bluuebunny/crossref_metadata_2025 huggingface dataset:
The use of high frequency oscillatory ventilation in a pediatric oncology intensive care unit
Authors: Faqih Nesreen A. , Qabba'h Su'ad H. , Rihani Rawad S. , Ghonimat Iyad M. , Yamani Yousef M. , Sultan Iyad Y.
Published: August 2011

Background

High frequency oscillatory ventilation (HFOV) has been successfully used in the management of acute respiratory distress syndrome (ARDS) in children. The aim of our study is to determine its effectiveness in pediatric patients with cancer or post hematopoietic stem cell transplantation (HSCT) diagnosed with ARDS.

Procedure

A retrospective case review, in a pediatric intensive care unit (PICU) in a tertiary‐care oncology center in Amman, Jordan. Patients included were children with cancer and/or receiving allogeneic HSCT who were diagnosed with ARDS and placed on HFOV from January 2007 to February 2009.

Results

Data from 12 pediatric oncology patients on HFOV were analyzed for demographics, oncological diagnosis, PRISM III scores, ventilator settings before switching to HFOV and 24 hours after switching, complications, and outcomes. Alveolar–arterial oxygen (A–a) gradient and oxygen index (OI) were calculated, and pressure of arterial CO2 (PaCO2) was measured before and 24 hours after switching. Endpoints were successful extubation and discharge, or death while intubated. After 24 hours on HFOV, the A–a gradient decreased significantly in all patients (from a median of 564–267 torr; P = 0.001). OI decreased in all but two patients who died (median 17); PaCO2 decrease was not significant. Five patients died (two of them post‐HSCT) and the 7 (58%) survivors were weaned from HFOV (median, 9 days) and discharged.

Conclusions

HFOV improves gas exchange and is useful in managing critically ill children with cancer and post‐HSCT patients who develop ARDS. Pediatr Blood Cancer 2012; 58: 384–389. © 2011 Wiley Periodicals, Inc.
Studies on morphology and mechanical properties of dispersing intercalated silane montmorillonite in polypropylene matrix
Authors: Liu Sung‐Po
Published: August 2011

We used a plastograph‐mixer by the twin‐screw mixed method to obtain the standard shaped specimens of polymer‐clay nanocomposites (PCN) to prepare polypropylene (PP)/silane montmorillonite (MMT) nanocomposites pellets, grafting with two kinds of different surfactant—hard grafting agent maleic anhydride (MA) or soft grafting agent thermoplastic polyolefin elastomers (TPO). The chemical structure and polymer morphology of these as‐synthesized PCN specimens were characterized by a wide‐angle powder X‐ray diffraction (XRD) and a scanning electron microscopy (SEM). In addition, we prepared these experimental specimens in order to probe into their mechanical properties. The tests used were: layer distance of PCN, tensile, impact, shore‐hardness, wearing tests, and so on. In addition, we used XRD to make the characterization analysis, and compare it to scatter and layer‐distance. It was found that when the MA is increased into the MMT, the layer‐distance at 3 wt% increased from 2.11 nm to 3.54 nm; when increasing the TPO into the MMT, layer‐distance at 3 wt% increased to the 3.28 nm. For the mechanical property, it was found that these specimens grafted with the MA have the following results: in the tensile test, the MMT weight percentage of 1 wt% had the best result, increasing by 3.2%. In the shore hardness test, the MMT of 3 wt% strengthens by 5.41%. In addition, the mechanical property of the specimens that grafted to the TPO decreased almost immediately at 1 wt%, but increased at 3–5 wt% trends. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Comparison of prevalence of toxoplasma and cytomegalovirus infection in cases with fetal ultrasound markers in the second trimester of pregnancy
Authors: Beke Artúr , Latkóczy Krisztina , Nagy Gyula Richárd , Dudnyikova Anna , Csaba Ákos , Szabó István , Papp Csaba , Rigó János
Published: August 2011

Objectives

To evaluate the prevalence of toxoplasma and cytomegalovirus (CMV) infections in cases of ultrasound anomalies detected in the second trimester of pregnancy.

Methods

Serological examinations for toxoplasma and CMV infection were carried out in 655 cases with sonographic findings suggestive of fetal infection, 612 cases with single ultrasound markers and 43 cases with two or more markers.

Results

In cases of single ultrasound markers, serological examination diagnosed recent toxoplasma infection in 107/612 cases (17.5%) and recent CMV infection in 75 cases (12.3%). Recent toxoplasma infection accounted for 13.8% (52/377) of the intracranial sonographic findings and 23.9% (45/188) of the abdominal findings, whereas recent CMV infections accounted for 12.2 (46/377) and 11.7% (22/188), respectively. Recent CMV infection with sonographic manifestations had higher rates of intracranial than intra‐abdominal sonographic findings (46/75 or 61% vs 22/75 or 29%), whereas recent toxoplasma infection with sonographic manifestations had similar rates of intracranial (52/107 or 49%) and intra‐abdominal (45/107 or 42%) findings. In cases of two or more ultrasound markers, serological examination diagnosed recent toxoplasma infection in 12/43 cases (27.9%) and recent CMV infection in 10/43 cases (23.3%).

