strong for the low contents of iron of alloy. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phonon frequency calculations of GdBCO and PrBCO
Authors: Tavana A. , Khosroabadi H. , Akhavan M.
Published: August 2006

Ab initio frozen‐phonon calculations have been performed for k = 0 Ag Raman modes of superconducting GdBa2Cu3O7 and insulating PrBa2Cu3O7. We have used the generalized gradient approximation full‐potential linear augmented plane‐wave method in our calculations by Wien2k code. Results have been compared with other computational and experimental data for similar systems. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Time dependence of magnetization in Fe1–xCox fine particles
Authors: Zoriasatain S. , Sebt S.A. , Akhavan M.
Published: August 2006

The change of the applied field in a medium containing anisotropic magnetic grains, makes the number of magnetic moments in the field direction, and in the opposite direction to vary. Near H = H c, probability of transition between the two minimum energies (SW model) increases strongly and the magnetization of system varies rapidly. We measured the time dependence of magnetization for various Fe1–xCox samples, in the presence of some step fields. These samples were grown via solving iron, and cobalt salts with borohydride and then, heat treatment was accomplished on them. The results of time measurement of magnetization in step fields reveals a linear proportionality between coercivity and magnetic stability. We have analyzed these results using magnetization models. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Determination of the pinned vortex fraction in type‐II superconductors
Authors: Bouaaddi A. , Taoufik A. , Labrag A. , Bghour M. , Abaragh A. , Ramzi A. , Senoussi S.
Published: August 2006

In this article we intend to study the pinned vortex fraction in a type II superconductors. The sample used is the YBa2Cu3O7‐γ. This fraction pinned is determined from the comparison of the experimental results and the theoretical results previously definite. In continuation one will study the variations of this fraction according to the temperature of the applied magnetic field and the electric current crossing the sample. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Apical oxygen, 3D‐2D cross over and superconductivity in Sm2–xCexCuO4–δ
Authors: Boujida M.
Published: August 2006

In spite of the vast amount of experimental and theoretical articles accumulated in HTSC, the mechanism of the interaction driving charge carriers to form Cooper pairs below Tc is still unknown. The comparison of the normal state transport properties of YBa2Cu3O7–δ and the Sm2–xCexCuO4–δ [1, 2] might shed some light on the microscopic origin of HTSC. In comparison to the YBCO, the apical oxygen in Sm2–xCexCuO4–δ [3] destroys the superconductivity via the vertical ionic bonding which localizes the charge in the Cu‐O squares, however the hole transfer by moving O(4) towards the CuO2 planes, leads to the optimization of YBCO properties. The behaviour of C axis parameter vs the oxygen content cannot be explained by a BSC mechanism. The high amount of anisotropy ratio [4] is explained by the sheer square planes in NCCO system, i.e. without apical oxygen (SC with Tc maximum). From the data of the resistivity in the normal state, we conclude the observation of a 3D‐2D cross over only in Sm2–xCexCuO4–δ [2] and Nd2–xCexCuO4–δ [5] which is also related to its high anisotropy. The competition between anisotropy and superconductivity destroys the superconducting state in the 2D limit even in the ground state. In this material the superconductivity cannot be enhanced at high temperature because the compound is a quasi 2D system (sheer square planes of CuO2) and the cuprate superconductors is a genuine three‐dimensional (3D) phenomenon [6]. The Josephson coupling between the different layers is S‐I‐S for NCCO and S‐N‐S for YBCO, thus the Lawrence and Doniach model (LD) [7] with neighbouring layers coupled by the Josephson tunnelling is appropriate. In summary the behaviour of apical oxygen is intrinsically different in the two kinds of cuprates. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Neutron diffraction line broadening of twins in YBa2Cu3O6+x (0 < x < 1) at high temperatures
Authors: Khoshnevisan B. , Ross D. K.
Published: August 2006

We report here on the nature of the twinning associated with the tetragonal to orthorhombic I (T/OI) phase transition in YBCO, for temperatures between 500 °C and 600 °C. In situ neutron diffraction measurements show the coexistence of the T and split OI peaks in the vicinity of the transition. However, by direct numerical simulation, we show that this is to be expected from the twinned OI structure when the separation of adjacent twinning planes and the orthorhombicity both approach zero. It is demonstrated that the observed hkl‐dependent peak broadening is consistent with this interpretation. A comparison of the measured and simulated peak shapes enables us to make an approximate estimate of the actual twin widths for a given orthorhombicity. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The effect of phonon‐electron thermal decoupling on the low‐T thermal conductivity data of cuprates
Authors: Smith M. F.
Published: August 2006

We describe how the anomalous decrease in the thermal conductivity, which has been observed in several cuprates at sub‐Kelvin temperatures, occurs because of the thermal decoupling of phonons and electrons. In typical experimental conditions for these ultra‐low‐T thermal conductivity measurements, the initial heat current is provided to the electrons in the sample mainly by phonons. The phonon‐electron heat transfer rate falls rapidly with decreasing temperature and, below a characteristic temperature scale that we identify to be roughly 200 mK in typical cuprates, a heat‐current bottleneck develops. The electronic heat current thus becomes limited by electron‐phonon heat transfer and acquires an anomalous temperature dependence. This results in the apparent low‐T downturn of the thermal conductivity. We account for the temperature and magnetic field dependence of the low‐T thermal conductivity in both the normal and superconducting states, obtaining quantitative agreement with the data. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Risks and Challenges of Surgical Glove Failure
Authors: Rabussay Dietmar , Korniewicz Denise M.
Published: August 2006

