bluuebunny/crossref_metadata_2025 huggingface dataset:
An XPS investigation of (La2O3)1‐x (CeO2)2x (ZrO2)2 compounds
Authors: Beche Eric , Peraudeau Gilles , Flaud Valérie , Perarnau Danielle
Published: February 2012

(La2O3)1‐x (CeO2)2x (ZrO2)2 mixed oxides (LCZ) where 0 ≤ x ≤ 1 were synthesised from commercial La2O3, CeO2 and ZrO2 powders and co‐melted in a 2‐kW solar furnace. These samples were re‐oxidised in air at temperatures that ranged from 900 K to 1100 K. The microstructures of the LC, LCZ and CZ oxides were investigated by XPS and XRD. Core‐level spectroscopy (XPS) has been used to study electronic states (III) and (IV) of the Ce 3 d5/2 and Ce 3 d3/2 levels. The resolved components of the Ce 3 d3/2,5/2 features were identified. The rate of Ce3+ and Ce4+ states were calculated for different values of x (0.1–1). The nature of the chemical bonds of Ce and O were determined from the Ce 3 d3/2,5/2 and O 1 s photoelectron peaks, respectively.The XRD study revealed the presence of solid solutions (LCZ and CZ). The presence of crystalline phases (pyrochlore and fluorite‐like structures) depends on the value of x. A decrease in the lattice parameter was observed with increasing x. La atoms were substituted by Ce atoms in a solid solution, and the oxygen vacancies were filled. The amount of fluorite‐like phase increases with an increasing amount of Ce atoms. Copyright © 2012 John Wiley & Sons, Ltd.
Toxicity and Cellular Uptake of Gold Nanorods in Vascular Endothelium and Smooth Muscles of Isolated Rat Blood Vessel: Importance of Surface Modification
Authors: Alkilany Alaaldin M. , Shatanawi Alia , Kurtz Timothy , Caldwell Ruth B. , Caldwell R. William
Published: February 2012

Gold nanorods (GNRs) have promising applications in drug delivery and cancer treatment and are generally administered via direct injection into the circulation. Thus it is necessary to evaluate their potential adverse effects on blood vessels. Herein, GNRs with various surface modifications are used to evaluate the toxicity and cellular uptake of GNRs into vascular endothelial and smooth muscle cells of isolated rat aortic rings. Surfactant‐capped GNRs are synthesized and either coated with polyelectrolyte (PE) to prepare PE‐GNRs, or modified with thiolated polyethylene glycol (PEG) to prepare PEG‐GNRs. Using toxicity assays, small‐vessel myography, fluorescence microscopy, and electron microscopy, it is shown that therapeutic concentrations of PE‐GNRs but not PEG‐GNRs are toxic to the vascular endothelium, which leads to an impaired relaxation function of aortic rings. However, no toxicity to smooth muscles is observed. Moreover, electron microscopy analysis confirms the cellular uptake of PE‐GNRs but not PEG‐GNRs into the endothelium of exposed aortic rings. The difference in toxicity and cellular uptake of PE‐GNRs versus PEG‐GNRs is explained and linked to free surfactant molecules and protein adsorption, respectively. The results indicate that toxicity and cellular uptake in the vascular endothelium in blood vessels are potential adverse effects of systemically administered GNR solutions, which can be prevented by appropriate surface functionalization.
Interactions of Gold Nanoparticles with the Interior of Hollow Graphitized Carbon Nanofibers
Authors: La Torre Alessandro , Fay Michael W. , Rance Graham A. , del Carmen Gimenez‐Lopez Maria , Solomonsz William A. , Brown Paul D. , Khlobystov Andrei N.
Published: February 2012

Interactions of free‐standing gold nanoparticles and hollow graphitized nanofibers in colloidal suspension are investigated, revealing the first example of the controlled arrangement of nanoparticles inside nano‐containers, as directed by their internal structure. The ordering is highly effective for small gold nanoparticles whose sizes are commensurate with the height of graphitic step‐edges in the graphitized carbon nanofibers and is less effective for larger gold nanoparticles. Studies aimed at understanding the role of the organic‐solvent surface tension, employed for the filling experiments, demonstrate that gold nanoparticles become preferentially anchored into the hollow graphitized carbon nanofibers under a mixture of pentane/CO2 in supercritical conditions. It is shown that a three‐step cleaning procedure enables effective removal of gold nanoparticles adsorbed on the exterior surface of graphitized carbon nanofibers, while ordered arrays of encapsulated nanoparticles are retained.
Are We Surrounded by Penguins? The Diffusion of System Dynamics in Academia Analysed with System Dynamics
Authors: Thun Jörn‐Henrik , Strohhecker Jürgen
Published: February 2012

This paper investigates the diffusion of system dynamics as research paradigm for academics. It deals with the question whether the diffusion process of system dynamics is influenced by network externalities. The so‐called penguin effect and bandwagon effect have an impact on the diffusion process assuming the existence of such network externalities. Based on a system dynamics model building on the well‐established bass model, leverage points for a successful diffusion of system dynamics will be derived by incorporating network externalities. Copyright © 2012 John Wiley & Sons, Ltd.
Is Cooperation a Panacea? The Effect of Cooperative Response to Task Conflict on Team Performance
Authors: Chen Zhen‐Jiao , Qin Xin , Vogel Douglas
Published: February 2012

