bluuebunny/crossref_metadata_2025 huggingface dataset:
Travel Narrative and the Ends of Modernity
Authors: Burton Stacy
Published: December 2013

Over the past century, narratives of travel changed in response to modernist and postmodernist literary innovation, world wars, the demise of European empires, and the effect of new technologies and media on travel experience. Yet existing critical studies have not examined fully how the genre changes or theorized why. This study investigates the evolution of Anglophone travel narrative from the 1920s to the present, addressing the work of canonical authors such as T. E. Lawrence, W. H. Auden and Rebecca West; best-sellers by Peter Fleming and H. V. Morton; and texts by Colin Thubron, Andrew X. Pham, Rosemary Mahoney, and others. It argues that the genre's most important transformation lies in its reinvention as a means of narrating the subjective experience of violence, cultural upheaval, and decline. It will interest scholars and students of travel writing, modernism and postmodernism, English and American literature, and the history and sociology of travel.
From Classrooms to Conflict in Rwanda
Authors: King Elisabeth
Published: December 2013

This book questions the conventional wisdom that education builds peace by exploring the ways in which ordinary schooling can contribute to intergroup conflict. Based on fieldwork and comparative historical analysis of Rwanda, it argues that from the colonial period to the genocide, schooling was a key instrument of the state in contributing to the construction, awareness, collectivization and inequality of ethnic groups in Rwanda - all factors that underlay conflict. The book further argues that today's post-genocide schools are dangerously replicating past trends. This book is the first to offer an in-depth study of education in Rwanda and to analyze its role in the genesis of conflict. The book demonstrates that to build peace, we cannot simply prescribe more education, but must understand who has access to schools, how schools are set up, and what and how they teach.
The Cartographic State
Authors: Branch Jordan
Published: December 2013

Why is today's world map filled with uniform states separated by linear boundaries? The answer to this question is central to our understanding of international politics, but the question is at the same time much more complex - and more revealing - than we might first think. This book examines the important but overlooked role played by cartography itself in the development of modern states. Drawing upon evidence from the history of cartography, peace treaties and political practices, the book reveals that early modern mapping dramatically altered key ideas and practices among both rulers and subjects, leading to the implementation of linear boundaries between states and centralized territorial rule within them. In his analysis of early modern innovations in the creation, distribution and use of maps, Branch explains how the relationship between mapping and the development of modern territories shapes our understanding of international politics today.
Foundation Myths and Politics in Ancient Ionia
Authors: Mac Sweeney Naoíse
Published: December 2013

This book examines foundation myths told about the Ionian cities during the archaic and classical periods. It uses these myths to explore the complex and changing ways in which civic identity was constructed in Ionia, relating this to the wider discourses about ethnicity and cultural difference that were current in the Greek world at this time. The Ionian cities seem to have rejected oppositional models of cultural difference which set in contrast East and West, Europe and Asia, Greek and Barbarian, opting instead for a more fluid and nuanced perspective on ethnic and cultural distinctions. The conclusions of this book have far-reaching implications for our understanding of Ionia, but also challenge current models of Greek ethnicity and identity, suggesting that there was a more diverse conception of Greekness in antiquity than has often been assumed.
Immunogenic activity of the fish tapewormPterobothrium heteracanthum(Trypanorhyncha: Pterobothriidae) in BALB/c mice
Authors: Mattos D.P.B.G. , Verícimo M.A. , Lopes L.M.S. , São Clemente S.C.
Published: December 2013

The aim of this study was to verify the immunogenicity ofPterobothrium heteracanthum(Cestoda: Trypanorhyncha) crude protein extract (PH-CPE) in BALB/c mice. The parasites were obtained fromMicropogonias furnieri(Osteichthyes: Sciaenidae). Groups of six mice were each immunized with 10, 50 or 100 μg of PH-CPE, on days 0 and 35. Both specific IgG and IgE responses were developed after immunization. The immunoblot assay revealed that specific IgG recognizes PH-CPE proteins with two molecular weight ranges, 60–75 and 30–40 kDa, and that IgE recognizes larger proteins over 120 kDa. This appears to be the first report on the immunogenicity of metacestodes within the Pterobothriidae and that PH-CPE is a potential inducer of a specific IgE response.
Topological simultaneous localization and mapping: a survey
Authors: Boal Jaime , Sánchez-Miralles Álvaro , Arranz Álvaro
Published: December 2013

