Search

INTRODUCTION: Diffuse Intrinsic Pontine Glioma (DIPG) is a devastating high-grade glioma localized in the brainstem that occurs almost exclusively in children. The significant mortality rates of DIPG stem largely from its capacity to invade adjacent normal brain. We have previously published studies identifying the axon guidance factor, neogenin as a key driver regulating brain tumor cell invasion in medulloblastoma, glioblastoma and DIPG in vitro. Here we expand this work with an in vivo model to validate neogenin as promising inducer of DIPG invasion. METHODS: CRISPR-Cas9 system was used to knock-out the neogenin gene in DIPG cells. After validation of the knockout (KO) in vitro by RTqPCR, Western blot, and immunofluroresence, the cells were orthotopically implanted in the pons of nude mice (n=8/group) with a stereotactic frame. Tumor growth and dissemination were monitored using the In Vivo Imaging System (IVIS). Then, brains and spinal cords were collected, and H&E staining was performed. RESULTS:In vitro studies confirmed the KO of neogenin in DIPG cells. In vivo studies revealed that the neogenin total KO group had no progression of the tumor without any dissemination after 4-6 weeks, in marked contrast to the WT group, which exhibited steady growth and widespread dissemination into the spine. Immunohistochemistry confirmed the IVIS results. CONCLUSION: Expanding on previous work, this data suggests that neogenin is a major contributor of DIPG cell invasion and dissemination. The blockade of neogenin in DIPG cells demonstrates the potential utility of neogenin as potential therapeutic target, capable of reducing tumor growth and stopping tumor cell dissemination.

High dielectric constant (high-k) materials development has been pivotal in Moore's scaling of CMOS logic to address short-channel effects leading to source-drain leakage. High-k dielectrics technology is crucial to CMOS scaling down to the ultimate node. In addition, the maturing material science and technology of high permittivity materials found several other applications in emerging logic and memory devices for classical and quantum information processing within von- Neumann and non Von-Neumann schemes, as well as in other application areas such as spintronics, energy harvesting and production, sensors, and neuroelectronics. This paper focuses on a brief description of the state of the art and future prospects of high-k dielectrics for devices with logic functionalities.

Introduction: A major difficulty in treating moyamoya disease is the lack of effective methods to detect novel or progressive disease prior to the onset of disabling stroke. More importantly, a tool to better stratify operative candidates and quantify response to therapy could substantively complement existing methods. Here, we present proof-of-principle data supporting the use of urinary biomarkers as diagnostic adjuncts in pediatric moyamoya patients. Methods: Urine and cerebrospinal fluid specimens were collected from pediatric patients with moyamoya disease and a cohort of age and sex-matched control patients. Clinical and radiographic data were paired with measurements of a previously validated panel of angiogenic proteins quantified by ELISA. Results were compared to age and sex-matched controls and subjected to statistical analyses. Results: Evaluation of a specific panel of urinary and cerebrospinal fluid biomarkers by ELISA demonstrated significant elevations of angiogenic proteins in samples from moyamoya patients compared to matched controls. ROC curves for individual urinary biomarkers, including MMP-2, MMP-9, MMP-9/NGAL, and VEGF, showed excellent discrimination. The optimal urinary biomarker was MMP-2, providing a sensitivity of 88%, specificity of 100%, and overall accuracy of 91%. Biomarker levels changed in response to therapy and correlated with radiographic evidence of revascularization. Conclusions: We report, for the first time, identification of a panel of urinary biomarkers that predicts the presence of moyamoya disease. These biomarkers correlate with presence of disease and can be tracked from the central nervous system to urine. These data support the hypothesis that urinary proteins are useful predictors of the presence of moyamoya disease and may provide a basis for a novel, non-invasive method to identify new disease and monitor known patients following treatment.

The implementation of nano-engineered composite oxides opens up the way towards the development of a novel class of functional materials with enhanced electrochemical properties. Here we report on the realization of vertically aligned nanocomposites of lanthanum strontium manganite and doped ceria with straight applicability as functional layers in high-temperature energy conversion devices. By a detailed analysis using complementary state-of-the-art techniques, which include atom-probe tomography combined with oxygen isotopic exchange, we assess the local structural and electrochemical functionalities and we allow direct observation of local fast oxygen diffusion pathways. The resulting ordered mesostructure, which is characterized by a coherent, dense array of vertical interfaces, shows high electrochemically activity and suppressed dopant segregation. The latter is ascribed to spontaneous cationic intermixing enabling lattice stabilization, according to density functional theory calculations. This work highlights the relevance of local disorder and long-range arrangements for functional oxides nano-engineering and introduces an advanced method for the local analysis of mass transport phenomena.