Conclusions

Ultrasound findings suspicious for toxoplasma and CMV infection are not pathognomonic for either pathologic entity. Copyright © 2011 John Wiley & Sons, Ltd.
Controlled ring‐opening polymerization of ε‐caprolactone initiated by in situ formed yttrium trisalicylaldimine complexes, and their study by density functional theory
Authors: Ni Xufeng , Liang Zhenhua , Ling Jun , Li Xue , Shen Zhiquan
Published: August 2011

A series of yttrium trisalicylaldimine complexes formed in situ by the reaction of trialkyl complex [Y(CH2SiMe3)3(THF)2] (THF is tetrahydrofuran) with three equivalent salicylaldimines were used as initiators for the ring‐opening polymerization of ε‐caprolactone. Electronic and steric effects of the salicylaldimine ligand played important roles on the catalytic properties of the yttrium complexes. The yttrium trisalicylaldimine complex Y(L7)3 (L7 = (S)‐2,4‐di‐tert‐butyl‐6‐[(1‐phenylethylimino)methyl]phenol) most effectively initiated controlled ring‐opening polymerization of ε‐caprolactone to prepare poly(ε‐caprolactone)s with high molecular weights and moderate molecular weight distributions. Obtained by density functional theory calculations, the optimized geometries of the four different active centers with four salicylaldimine ligands explained the experimental results. Copyright © 2011 Society of Chemical Industry
A comprehensive approach to the prevention of bronchopulmonary dysplasia
Authors: Kugelman Amir , Durand Manuel
Published: August 2011

The current bronchopulmonary dysplasia (BPD) is seen in infants born extremely premature, with less severe respiratory distress syndrome (RDS) and who received prenatal steroids—“new BPD”. The pathophysiology of BPD is based on an impairment of lung maturation with prenatal and postnatal multi‐hit insults and genetic susceptibility. This multifactorial pathophysiology of BPD suggests that no single “magic bullet” will prevent it. Thus, to avoid BPD we need to implement a complex and comprehensive strategy.

This strategy is based on ventilatory and non‐ventilatory measures. The ventilatory route allows an individualized endotracheal intubation approach. Early lung recruitment with nasal respiratory support (nasal continuous positive airway pressure [NCPAP] or nasal intermittent positive pressure ventilation [NIPPV] / synchronized NIPPV [SNIPPV]) and the INSURE (intubation, surfactant and early extubation) approach are discussed. Initial treatment with NCPAP did not reduce the rate of BPD compared to endotracheal ventilation and surfactant administration. While NIPPV/SNIPPV may have short‐term advantages over NCPAP, the effect on BPD needs to be further studied. During hospitalization the respiratory goals should aim for adequate oxygenation, permissive hypercapnia, and gentle ventilation. However, these goals were found to have short‐term benefits but did not reduce significantly the rate of BPD. Selective use of a short course of low dose corticosteroids can be considered after the first or second week of life in infants who are unable to be weaned from the ventilator and are at high risk for BPD. Non‐ventilatory measures include early nutritional support with fluid restriction, caffeine and consideration of vitamin A. Hemodynamic significant patent ductus arteriosus (PDA) may be associated with BPD, but medical or surgical treatment of PDA were not shown to decrease BPD. Each component and the strategy as a whole needs to be further studied in large randomized prospective studies or by meta‐analyses, especially in the target population of extremely premature infants who are the most prone to BPD. Pediatr Pulmonol. 2011; 46: 1153–1165. © 2011 Wiley Periodicals, Inc.
Can a chitin‐synthesis‐inhibiting turfgrass fungicide enhance black cutworm susceptibility to a baculovirus?
Authors: Bixby‐Brosi Andrea J , Potter Daniel A
Published: August 2011

BACKGROUND: Developmental resistance, i.e. reduced virulence and speed of kill of late instars, is a limiting factor in the use of baculoviruses for caterpillar control. Agrotis ipsilon multicapsid nucleopolyhedrovirus (AgipMNPV) is highly infective to young black cutworms, Agrotis ipsilon, but too slow‐acting against late instars for effective curative control on golf courses or sports fields. Chitin‐synthesis‐inhibiting fungicides containing the active ingredient polyoxin‐d are used to control fungal diseases in turfgrass, and similar compounds have been shown in the laboratory to synergize baculoviruses by disrupting peritrophic membrane function. This study tested whether applying the virus together with such a fungicide can synergize AgipMNPV activity against A. ipsilon in turfgrass.

RESULTS: The addition of a chitin synthesis inhibitor failed to increase AgipMNPV infectivity to A. ipsilon in the field. Rather, delayed and slightly reduced mortality from viral infection was seen when larvae fed on fungicide/virus‐treated grasses as opposed to virus‐only treatments. Choice tests revealed the fungicide residues to be a mild feeding deterrent.

