bluuebunny/crossref_metadata_2025_split huggingface dataset:
General Corrosion Behavior of N06022 in Super Concentrated Brines at Temperatures Higher than 100°C
Authors: Rebak Raul B. 
Published: February 2009

AbstractAlloy 22 (N06022) is a highly corrosion resistant nickel based alloy. Extensive research has been conducted in the last eight years on the corrosion behavior of Alloy 22, mainly regarding its resistance to localized corrosion. Less attention has been paid to the general corrosion resistance in highly concentrated brines that may result from the deliquescence of salts contained in dust. Salts such as mixtures of NaCl, KCl, CaCl2, NaNO3, and KNO3 may deliquesce at temperatures above 100°C through absorption of moisture from the air. Electrochemical tests were used to assess the general corrosion behavior of Alloy 22 in brines with chloride and nitrate concentrations ranging from 8 molal to 100 molal in the temperature range 100 to 160°C. The effect of mixed anions and cations was also studied. Results show that, even for short-term immersion periods, the corrosion rate of Alloy 22 in high temperatures super concentrated brines is generally below 10 μm/year.
Hydrogen Storage Properties, Metallographic Structures and Phase Transitions of Mg-based Alloys Prepared by Super Lamination Technique
Authors: Takeichi Nobuhiko , Tanaka Koji , Tanaka Hideaki , Kuriyama Nobuhiro , Ueda Tamotsu T , Tsukahara Makoto , Miyamura Hiroshi , Kikuchi Shiomi 
Published: February 2009

AbstractWe have prepared Mg/Pd laminate composites with (Mg/Pd)=6, 3 and 2.5 atom ratios, by a super lamination technique. The homogeneous Mg-Pd intermetallic compounds, Mg6Pd, Mg3Pd and Mg5Pd2, are formed during the initial activation process. We investigated the hydrogen storage properties of these materials. The compounds can reversibly absorb and desorb a large amount of hydrogen, up to 1.46˜0.9 H/M, at 573 K. Except for the Mg5Pd2-hydrogen system, the pressure composition-isotherms show two plateaux. The mechanism of the phase transition during hydrogenation/dehydrogenation was analyzed by in-situ XRD measurements. These intermetallic compounds absorb and desorb hydrogen through reversible multistage disproportionation and recombination processes.
Alloying Effect on Mechanical and Chemical Properties of Cold-rolled Ni3(Si,Ti) Foils
Authors: Fujimoto Y. , Kaneno Yasuyuki , Takasugi Takayuki 
Published: February 2009

AbstractFour kinds of L12-type Ni3(Si,Ti) intermetallic alloys with a quaternary element X (X: Al, Cr, Co and Mo) were warm rolled accompanied by intermediate annealing and then cold rolled to thin foils. The effects of alloying element on microstructure, tensile properties and oxidation resistance of the cold-rolled Ni3(Si,Ti) foils were investigated. The Al-added Ni3(Si,Ti) alloy showed an L12 single-phase microstructure, while the Cr-, Co- and Mo-added Ni3(Si,Ti) alloys exhibited a two-phase microstructure consisting of L12 and fcc Ni solid solution phases. Room-temperature strength of the Ni3(Si,Ti) foils was slightly enhanced by the addition of quaternary element, whereas high-temperature strength was significantly enhanced especially by the addition of Mo and Co. High-temperature tensile elongation was remarkably improved by the addition of all the elements investigated. On the other hand, oxidation resistance was improved by the addition of Al and Cr.
Fracture and Fatigue of Niobium Silicide Alloys
Authors: Herman David M. , Bewlay Bernard P , Cretegny Laurent , DiDomizio Richard , Lewandowski John 
Published: February 2009

AbstractThe fracture and fatigue behavior of refractory metal silicide alloys/composites is significantly affected by the mechanical behavior of the refractory metal phase. This paper reviews some of the balance of properties obtained in the alloys/composites based on the Nb-Si system. Since some of the alloy/composite properties are dominated by the behavior of the refractory metal phase, the paper begins with a review of data on monolithic Nb and its alloys. This is followed by presentation of results obtained on Nb-Si alloys/composites and a comparison to behavior of some other high temperature systems.
Modeling of Microstructure Evolution in Nb-Si Eutectic Alloy Using Cellular Automaton Method
Authors: Ohsasa Kenichi , Miura Seiji 
Published: February 2009