Task conflict is unavoidable, and cooperation is widely adopted to manage task conflict within work teams. Prior studies demonstrated that the effects of cooperative response to task conflict on team performance can be positive or none. To explain the inconsistent effects, based on cooperation and competition theory, this study explores how and when cooperative response to task conflict increases team performance. Seventy‐one work teams from Chinese organizations responded to a survey. Results show that knowledge integration mediates the positive effect of cooperative response to task conflict on team performance. More interestingly, need for cognition and resource interdependence moderate the aforementioned mediating process in such a way that cooperative response increases team performance through knowledge integration only when need for cognition is high or when resource interdependence is high. Finally, theoretical and managerial implications are discussed. Copyright © 2012 John Wiley & Sons, Ltd.
Group Model‐Building ‘Scripts’ as a Collaborative Planning Tool
Authors: Hovmand Peter S. , Andersen David F. , Rouwette Etiënne , Richardson George P. , Rux Krista , Calhoun Annaliese
Published: February 2012

Group model building (GMB) is a participatory method for involving stakeholders in the process of developing system dynamics models. GMB has historically consisted of undocumented structured small‐group exercises. This paper describes an effort to document GMB scripts called Scriptapedia, and how documented GMB scripts can be used to design more effective GMB sessions that address cultural and ideological barriers to collaboration. A case study of a project to develop a coordinated community response to domestic violence is used to illustrate the use of scripts for planning collaboration. The paper concludes with a discussion of potential limitations of scripts and implications for future research. Copyright © 2012 John Wiley & Sons, Ltd.
A Novel Process Control Model for Extracting Vanadium Semi‐Steel in Basic Oxygen Furnace Based on Steelmaking Mechanism
Authors: Chen Kai , Zheng Zhong , Gao Xiaoqiang
Published: February 2012

A novel process control model for basic oxygen furnace (BOF) steelmaking is proposed based on metallurgy mechanism, with lower contents of carbon, manganese, silicon, and lower temperature in semi‐steel after extracting vanadium. According to mass balance and heat balance, a static control model is built up, with slagging model, temperature model, and oxygen supply model. When actual amount of oxygen supply reaches 85% of theoretical value calculated by static model, quasi‐dynamic control model is activated to predict carbon and temperature in later period of steelmaking. A steelmaking process control system for semi‐steel smelting on 120 tonne BOF is developed in a steelmaking plant in China. Based on test of three steel grades, this model acts a guide for BOF steelmaking with semi‐steel, not only providing tactic, but also pointing out a feasible method for BOF process control without sub‐lance or off‐gas analyzer.
Sigma‐1 receptor chaperones regulate the secretion of brain‐derived neurotrophic factor
Authors: Fujimoto Michiko , Hayashi Teruo , Urfer Roman , Mita Shiro , Su Tsung‐Ping
Published: February 2012

The sigma‐1 receptor (Sig‐1R) is a novel endoplasmic reticulum (ER) molecular chaperone that regulates protein folding and degradation. The Sig‐1R activation by agonists is known to improve memory, promote cell survival, and exert an antidepressant‐like action in animals. Cutamesine (SA4503), a selective Sig‐1R ligand, was shown to increase BDNF in the hippocampus of rats. How exactly the intracellular chaperone Sig‐1R or associated ligand causes the increase of BDNF or any other neurotrophins is unknown. We examined here whether the action of Sig‐1Rs may relate to the post‐translational processing and release of BDNF in neuroblastoma cell lines. We used in vitro assays and confirmed that cutamesine possesses the bona fide Sig‐1R agonist property by causing the dissociation of BiP from Sig‐1Rs. The C‐terminus of Sig‐1Rs exerted robust chaperone activity by completely blocking the aggregation of BDNF and GDNF in vitro. Chronic treatment with cutamesine in rat B104 neuroblastoma caused a time‐ and dose‐dependent potentiation of the secretion of BDNF without affecting the mRNA level of BDNF. Cutamesine decreased the intracellular level of pro‐BDNF and mature BDNF whereas increased the extracellular level of mature BDNF. The pulse‐chase experiment indicated that the knockdown of Sig‐1Rs decreased the secreted mature BDNF in B104 cells without affecting the synthesis of BDNF. Our findings indicate that, in contrast to clinically used antidepressants that promote the transcriptional upregulation of BDNF, the Sig‐1R agonist cutamesine potentiates the post‐translational processing of neurotrophins. This unique pharmacological profile may provide a novel therapeutic opportunity for the treatment of neuropsychiatric disorders. Synapse, 2012. © 2012 Wiley Periodicals, Inc.
Proposing the hexagrid system as a new structural system for tall buildings
Authors: Mashhadiali Niloufar , Kheyroddin Ali
Published: February 2012