One of the main challenges in robotics is navigating autonomously through large, unknown, and unstructured environments. Simultaneous localization and mapping (SLAM) is currently regarded as a viable solution for this problem. As the traditional metric approach to SLAM is experiencing computational difficulties when exploring large areas, increasing attention is being paid to topological SLAM, which is bound to provide sufficiently accurate location estimates, while being significantly less computationally demanding. This paper intends to provide an introductory overview of the most prominent techniques that have been applied to topological SLAM in terms of feature detection, map matching, and map fusion.
Evaluation of C-Band Precise Orbit Determination of Geostationary Earth Orbit Satellites based on the Chinese Area Positioning System
Authors: Fen Cao , XuHai Yang , MuDan Su , ZhiGang Li , Liang Chen , WeiChao Li , BaoQi Sun , Yao Kong , Pei Wei , ChuGang Feng
Published: December 2013

Geostationary Earth Orbit (GEO) satellites play a significant role in the space segment of the Chinese Area Navigation System. The C-Band transfer ranging method developed by the National Time Service Center (NTSC) has been widely used in the Chinese Area Positioning System (CAPS), with its advantages of separating satellite ranging from time synchronization and being unaffected by weather. The explicit ranging correction models for the C-Band transfer ranging method are introduced in detail in this article for the first time. Precise Orbit Determination (POD) using C-Band pseudo-range observation of GEO satellite 2010-001A in July 2012 has been conducted. The residual Root Mean Square (RMS) of each site and POD are analysed with orbit difference over overlaps of adjacent orbit arcs. Moreover, the orbit of the GEO satellite has been evaluated by Satellite Laser Ranging (SLR) data from both domestic and foreign SLR sites for the first time. The residual RMS of POD using C-Band observation is better than 0·1 m, and the orbit difference over overlaps of adjacent orbit arcs is better than 3 m. In addition, the residual RMS in line-of-sight for a SLR site in China are better than 1 m, while the RMS for the Yarragadee site in Australia is about 3·4 m. It has been shown that the GEO satellite orbit accords very well with the C-Band observation. Also, the distribution of CAPS stations affects the orbit precision. All sites in CAPS are now located in China with low and medium latitudes. The residual RMS of the SLR site in the southern hemisphere is larger than that of the site in China.
Implantable CPW-fed rectangular patch antenna for ISM band biomedical applications
Authors: Ashok Kumar Srinivasan , Shanmuganantham Thangavelu
Published: December 2013

Implantable antennas have recently been receiving substantial attention for medical diagnosis and treatment. In this paper, a coplanar waveguide-fed monopole antenna for industrial, scientific, and medical (ISM) band biomedical applications is proposed. The antenna has a simple structure is placed on human tissues such as muscle, fat, and skin. The designed antenna is made compatible for implantation by embedding it in an FR4 substrate. The proposed antenna is simulated using the method of moment's software IE3D by assuming the predetermined dielectric constant for the human muscle tissue, fat, and skin. The antenna operates in the frequency of ISM bands, 2.4–2.48 GHz. Simulated and measured gains attain −7.7 and −8 dBi in the frequency of 2.45 GHz. The radiation pattern, return loss, current distribution, and gain of these antennas were examined and characterized.
Pushing the humanitarian agenda through engagement with business actors: the ICRC's experience
Authors: Voillat Claude
Published: December 2013