AbstractA numerical model was developed for the simulation of microstructure evolution during the solidification of Nb-Si eutectic alloy. In this model, the cellular automaton method was used to simulate the eutectic growth of Nb solid solution and Nb3Si intermetallics. Diffusion in liquid, mass conservation at the solid/liquid interface and local equilibrium at the solid/liquid interface with consideration of curvature undercooling were solved to determine the positions of the Nb/liquid and Nb3Si/liquid interfaces. In the alloy with eutectic composition of 0.18at%Nb, irregular eutectic growth morphology was observed in relatively lower undercooling region. On the other hand, in higher undercooling region over 50K, dendrite morphology of Nb3Si was observed. An alloy with hypo-eutectic composition, cell and dendrite morphology were observed in lower undercooling region, while coupling eutectic morphology was formed in higher undercooling region over 25K.The growth velocity of the coupling growth increased with increase in the degree of undercooling of melt.
High-temperature Deformation Kinetics of Gold at 473K to 773K
Authors: Bhakhri Vineet , Klassen Robert J. 
Published: February 2009

AbstractHigh-temperature constant-force indentation creep tests of 200 seconds duration were performed on an annealed gold specimen at 473K to 773K, to investigate the dependence of the micro-/nano-indentation deformation kinetics upon indentation stress, temperature and time. The indent stress displayed a clear indentation size effect at 473 K. An analysis of the measured indentation creep rate, and its dependence upon temperature and stress, indicate that the strength of the deformation rate limiting obstacles increases with temperature. This is consistent with the expected temperature dependent evolution of the dislocation cell structure whose boundaries become the primary obstacles to dislocation glide.
The Role of Defects in Carbon Nanostructures Probed through Ion Implantation and Electrochemistry
Authors: Hoefer Mark , Nichols Jeffrey , Bandaru Prabhakar 
Published: February 2009

ABSTRACTAs carbon nanotubes (CNTs) inevitably contain defects, an understanding of their effect on the electrochemical behavior is crucial. We consider, through Cyclic Voltammetry and Raman Spectroscopy, the influence of both intrinsic and extrinsically introduced defects. Bamboo and hollow multi-walled carbon nanotube morphologies provided examples of the former while the controlled addition of Argon and Hydrogen ions was used for studying extrinsic defects. We show that the electrocatalytic response of the hollow type CNTs can be tailored significantly, while bamboo type CNTs have innately high reactive site densities and are less amenable to modification. Argon irradiation also differs greatly from that of Hydrogen irradiation. CNT irradiation with Argon appears to positively charge CNTs, while Hydrogen irradiation neutralizes defects further allowing for the tuning of CNT defect density. The work has implications in the design of nanotube and nanowire based chemical sensors.
Effect of the powering frequency on the synthesis of carbon nanostructures by AC arc discharge at atmospheric pressure
Authors: Vittori Antisari Marco , Mirabile Gattia Daniele , Marazzi Renzo , Piscopiello Emanuela , Montone Amelia 
Published: February 2009

ABSTRACTIn this paper we report about the synthesis of single wall carbon nanohorns and highly convoluted graphite sheets by AC powered arc discharge carried out between pure graphite electrodes. The arc is ignited in air and the arched electrodes are surrounded by a cylindrical collector which collects the synthesized material and contributes to control the synthesis environment. With the purpose of studying the effect of the process variables, in this work we have explored the effect of the powering frequency on the structure of the synthesized material and on the yield of the process. Preliminary experimental results on tests carried out at constant voltage, show that the process yield is strongly influenced by the powering frequency and that higher yields are obtained at low frequency. The structure of the resulting soot has been characterized by transmission electron microscopy. Two kinds of microstructures are found by TEM observation constituted by highly convoluted graphene sheets, having locally the nanohorn morphology, and better organized nano-balls where also graphite nano-sheets can be locally found. The relative abundance of the two kinds of particles appears to depend on the powering frequency with a larger amount of the latter observed in samples synthesized at high frequency.
Fabrication of Highly Porous Zinc and Zinc Oxide Nanostructures
Authors: LaForge Joshua Michael , Brett Michael J. 
Published: February 2009