In order to improve the efficiency of tube‐type structures in tall buildings, a new structural system, called hexagrid, is introduced in this paper. In comparison with diagrid system, it consists of multiple hexagonal grids on the face of the building. In this research, a set of structures using diagrid system having four various diagonal angles and hexagrid system were designed on a strength and stiffness‐based approach for buildings with 30, 50, 70 and 90 stories to withstand wind load. The impact of different geometric configurations of structural members on the maximum lateral displacement and architectural performance in both diagrid and hexagrid systems is compared. The stiffness sensitivity using a similar interior bracing system in both systems is also discussed. In this study, the seismic performance of a 30‐story diagrid structure and a hexagrid structure was evaluated using nonlinear static and dynamic analyses. According to the results, the hexagrid system has a better architectural view and more ductility and stiffness sensitivity, which are about three times than that of the diagrid system. And finally, in comparison with the diagrid system, the hexagrid system has enough potential to push the height limit. The guidelines discussed here are for architectural and structural engineers to improve freehand design. Copyright © 2012 John Wiley & Sons, Ltd.
aMC@NLO predictions for Wjj production at the Tevatron
Authors: Frederix Rikkert , Frixione Stefano , Hirschi Valentin , Maltoni Fabio , Pittau Roberto , Torrielli Paolo
Published: February 2012

Abstract

We use aMC@NLO to predict theℓν + 2-jet cross section at the NLO accuracy in QCD matched to parton shower simulations. We find that the perturbative expansion is well behaved for all the observables we study, and in particular for those relevant to the experimental analyses. We therefore conclude that NLO corrections to this process cannot be responsible for the excess of events in the dijet invariant mass observed by the CDF collaboration.
Biodiesel/Diesel Blends Classification with Respect to Base Oil Using NIR Spectrometry and Chemometrics Tools
Authors: Silva Gildo W. B. , Gomes Adriano A. , da Silva Priscila , Costa Gean B. , Fernandes David Douglas Sousa , Fontes Marcelo M. , Veras Germano
Published: February 2012

In this work, rapid and non‐destructive methodology is proposed for screening of biodiesel/diesel blends with respect to the base oil, using near infrared spectroscopy and multivariate data analysis, since for both pure biodiesel and blends, the biodiesel/diesel are targets for tampering. Blends of diesel with cotton, sunflower and soybean oils were employed in this study. Two approaches were evaluated in the building of the classification model, using full‐spectrum Soft Independent Modelling of Class Analogy (SIMCA), and Principal Component Analysis–Linear Discriminant Analysis (PCA–LDA). The other approaches were the use of variable selection employing Genetic Algorithm (GA), Successive Projection Algorithm (SPA) and Stepwise all coupled with the LDA model. The results showed which preprocessed NIR spectra and chemometrics are a viable alternative the conventional methods that involve the consumption of large volumes of reagents. Multivariate data analysis methods using selected variables showed a better performance than the methods using a full spectrum.
Biblical Literalism: A Test of the Compensatory Schema Hypothesis among Anglicans in England
Authors: Village Andrew
Published: February 2012

The compensatory schema hypothesis (Hoffmann and Bartkowski, Soc Forces 86:1245–1272, 2008) has been used to explain why women seem to have higher levels of biblical literalism than men in some Christian denominations. Based on social structuration and gender theories, it proposes that biblical literalism is a key social schema in some denominations that deny women access to institutional power. Women compensate for the lack of access to institutional social resources (leadership) by stressing the accepted schema (literalism) more strongly than men. The theory was tested using two samples from the Church of England, one lay ( N = 394) and one ordained ( N = 1,052). Laywomen were more literal than laymen among evangelicals and Anglo-catholics, where opposition to women's ordination is highest, but in both cases the difference was largely explained by differences in education levels between the sexes. Clergywomen, with access to leadership resources, were less literal than clergymen in both Anglo-catholic and evangelical traditions. The results offer rather weak support for the compensatory schema hypothesis, and alternative explanations of the findings are discussed.
Gender Ideology and Religion: Does a Masculine Image of God Matter?
Authors: Whitehead Andrew L.
Published: February 2012

A number of recent studies explore predictors of gender ideology due to its consistent influence on a range of outcomes. Another growing body of research investigates the effects of images of God on an assortment of attitudes. This study unites these two strands of research to provide an account of the association between religious belief and gender ideology. Using data from a national random survey and multivariate analysis, I examine whether a masculine image of God is significantly associated with a more conservative gender ideology. The results demonstrate that viewing God as a “he” is robustly associated with a more traditional gender ideology.
GOVERNMENT AS INVESTOR: TAX POLICY AND THE STATE
Authors: Macey Jonathan R.
Published: February 2012

This article analogizes the state, in its role as tax collector, to
that of an investor, or to be more precise, that of a residual claimant on
the earnings of all of the people and firms subject to the taxing power of
the state. The relationship between modern democracy and its citizens
would be strengthened if this analogy were more widely acknowledged
because it recognizes citizen-taxpayers as contracting partners with the
state. Unlike other libertarian conceptions of the state's taxing
authority, the framework developed here does not jeopardize the state's
ability to collect the revenues it needs to provide for the protections of
its citizens.

The state-as-investor framework developed in this Article leads to a
number of tax policy improvements. The framework suggests limits on the
government's ability to change people's tax status after they have already
embarked on careers and made the sunken, non-diversifiable investments in
human capital that such career training requires. The framework advanced
here also suggests that people should be able to make a once-in-a lifetime
payment in lieu of taxes to the state in order to discharge their tax
liability. This approach articulated here also seems superior to the
utopian suggestion offered by Ayn Rand that taxation be voluntary, as well
as to the unrealistic suggestion made by Nozick that income taxes are
violative of man's natural rights.
Transportation-Related Injuries and Fatalities among Emergency Medical Technicans and Paramedics
Authors: Maguire Brian J.
Published: February 2012

Introduction: This is the first study using national data to evaluate transportation risks among emergency medical technicians (EMTs) and paramedics (to be referred to hereafter as “EMTs”) in the United States.