Large companies can have both massively positive and massively negative impacts on communities, be it directly through their operations or indirectly through their influence on decision-makers. This is particularly true when business operations take place in conflict-affected or high-risk areas. Humanitarian organisations endeavouring to bring protection and/or assistance in these areas cannot, therefore, ignore these influential actors. Engagement with business actors – as well as with any other societal actor – should be framed within a clear rationale in order to deliver positive results. This article introduces the rationale that has been developed by the International Committee of the Red Cross (ICRC) and offers some examples of past engagement between the ICRC and business actors. It notes that occasions for humanitarian organisations to engage with business actors are likely to become more frequent in the coming years and argues that this trend, if properly managed, offers humanitarian organisations opportunities to leverage energies, know-how, and resources from the business sector for the benefit of the persons and communities that humanitarian organisations strive to protect and assist.
Mikrobielles Umfeld und allergische Erkrankungen im Kindesalter
Authors: Braun-Fahrländer Charlotte
Published: December 2013

Asthma bronchiale und Allergien gehören zu den wichtigsten chronischen Erkrankungen im Kindesalter. Ihre Häufigkeit hat im Verlauf der zweiten Hälfte des 20. Jahrhunderts deutlich zugenommen, scheint sich jetzt aber auf hohem Niveau zu stabilisieren. Obwohl der genetische Hintergrund eines Individuums maßgeblichen Einfluss hat auf das Risiko, an Asthma oder Allergien zu erkranken, scheint die Zunahme der Prävalenz vor allem mit Veränderungen in der Umwelt im Zusammenhang zu stehen. Die Forschung nach Umweltursachen für Asthma und Allergien hat sich lange auf Risikofaktoren konzentriert. Mittlerweile liegt der Fokus mehr auf protektiven Faktoren, also Umwelteinflüssen, die vor dem Entstehen eines Asthma oder Allergien schützen, und die möglicherweise mit der Verbreitung des „westlichen Lebensstil“ teilweise verloren gegangen sind. Der Artikel diskutiert die Rolle von Umweltallergenen, die Hygienehypothese und die Impulse, die die Studien von bäuerlichen und nicht-bäuerlichen Kinderkohorten für die heute aktuelle Mikrobiomforschung ausgelöst haben. Die Veränderungen im alltäglichen mikrobiellen Umfeld scheinen einen wichtigen, wenngleich nicht den einzigen Beitrag für die Zunahme von kindlichem Asthma und allergischen Erkrankungen zu leisten.
Update – Gesundheitsrisiken durch ionisierende Strahlung in der medizinischen Diagnostik
Authors: Knüsli Claudio , Walter Martin
Published: December 2013

Ionisierende Strahlung gehört zu den am besten untersuchten exogenen Noxen. Seit Beginn des 20. Jahrhunderts ist bekannt, dass ihre Anwendung in der Röntgendiagnostik Krebs verursachen kann – in den Anfängen der Radiologie waren oft Ärztinnen und Ärzte selber betroffen. Deshalb kommt dem Strahlenschutz in der medizinischen Radiologie eine zentrale Bedeutung zu. Im Bereich niederer Strahlendosen unter 100 Millisievert (mSv) besteht großer Forschungsbedarf, da nebst Malignomen eine Zunahme von kardiovaskulären Erkrankungen, Missbildungen und genetischen Folgen beobachtet wurde. Besonders Ungeborene, Kinder und Jugendliche sind strahlensensibel. Bisherige Berechnungsmodelle zu den Gesundheitsrisiken, die sich in erster Linie auf Untersuchungen der japanischen Atombombenopfer abstützen, weisen Unsicherheiten auf. Neue umfangreiche Studien aus England und Australien zur Krebsinzidenz nach Computertomographie – heute Hauptquelle ionisierender Strahlung in der medizinischen Diagnostik – bestätigen, dass bereits kleinste Strahlendosen im Bereich unter 5 mSv kanzerogen sind. In der bildgebenden Diagnostik sollen deshalb wo immer möglich nichtionisierende Methoden wie Ultraschall oder Magnetresonanztomographie bevorzugt werden.
Freiwilliger Verzicht auf Nahrung und Flüssigkeit in der Palliative Care: ein Mapping Review
Authors: Klein Remane Ursula , Fringer André
Published: December 2013