CONCLUSION: Because polyoxin‐d does not deactivate AgipMNPV, the two substances are compatible. However, combination applications of polyoxin‐d and Agip MNPV on turfgrass might interfere with larval ingestion of a lethal virus dose, resulting in prolonged larval feeding in the field. Copyright © 2011 Society of Chemical Industry
Scaling effect of flexoelectric (Ba,Sr)TiO3microcantilevers
Authors: Huang Wenbin , Kim Kyungrim , Zhang Shujun , Yuan Fuh‐Gwo , Jiang Xiaoning
Published: August 2011

The flexoelectric microcantilever offers an alternative approach for the development of micro/nano‐sensors. The transverse flexoelectric coefficientsµ12of barium strontium titanate microcantilevers were measured at room temperature, and found to keep the same value of 8.5 µC/m for microcantilevers with thickness ranging from 30 µm to 1.4 mm. The calculated effective piezoelectric coefficient and electrical energy density of flexoelectric cantilevers are superior to those of their piezoelectric counterparts, suggesting that the flexoelectricity‐induced polarization can be significantly increased as structures are scaled down due to the scaling effect of strain gradient, holding promise for flexoelectric micro/nano cantilever sensing applications. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
MITSIO—an architecture for the management of interactive tasks and the semantic integration of ontologies in the mobile grid
Authors: Borges Vinicius C. M. , Rossetto A. G. M. , Silva A. P. C. , Dantas M. A. R.
Published: August 2011

The interaction between mobile and grid environments in building a transparent infrastructure for mobile users, involves several factors from both wired and wireless networks. These include the following: coordinated application executions, the management of inherent characteristics of mobile devices (disconnections and the problem of a reduced battery lifetime), and making a selection of suitable heterogeneous resources in wired network, which are distinctly in terms of their virtual organizations. For this reason, the main goal of the architecture is the provision of more complete transparency for mobile users, when they need to access the processing capacity of the grid computing environment. To achieve this, this paper outlines an architecture, called MITSIO, together with a prototype implementation that takes these factors into consideration. Furthermore, the study examines two case studies that provide evidence of the capacities of the proposed architecture. The first case study shows how the architecture enables mobile devices to consume less battery power (approximately 31%, for submitting and monitoring applications). The second case provides evidence of its capacity to select resources from different virtual organizations through the semantic integration of multiple ontologies.
Pseudo Panels as an Alternative Study Design
Authors: Frethey-Bentham Catherine
Published: August 2011

Marketing academics and practitioners increasingly recognise the importance of studying the dynamic nature of consumer attitudes and behaviour. However, recent works highlight a dearth of longitudinal studies into consumer dynamics published in marketing academic literature ( Leonidou et al., 2010 ; Rindfleisch et al., 2008 ; Williams and Plouffe, 2007 ). In an attempt to address this gap, this article evaluates the ability of available research designs to meet various research objectives in the study of consumer dynamics. This evaluation highlights the need for a technique capable of modelling gross and individual level change using repeated cross-sectional data. The article proposes the use of pseudo panels to address this gap and advances the use of data fusion techniques for matching independent samples over multiple time periods to create these pseudo panels.
Late Quaternary paleoenvironments and paleoclimatic conditions in the distal Andean piedmont, southern Mendoza, Argentina
Authors: Tripaldi Alfonsina , Zárate Marcelo A. , Brook George A. , Li Guo-Qiang
Published: August 2011

The Andean piedmont of Mendoza is a semiarid region covered by extensive and partially vegetated dune fields consisting of mostly inactive aeolian landforms of diverse size and morphology. This paper is focused on the San Rafael plain (SRP) environment, situated in the distal Andean piedmont of Mendoza (34° 30′S), and reports the sedimentology and OSL chronology of two representative exposures of late Quaternary deposits, including their paleoenvironmental and paleoclimatic significance. Eleven facies, including channel, floodplain, fluvio–aeolian interaction, and reworked pyroclastic and aeolian deposits, were described and grouped into two facies associations (FA1 and FA2). FA1 was formed by unconfined sheet flows, minor channelized streams and fluvial–aeolian interaction processes. FA2 was interpreted as aeolian dune and sand-sheet deposits. OSL chronology from the SRP sedimentary record indicates that between ca. 58–39 ka and ca. 36–24 ka (MIS 3), aggradation was governed by ephemeral fluvial processes (FA1) under generally semiarid conditions. During MIS 2, the last glacial maximum (ca. 24–12 ka), a major climatic shift to more arid conditions is documented by significant aeolian activity (FA2) that became the dominant sedimentation process north of the Diamante–Atuel fluvial system. The inferred paleoenvironmental conditions from the SRP sections are in broad agreement with regional evidence.
Development of Statewide Geriatric Patients Trauma Triage Criteria
Authors: Werman Howard A. , Erskine Timothy , Caterino Jeffrey , Riebe Jane F. , Valasek Tricia ,   Members of the Trauma Committee of the State of Ohio EMS Board
Published: August 2011

Introduction: The geriatric population is unique in the type of traumatic injuries sustained, physiological responses to those injuries, and an overall higher mortality when compared to younger adults. No published, evidence-based, geriatric-specific field destination criteria exist as part of a statewide trauma system. The Trauma Committee of the Ohio Emergency Medical Services (EMS) Board sought to develop specific criteria for geriatric trauma victims.

Methods: A literature search was conducted for all relevant literature to determine potential, geriatric-specific, field-destination criteria. Data from the Ohio Trauma Registry were used to compare elderly patients, defined as age >70 years, to all patients between the ages of 16 to 69 years with regards to mortality risk in the following areas: (1) Glasgow Coma Scale (GCS) score; (2) systolic blood pressure (SBP); (3) falls associated with head, chest, abdominal or spinal injury; (4) mechanism of injury; (5) involvement of more than one body system as defined in the Barell matrix; and (6) co-morbidities and motor vehicle collision with one or more long bone fracture. For GCS score and SBP, those cut-off points with equal or greater risk of mortality as compared to current values were chosen as proposed triage criteria. For other measures, any criterion demonstrating a statistically significant increase in mortality risk was included in the proposed criteria.