The relationship between infection control standards and surgical gloving practices is an important issue in combating infectious disease. For their own and their patients' protection, health care personnel must rely on the barrier qualities of gloves more than ever before. Both surgical and examination gloves fail frequently, which puts health care providers and patients at risk of acquiring fluid‐borne pathogens. This paper discusses current guidelines, the risk of infection by viral and bacterial pathogens, controversial issues involving gloving practices, and recommendations to improve infection control practices. AORN J 66 (Nov 1997) 867‐888.
Patients' Responses to the Angioplasty Experience: A Qualitative Study
Authors: Sapnas Kathryn G.
Published: August 2006

Patients' Responses to the Angioplasty Experience: A Qualitative Study, M. Gulanick, American Journal of Critical Care, Vol 6, January 1997, 25–31
Occupational Health Nursing Care Guidelines
Authors: Watkins Gwendolyn R.
Published: August 2006

Occupational Health Nursing Care Guidelines Edited by Debra Daly‐Gawenda, Edsel K. Hudson, Carol Perea 1997, 336 pp $49.95 paperback
ANAC's Core Curriculum for HIV/AIDS Nursing
Authors: Lampkins Gwendolyn T.
Published: August 2006

ANAC's Core Curriculum for HIV/AIDS Nursing Edited by Kathleen Casey, Felissa L. Cohen, Anne Hughes 1996, 456 pp $46 paperback
Decreasing Surgical Risks for Patients with Obstructive Sleep Apnea
Authors: Yantis Mary Ann
Published: August 2006

The prevalence of obstructive sleep apnea (OSA) has only recently been appreciated, in part because the signs and symptoms of OSA were previously overlooked. The identification of this disorder is extremely important before surgery to allow appropriate airway management. This article presents a brief overview of sleep apnea, its symptoms, and potential consequences. Nursing interventions are given for the preoperative, intraoperative, and postoperative phases. A resource list of agencies and internet sites that reference OSA is included for additional information. AORN J 68 (July 1998) 50–55.
Managing the Patient with Perforated Intrathoracic Esophagus
Authors: Graling P.R. , Hetrick V.L. , Vaughan B. , Kiernan P.D.
Published: August 2006

The thoracic perioperative specialty team members at Inova Fairfax Hospital, Falls Church, Va, designed guidelines to improve the management of patients with esophageal perforations. They performed a retrospective analysis of 41 patients who were diagnosed with thoracic esophageal perforations from Sept 1, 1979, through Sept 1, 1996. The review affirmed their philosophy of aggressive, surgical intervention for perforations, particularly for patients diagnosed early (ie, within 24 hours). The process of examining and communicating the results among OR nurses, anesthesia care providers, and surgeons resulted in the increased efficiency and appropriateness with which patients were incorporated into the hospital's surgical and medical treatment groups. AORN J 68 (July 1998) 56–67.
Can a Threshold Limit Value for Natural Rubber Latex Air‐Borne Allergens be Defined?
Authors: Steelman Victoria M.
Published: August 2006

Can a Threshold Limit Value for Natural Rubber Latex Air‐Borne Allergens be Defined?, X Baur, Z Chen, H Allmers, Journal of Allergy and Clinical Immunology, 101, January 1998, 24–27
Sterilization Technology for the Health Care Facility
Authors: Clayton Judith
Published: August 2006

Sterilization Technology for the Health Care Facility, second ed By Marimargaret Reichert, Jack H. Young 1997, 307 pp $89 spiralbound
Hydrothermal activity and magma genesis along a propagating back‐arc basin: Valu Fa Ridge (southern Lau Basin)
Authors: Fretzdorff S. , Schwarz‐Schampera U. , Gibson H. L. , Garbe‐Schönberg C.‐D. , Hauff F. , Stoffers P.
Published: August 2006

Valu Fa Ridge is an intraoceanic back‐arc spreading center located at the southern prolongation of the Lau basin. Bathymetric observations as well as detailed sampling have been carried out along the spreading axis in order to trace hydrothermal and volcanic activity and to study magma generation processes. The survey shows that widespread lava flows from recent volcanic eruptions covered most of the Vai Lili hydrothermal vent field; only diffuse low‐temperature discharge and the formation of thin layers of siliceous precipitates have been observed. Evidence of present‐day hydrothermal activity at the Hine Hina site is indicated by a thermal anomaly in the overlying water column. Our studies did not reveal any signs of hydrothermal activity either above the seismically imaged magma chamber at 22°25′S or across the southern rift fault zone (22°51′S). Lavas recovered along the Valu Fa Ridge range from basaltic andesites to rhyolites with SiO2 contents higher than reported from any other intraoceanic back‐arc basin. On the basis of the highly variable degrees of crystal fractionation along axis, the development of small disconnected magma bodies is suggested. In addition, the geochemical character of the volcanic rocks shows that the transition zone from oceanic spreading to propagating rifting is located south of the Hine Hina vent field in the vicinity of 22°35′S.
Oxalic acid in clear and cloudy atmospheres: Analysis of data from International Consortium for Atmospheric Research on Transport and Transformation 2004
Authors: Sorooshian Armin , Varutbangkul Varuntida , Brechtel Fred J. , Ervens Barbara , Feingold Graham , Bahreini Roya , Murphy Shane M. , Holloway John S. , Atlas Elliot L. , Buzorius Gintas , Jonsson Haflidi , Flagan Richard C. , Seinfeld John H.
Published: August 2006