Der freiwillige Verzicht auf Nahrung und Flüssigkeit (FVNF) stellt für Menschen in palliativen Situationen eine Möglichkeit dar, das Sterben zu beschleunigen, um ihr Leiden zu begrenzen. Diese Arbeit beleuchtet mittels eines Mapping Reviews die medizinisch-pflegerisch, ethisch und juristisch wichtigen Aspekte bei der Begleitung von Menschen in palliativen Situationen, welche freiwillig auf Nahrung und Flüssigkeit verzichten, um zu sterben. Der Sterbewunsch wird durch psychische, soziale, spirituelle und physische Faktoren beeinflusst. FVNF ist eine wenig bekannte, legale und selbstständig durchführbare Möglichkeit, einen vorzeitigen Tod herbeizuführen. Bei einer Flüssigkeitszufuhr von 40 ml täglich dauert der Sterbeprozess ein bis drei Wochen. FVNF kann als natürlicher Tod, als Behandlungsverzicht oder als Suizid betrachtet werden. Im Gegensatz zum Tod durch Suizidbeihilfe oder Euthanasie durchleben die Sterbenden einen «natürlichen Sterbeprozess» und die Entscheidung ist in den ersten Tagen reversibel. Die Tatherrschaft liegt bei den Sterbewilligen. Fachpersonen und Angehörige leisten keine Sterbehilfe, sondern begleiten das Sterben. Alle Beteiligten sind bei der Entscheidungsfindung und bei der Durchführung mit verschiedenen ethischen Problemen konfrontiert. Weitere Forschung zu FVNF und den damit verbundenen Herausforderungen ist notwendig.
Phenotypic and transcriptional profile correlates with functional plasticity of antigen‐specific CD4+ T cells
Authors: Edwards Emily SJ , Smith Corey , Khanna Rajiv
Published: December 2013

The role of CD4+ T cells in the control of infectious pathogens is highly complex with a myriad of functions but how these T cells acquire differential functional potentiality remains poorly defined. Here we show that human cytomegalovirus (CMV)‐specific CD4+ T cells directed towards different viral antigens expressed predominantly TNF‐α alone or TNF‐α and IFN‐γ. TNF‐α+ and IFN‐γ+ CD4+ T cells expressed significantly higher levels of T‐box transcription factors T‐bet with graded loss of Eomesodermin (Eomes) expression (T‐betHiEomesHi/Lo) when compared with TNF‐α+ CD4+ T cells expressing lower levels of both T‐bet and Eomes (T‐bet−Eomes−). Furthermore, TNF‐α+ and IFN‐γ+ CD4+ T cells expressed significantly higher levels of perforin and interleukin (IL)‐2 and displayed a terminally differentiated phenotype (CCR7−CD27−CD45RA−CD57+CD62L−). In contrast, TNF‐α+ alone CMV‐specific CD4+ T cells were predominantly early‐memory phenotype with a proportion of these cells displaying T memory stem‐cell phenotype (CD95+CD45RA+CCR7+CD27+). In vitro stimulation of CMV‐specific CD4+ T cells with viral antigen in the presence of IL‐12 was sufficient to dramatically change the transcriptional and functional profile of TNF‐α+ CD4+ T cells, whereas TNF‐α+ and IFN‐γ+ CD4+ T cells remained unaltered. These findings illustrate an intrinsic link between cytokine expression, transcriptional regulation and cellular differentiation, and their impact on functional plasticity of virus‐specific CD4+ T cells.
Ultrahigh relaxivity and safe probes of manganese oxide nanoparticles for in vivo imaging
Authors: Xiao J. , Tian X. M. , Yang C. , Liu P. , Luo N. Q. , Liang Y. , Li H. B. , Chen D. H. , Wang C. X. , Li L. , Yang G. W.
Published: December 2013