ABSTRACTGlancing angle deposition (GLAD) is a physical vapor deposition technique that depends on a highly oblique flux angle to create porous, large surface area thin films via self-shadowing. Control of the deposition parameters may provide a means to tune film porosity for zinc oxide sensors and photovoltaic devices. However, the self-shadowing mechanism requires a collimated particle flux, and therefore GLAD performs best under high vacuum. Creating structured films with sputtered GLAD is difficult since the high chamber pressure (>1 mTorr) necessary to maintain the sputter plasma reduces the mean-free-path of flux particles to less than 100 mm. By using an aperture to reduce the angle subtended by the target from the perspective of the substrate, maintaining an argon plasma pressure of 1.4 mTorr, and reducing the throw distance to less than 50 mm we were able to produce structured, polycrystalline, zinc thin films via GLAD. At oblique flux angles, highly porous films consisting of randomly oriented nanorods are grown. The nanorods have diameters between 10-100 nanometers with lengths up to several micrometers. Annealing at temperatures up to 250 °C in air produces polycrystalline zinc oxide with minimal changes to the film structure. We present details of the thin film fabrication process for the convoluted nanorod film morphology. We report characterization results for films produced at several deposition angles before and after annealing using scanning electron microscopy (SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM).
Growth and survival of northern leopard frog (Rana pipiens) tadpoles exposed to two common pesticides
Authors: Shenoy Kausalya , Cunningham B. Thomas , Enfroe James W. R. , Crowley Philip H. 
Published: February 2009

AbstractAquatic pollution is an important factor implicated in global amphibian declines. Often amphibians are exposed to sublethal levels of agrochemicals continuously throughout their larval period either because of application regimes or persistence of the chemicals in the larvae's environment. Although most studies have examined the effects of one-time or short-term exposure to contaminants on amphibian larvae, few have investigated the implications of continuous exposure over a substantial interval during larval development. We examined the effects of continuous exposure to environmentally relevant concentrations of two common pesticides—endosulfan (0.2, 1, and 5 μg/L) and mancozeb (16, 80, and 400 μg/L)—on the growth and survival of leopard frog tadpoles. The concentrations used are comparable to those estimated to be found in waterbodies near agricultural fields. The exposure period was seven weeks. Mortality was recorded daily, and length was measured photographically once before and twice during the exposure period. Both chemicals greatly reduced survival at these concentrations. Hazard ratios were significantly positive for all treatments. Growth rates of tadpoles exposed to endosulfan were not significantly reduced, but exposure to all three levels of mancozeb resulted in reduced growth rates. These results underscore the importance of further investigation into the effects of endosulfan and mancozeb on environmental and wildlife health.
Sorption of nitroaromatics to soils: Comparison of the importance of soil organic matter versus clay
Authors: Zhang Dongmei , Zhu Dongqiang , Chen Wei 
Published: February 2009

Abstract
Nitroaromatic compounds are produced and used in large quantities worldwide and are frequently detected contaminants in the environment. Sorption is one of the fundamental processes controlling the transport and availability of nitroaromatics, but previous studies have focused mainly on sorption to model clay minerals, whereas little attention has been paid to the sorptive interactions with natural soils. Findings in this study show that soil organic matter (SOM) was the predominant soil component controlling sorption of 2,4-dinitrotoluene and nitrobenzene to three typical Chinese soils, and sorption to clay minerals was much less important. The weak sorption to clay minerals was due to the type of exchangeable cations of the soils, and after saturating the soil clay minerals with K+ and Cs+, sorption to clay minerals increased significantly. Compared with the apolar phenanthrene, 2,4-dinitrotoluene and nitrobenzene exhibited much higher nonhydrophobic affinity to SOM, likely because of the π-π electron donor-acceptor interaction between the nitroaromatic molecules and the aromatic structure of the SOM. Moreover, the polarity and aromaticity of SOM might also have important effects on sorption of nitroaromatics. Sorption of nitroaromatics to natural soils appears to be more complicated than sorption of apolar hydrophobic organic compounds, and this complexity should be taken into account in environmental management such as risk calculation and transport modeling.
Development of a New Polymer Inhibitor Chemistry for Downhole Squeeze Applications
Authors: Montgomerie Harry , Chen Ping , Hagen Thomas , Vikane Olav , Matheson Rozenn , Leirvik Vibeke , Frøytlog Cato , Sæten Jens Olav 
Published: February 2009