Humanity is on a deeply unsustainable trajectory. We are exceeding planetary boundaries and unlikely to meet many international sustainable development goals and global environmental targets. Until recently, there was no broadly accepted framework of interventions that could ignite the transformations needed to achieve these desired targets and goals.As a component of the IPBES Global Assessment, we conducted an iterative expert deliberation process with an extensive review of scenarios and pathways to sustainability, including the broader literature on indirect drivers, social change and sustainability transformation. We asked, what are the most important elements of pathways to sustainability?Applying a social–ecological systems lens, we identified eight priority points for intervention (leverage points) and five overarching strategic actions and priority interventions (levers), which appear to be key to societal transformation. The eight leverage points are: (1) Visions of a good life, (2) Total consumption and waste, (3) Latent values of responsibility, (4) Inequalities, (5) Justice and inclusion in conservation, (6) Externalities from trade and other telecouplings, (7) Responsible technology, innovation and investment, and (8) Education and knowledge generation and sharing. The five intertwined levers can be applied across the eight leverage points and more broadly. These include: (A) Incentives and capacity building, (B) Coordination across sectors and jurisdictions, (C) Pre‐emptive action, (D) Adaptive decision‐making and (E) Environmental law and implementation. The levers and leverage points are all non‐substitutable, and each enables others, likely leading to synergistic benefits. Transformative change towards sustainable pathways requires more than a simple scaling‐up of sustainability initiatives—it entails addressing these levers and leverage points to change the fabric of legal, political, economic and other social systems. These levers and leverage po

At the end of a rush lasting over half a century, in which CMOS technology has been experiencing a constant and breathtaking increase of device speed and density, Moore's law is approaching the insurmountable barrier given by the ultimate atomic nature of matter. A major challenge for 21st century scientists is finding novel strategies, concepts and materials for replacing silicon-based CMOS semiconductor technologies and guaranteeing a continued and steady technological progress in next decades. Among the materials classes candidate to contribute to this momentous challenge, oxide films and heterostructures are a particularly appealing hunting ground. The vastity, intended in pure chemical terms, of this class of compounds, the complexity of their correlated behaviour, and the wealth of functional properties they display, has already made these systems the subject of choice, worldwide, of a strongly networked, dynamic and interdisciplinary research community. Oxide science and technology has been the target of a wide four-year project, named Towards Oxide-Based Electronics (TO-BE), that has been recently running in Europe and has involved as participants several hundred scientists from 29 EU countries. In this review and perspective paper, published as a final deliverable of the TO-BE Action, the opportunities of oxides as future electronic materials for Information and Communication Technologies ICT and Energy are discussed. The paper is organized as a set of contributions, all selected and ordered as individual building blocks of a wider general scheme. After a brief preface by the editors and an introductory contribution, two sections follow. The first is mainly devoted to providing a perspective on the latest theoretical and experimental methods that are employed to investigate oxides and to produce oxide-based films, heterostructures and devices. In the second, all contributions are dedicated to different specific fields of applications of oxide thin films and

QC 20210112

At the end of a rush lasting over half a century, in which CMOS technology has been experiencing a constant and breathtaking increase of device speed and density, Moore's law is approaching the insurmountable barrier given by the ultimate atomic nature of matter. A major challenge for 21st century scientists is finding novel strategies, concepts and materials for replacing silicon-based CMOS semiconductor technologies and guaranteeing a continued and steady technological progress in next decades. Among the materials classes candidate to contribute to this momentous challenge, oxide films and heterostructures are a particularly appealing hunting ground. The vastity, intended in pure chemical terms, of this class of compounds, the complexity of their correlated behaviour, and the wealth of functional properties they display, has already made these systems the subject of choice, worldwide, of a strongly networked, dynamic and interdisciplinary research community. Oxide science and technology has been the target of a wide four-year project, named Towards Oxide-Based Electronics (TO-BE), that has been recently running in Europe and has involved as participants several hundred scientists from 29 EU countries. In this review and perspective paper, published as a final deliverable of the TO-BE Action, the opportunities of oxides as future electronic materials for Information and Communication Technologies ICT and Energy are discussed. The paper is organized as a set of contributions, all selected and ordered as individual building blocks of a wider general scheme. After a brief preface by the editors and an introductory contribution, two sections follow. The first is mainly devoted to providing a perspective on the latest theoretical and experimental methods that are employed to investigate oxides and to produce oxide-based films, heterostructures and devices. In the second, all contributions are dedicated to different specific fields of applications of oxide thin films and