Mn-based nanoparticles (NPs) have emerged as new class of probes for magnetic resonance imaging due to the impressive contrast ability. However, the reported Mn-based NPs possess low relaxivity and there are no immunotoxicity data regarding Mn-based NPs as contrast agents. Here, we demonstrate the ultrahigh relaxivity of water protons of 8.26 mM−1s−1 from the Mn3O4 NPs synthesized by a simple and green technique, which is twice higher than that of commercial gadolinium (Gd)-based contrast agents (4.11 mM−1s−1) and the highest value reported to date for Mn-based NPs. We for the first time demonstrate these Mn3O4 NPs biocompatibilities both in vitro and in vivo are satisfactory based on systematical studies of the intrinsic toxicity including cell viability of human nasopharyngeal carcinoma cells, normal nasopharyngeal epithelium, apoptosis in cells and in vivo immunotoxicity. These findings pave the way for the practical clinical diagnosis of Mn based NPs as safe probes for in vivo imaging.
Rapid quantification and comparison of major volatile compounds of ciders from France (Normandy and Brittany) using microextraction by packed sorbent (MEPS)
Authors: Haider Waqar , Barillier Daniel , Hayat Akhtar , Gaillard Jean-Luc , Ledauphin Jérôme
Published: December 2013

The volatile composition of French ciders from two different regions was statistically compared by using microextraction by packed sorbent followed by analysis by GC-MS and GC-FID.
Functional disruption of HypB, a GTPase of Helicobacter pylori, by bismuth
Authors: Xia Wei , Li Hongyan , Sun Hongzhe
Published: December 2013

Bismuth (Bi3+) binds equal molar amounts of HypB from Helicobacter pylori at the conserved metal site, and concomitantly induces the protein dimerization and excess Bi3+ causes further oligomerization of HypB, resulting in HypB GTPase dysfunction.
Ni(ii)–salt catalyzed activation of primary amine-sp3Cα–H and cyclization with 1,2-diketone to tetrasubstituted imidazoles
Authors: Samanta Srikanta , Roy Dipanwita , Khamarui Saikat , Maiti Dilip K.
Published: December 2013

NiCl2·6H2O and Ni(OAc)2·4H2O were found as efficient catalysts for C–H activation of benzyl and aliphatic amines for an unprecedented multi C–N bond forming cyclization with 1,2-diketones under refluxing toluene to furnish highly substituted and polycyclic imidazoles.
The role of surface Zn2+ ions in the transesterification of vegetable oils over ZnO supported on Al2O3 and Fe2O3
Authors: Thirunavukkarasu K. , Sankaranarayanan T. M. , Pandurangan A. , Vijaya Shanthi R. , Sivasanker S.
Published: December 2013

ZnO–Al2O3 and ZnO–Fe2O3 with different loadings of ZnO (5–20 wt%) along with ZnAl2O4 and ZnFe2O4 were prepared and tested in the transesterification of sunflower, waste cooking oil and Jatropha oil.
Developing an efficient catalyst for controlled oxidation of small alkanes under ambient conditions
Authors: Nagababu Penumaka , Yu Steve S.-F. , Maji Suman , Ramu Ravirala , Chan Sunney I.
Published: December 2013

Catalysis of alkane oxidation by a tricopper complex. The tricopper complex can mediate efficient conversion of small alkanes to their corresponding alcohols without over oxidation under ambient conditions.
Vibrational spectroscopic studies and DFT calculations on NaCH3CO2(aq) and CH3COOH(aq)
Authors: Rudolph Wolfram W. , Fischer Dieter , Irmer Gert
Published: December 2013

NaCH3CO2(aq) and CH3COOH(aq) were studied using Raman and infrared spectroscopy over a large concentration range, in the terahertz region and up to 4000 cm−1. Band assignments for CH3CO2−(aq) and CH3COOH(aq) were carried out under guidance of DFT frequencies.
A tetradentate metalloligand: synthesis and coordination behaviour of a 2-pyridyl-substituted cyclobutadiene iron complex
Authors: Rezaei Rad Babak , Herrmann Dirk , Lescop Christophe , Wolf Robert
Published: December 2013