Hypothesis: This epidemiological study compares the transportation risks for EMTs to the transportation risks for all workers in the US.

Methods: The rates, relative risks, and proportions associated with the 1,050 injury cases with lost work days, and 30 fatalities resulting from transportation incidents occurring to EMTs in the US between 2006 and 2008 are described.

Results: The risk of transportation-related injury for EMTs in the US is about five times higher than the national average. Females were the victims in 53% of the cases yet females only accounted for about 27% of employment in this occupation. Twenty percent of cases resulted in 31 or more lost work days. There were 30 transportation related fatalities.

Conclusions: The US national EMS system is built on the premise of having an unlimited supply of 20 year olds interested in, and dedicated to, the provision of EMS care. Not only do we not have an unlimited supply of 20 year olds, we may be rapidly losing our current workforce through clearly preventable risks such as transportation incidents.

Emergency medical services workers face a rate of occupational injury that is much higher than the national average and transportation-related events are a significant component of that risk. Resources must be devoted to further research, and to the development and evaluation of interventions designed to mitigate these transportation-related hazards.
The “Trauma Signature:” Understanding the Psychological Consequences of the 2010 Haiti Earthquake
Authors: Shultz James M. , Marcelin Louis Herns , Madanes Sharon B. , Espinel Zelde , Neria Yuval
Published: February 2012

The 2010 Haiti earthquake was one of the most catastrophic episodes in history, leaving 5% of the nation’s population killed or injured, and 19% internally displaced. The distinctive combination of earthquake hazards and vulnerabilities, extreme loss of life, and paralyzing damage to infrastructure, predicts population-wide psychological distress, debilitating psychopathology, and pervasive traumatic grief. However, mental health was not referenced in the national recovery plan. The limited MHPSS services provided in the first eight months generally lacked coordination and empirical basis.

There is a need to customize and coordinate disaster mental health assessments, interventions, and prevention efforts around the novel stressors and consequences of each traumatic event. An analysis of the key features of the 2010 Haiti earthquake was conducted, defining its “Trauma Signature” based on a synthesis of early disaster situation reports to identify the unique assortment of risk factors for post-disaster mental health consequences. This assessment suggests that multiple psychological risk factors were prominent features of the earthquake in Haiti. For rapid-onset disasters, Trauma Signature (TSIG) analysis can be performed during the post-impact/pre-deployment phase to target the MHPSS response in a manner that is evidence-based and tailored to the event-specific exposures and experiences of disaster survivors. Formalization of tools to perform TSIG analysis is needed to enhance the timeliness and accuracy of these assessments and to extend this approach to human-generated disasters and humanitarian crises.
Bypassing Shame and Conversion Disorder
Authors: Bota Robert G. , Ricci Walter F , Preda Adrian
Published: February 2012

We report a case of conversion disorder (partial aphonia) that was successfully treated with speech therapy. During the one year duration of this illness, the patient regained transiently (minutes) her normal speech on a few occasions, independently of concomitant pharmacological interventions. One year after recovery she developed aphonia for the second time, which responded again to speech therapy, although the response rate was slower. Several mechanisms of conversion disorder are reviewed as specifically applied to this case. The possible role of pertinent shame mechanisms in the conversion pathology is discussed.
Pharmaceutical Modulation of the Renin Angiotensin Aldosterone System for
Stroke Prevention: A Review of Experimental and Clinical Evidence
Authors: Moutzouri Elisavet , Daios George , Elisaf Moses , Milionis Haralampos J.
Published: February 2012

The renin angiotensin aldosterone system (RAAS) has been implicated in the pathogenesis
of cerebrovascular diseases. During the past decades, AU: INCLUDE A NUMBER?
RAAS has gained attention as an important therapeutic target in cardiovascular medicine.
Modulation of the RAAS for primary and secondary stroke prevention seems an appealing
strategy. Several experimental studies have showed that pre-treatment with RAAS inhibitors
prior to the initiation of ischemia exerts favorable effects on infarct volume, brain
edema, and cerebral blood flow in the marginal zone. Furthermore, the activation of
angiotensin receptor type 2 has been associated with neuroprotective effects. Accumulating
evidence based on recent clinical trials indicate that blockade of RAAS has a potential
role in stroke prevention. This review summarizes the pathophysiological aspects of brain
RAAS and its constituents, presents experimental data on the neuroprotective actions of
RAAS inhibitors and available evidence regarding their effects on stroke risk, and discuss
future directions for research.
Thermal infrared spectroscopy and partial least squares regression to determine mineral modes of granitoid rocks
Authors: Hecker Christoph , Dilles John H. , van der Meijde Mark , van der Meer Freek D.
Published: February 2012