At the end of a rush lasting over half a century, in which CMOS technology has been experiencing a constant and breathtaking increase of device speed and density, Moore's law is approaching the insurmountable barrier given by the ultimate atomic nature of matter. A major challenge for 21st century scientists is finding novel strategies, concepts and materials for replacing silicon-based CMOS semiconductor technologies and guaranteeing a continued and steady technological progress in next decades. Among the materials classes candidate to contribute to this momentous challenge, oxide films and heterostructures are a particularly appealing hunting ground. The vastity, intended in pure chemical terms, of this class of compounds, the complexity of their correlated behaviour, and the wealth of functional properties they display, has already made these systems the subject of choice, worldwide, of a strongly networked, dynamic and interdisciplinary research community. Oxide science and technology has been the target of a wide four-year project, named Towards Oxide-Based Electronics (TO-BE), that has been recently running in Europe and has involved as participants several hundred scientists from 29 EU countries. In this review and perspective paper, published as a final deliverable of the TO-BE Action, the opportunities of oxides as future electronic materials for Information and Communication Technologies ICT and Energy are discussed. The paper is organized as a set of contributions, all selected and ordered as individual building blocks of a wider general scheme. After a brief preface by the editors and an introductory contribution, two sections follow. The first is mainly devoted to providing a perspective on the latest theoretical and experimental methods that are employed to investigate oxides and to produce oxide-based films, heterostructures and devices. In the second, all contributions are dedicated to different specific fields of applications of oxide thin films and

This paper is the outcome of a community initiative to identify major unsolved scientific problems in hydrology motivated by a need for stronger harmonisation of research efforts. The procedure involved a public consultation through online media, followed by two workshops through which a large number of potential science questions were collated, prioritised, and synthesised. In spite of the diversity of the participants (230 scientists in total), the process revealed much about community priorities and the state of our science: a preference for continuity in research questions rather than radical departures or redirections from past and current work. Questions remain focused on the process-based understanding of hydrological variability and causality at all space and time scales. Increased attention to environmental change drives a new emphasis on understanding how change propagates across interfaces within the hydrological system and across disciplinary boundaries. In particular, the expansion of the human footprint raises a new set of questions related to human interactions with nature and water cycle feedbacks in the context of complex water management problems. We hope that this reflection and synthesis of the 23 unsolved problems in hydrology will help guide research efforts for some years to come.

At the end of a rush lasting over half a century, in which CMOS technology has been experiencing a constant and breathtaking increase of device speed and density, Moore's law is approaching the insurmountable barrier given by the ultimate atomic nature of matter. A major challenge for 21st century scientists is finding novel strategies, concepts and materials for replacing silicon-based CMOS semiconductor technologies and guaranteeing a continued and steady technological progress in next decades. Among the materials classes candidate to contribute to this momentous challenge, oxide films and heterostructures are a particularly appealing hunting ground. The vastity, intended in pure chemical terms, of this class of compounds, the complexity of their correlated behaviour, and the wealth of functional properties they display, has already made these systems the subject of choice, worldwide, of a strongly networked, dynamic and interdisciplinary research community. Oxide science and technology has been the target of a wide four-year project, named Towards Oxide-Based Electronics (TO-BE), that has been recently running in Europe and has involved as participants several hundred scientists from 29 EU countries. In this review and perspective paper, published as a final deliverable of the TO-BE Action, the opportunities of oxides as future electronic materials for Information and Communication Technologies ICT and Energy are discussed. The paper is organized as a set of contributions, all selected and ordered as individual building blocks of a wider general scheme. After a brief preface by the editors and an introductory contribution, two sections follow. The first is mainly devoted to providing a perspective on the latest theoretical and experimental methods that are employed to investigate oxides and to produce oxide-based films, heterostructures and devices. In the second, all contributions are dedicated to different specific fields of applications of oxide thin films and

This paper is the outcome of a community initiative to identify major unsolved scientific problems in hydrology motivated by a need for stronger harmonisation of research efforts. The procedure involved a public consultation through online media, followed by two workshops through which a large number of potential science questions were collated, prioritised, and synthesised. In spite of the diversity of the participants (230 scientists in total), the process revealed much about community priorities and the state of our science: a preference for continuity in research questions rather than radical departures or redirections from past and current work. Questions remain focused on the process-based understanding of hydrological variability and causality at all space and time scales. Increased attention to environmental change drives a new emphasis on understanding how change propagates across interfaces within the hydrological system and across disciplinary boundaries. In particular, the expansion of the human footprint raises a new set of questions related to human interactions with nature and water cycle feedbacks in the context of complex water management problems. We hope that this reflection and synthesis of the 23 unsolved problems in hydrology will help guide research efforts for some years to come.