Summary
Scale inhibitor squeeze treatments have regularly been conducted to prevent both sulphate and carbonate scale depositions in a specific North Sea field for more than 10 years. However, some wells, in which the fluid is producing from the "clean" sandstone formation, have experienced relatively short squeeze lives, when squeezing a conventional phosphonate scale inhibitor treatment. A research program has been conducted to develop a novel polymer scale inhibitor chemistry, which combines performance in a number of laboratory static and dynamic tests, with improved scale inhibitor adsorption properties on "clean" sandstone formations. Field trials have also been conducted with satisfactory results.
This paper outlines the concept of how novel scale inhibitor chemistry was developed by incorporating a special monomer to make the final copolymer scale inhibitor. The monomer was introduced to enhance the inhibitor adsorption properties, because it carries a special functional group to improve the scale inhibitor affinity for the reservoir rock. This special functional group plays a key role for the newly developed scale inhibitor, to give improved and acceptable squeeze lives. A critical aspect of the program included optimizing the monomer content to achieve a good adsorption/desorption balance, to ensure that the scale inhibitor would be desorbed/released from the reservoir rock to meet the requirements of an acceptable squeeze program. An added bonus was that the environmental properties of the scale inhibitor polymer were also improved because of the introduction of the special monomer. A number of beaker and dynamic loop tests were conducted and the inhibitor showed an excellent efficiency in both sulphate and carbonate scale inhibition performance tests under the test conditions adopted.
This paper also presents detailed laboratory and field data; the treatment design strategy and deployment method adopted for the scale inhibitor.
Kainic acid lesion-induced spatial memory deficits of rats
Authors: Hritcu Lucian , Nabeshima Toshitaka 
Published: February 2009

Abstract
The effects of lesioning the ventral tegmental area (VTA) or substantia nigra (SN) neurons by means of bilateral stereotaxic microinjections of kainic acid (KA) (0.4 mM) were investigated to clarify the role of the VTA and the SN neurons in learning and memory processes. The present study demonstrates that KA in the SN and the VTA lesioned rats significantly decreased spontaneous alternation in Y-maze task, working memory and reference memory in radial 8 arm-maze task, suggesting effects on spatial memory performance. Our findings provide further support for the role of the VTA and the SN neurons in processing and storage of information.
Hydrogen peroxide-induced response in E. coli and S. cerevisiae: different stages of the flow of the genetic information
Authors: Semchyshyn Halyna 
Published: February 2009

Abstract
Adaptation to oxidative stress is a major topic in basic and applied research. Cell response to stressful changes is realized through coordinated reorganization of gene expression. E. coli and S. cerevisiae are extremely amenable to genetic or molecular biological and biochemical approaches, which make these microorganisms suitable models to study stress response at a molecular level in prokaryotes and eukaryotes, respectively. The main focus of this review is (i) to discuss transcriptional control of global response to hydrogen peroxide in E. coli and S. cerevisiae, (ii) to summarize recent literature data on E. coli and S. cerevisiae adaptive response to oxidative stress at different stages of the flow of the genetic information: from transcription and translation to functionally active proteins and (iii) to discuss possible reasons for a lack of correlation between the expression of certain antioxidant genes at different levels of cellular organization.
In vivo effects of N/OFQ(1–13)NH2 and its structural analogue [ORN9]N/OFQ(1–13)NH2 on carrageenan-induced inflammation: rat-paw oedema and antioxidant status
Authors: Zamfirova Rositsa , Tzvetanova Elina , Alexandrova Albena , Petrov Lubomir , Mateeva Polina , Pavlova Almira , Kirkova Margarita , Todorov Simeon 
Published: February 2009

Abstract
The effects of nociceptin(1–13)NH2 (N/OFQ(1–13)NH2) and its structural analogue [Orn9]N/OFQ(1–13)NH2 on acute carrageenan (CG)-induced peripheral inflammation and paw antioxidant status were studied. CG was injected intraplantarly in the right hind paw of rats and the volume of the inflamed paw was measured each 30 min for a period of 4h. When administered simultaneously with CG, N/OFQ(1–13)NH2 decreased the paw volume, whereas if injected 15 min before CG it had no effect. [Orn9]N/OFQ(1–13)NH2 produced the opposite effects at the same time-intervals of its administration. We also investigated whether these neuropeptides influence CG-induced changes in cell antioxidant system, especially at the 4th hour of CG administration. CG alone decreased the glutathione level and superoxide dismutase activity, as measured in post-nuclear homogenate of the inflamed paw. However, CG injection increased glutathione peroxidase and glucose-6-phospate dehydrogenase activities, while the activity of glutathione reductase was unchanged. The peptides themselves did not change all measured parameters. Moreover, neither N/OFQ(1–13)NH2 nor [Orn9]N/OFQ(1–13)NH2 modified CG-induced changes in the antioxidant status, regardless of the time of their injection (simultaneously or 15 min before CG). The present results suggest that N/OFQ(1–13)NH2 and [Orn9]N/OFQ(1–13)NH2 most likely affect the neuronal inflammation, rather than act as pro- or antioxidants.
The effects of disodium pamidronate on human polymorphonuclear leukocytes and platelets: An in vitro study
Authors: Salvolini Eleonora , Orciani Monia , Vignini Arianna , Primio Roberto , Mazzanti Laura 
Published: February 2009