Results: The following criteria were identified as geriatric-specific criteria: (1) GCS score <14 in the presence of known or suspected traumatic brain trauma; (2) SBP <100 mmHg; (3) fall from any height with evidence of traumatic brain injury: (4) multiple body-system injuries; (5) struck by a moving vehicle; and (6) the presence of any proximal long bone fracture following motor vehicle trauma. In addition, these data suggested that elderly patients with specific co-morbidities be given strong consideration for evaluation in a trauma center.

Conclusions: The state of Ohio is the first state to develop evidence-based geriatric-specific field-destination criteria using data from its state-mandated trauma registry. Further analysis of these criteria will help determine their effects on over-triage and under-triage of geriatric victims of traumatic injuries and the impact on the overall mortality in the elderly.
Laptop Composition at the Turn of the Millennium: Repetition and Noise in the Music of Oval, Merzbow, and Kid606
Authors: LATARTARA JOHN
Published: August 2011

Laptop composition – the creation and performance of music primarily using laptop computers – emerged as an important musical activity in the last decade of the twentieth century. While much has been written about the cultural and conceptual significance of this new music, less has been published regarding the sonic structure of specific works. This article explores the musical structure and design of compositions by three laptop composers at the turn of the millennium: ‘Untitled #2’ by Oval (Markus Popp), ‘Cow Cow’ by Merzbow (Masami Akita), and ‘Powerbookfiend’ by Kid606 (Miguel De Pedro). Each piece is analysed using spectrographic images, representations of musical sound that allow for the precise measurement of frequency and intensity. Repetition and noise are revealed as musical characteristics common to all three pieces, defining both smaller-scale patterns and large-scale designs. Using the conceptual vocabulary of Paul Virilio and Gilles Deleuze, repetition and noise are framed in relation to a ‘machine aesthetic’ and ‘difference and repetition’.
Non‐volcanic tremor and discontinuous slab dehydration
Authors: Fagereng Åke , Diener Johann F. A.
Published: August 2011

Non‐volcanic tremor is a recently discovered fault slip style occurring with remarkable regularity in space near the down‐dip end of the locked zone on several subduction thrust interfaces. The physical mechanisms and the controls on the location of tremor have not yet been determined. We calculate the stable mineral assemblages and their water content in the subducting slab, and find that slab dehydration is not continuous, but rather restricted to a few reactions localised in pressure‐temperature space. Along geothermal gradients applicable to Shikoku and Cascadia ‐ where tremor has been relatively easy to detect ‐ tremor locations correlate with discontinuous and localised voluminous water release from the breakdown of lawsonite and chlorite + glaucophane respectively. The shape of the pressure‐temperature path for subducting slabs prevents fluid release at depths above and below where these dehydration reactions occur. We conclude that abundant tremor activity requires metamorphic conditions where localised dehydration occurs during subduction, and this may explain why tremor appears more abundant in some subduction zones than others.
The mRNA‐Binding Protein Zfp36 Is Upregulated by β‐Adrenergic Stimulation and Represses IL‐6 Production in 3T3‐L1 Adipocytes
Authors: Brahma Pavna K. , Zhang Huanchun , Murray Betsy S. , Shu Feng‐jue , Sidell Neil , Seli Emre , Kallen Caleb B.
Published: August 2011

Obesity produces a chronic inflammatory state that contributes to the development of diabetes and atherosclerosis. In obese humans, fat depot adipocytes and macrophages produce inflammatory cytokines and other factors which exert unfavorable local and systemic immune responses. The expression of many cytokines is modulated at the post‐transcriptional level by mRNA‐binding proteins which recognize AU‐rich elements (AREs) in the 3′‐untranslated regions (3′‐UTR) of these transcripts. One such protein, zinc finger protein 36 (Zfp36), is known to destabilize target mRNAs leading to decreased cytokine expression. Few regulators of Zfp36 expression in adipocytes have been described and mRNA targets of Zfp36 in adipocytes are largely unknown. We found that macrophage‐derived inflammatory stimuli enhanced endogenous Zfp36 expression in 3T3‐L1 adipocytes. Furthermore, the β‐adrenergic receptor agonist isoproterenol (Iso) and the glucocorticoid dexamethasone (Dex) each enhanced Zfp36 expression in adipocytes, the former most likely via a cyclic adenosine monophosphate (cAMP)‐dependent pathway. By contrast, Zfp36 expression in murine macrophages (RAW 264.7) was not enhanced by exposure to Dex but was stimulated by retinoic acid (RA). Zfp36 inhibited basal and lipopolysaccharide (LPS)‐stimulated interleukin‐6 (IL‐6) expression in adipocytes. These data reveal important and cell type‐specific modulators of Zfp36 expression in adipocytes and macrophages and identify Zfp36 as a potent repressor of adipocyte‐derived IL‐6. Furthermore, this work identifies new factors that stimulate adipocyte Zfp36 expression that are neither classically inflammatory nor mitogenic. Upregulating an mRNA‐binding protein for therapeutic purposes may provide a novel mechanistic approach with which to treat diverse inflammatory disorders including common conditions associated with obesity.
Respiratory-induced coenzyme Q biosynthesis is regulated by a phosphorylation cycle of Cat5p/Coq7p
Authors: Martín-Montalvo Alejandro , González-Mariscal Isabel , Padilla Sergio , Ballesteros Manuel , Brautigan David L. , Navas Plácido , Santos-Ocaña Carlos
Published: August 2011