At the end of a rush lasting over half a century, in which CMOS technology has been experiencing a constant and breathtaking increase of device speed and density, Moore's law is approaching the insurmountable barrier given by the ultimate atomic nature of matter. A major challenge for 21st century scientists is finding novel strategies, concepts and materials for replacing silicon-based CMOS semiconductor technologies and guaranteeing a continued and steady technological progress in next decades. Among the materials classes candidate to contribute to this momentous challenge, oxide films and heterostructures are a particularly appealing hunting ground. The vastity, intended in pure chemical terms, of this class of compounds, the complexity of their correlated behaviour, and the wealth of functional properties they display, has already made these systems the subject of choice, worldwide, of a strongly networked, dynamic and interdisciplinary research community. Oxide science and technology has been the target of a wide four-year project, named Towards Oxide-Based Electronics (TO-BE), that has been recently running in Europe and has involved as participants several hundred scientists from 29 EU countries. In this review and perspective paper, published as a final deliverable of the TO-BE Action, the opportunities of oxides as future electronic materials for Information and Communication Technologies ICT and Energy are discussed. The paper is organized as a set of contributions, all selected and ordered as individual building blocks of a wider general scheme. After a brief preface by the editors and an introductory contribution, two sections follow. The first is mainly devoted to providing a perspective on the latest theoretical and experimental methods that are employed to investigate oxides and to produce oxide-based films, heterostructures and devices. In the second, all contributions are dedicated to different specific fields of applications of oxide thin films and

At the end of a rush lasting over half a century, in which CMOS technology has been experiencing a constant and breathtaking increase of device speed and density, Moore’s law is approaching the insurmountable barrier given by the ultimate atomic nature of matter. A major challenge for 21st century scientists is finding novel strategies, concepts and materials for replacing silicon-based CMOS semiconductor technologies and guaranteeing a continued and steady technological progress in next decades. Among the materials classes candidate to contribute to this momentous challenge, oxide films and heterostructures are a particularly appealing hunting ground. The vastity, intended in pure chemical terms, of this class of compounds, the complexity of their correlated behaviour, and the wealth of functional properties they display, has already made these systems the subject of choice, worldwide, of a strongly networked, dynamic and interdisciplinary research community. Oxide science and technology has been the target of a wide four-year project, named Towards Oxide-Based Electronics (TO-BE), that has been recently running in Europe and has involved as participants several hundred scientists from 29 EU countries. In this review and perspective paper, published as a final deliverable of the TO-BE Action, the opportunities of oxides as future electronic materials for Information and Communication Technologies ICT and Energy are discussed. The paper is organized as a set of contributions, all selected and ordered as individual building blocks of a wider general scheme. After a brief preface by the editors and an introductory contribution, two sections follow. The first is mainly devoted to providing a perspective on the latest theoretical and experimental methods that are employed to investigate oxides and to produce oxide-based films, heterostructures and devices. In the second, all contributions are dedicated to different specific fields of applications of oxide thin

Purpose: To examine the ergogenic potential of creatine (Cr), sodium bicarbonate (SB),and Cr+SBafter completion of a resistance exercise bout (REB).Methods: Following recruitment,27trained males (26.8±5.7 years old) completed a one repetition maximum strength (1RM) test in the parallel squat (120.9±28.2kg). Participants then followed a standardised meal plan for 4 days whilst ingesting one of 4 supplements, and on day 5 they undertook the REB. This was a double blind randomised placebo-controlled study where participants ingested one of the following: Placebo (PLA, n=7), Cr (20g/d-1& PLA, n=8), SB (0.5 g/kg-1/d-1&PLA, n=6), andCr+SB (5 g/d-1 of Cr & 0.5 g/kg-1/d-1 SB, n=6) divided in 4 doses. The REB consisted of 4x10 repetitions (70% of 1RM, 1½ min recovery). The primary performance outcome was a 5th set (70% of 1RM) performed to volitional exhaustion.Blood glucose and lactate, heart rate, ratings of perceived exertion, sickness and stomachache scales, and time to complete each set were also recorded.Results:Participants in Cr, SB, and Cr+SB completed the required number of repetitions at 70% of 1RM however in PLA they completed the same repetitions at lower intensity (68+3.4%). Participants in PLA, Cr, SB, and Cr+SB completed 8(±1.6), 11(±5.5), 9(±3.7), and 11(±3.3) repetitions respectively during the 5th set. Despite the fact that no significant differences were observed in performance, small (SB: 0.4) and moderate effect (Cr: 0.7; Cr+SB: 1.0) sizes were observed in relation to PLA. Body mass increasedsignificantly after Cr (78.1±8.9 kg pre vs 79.1±8.9 kg post, p<0.05). No other significant differences existed in recorded variables.Conclusions: Performance gains were of higher magnitude in the Cr+SB and Cr groups. Co-ingestion of a small amount of Cr (5 g/d-1) with a standard dose ofSB (0.5 g/kg-1/d-1)appears to be equally beneficial asingestion of a standard dose of Cr (20 g/d-1). The Cr+SB was not associated with significant gains in body mass which may be bene