In this paper, we present an approach to extracting mineralogic information from thermal infrared (TIR) spectra that is not based on an input library of pure mineral spectra nor tries to extract spectral end‐members from the data. Instead, existing modal mineralogy for a number of samples are used to build a partial least squares regression (PLSR) model that links the mineralogy of the samples to their respective TIR spectral signatures. The resulting PLSR models can be applied to a larger group of samples for which the mineralogic composition can be estimated from the TIR spectra alone. Thermal infrared reflectance spectra were recorded from 1330–625 cm−1 (7.5 to 16.0 μm). The method is tested on igneous rocks from a porphyry copper deposit in Yerington, Nevada. As a reference, modal mineralogic composition was determined with traditional polarization microscopy on thin sections. Partial least squares regression models were developed to link the thermal infrared spectra to the thin section determined mineral modes of alkali feldspar, plagioclase and quartz, as well as the average plagioclase composition information. Results indicate that rock samples can be classified successfully in a quartz‐alkali feldspar‐plagioclase diagram based on thermal infrared spectroscopy and partial least squares regression modeling. Estimated errors for the mineralogic composition model results were found to be smaller or equal to traditional methods with errors of ±5.1% (absolute) for alkali feldspar, ±8.5% (absolute) for plagioclase and ±6.9% (absolute) for quartz. The regression model for plagioclase composition predicted with estimated errors of ±7.8 mol% anorthite.
Computing uncertainties in ionosphere‐airglow models: I. Electron ﬂux and species production uncertainties for Mars
Authors: Gronoff Guillaume , Simon Wedlund Cyril , Mertens Christopher J. , Lillis Robert J.
Published: February 2012

The ionization and excitation of atoms and molecules in the upper atmospheres of the Earth and planets are computed by a number of physical models. From these calculations, quantities measurable by dedicated satellite experiments such as airglow and electron fluxes can be derived. It is then possible to compare model and observation to derive more fundamental physical properties of the upper atmospheres, for example, the density as a function of altitude. To ensure the accuracy of these retrieval techniques, it is important to have an estimation of the uncertainty of these models and to have ways to account for these uncertainties. The complexity of kinetic models for computing the secondary production of excited state species (including ions) makes it a difficult evaluation, and studies usually neglect or underestimate it. We present here a Monte‐Carlo approach to the computation of model uncertainties. As an example, we studied several aspects of the model uncertainties in the upper atmosphere of Mars, including the computed secondary electron flux and the production of the main ion species. Our simulations show the importance of improving solar flux models, especially on the energy binning and on the photon impact cross sections, which are the main sources of uncertainties on the dayside. The risk of modifying cross sections on the basis of aeronomical observations is highlighted for the case of Mars, while accurate uncertainties are shown to be crucial for the interpretation of data from the particle detectors onboard Mars Global Surveyor. Finally, it shows the importance of AtMoCiad, a public database dedicated to the evaluation of aeronomy cross section uncertainties. A detailed study of the resulting emissions cross sections uncertainties is the focus of a forthcoming paper (Gronoff et al., 2012) in which the outputs discussed in the present paper are used to compute airglow uncertainty, and the overall result is compared with the data from the SPICAM UV spectrometer onboard Mars Express.
Toward reduction of model uncertainty: Integration of Bayesian model averaging and data assimilation
Authors: Parrish Mark A. , Moradkhani Hamid , DeChant Caleb M.
Published: February 2012

Multimodeling in hydrologic forecasting has proved to improve upon the systematic bias and general limitations of a single model. This is typically done by establishing a new model as a linear combination or a weighted average of several models with weights on the basis of individual model performance in previous time steps. The most commonly used multimodeling method, Bayesian model averaging (BMA), assumes a fixed probability distribution around individual models' forecast in establishing the prior and uses a calibration period to determine static weights for each individual model. More recent work has focused on a sequential Bayesian model selection technique with weights that are adjusted at each time step in an attempt to accentuate the dynamics of an individual model's performance with respect to the system's response. However, these approaches still assume a fixed distribution around the individual models' forecast. A new sequential Bayesian model‐averaging technique is developed incorporating a sliding window of individual model performance around the forecast. Additionally, this new technique relaxes the fixed distribution assumption in establishing the prior utilizing a particle filter data assimilation method that reflects both the performance dynamics of the models' forecasts along with their uncertainty. A comparative analysis of the different BMA strategies is performed across different rates of change in the hydrograph. Results show that methods employing the particle filter show higher probabilistic skill in high ranges of volatility but are overconfident in medium and low ranges of volatility.
Nitric Oxide: Considerations for the Treatment of Ischemic Stroke
Authors: Terpolilli Nicole A , Moskowitz Michael A , Plesnila Nikolaus
Published: February 2012

Some 40 years ago it was recognized by Furchgott and colleagues that the endothelium releases a vasodilator, endothelium-derived relaxing factor (EDRF). Later on, several groups identified EDRF to be a gas, nitric oxide (NO). Since then, NO was identified as one of the most versatile and unique molecules in animal and human biology. Nitric oxide mediates a plethora of physiological functions, for example, maintenance of vascular tone and inflammation. Apart from these physiological functions, NO is also involved in the pathophysiology of various disorders, specifically those in which regulation of blood flow and inflammation has a key role. The aim of the current review is to summarize the role of NO in cerebral ischemia, the most common cause of stroke.
Recent advances in imaging and monitoring of heterogeneous catalysts with Raman spectroscopy
Authors: Calvino-Casilda Vanesa , Bañares Miguel A.
Published: February 2012