Oxalic acid is often the leading contributor to the total dicarboxylic acid mass in ambient organic aerosol particles. During the 2004 International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) field campaign, nine inorganic ions (including SO42−) and five organic acid ions (including oxalate) were measured on board the Center for Interdisciplinary Remotely Piloted Aircraft Studies (CIRPAS) Twin Otter research aircraft by a particle‐into‐liquid sampler (PILS) during flights over Ohio and surrounding areas. Five local atmospheric conditions were studied: (1) cloud‐free air, (2) power plant plume in cloud‐free air with precipitation from scattered clouds overhead, (3) power plant plume in cloud‐free air, (4) power plant plume in cloud, and (5) clouds uninfluenced by local pollution sources. The aircraft sampled from two inlets: a counterflow virtual impactor (CVI) to isolate droplet residuals in clouds and a second inlet for sampling total aerosol. A strong correlation was observed between oxalate and SO42− when sampling through both inlets in clouds. Predictions from a chemical cloud parcel model considering the aqueous‐phase production of dicarboxylic acids and SO42− show good agreement for the relative magnitude of SO42− and oxalate growth for two scenarios: power plant plume in clouds and clouds uninfluenced by local pollution sources. The relative contributions of the two aqueous‐phase routes responsible for oxalic acid formation were examined; the oxidation of glyoxylic acid was predicted to dominate over the decay of longer‐chain dicarboxylic acids. Clear evidence is presented for aqueous‐phase oxalic acid production as the primary mechanism for oxalic acid formation in ambient aerosols.
Intercomparison of ultraviolet photometry and gas‐phase titration techniques for ozone reference standards at ambient levels
Authors: Tanimoto Hiroshi , Mukai Hitoshi , Hashimoto Shigeru , Norris James E.
Published: August 2006

Intercomparison experiments were made between two independent techniques for ozone (O3) reference standards often used as the primary standards in air quality monitoring networks. These techniques include ultraviolet absorption photometry of O3 at the 253.7‐nm Hg line and gas‐phase titration of O3 with excess NO. For ultraviolet photometry, a well‐designed and maintained standard reference photometer (SRP) built by the National Institute of Standards and Technology (USA) was employed. For gas‐phase titration (GPT), an existing system was significantly modified by the National Institute for Environmental Studies (Japan) by using gravimetric NO/N2 standard gases, accurate flow measurement systems based on laminar flow elements, and two chemiluminescence NO detectors to minimize uncertainty in the measurements, which had previously been a major shortcoming of this method. Uncertainty in the improved GPT system was reduced to less than 0.4% above 100 nmol mol−1 O3 mole fraction. A series of comparison runs between the two methods over the course of 13 months from August 2004 to August 2005 showed a significant discrepancy, which cannot be explained by the measurement uncertainties attributed to either SRP or GPT in the range of 80–800 nmol mol−1 O3, where GPT was about 2% higher than SRP. This result indicates possible biases in the currently existing O3 reference standards and warrants further studies to identify and characterize possible sources of the systematic discrepancy.
Relationship between the boreal spring Hadley circulation and the summer precipitation in the Yangtze River valley
Authors: Zhou Botao , Wang Huijun
Published: August 2006

The connection between the boreal spring Hadley circulation (HC) and variability of the following summer east Asian atmospheric circulations and precipitation in the Yangtze River valley is investigated through an analysis of the observed data in this study. It is found that there is a significantly positive correlation between HC and the summer rainfall in the Yangtze River valley. This relationship is well supported by the changes of atmospheric general circulation backgrounds and water vapor conditions related to the variation of the preceding boreal spring HC. The summer situations of strengthened western Pacific subtropical high (WPSH), intensified South Asian high (SAH), southward located east Asian jet (EAJ) and enhanced water vapor corresponding to strong spring HC provide favorable conditions for increasing the precipitation in the Yangtze River valley and vice versa. The possible mechanism how the boreal spring HC affects summer atmospheric circulations is identified preliminarily in the study. Results show that sea surface temperature (SST) anomalies in the Indian Ocean and South China Sea may play an important role in linking the spring HC and summer atmospheric circulations. Spring HC may evoke SST anomalies in the Indian Ocean and South China Sea, which can persist from spring to summer and in turn give rise to anomalous east Asian summer monsoon. As a result, summer rainfall in the Yangtze River valley may be influenced.