Purpose: To examine the ergogenic potential of creatine (Cr), sodium bicarbonate (SB),and Cr+SBafter completion of a resistance exercise bout (REB).Methods: Following recruitment,27trained males (26.8±5.7 years old) completed a one repetition maximum strength (1RM) test in the parallel squat (120.9±28.2kg). Participants then followed a standardised meal plan for 4 days whilst ingesting one of 4 supplements, and on day 5 they undertook the REB. This was a double blind randomised placebo-controlled study where participants ingested one of the following: Placebo (PLA, n=7), Cr (20g/d-1& PLA, n=8), SB (0.5 g/kg-1/d-1&PLA, n=6), andCr+SB (5 g/d-1 of Cr & 0.5 g/kg-1/d-1 SB, n=6) divided in 4 doses. The REB consisted of 4x10 repetitions (70% of 1RM, 1½ min recovery). The primary performance outcome was a 5th set (70% of 1RM) performed to volitional exhaustion.Blood glucose and lactate, heart rate, ratings of perceived exertion, sickness and stomachache scales, and time to complete each set were also recorded.Results:Participants in Cr, SB, and Cr+SB completed the required number of repetitions at 70% of 1RM however in PLA they completed the same repetitions at lower intensity (68+3.4%). Participants in PLA, Cr, SB, and Cr+SB completed 8(±1.6), 11(±5.5), 9(±3.7), and 11(±3.3) repetitions respectively during the 5th set. Despite the fact that no significant differences were observed in performance, small (SB: 0.4) and moderate effect (Cr: 0.7; Cr+SB: 1.0) sizes were observed in relation to PLA. Body mass increasedsignificantly after Cr (78.1±8.9 kg pre vs 79.1±8.9 kg post, p<0.05). No other significant differences existed in recorded variables.Conclusions: Performance gains were of higher magnitude in the Cr+SB and Cr groups. Co-ingestion of a small amount of Cr (5 g/d-1) with a standard dose ofSB (0.5 g/kg-1/d-1)appears to be equally beneficial asingestion of a standard dose of Cr (20 g/d-1). The Cr+SB was not associated with significant gains in body mass which may be bene

What are the political consequences of democratization assistance to regimes transitioning from authoritarian rule? By exploiting the downstream effects of a field experiment designed to encourage citizen monitoring of Georgia’s 2008 parliamentary elections, we evaluate the political consequences of one type of democracy promotion aid. The intervention increased citizen activism, but it also had the unanticipated effect of suppressing overall voter turnout by approximately 5%. We hypothesize that the civic education campaign was interpreted as a sign of increased political attention to a selected voting precinct, which suppressed opposition turnout. Two additional experiments provide additional evidence for the hypothesis.

In this study, Si and C were incorporated into polycrystalline MgB2 via in situ reaction of Mg and B with either SiC or with separate Si and C (Si+C). The electrical transport and magnetic properties of the two series of samples were compared. The corrected resistivity at 40K, pA(40K), is higher for the SiC reacted samples regardless of carbon (C) substitution level, indicating larger intragrain scattering because of the simultaneous reaction between Mg and SiC and carbon substitution during the formation of MgB2. In addition, because of the cleaner reaction route for the SiC reacted samples, the calculated active area that carries current, AF, is twice that of the (Si+C) samples. On the other hand, the upper critical field, Hc2, was similar for both sets of samples despite their different C substitution levels which proves the importance of defect scattering in addition to C substitution level. Hence, the form of the precursor reactants is critical for tuning the form of Hc2(T).

In this study, Si and C were incorporated into polycrystalline MgB2 via in situ reaction of Mg and B with either SiC or with separate Si and C (Si+C). The electrical transport and magnetic properties of the two series of samples were compared. The corrected resistivity at 40K, pA(40K), is higher for the SiC reacted samples regardless of carbon (C) substitution level, indicating larger intragrain scattering because of the simultaneous reaction between Mg and SiC and carbon substitution during the formation of MgB2. In addition, because of the cleaner reaction route for the SiC reacted samples, the calculated active area that carries current, AF, is twice that of the (Si+C) samples. On the other hand, the upper critical field, Hc2, was similar for both sets of samples despite their different C substitution levels which proves the importance of defect scattering in addition to C substitution level. Hence, the form of the precursor reactants is critical for tuning the form of Hc2(T).

In this study, Si and C were incorporated into polycrystalline MgB2 via in situ reaction of Mg and B with either SiC or with separate Si and C (Si+C). The electrical transport and magnetic properties of the two series of samples were compared. The corrected resistivity at 40K, pA(40K), is higher for the SiC reacted samples regardless of carbon (C) substitution level, indicating larger intragrain scattering because of the simultaneous reaction between Mg and SiC and carbon substitution during the formation of MgB2. In addition, because of the cleaner reaction route for the SiC reacted samples, the calculated active area that carries current, AF, is twice that of the (Si+C) samples. On the other hand, the upper critical field, Hc2, was similar for both sets of samples despite their different C substitution levels which proves the importance of defect scattering in addition to C substitution level. Hence, the form of the precursor reactants is critical for tuning the form of Hc2(T).