AbstractRecent reports have indicated that, as well as having antiresorptive effects, bisphosphonates could have an application as anti-inflammatory drugs. Our aim was to investigate whether this anti-inflammatory action could be mediated by the nitric oxide (NO) released by the leukocytes migrating to the site of inflammation. In particular, we investigated in vitro the intracellular calcium concentration ([Ca2+]i), the level of NO released by PMN and platelets, and the PMN myeloperoxidase activity after incubation with disodium pamidronate, since there was a postulated modulatory effect of this aminosubstituted bisphosphonate on leukocytes both in vitro and in vivo. Our data shows that the pamidronate treatment provoked a significant increase in the [Ca2+]i parallel to the enhancement in NO release, suggesting a possible activation of constitutive nitric oxide synthase, while the myeloperoxidase activity was significantly reduced. In conclusion, we hypothesized that treatment with pamidronate could stimulate NO-production by cells present near the bone compartment, thus constituting a protective mechanism against bone resorption occurring during inflammation. In addition, PMN- and platelet-derived NO could act as a negative feed-back signal to restrict the inflammatory processes.
The expression of protein kinase B in gastric cancer cell apoptosis induced by 12-O-tetradecanoylphorbol-1, 3-acetate
Authors: Zhang Bing , Xia Chun 
Published: February 2009

AbstractProtein kinase B (PKB/Akt) is a serine-threonine kinase functioning downstream of phosphatidylinositol 3-kinase (PI-3 kinase) in response to mitogen or growth factor stimulation. In several cell types, it plays an important anti-apoptotic role. TPA is a potent regulator of the growth of many different cell types. Here, we detected that TPA could induce cell apoptosis in the gastric cancer cell line, BGC-823. We also found that TPA inhibited the expression of PKB/Akt in a TPA concentration- and time-dependent manner. Furthermore, TPA inhibited the phosphorylation of PKB at Ser473, but did not affect the phosphorylation of Thr308. It only attenuated the expression of PKB/Akt and the phosphorylation of Ser473 in the cell nucleus, whereas it did not change the PKB/Akt distribution in BGC-823 cells. These results suggest that PKB/Akt inhibition by TPA may be the important factor in the mechanism of effect of TPA on gastric cell lines.
Towards optimum permeability reduction in porous media using biofilm growth simulations
Authors: Pintelon T.R.R. , Graf von der Schulenburg D.A. , Johns M.L. 
Published: February 2009

AbstractWhile biological clogging of porous systems can be problematic in numerous processes (e.g., microbial enhanced oil recovery—MEOR), it is targeted during bio‐barrier formation to control sub‐surface pollution plumes in ground water. In this simulation study, constant pressure drop (CPD) and constant volumetric flow rate (CVF) operational modes for nutrient provision for biofilm growth in a porous system are considered with respect to optimum (minimum energy requirement for nutrient provision) permeability reduction for bio‐barrier applications. Biofilm growth is simulated using a Lattice‐Boltzmann (LB) simulation platform complemented with an individual‐based biofilm model (IbM). A biomass detachment technique has been included using a fast marching level set (FMLS) method that models the propagation of the biofilm–liquid interface with a speed proportional to the adjacent velocity shear field. The porous medium permeability reduction is simulated for both operational modes using a range of biofilm strengths. For stronger biofilms, less biomass deposition and energy input are required to reduce the system permeability during CPD operation, whereas CVF is more efficient at reducing the permeability of systems containing weaker biofilms. Biotechnol. Bioeng. 2009;103: 767–779. © 2009 Wiley Periodicals, Inc.