CoQ6 (coenzyme Q6) biosynthesis in yeast is a well-regulated process that requires the final conversion of the late intermediate DMQ6 (demethoxy-CoQ6) into CoQ6 in order to support respiratory metabolism in yeast. The gene CAT5/COQ7 encodes the Cat5/Coq7 protein that catalyses the hydroxylation step of DMQ6 conversion into CoQ6. In the present study, we demonstrated that yeast Coq7 recombinant protein purified in bacteria can be phosphorylated in vitro using commercial PKA (protein kinase A) or PKC (protein kinase C) at the predicted amino acids Ser20, Ser28 and Thr32. The total absence of phosphorylation in a Coq7p version containing alanine instead of these phospho-amino acids, the high extent of phosphorylation produced and the saturated conditions maintained in the phosphorylation assay indicate that probably no other putative amino acids are phosphorylated in Coq7p. Results from in vitro assays have been corroborated using phosphorylation assays performed in purified mitochondria without external or commercial kinases. Coq7p remains phosphorylated in fermentative conditions and becomes dephosphorylated when respiratory metabolism is induced. The substitution of phosphorylated residues to alanine dramatically increases CoQ6 levels (256%). Conversely, substitution with negatively charged residues decreases CoQ6 content (57%). These modifications produced in Coq7p also alter the ratio between DMQ6 and CoQ6 itself, indicating that the Coq7p phosphorylation state is a regulatory mechanism for CoQ6 synthesis.
Feedback control of major disruptions in International Thermonuclear Experimental Reactor
Authors: Sen A. K.
Published: August 2011

It is argued that major disruptions in ITER can be avoided by the feedback control of the causative MHD precursors. The sensors will be 2D-arrays of ECE detectors and the suppressors will be modulated ECH beams injected radially to produce non-thermal radial pressures to counter the radial dynamics of MHD modes. The appropriate amplitude and phase of this signal can stabilize the relevant MHD modes and prevent their evolution to a major disruption. For multimode MHD precursors, an optimal feedback scheme with a Kalman filter is discussed.
Vortex collapse for the L2-critical nonlinear Schrödinger equation
Authors: Simpson G. , Zwiers I.
Published: August 2011

The focusing cubic nonlinear Schrödinger equation in two dimensions admits vortex solitons, standing wave solutions with spatial structure, Q(m)(r, θ) = eimθR(m)(r). In the case of spin m = 1, we prove there exists a class of data that collapse with the vortex soliton profile at the log-log rate. This extends the work of Merle and Raphaël (the case m = 0) and suggests that the L2 mass that may be concentrated at a point during generic collapse may be unbounded. Difficulties with m ⩾ 2, or when the spin symmetry is broken, are also discussed.
Effect of temperature on structure and water transport of hydrated sulfonated poly(ether ether ketone): A molecular dynamics simulation approach
Authors: Brunello Giuseppe F. , Mateker William R. , Lee Seung Geol , Choi Ji Il , Jang Seung Soon
Published: August 2011

The effects of temperature on hydrated sulfonated poly(ether ether ketone) are studied using molecular dynamics. Three different temperature conditions (298 K.15 K, 323.15 K, and 353.15 K) with two different water contents (10 wt. % and 20 wt. %) are simulated. Analyzing the pair correlation functions, it is found that there is limited temperature effect on the distribution and solvation of the sulfonate groups. The structure factor analysis shows that the temperature dependence of the nanophase-segregated morphology is not significant in the simulated temperature range. On the contrary, the structure factors S(q) at ∼30 Å (q = ∼0.2 Å−1) and ∼13 Å (q = ∼0.5 Å−1) clearly increase with water content, indicating that the development of water channels is mostly affected by the water content. Within such water phase in the nanophase-segregated structure, the internal structure of water phase becomes more developed with decreasing temperature and increasing water content. By analyzing the mean square displacement of the water molecules, it is also found that self-diffusion of water is enhanced with the increasing temperature. From the observation that the activation energies calculated from such temperature dependency are very similar (Ea = 25.7 kJ/mol and Ea = 24.9 kJ/mol for 10 wt. % and 20 wt. %, respectively), it is inferred that the extent of the structural change in the water phase as a function of temperature is very similar between the 10 wt. % water content and the 20 wt. % water content. Compared to the bulk water (13.2 kJ/mol) and the water in Nafion (16.7-18.9 kJ/mol), it is confirmed that more nanophase-segregation enhances water transport through the membrane.
Non-volatile magnonic logic circuits engineering
Authors: Khitun Alexander , Wang Kang L.
Published: August 2011

We propose a concept of magnetic logic circuits engineering, which takes an advantage of magnetization as a computational state variable and exploits spin waves for information transmission. The circuits consist of magneto-electric cells connected via spin wave buses. We present the result of numerical modeling showing the magneto-electric cell switching as a function of the amplitude as well as the phase of the spin wave. The phase-dependent switching makes it possible to engineer logic gates by exploiting spin wave buses as passive logic elements providing a certain phase-shift to the propagating spin waves. We present a library of logic gates consisting of magneto-electric cells and spin wave buses providing 0 or π phase shifts. The utilization of phases in addition to amplitudes is a powerful tool which let us construct logic circuits with a fewer number of elements than required for CMOS technology. As an example, we present the design of the magnonic Full Adder circuit comprising only 5 magneto-electric cells. The proposed concept may provide a route to more functional wave-based logic circuitry with capabilities far beyond the limits of the traditional transistor-based approach.
Atomic-scale characterization of the N incorporation on GaAs(001)
Authors: Ohtake Akihiro
Published: August 2011