In this study, Si and C were incorporated into polycrystalline MgB2 via in situ reaction of Mg and B with either SiC or with separate Si and C (Si+C). The electrical transport and magnetic properties of the two series of samples were compared. The corrected resistivity at 40K, pA(40K), is higher for the SiC reacted samples regardless of carbon (C) substitution level, indicating larger intragrain scattering because of the simultaneous reaction between Mg and SiC and carbon substitution during the formation of MgB2. In addition, because of the cleaner reaction route for the SiC reacted samples, the calculated active area that carries current, AF, is twice that of the (Si+C) samples. On the other hand, the upper critical field, Hc2, was similar for both sets of samples despite their different C substitution levels which proves the importance of defect scattering in addition to C substitution level. Hence, the form of the precursor reactants is critical for tuning the form of Hc2(T).

In the present work, Raman spectroscopy is employed to study the strain and carbon substitution effect of SiC doped polycrystalline MgB2. We demonstrated that Raman spectroscopy analysis is more accurate to estimate the carbon substitution compared to the X-ray diffraction analysis. Raman result showed that lattice shrinkage cannot account alone for carbon incorporation where high level of lattice distortion is attributing to both C substitution and lattice strain effect. Our result provides alternative explanation for lattice variation in the non-carbon doped MgB2 which is basically due to lattice strain.

In the present work, Raman spectroscopy is employed to study the strain and carbon substitution effect of SiC doped polycrystalline MgB2. We demonstrated that Raman spectroscopy analysis is more accurate to estimate the carbon substitution compared to the X-ray diffraction analysis. Raman result showed that lattice shrinkage cannot account alone for carbon incorporation where high level of lattice distortion is attributing to both C substitution and lattice strain effect. Our result provides alternative explanation for lattice variation in the non-carbon doped MgB2 which is basically due to lattice strain.

In the present work, Raman spectroscopy is employed to study the strain and carbon substitution effect of SiC doped polycrystalline MgB2. We demonstrated that Raman spectroscopy analysis is more accurate to estimate the carbon substitution compared to the X-ray diffraction analysis. Raman result showed that lattice shrinkage cannot account alone for carbon incorporation where high level of lattice distortion is attributing to both C substitution and lattice strain effect. Our result provides alternative explanation for lattice variation in the non-carbon doped MgB2 which is basically due to lattice strain.

Raman spectroscopy is employed to study both the strain and the carbon substitution level in SiC-doped MgB2 bulk samples. Raman spectroscopy was demonstrated to be a better method to distinguish the individual influences of strain and carbon than standard X-ray diffraction. It is found that the lattice parameter correlation method for C content determination is invalid for highly strained samples. Our result also provides an alternative explanation for lattice variation in non-carbon-doped MgB2, which is basically due to lattice strain.

In the present work, Raman spectroscopy is employed to study the strain and carbon substitution effect of SiC doped polycrystalline MgB2. We demonstrated that Raman spectroscopy analysis is more accurate to estimate the carbon substitution compared to the X-ray diffraction analysis. Raman result showed that lattice shrinkage cannot account alone for carbon incorporation where high level of lattice distortion is attributing to both C substitution and lattice strain effect. Our result provides alternative explanation for lattice variation in the non-carbon doped MgB2 which is basically due to lattice strain.

Raman spectroscopy is employed to study both the strain and the carbon substitution level in SiC-doped MgB2 bulk samples. Raman spectroscopy was demonstrated to be a better method to distinguish the individual influences of strain and carbon than standard X-ray diffraction. It is found that the lattice parameter correlation method for C content determination is invalid for highly strained samples. Our result also provides an alternative explanation for lattice variation in non-carbon-doped MgB2, which is basically due to lattice strain.

In the present work, Raman spectroscopy is employed to study the strain and carbon substitution effect of SiC doped polycrystalline MgB2. We demonstrated that Raman spectroscopy analysis is more accurate to estimate the carbon substitution compared to the X-ray diffraction analysis. Raman result showed that lattice shrinkage cannot account alone for carbon incorporation where high level of lattice distortion is attributing to both C substitution and lattice strain effect. Our result provides alternative explanation for lattice variation in the non-carbon doped MgB2 which is basically due to lattice strain.