Catalysis is a complex multidisciplinary science that enables efficient performance in energy, automotive, chemical and pharmaceutical industries; most chemical reactions are catalyzed and it is a science that cannot be understood without spectroscopy. Spectroscopy is the enabling tool for knowledge-based design of highly efficient and stable catalysts. This review presents the progress of operando Raman spectroscopy during reaction and temperature-programmed treatments for heterogeneous catalysts (solid-gas and solid-liquid), with particular emphasis on the combination with other techniques, by extending it to space-resolved analyses and as a tool for mechanism investigation and monitoring in the liquid phase. Operando techniques are a key tool to understand catalysis and for monitoring and controlling catalytic processes. We summarize the most relevant research lines where Raman spectroscopy is applied in catalysis, challenges, hurdles and opportunities. This review outlines the versatility of Raman spectroscopy, for real-time analyses, in situ variable-programmed investigations and reaction studies. Spectroscopic information can be enhanced in a quantitative or qualitative manner, i.e., by using high-throughput Raman setups or by combining several spectroscopic techniques in a sample, respectively. This compilation outlines the posibilities of signal enhancement by resonance or SERS, and expanding it to mapping. We also comment developments for Raman imaging of profiles during catalyst synthesis and during reaction. Finally, this review summarizes the progress made in the liquid phase, to study catalyst synthesis, to monitor and investigate reaction mechanism and progress. The simultaneous combination of Raman with other complementary techniques is presented for these three lines of development. The current scenario presents an extraordinary perspective on opportunities for future developments.
Catalytic reforming of logistic fuels at high-temperatures
Authors: Deutschmann Olaf
Published: February 2012

This chapter reviews recent studies of catalytic reforming of logistic fuels at high-temperature. Aside from steam and autothermal reforming, special consideration is given to partial oxidation conditions. Natural gas, gasoline, diesel, and ethanol containing fuels are discussed. Methane and iso-octane as fuel surrogates are exemplarily used to explain the behavior of the reformers in particular focusing on the interaction of heterogeneous and homogeneous chemical reactions and mass and heat transport. As catalyst of choice for reforming, rhodium-based systems are in the focus of this review but alternate catalysts are noted as well.
Asymmetric organocatalyzed Morita-Baylis-Hillman reactions
Authors: Guillena Gabriela , Ramón Diego J. , Yus Miguel
Published: February 2012

The use of organocatalyst to promote the Morita-Baylis-Hillman (MBH) and aza-MBH reaction is an asymmetric and atom-economic way to obtain functionalized allylic alcohols or amines respectively, which have recently been well exploited, providing access to chiral densely functionalized products, which are valuable building blocks that can be further applied in the synthesis of complex natural products.
Micromagnetic analysis of the magnetization dynamics driven by the Oersted field in permalloy nanorings
Authors: Martinez Eduardo
Published: February 2012

The magnetization dynamics in a thin ferromagnet ring driven by the Oersted field created by injecting a current along an infinite conductive wire is analyzed by means of micromagnetic simulations. Two different processes are studied: (i) the transition from an onion state to a vortex configuration when the conducting wire was placed in the center of the ring and (ii) the switching of the vortex circulation when the conducting wire is displaced from the center of the ring. The results are in good agreement with recent experimental observations, where the Oersted field was produced by an atomic force microscope tip, and the analysis provides a preliminary study for future designs of memory devices–based thin ferromagnetic rings.
A memristor based on current-induced domain-wall motion in a nanostructured giant magnetoresistance device
Authors: Münchenberger Jana , Reiss Günter , Thomas Andy
Published: February 2012

The possibility of controlling the resistance of a memristive giant magnetoresistance (GMR) system via current-induced domain-wall motion was investigated. For a narrow spin-valve structure, current-induced domain-wall motion in the free layer can be detected once the current density exceeds a critical threshold. Then, the resistance of the device depends on the position of the domain wall. The GMR system shows a MR ratio of 10% in the as-prepared state. Narrow stripes were fabricated by e-beam lithography and ion-beam etching with a width of 200 nm. The stripes exhibit GMR ratios up to 8% at room temperature. Micromagnetic simulations of the domain-wall motion in the free layer allow an estimation of the time scale of the domain-wall migration in the stripe. Furthermore, the simulations were compared with measured critical current densities in the free layer with and without an applied external field.
Proton emission from a laser ion source
Authors: Torrisi L. , Cavallaro S. , Cutroneo M. , Margarone D. , Gammino S.
Published: February 2012

At intensities of the order of 1010 W/cm2, ns pulsed lasers can be employed to ablate solid bulk targets in order to produce high emission of ions at different charge state and kinetic energy. A special interest is devoted to the production of protons with controllable energy and current from a roto-translating target irradiated in repetition rate at 1–10 Hz by a Nd:Yag pulsed laser beam. Different hydrogenated targets based on polymers and hydrates were irradiated in high vacuum. Special nanostrucutres can be embedded in the polymers in order to modify the laser absorption properties and the amount of protons to be accelerated in the plasma. For example, carbon nanotubes may increase the laser absorption and the hydrogen absorption to generate high proton yields from the plasma. Metallic nanostrucutres may increase the electron density of the plasma and the kinetic energy of the accelerated protons. Ion collectors, ion energy analyzer, and mass spectrometers, used in time-of-flight configuration, were employed to characterize the ion beam properties. A comparison with traditional proton ion source is presented and discussed.
Monoenergetic proton emission from nuclear reaction induced by high intensity laser-generated plasma
Authors: Torrisi L. , Cavallaro S. , Cutroneo M. , Giuffrida L. , Krasa J. , Margarone D. , Velyhan A. , Kravarik J. , Ullschmied J. , Wolowski J. , Szydlowski A. , Rosinski M.
Published: February 2012