The initial nitridation processes of GaAs(001) have been systematically studied using reflection high-energy electron diffraction, scanning tunneling microscopy, and x-ray photoelectron spectroscopy. The structure and composition of the nitrided surface strongly depends on the preparation condition. The amount of N atoms decreases with increasing substrate temperature, which is due to the desorption of N at higher temperatures. The surface nitrided without As4 flux shows a N-induced (3 × 3) reconstruction tentatively associated with a N-N dimer formation at the surface layer. N incorporation is less promoted when the initial GaAs surface is exposed to active N species under the As4 flux, because of the replacement of N atoms by the arriving As atoms. We found that N atoms are initially incorporated in the substitutional site at the central position below two As-As dimers in the β2(2 × 4) structure.
Three-dimensional PN junction capacitor for passive integration
Authors: Wang Huijuan , Wan Lixi , Yu Daquan , Guidotti Daniel , He Ran , Dai Fengwei , Cao Liqiang , Zhang Xia , Zhao Ning , Guo Xueping
Published: August 2011

A wafer level three-dimensional (3D) PN junction capacitor for passive device integration on Si is developed. The 3D capacitor structure is created by deep trench etching of Si and appropriate doping. The salient characteristics of the PN junction capacitors fabricated in this study are as follows. The maximum areal capacitance density is 11.5 fF/μm2, the highest breakdown voltage is −20 V, and the minimum leakage current is 5 nA at an applied reverse voltage of −5 V. In comparison with the planar PN junction capacitor, the 3D junction capacitor can provide 8-12 times the capacitance density at the same doping concentration.
Realistic upconverter-enhanced solar cells with non-ideal absorption and recombination efficiencies
Authors: Atre Ashwin C. , Dionne Jennifer A.
Published: August 2011

Upconverting materials can be used to increase the energy conversion efficiency of a solar cell. Such materials convert low-energy transmitted photons to higher-energy photons that can be absorbed by the cell, substantially reducing the spectral mismatch between the cell and the solar spectrum. Previously, the performance enhancements achievable with an ideal upconverter-solar cell system were theoretically investigated. Here, we perform a comprehensive analysis to determine the effects of non-ideal cell and upconverter systems, accounting for non-ideal absorption and radiative recombination. We also allow for realistic nonradiative relaxation within the upconverter. The system is modeled using a detailed balance approach, with the upconverter treated as a series connection of two small-bandgap solar cells and a large-bandgap light emitting diode. We demonstrate that significant improvements in efficiency are possible even for nonconcentrated light, as long as the upconverter includes a small nonradiative relaxation pathway. Furthermore, we show that the existence of a nonradiative relaxation event in the upconverter is necessary for improved power conversion when cell absorption efficiency is low. Our results indicate that the efficiencies of both conventional-Si and thin film photovoltaic cells can be substantially improved with upconverting materials, even including non-idealities.
Decoupling single nanowire mobilities limited by surface scattering and bulk impurity scattering
Authors: Khanal D. R. , Levander A. X. , Yu K. M. , Liliental-Weber Z. , Walukiewicz W. , Grandal J. , Sánchez-García M. A. , Calleja E. , Wu J.
Published: August 2011

We demonstrate the isolation of two free carrier scattering mechanisms as a function of radial band bending in InN nanowires via universal mobility analysis, where effective carrier mobility is measured as a function of effective electric field in a nanowire field-effect transistor. Our results show that Coulomb scattering limits effective mobility at most effective fields, while surface roughness scattering only limits mobility under very high internal electric fields. High-energy α particle irradiation is used to vary the ionized donor concentration, and the observed decrease in mobility and increase in donor concentration are compared to Hall effect results of high-quality InN thin films. Our results show that for nanowires with relatively high doping and large diameters, controlling Coulomb scattering from ionized dopants should be given precedence over surface engineering when seeking to maximize nanowire mobility.
Ultrafast dynamics of aniline in the 294-234 nm excitation range: The role of the πσ* state
Authors: Montero Raúl , Conde Álvaro Peralta , Ovejas Virginia , Martínez Roberto , Castaño Fernando , Longarte Asier
Published: August 2011

The ultrafast relaxation of jet-cooled aniline was followed by time-resolved ionization, after excitation in the 294-234 interval. The studied range of energy covers the absorption of the two bright ππ* excitations, S1 and S3, and the almost dark S2 (πσ*) state. The employed probe wavelengths permit to identify different ultrafast time constants related with the coupling of the involved electronic surfaces. A τ1 = 165 ± 30 fs lifetime is attributed to dynamics along the S2 (πσ*) repulsive surface. Other relaxation channels as the S1→S0 and S3→S1 internal conversion are also identified and characterized. The work provides a general view of the photophysics of aniline, particularly regarding the role of the πσ* state. This state appears as minor dissipation process due to the ineffective coupling with the bright S1 and S3 states, being the S1→S0 internal conversion the main non-radiative process in the full studied energy range. Additionally, the influence of the off-resonance adiabatic excitation of higher energy electronic states, particularly S3, is also observed and discussed.
Droplet formation in microfluidic cross-junctions
Authors: Liu Haihu , Zhang Yonghao
Published: August 2011