Coated conductor by MOCVD shows the best Ic × L performance currently, but cost reduction is still ongoing issue. R&D effort for a process capable of utilizing cheap alternative precursors were tried by many research groups but few of them showed results having potential for replacing current MOCVD. Spray pyrolysis method adopting ultrasonic atomization was tried as one of the possible options. Y123 films have been deposited on LaAlO3 (100) single-crystal and IBAD substrates by aerosol assisted spray pyrolysis method. Ultrasonic atomization was used in order to generate fine droplets of precursor solution made of Y, Ba, Cu nitrate. A pre-heater was located between spraying nozzle and substrate for fast drying and enhancing decomposition of precursors. SEM and XRD observation revealed that deposited films have smooth and dense microstructure. The influence of operating parameters such as cation stoichiometry, oxygen partial pressure, substrate temperature on the microstructure, formation of superconducting 123 phases and superconducting properties of deposited films were tested. Ex-situ conversion was tried to decrease the possible reactions between precursor compounds and buffer layer materials of metal substrate showed the possibility of adopting this technique for epitaxial growth of 123 phase on metal substrate.

In the present work, Raman spectroscopy is employed to study the strain and carbon substitution effect of SiC doped polycrystalline MgB2. We demonstrated that Raman spectroscopy analysis is more accurate to estimate the carbon substitution compared to the X-ray diffraction analysis. Raman result showed that lattice shrinkage cannot account alone for carbon incorporation where high level of lattice distortion is attributing to both C substitution and lattice strain effect. Our result provides alternative explanation for lattice variation in the non-carbon doped MgB2 which is basically due to lattice strain.

Coated conductor by MOCVD shows the best Ic × L performance currently, but cost reduction is still ongoing issue. R&D effort for a process capable of utilizing cheap alternative precursors were tried by many research groups but few of them showed results having potential for replacing current MOCVD. Spray pyrolysis method adopting ultrasonic atomization was tried as one of the possible options. Y123 films have been deposited on LaAlO3 (100) single-crystal and IBAD substrates by aerosol assisted spray pyrolysis method. Ultrasonic atomization was used in order to generate fine droplets of precursor solution made of Y, Ba, Cu nitrate. A pre-heater was located between spraying nozzle and substrate for fast drying and enhancing decomposition of precursors. SEM and XRD observation revealed that deposited films have smooth and dense microstructure. The influence of operating parameters such as cation stoichiometry, oxygen partial pressure, substrate temperature on the microstructure, formation of superconducting 123 phases and superconducting properties of deposited films were tested. Ex-situ conversion was tried to decrease the possible reactions between precursor compounds and buffer layer materials of metal substrate showed the possibility of adopting this technique for epitaxial growth of 123 phase on metal substrate.

SiC was mixed with Mg and B and reacted by either a one-step in situ or two-step method at 650 or 850 °C. By doing so, it was possible to determine the extent to which scattering via C doping influences the magnitude of field dependent critical current density, Jc(H), compared to pinning via generation of microstructural disorder. The one-step reaction method leads to Mg2Si formation and at the same time to more C doping of MgB2 than the two-step method. Carbon increases both the irreversibility field, Hirr, and upper critical field, Hc2 (TK). However, for the temperatures (6 and 20 K) and fields (up to 7 T) studied, pinning rather than scattering overwhelmingly dominates the magnitude of the field dependent critical current density.

SiC was mixed with Mg and B and reacted by either a one-step in situ or two-step method at 650 or 850 °C. By doing so, it was possible to determine the extent to which scattering via C doping influences the magnitude of field dependent critical current density, Jc(H), compared to pinning via generation of microstructural disorder. The one-step reaction method leads to Mg2Si formation and at the same time to more C doping of MgB2 than the two-step method. Carbon increases both the irreversibility field, Hirr, and upper critical field, Hc2 (TK). However, for the temperatures (6 and 20 K) and fields (up to 7 T) studied, pinning rather than scattering overwhelmingly dominates the magnitude of the field dependent critical current density.

SiC was mixed with Mg and B and reacted by either a one-step in situ or two-step method at 650 or 850 °C. By doing so, it was possible to determine the extent to which scattering via C doping influences the magnitude of field dependent critical current density, Jc(H), compared to pinning via generation of microstructural disorder. The one-step reaction method leads to Mg2Si formation and at the same time to more C doping of MgB2 than the two-step method. Carbon increases both the irreversibility field, Hirr, and upper critical field, Hc2 (TK). However, for the temperatures (6 and 20 K) and fields (up to 7 T) studied, pinning rather than scattering overwhelmingly dominates the magnitude of the field dependent critical current density.