A 1016 W/cm2 Asterix laser pulse intensity, 1315 nm at the fundamental frequency, 300 ps pulse duration, was employed at PALS laboratory of Prague, to irradiate thick and thin primary CD2 targets placed inside a high vacuum chamber. The laser irradiation produces non-equilibrium plasma with deutons and carbon ions emission with energy of up to about 4 MeV per charge state, as measured by time-of-flight (TOF) techniques by using ion collectors and silicon carbide detectors. Accelerated deutons may induce high D-D cross section for fusion processes generating 3 MeV protons and 2.5 MeV neutrons, as measured by TOF analyses. In order to increase the mono-energetic proton yield, secondary CD2 targets can be employed to be irradiated by the plasma-accelerated deutons. Experiments demonstrated that high intensity laser pulses can be employed to promote nuclear reactions from which characteristic ion streams may be developed. Results open new scenario for applications of laser-generated plasma to the fields of ion sources and ion accelerators.
Production of a highly charged uranium ion beam with RIKEN superconducting electron cyclotron resonance ion source
Authors: Higurashi Y. , Ohnishi J. , Nakagawa T. , Haba H. , Tamura M. , Aihara T. , Fujimaki M. , Komiyama M. , Uchiyama A. , Kamigaito O.
Published: February 2012

A highly charged uranium (U) ion beam is produced from the RIKEN superconducting electron cyclotron resonance ion source using 18 and 28 GHz microwaves. The sputtering method is used to produce this U ion beam. The beam intensity is strongly dependent on the rod position and sputtering voltage. We observe that the emittance of U35+ for 28 GHz microwaves is almost the same as that for 18 GHz microwaves. It seems that the beam intensity of U ions produced using 28 GHz microwaves is higher than that produced using 18 GHz microwaves at the same Radio Frequency (RF) power.
A review of ion sources for medical accelerators (invited)
Authors: Muramatsu M. , Kitagawa A.
Published: February 2012

There are two major medical applications of ion accelerators. One is a production of short-lived isotopes for radionuclide imaging with positron emission tomography and single photon emission computer tomography. Generally, a combination of a source for negative ions (usually H- and/or D-) and a cyclotron is used; this system is well established and distributed over the world. Other important medical application is charged-particle radiotherapy, where the accelerated ion beam itself is being used for patient treatment. Two distinctly different methods are being applied: either with protons or with heavy-ions (mostly carbon ions). Proton radiotherapy for deep-seated tumors has become widespread since the 1990s. The energy and intensity are typically over 200 MeV and several 1010 pps, respectively. Cyclotrons as well as synchrotrons are utilized. The ion source for the cyclotron is generally similar to the type for production of radioisotopes. For a synchrotron, one applies a positive ion source in combination with an injector linac. Carbon ion radiotherapy awakens a worldwide interest. About 6000 cancer patients have already been treated with carbon beams from the Heavy Ion Medical Accelerator in Chiba at the National Institute of Radiological Sciences in Japan. These clinical results have clearly verified the advantages of carbon ions. Heidelberg Ion Therapy Center and Gunma University Heavy Ion Medical Center have been successfully launched. Several new facilities are under commissioning or construction. The beam energy is adjusted to the depth of tumors. It is usually between 140 and 430 MeV/u. Although the beam intensity depends on the irradiation method, it is typically several 108 or 109 pps. Synchrotrons are only utilized for carbon ion radiotherapy. An ECR ion source supplies multi-charged carbon ions for this requirement. Some other medical applications with ion beams attract developer's interests. For example, the several types of accelerators are under development for the boron neutron capture therapy. This treatment is conventionally demonstrated by a nuclear reactor, but it is strongly expected to replace the reactor by the accelerator. We report status of ion source for medical application and such scope for further developments.
Electron density measurement of cesium seeded negative ion source by surface wave probe
Authors: Kisaki M. , Tsumori K. , Nakano H. , Ikeda K. , Osakabe M. , Nagaoka K. , Shibuya M. , Sato M. , Sekiguchi H. , Komada S. , Kondo T. , Hayashi H. , Asano E. , Takeiri Y. , Kaneko O.
Published: February 2012

Electron density measurements of a large-scaled negative ion source were carried out with a surface wave probe. By comparison of the electron densities determined with the surface wave probe and a Langmuir probe, it was confirmed that the surface wave probe is highly available for diagnostic of the electron density in H− ion sources. In addition, it was found that the ratio of the electron density to the H− ion density dramatically decreases with increase of a bias voltage and the H− ions become dominant negative particles at the bias voltage of more than 6 V.
The preliminary tests of the superconducting electron cyclotron resonance ion source DECRIS-SC2
Authors: Efremov A. , Bekhterev V. , Bogomolov S. , Drobin V. , Loginov V. , Lebedev A. , Yazvitsky N. , Yakovlev B.
Published: February 2012