Using a lattice Boltzmann multiphase model, three-dimensional numerical simulations have been performed to understand droplet formation in microfluidic cross-junctions at low capillary numbers. Flow regimes, consequence of interaction between two immiscible fluids, are found to be dependent on the capillary number and flow rates of the continuous and dispersed phases. A regime map is created to describe the transition from droplets formation at a cross-junction (DCJ), downstream of cross-junction to stable parallel flows. The influence of flow rate ratio, capillary number, and channel geometry is then systematically studied in the squeezing-pressure-dominated DCJ regime. The plug length is found to exhibit a linear dependence on the flow rate ratio and obey power-law behavior on the capillary number. The channel geometry plays an important role in droplet breakup process. A scaling model is proposed to predict the plug length in the DCJ regime with the fitting constants depending on the geometrical parameters.
Hilbert's projective metric in quantum information theory
Authors: Reeb David , Kastoryano Michael J. , Wolf Michael M.
Published: August 2011

We introduce and apply Hilbert's projective metric in the context of quantum information theory. The metric is induced by convex cones such as the sets of positive, separable or positive partial transpose operators. It provides bounds on measures for statistical distinguishability of quantum states and on the decrease of entanglement under protocols involving local quantum operations and classical communication or under other cone-preserving operations. The results are formulated in terms of general cones and base norms and lead to contractivity bounds for quantum channels, for instance, improving Ruskai's trace-norm contraction inequality. A new duality between distinguishability measures and base norms is provided. For two given pairs of quantum states we show that the contraction of Hilbert's projective metric is necessary and sufficient for the existence of a probabilistic quantum operation that maps one pair onto the other. Inequalities between Hilbert's projective metric and the Chernoff bound, the fidelity and various norms are proven.
Energy-loss rate of a fast particle in graphene
Authors: Ang Yee Sin , Zhang C. , Kee Chun Yun
Published: August 2011

The energy-loss rate of a fast particle in graphene is studied. The energy-loss rate always increases with increasing incident particle energy, which is quite unusual when compared to electron gas in normal metal. Graphene exhibits a “discriminating” behavior where there exists a low energy cut-off below which the scattering process is strictly forbidden, leading to lossless traverse of an external particle in graphene. This low energy cutoff is of the order of nearest neighbor hopping bandwidth. Our results suggest that backscattering is also absent in the external particle scattering of graphene.
On the optical polarization properties of semipolar InGaN quantum wells
Authors: Schade L. , Schwarz U. T. , Wernicke T. , Rass J. , Ploch S. , Weyers M. , Kneissl M.
Published: August 2011

Polarized photoluminescence of strained quantum wells grown on c–plane, semipolar (101−2), (112−2), (101−1), (202−1) planes, and nonpolar GaN substrates was studied experimentally and in theory. The observed optical polarization switching between the substrate orientations (101−2) and (112−2) is in accordance with our general model of polarization switching, based on a k→·p→ model of arbitrary substrate orientation. Spectrally resolved measurements of the polarization degree stemming from (101−2) samples show that the maximum of the polarization degree is red–shifted with respect to the maximum of the photoluminescence intensity. We ascribe this effect to an increased polarization of the transitions for higher indium content.
Stress changed damping and associated transforming behavior in a Ti48.5Ni51.5 strain glass
Authors: Wang Yu , Song Xiaoping , Ding Xiangdong , Yang Sen , Zhang Jian , Ren Xiaobing , Otsuka Kazuhiro
Published: August 2011

We report a changeable damping behavior by stress for Ti48.5Ni51.5 strain glass. This phenomenon originates from the change of its transforming route upon increasing stress. Under low stress, the damping behavior of Ti48.5Ni51.5 strain glass is due to the strain glass transition; however, the damping behavior under intermediate stress stems from a strain glass transition and a subsequent martensitic transition. More interestingly, under high stress, the damping behavior is caused by the martensitic transition. With a phenomenological model, the stress dependent transforming behavior of strain glass can be explained consistently.
High TC half-metallic fully-compensated ferrimagnetic Heusler compounds
Authors: Galanakis I. , Şaşıoğlu E.
Published: August 2011

Extensive ab-initio electronic structure calculations on Heusler alloys suggest that Cr2CoGa is the alloy of choice to achieve the half-metallic fully-compensated ferrimagnetism since (1) it has been already grown experimentally [T. Graf et al., Z. Anorg. Allg. Chem. 635, 976 (2009)], (2) half-metallic XA structure is favored energetically over all the studied lattice constant range with respect to the L21 which is not half-metallic, (3) the half-metallic gap is wide and the Fermi level falls at the middle of the gap and thus, it presents high degree of spin-polarization for a wide range of lattice constants, and (4) the Curie temperature is extremely high reaching the 1520 K.
Conducted growth of SrRuO3 nanodot arrays on self-ordered La0.18Sr0.82Al0.59Ta0.41O3(001) surfaces
Authors: Bachelet R. , Ocal C. , Garzón L. , Fontcuberta J. , Sánchez F.
Published: August 2011