When a current is applied perpendicular to the vortex lattice (VL), Lorentz force may cause the VL to drift and flux-flow dissipation is observed. When the current is parallel to the applied magnetic field in a Force-Free (FF) configuration, a dissipation is also observed but at higher values of applied current. It has been suggested that pinning as well as free surfaces play an important role in the stabilization of the VL in the FF configuration. In YBa2Cu3O7 thin films, FF configurations can be obtained when H ab with the current flowing parallel to the ab-planes. In this work we study the influence of thickness, growth method and pinning centers on the dissipation mechanism at Variable Lorentz Force and FF configurations. Comparisons of experiments done at Maximum and Variable Lorentz Force show that there are two pinning regimes when the field is rotated in these configurations; one consistent with only a decrease in the applied force, indicated by the overlap of the power law exponent of the current-voltage curves as the field is rotated toward the ab-planes, and another very close to the ab-planes, where the dissipation characteristics change., Prepared in collaboration with Los Alamos National Laboratory, Los Alamos, NM, and University of Cambridge, Cambridge, UK. Published in IEEE Transactions on Applied Superconductivity, Vol. 17, No. 2, p3697-3700, June 2007.

The Electra advanced pulsed power development program has the goal of developing and demonstrating pulsed power technology that is applicable for KrF (krypton fluoride) Laser IFE (inertial fusion energy). The application presents efficiency, lifetime and cost challenges that mandate the use of advanced pulse compression topologies. In turn, these advanced topologies require the development of critical components and the establishment of engineering criteria for use in designing them. The component most critical to realizing any of the advanced topologies under study is the primary energy transfer switch. Therefore, the program has been developing an advanced optically-triggered and pumped solid state switch that is expected to meet the efficiency, lifetime and cost requirements of an IFE driver. Liquid dielectric breakdown studies are also underway, with the intent to develop design criteria relevant to the large electrically stressed areas associated with a viable KrF IFE power plant. KrF IFE pulse compression and component concepts will be discussed as well as the most recent results from the solid-state switch development and liquid dielectric test efforts., Published in the Proceedings of the 2002 Power Modulator Conference, 25th International, held in Hollwood CA, p165-169, on 30 Jun 3 Jul 2002. The original document contains color images.

Spacer oligonucleotide typing (spoligotyping) is widely used for differentiation of bacteria of the Mycobacterium tuberculosis complex. However, the absence of any standardised method for concise description of spoligotypes makes it difficult to compare the results from different laboratories. This paper describes unambiguous, interconvertible systems for the designation of spoligotype patterns, the adoption of which will be beneficial to mycobacterial research.

Spacer oligonucleotide typing (spoligotyping) is widely used for differentiation of bacteria of the Mycobacterium tuberculosis complex. However, the absence of any standardised method for concise description of spoligotypes makes it difficult to compare the results from different laboratories. This paper describes unambiguous, interconvertible systems for the designation of spoligotype patterns, the adoption of which will be beneficial to mycobacterial research.

Two projects, Silver Stringers and Junior Journalists, are examples of a shift in the role of the news consumer - community members are actively engaged in publishing pursuits previously confined to the traditional media. Their activities range from news gathering and dissemination to asking questions and debating issues of importance, whether local, international, or topical in scope. This paper describes the evolution of these projects, the experiences of the participants, the technologies developed and employed, and the epistemological impact., QC 20100525

The properties of turbulent premixed flames were investigated both theoretically and experimentally. Attention was limited to hydrogen/air mixtures burning as either turbulent jet flames or a freely propagating flames in isotropic turbulence. The research has application to a variety to premixed turbulent combustion processes: underwater metal cutting at great depth, primary combustors for high-speed airbreathing propulsion systems, afterburners, fuel/ air explosions, and spark-ignition internal combustion engines. Major findings of this phase of the investigation are as follows: (1) effects of preferential diffusion are relevent for flames at high Reynolds number, retarding and enhancing the distortion of the flame surface by turbulence for stable and unstable conditions, respectively; (2) local turbulent burning velocity, flame brush thickness and the fractal dimension of the flame surface all increase with distance from the flameholder, with larger rates of increases at larger turbulence intensities; (3) estimates of flame properties using contemporary turbulence models were only fair because these methods cannot account for effects of preferential diffusion, distance from the flameholder and finite laminar flame speeds; and (4) the stochastic simulation duplicated measured trends of flame surface properties for neutral preferential diffusion conditions (the only case considered) but underestimated effects of turbulence (particularly near the flame tip) due to the limitations of a two-dimensional simulation.

This is the final technical report for an ONR contract. The scope of the effort for this period was to address novel methods of investigation of silver electrodes in order to better understand the chemical and physical processes which occur during charge and discharge. Three areas of study were covered by this effort. The first was the development of a mass spectrometric procedure to determine the distribution of silver (I) oxide and silver (II) oxide in a silver electrode at any stage of the charge-discharge process. The second was the development of a rapid analytical technique for the determination of silver (III) oxide in a silver electrode. The third was a preliminary study of the application of acoustic analysis to give a more complete understanding of the processes occuring during charge and discharge of silver electrodes. The results of these investigations are detailed in this report.