A new compact version of the “liquid He-free” superconducting ECR ion source, to be used as an injector of highly charged heavy ions for the MC-400 cyclotron, is designed and built at the Flerov Laboratory of Nuclear Reactions in collaboration with the Laboratory of High Energy Physics of JINR. The axial magnetic field of the source is created by the superconducting magnet and the NdFeB hexapole is used for the radial plasma confinement. The microwave frequency of 14 GHz is used for ECR plasma heating. During the first tests, the source shows a good enough performance for the production of medium charge state ions. In this paper, we will present the design parameters and the preliminary results with gaseous ions.
Beam purification by photodetachment (invited)
Authors: Liu Y. , Andersson P. , Beene J. R. , Forstner O. , Galindo-Uribarri A. , Gottwald T. , Hanstorp D. , Havener C. C. , Lindahl A. O. , Wendt K.
Published: February 2012

Ion beam purity is of crucial importance to many basic and applied studies in nuclear science. Selective photodetachment has been proposed to suppress unwanted species in negative ion beams while preserving the intensity of the species of interest. A highly efficient technique based on photodetachment in a gas-filled radio frequency quadrupole ion cooler has been demonstrated. In off-line experiments with stable ions, up to 104 times suppression of the isobar contaminants in a number of interesting radioactive negative ion beams has been demonstrated. For selected species, this technique promises new experimental possibilities in studies on exotic nuclei, accelerator mass spectrometry, and fundamental properties of negative atomic and molecular ions.
Multi-orbit tight binding calculations for spin transfer torque in magnetic tunneling junctions
Authors: You Chun-Yeol , Han Jae-Ho , Lee Hyun-Woo
Published: February 2012

We investigate the spin transfer torque (STT) with multi-orbit tight binding model in the magnetic tunneling junctions (MTJs). So far, most of the theoretical works based on the non-equilibrium Keldysh Green’s function method employ a single band model for the simplicity, except a few first principle studies. Even though the single band model captures main physics of STT in MTJ, multi-band calculation reveals new features of the STT that depend on band parameters, such as insulator bandgap, inter-band hopping energy of the ferromagnetic layer. We find that the sign change of perpendicular torkance with bandgap of the insulator layer, and when we allow the inter-band hopping, the bias dependences of perpendicular STT are dramatically changed, while no noticeable changes in parallel STT are found.
Theoretical investigation on the magnetic phase stability of Fe-doped Bi tellurides
Authors: Kim Miyoung , Song Jung-Hwan
Published: February 2012

The structural properties and magnetic phase stability of Fe-doped Bi2Te3 are studied in first principles by means of the highly precise full-potential linearized augmented plane-wave method within the generalized gradient approximation. Two different types of Fe doping, which are substitutional and interstitial, are examined, assuming about 8% of the Fe doping level, where the atomic structures are fully optimized by atomic force calculations. Our results show that: (i) ferromagnetic phases are energetically more stable over paramagnetic phases for both substitutional and interstitial Fe dopings, (ii) the substitutional Fe doping indicates a high magnetic phase with a largely enhanced Fe magnetic moment of 3.40 μB while the interstitial Fe doping shows the magnetic moment similar to the Fe bulk value, and (iii) the structural optimization reduces the Fe magnetic moments for both doping types while the overall effects on the total moment exhibit different results for different doping types.
Commissioning of heating neutral beams for COMPASS-D tokamak
Authors: Deichuli P. , Davydenko V. , Belov V. , Gorbovsky A. , Dranichnikov A. , Ivanov A. , Sorokin A. , Mishagin V. , Abdrashitov A. , Kolmogorov V. , Kondakov A.
Published: February 2012

Two neutral beam injectors have been developed for plasma heating on COMPASS-D tokamak (Institute of Plasma Physics, Prague). The 4-electrodes multihole ion-optical system with beam focusing was chosen to provide the low divergence 300 kW power in both deuterium and hydrogen atoms. The accelerating voltage is 40 kV at extracted ion current up to 15 A. The power supply system provides the continuous and modulated mode of the beam injection at a maximal pulse length 300 ms. The optimal arrangement of the cryopanels and the beam duct elements provides sufficiently short-length beamline which reduces the beam losses. The evolution of the impurities and molecular fraction content is studied in the process of the high voltage conditioning of the newly made ion sources. Two injectors of the same type have been successfully tested and are ready for operation at tokamak in IPP, Prague.
Surface plasma source with saddle antenna radio frequency plasma generator
Authors: Dudnikov V. , Johnson R. P. , Murray S. , Pennisi T. , Piller C. , Santana M. , Stockli M. , Welton R.
Published: February 2012

A prototype RF H− surface plasma source (SPS) with saddle (SA) RF antenna is developed which will provide better power efficiency for high pulsed and average current, higher brightness with longer lifetime and higher reliability. Several versions of new plasma generators with small AlN discharge chambers and different antennas and magnetic field configurations were tested in the plasma source test stand. A prototype SA SPS was installed in the Spallation Neutron Source (SNS) ion source test stand with a larger, normal-sized SNS AlN chamber that achieved unanalyzed peak currents of up to 67 mA with an apparent efficiency up to 1.6 mA/kW. Control experiments with H− beam produced by SNS SPS with internal and external antennas were conducted. A new version of the RF triggering plasma gun has been designed. A saddle antenna SPS with water cooling is fabricated for high duty factor testing.