We show that the surface of (001)-oriented La0.18Sr0.82Al0.59Ta0.41O3 (LSAT) single-crystalline substrates can be self-ordered as to become a laterally long-range ordered pattern of nanometric stripes of distinct composition. Atomically flat and periodically modulated, the resulting surface exhibits concomitant interface energy variations with an upper growing epilayer. By exploiting combined selective growth and epitaxial strain, these nanostructured substrates are used as templates to promote the self-formation of one-dimensional arrays of SrRuO3 dots.
Tailoring oxidation degrees of graphene oxide by simple chemical reactions
Authors: Wang Gongkai , Sun Xiang , Liu Changsheng , Lian Jie
Published: August 2011

High quality graphene oxide (GO) with controllable degrees of oxidation was synthesized by simple chemical reactions inspired by approaches to unzip single wall carbon nanotubes using strong oxidizing agents. As compared to the conventional Hummers method, these reactions are less exo-therm involved without emission of toxic gases. The structural characteristics of the synthesized GO with various oxidation degrees were evaluated by x-ray diffraction, x-ray photoelectron spectroscopy, Raman spectroscopy, thermal gravimetric analysis, and UV-vis-IR spectroscopy. GO with tailored degrees of oxidation displays tunable optoelectronic properties and may have a significant impact on developing graphene- or GO-based platforms for various technological applications.
Geometrical structure of benzene and naphthalene: Ultrahigh-resolution laser spectroscopy and ab initio calculation
Authors: Baba Masaaki , Kowaka Yasuyuki , Nagashima Umpei , Ishimoto Takayoshi , Goto Hitoshi , Nakayama Naofumi
Published: August 2011

Geometrical structures of the isolated benzene and naphthalene molecules have been accurately determined by using ultrahigh-resolution laser spectroscopy and ab initio calculation in a complementary manner. The benzene molecule has been identified to be planar and hexagonal (D6h) and the structure has been determined with accuracies of 2 × 10−14 m (0.2 mÅ; 1 Å = 1 × 10−10 m) for the C–C bond length and 1.0 × 10−13 m (1.0 mÅ) for the C–H bond length. The naphthalene molecule has been identified to be symmetric with respect to three coordinate axes (D2h) and the structure has been determined with comparable accuracies. We discuss the effect of vibrational averaging that is a consequence of zero-point motions on the uncertainty in determining the bond lengths.
From microns to kissing contact: Dynamic positioning of two nano-systems
Authors: Savage Kevin J. , Hawkeye Matthew M. , Soares Bruno F. , Baumberg Jeremy J.
Published: August 2011

Two conducting atomic force microscopy probes are brought into three-dimensional nanoscale “tip-to-tip” alignment with dynamically controlled spacing and ultra-wide optical access. We utilize resonant electrical parametric mixing, created by the electromechanically coupled tips, to extract the electronic signal due to nanoscale changes in inter-tip position. Experimental results match theory confirming the viability of the technique. By functionalizing the tip apexes, this advanced multi-functional observation platform allows simultaneous measurement of the optical and electronic response of nanoparticle dimers, at sub-nanometer separations.
The cumulative measure of a force: A unified kinetic theory for rigid-sphere and inverse-square force law interactions
Authors: Chang Yongbin , Viehland Larry A.
Published: August 2011

By introducing a cutoff on the cumulative measure of a force, a unified kinetic theory is developed for both rigid-sphere and inverse-square force laws. The difference between the two kinds of interactions is characterized by a parameter, γ, which is 1 for rigid-sphere interactions and -3 for inverse-square force law interactions. The quantities governed by γ include the specific reaction rates, kernels, collision frequencies, arbitrarily high orders of transition moments, arbitrarily high orders of Fokker-Planck expansion (also called Kramers-Moyal expansion) coefficients, and arbitrarily high orders of energy exchange rates. The cutoff constants are shown to be incomplete gamma functions of different orders. The widely used cutoff constant in plasma physics (usually known as Coulomb logarithm) is found to be exactly the zeroth order of the incomplete gamma function. The well known Arrhenius reaction rate formula comes from the first order of the incomplete gamma functions, while the negative first order can be used for fitting the fusion reaction rate between deuterium and tritium.
Achieving Targeted Environmental Flows: Alternative Allocation and Trading Models under Scarce Supply—Lessons from the Australian Reform Process
Authors: Loch Adam , Bjornlund Henning , McIver Ronald
Published: August 2011

The problem of water overallocation in many regions of the world involves how to include environmental flow provisions for long-term sustainability of river systems, especially under scarce supply conditions. Market mechanisms have provided pathways for returning water to rivers for environmental use. We argue that it is important to consider how both market mechanisms and initial water allocation models contribute to achieving satisfactory environmental flow outcomes. The Murray-Darling Basin (MDB) in Australia has had policy processes applied to it for almost twenty years to address these issues, and provides an excellent basis for case-study analysis. Two MDB case studies are used to consider differences in the interpretation and implementation of environmental flow requirements, and the potential for institutional inertia of the systems within which water markets operate. We identify two simplified models from these case studies—one prioritising environmental rights above consumptive extraction and the other prioritising consumptive and environmental rights equally. However, neither of these case-study models provides the full environmental flow spectrum of base in-stream flows to over-bank flush events. Our findings suggest that combining allocation and market-based rights (a third model) offers an effective means to deliver full-spectrum environmental flows. If governments provide prioritised environmental rights for base in-stream ecosystem benefits, together with targeted temporary and permanent water market acquisitions to meet environmental needs associated with over-bank floods and flushes, there will be lower potential for shortfalls relative to targeted environmental flow outcomes.