A novel cyclobutadiene iron complex with four 2-pyridyl-substitutents acts as a bis(bidentate) chelate ligand toward Zn2+ cations.
A mild and highly efficient laccase-mediator system for aerobic oxidation of alcohols
Authors: Zhu Chenjie , Zhang Zhi , Ding Weiwei , Xie Jingjing , Chen Yong , Wu Jinglan , Chen Xiaochun , Ying Hanjie
Published: December 2013

A mild and efficient system for enzyme laccase-catalyzed aerobic oxidation of alcohols has been developed with the aid of the highly active nitroxyl radical AZADO.
Synthesis of hierarchical MoS2 and its electrochemical performance as an anode material for lithium-ion batteries
Authors: Sun Panling , Zhang Wuxing , Hu Xianluo , Yuan Lixia , Huang Yunhui
Published: December 2013

Hydrothermally synthesized MoS2 products can be tuned from porous flowers to dense spheres by addition of NaOH.
Thermal dispersion and secondary crystallization of phase change memory cells
Authors: Deng Y. F. , Li Z. , Peng J. H. , Liu C. , Miao X. S.
Published: December 2013

The heat accumulation effect associated with heat dispersion process in phase change memory cell was analyzed. The pulse operating scheme was optimized. The pulse sequences with different intervals show distinct heat accumulation effect. A compact model with pulse sequence expansion was proposed, and the simulation result is close to the experiment data for a pulse sequence with interval 20 ns. The simulated R-V curves show that threshold voltage reduces with the decreasing pulse interval. The secondary crystallization and amorphization were used to explain the heat accumulation effect for high speed operation, cycling, and so on.
Observation of strongly forbidden solid effect dynamic nuclear polarization transitions via electron-electron double resonance detected NMR
Authors: Smith Albert A. , Corzilius Björn , Haze Olesya , Swager Timothy M. , Griffin Robert G.
Published: December 2013

We present electron paramagnetic resonance experiments for which solid effect dynamic nuclear polarization transitions were observed indirectly via polarization loss on the electron. This use of indirect observation allows characterization of the dynamic nuclear polarization (DNP) process close to the electron. Frequency profiles of the electron-detected solid effect obtained using trityl radical showed intense saturation of the electron at the usual solid effect condition, which involves a single electron and nucleus. However, higher order solid effect transitions involving two, three, or four nuclei were also observed with surprising intensity, although these transitions did not lead to bulk nuclear polarization—suggesting that higher order transitions are important primarily in the transfer of polarization to nuclei nearby the electron. Similar results were obtained for the SA-BDPA radical where strong electron-nuclear couplings produced splittings in the spectrum of the indirectly observed solid effect conditions. Observation of high order solid effect transitions supports recent studies of the solid effect, and suggests that a multi-spin solid effect mechanism may play a major role in polarization transfer via DNP.
Fluctuation effects on the order-disorder transition in polydisperse copolymer melts
Authors: Pandav Gunja , Ganesan Venkat
Published: December 2013

Using single chain in mean field simulation approach, we examine the influence of fluctuation effects on the order-disorder transition (ODT) of polydisperse copolymer systems. We consider two model systems: (i) molecular weight polydisperse systems represented by AB diblock copolymer melts having monodisperse A blocks and polydisperse B blocks; and (ii) compositionally polydisperse symmetric diblock copolymer systems. In each case, we present results for the fluctuation-induced shift in the ODT from the corresponding mean-field predictions. In both models, an increase in polydispersity enhances the influence of fluctuations. Moreover, for compositionally polydisperse systems, we observe that the effects of fluctuations show similar trends in systems containing quenched and annealed representation of sequences.
Comment on “Molecular dynamics simulation study of nonconcatenated ring polymers in a melt. I. Statics” [J. Chem. Phys. 134, 204904 (2011)]
Authors: Wittmer J. P. , Meyer H. , Johner A. , Obukhov S. , Baschnagel J.
Published: December 2013

Recent computational studies on melts of nonconcatenated rings suggest compact configurations of fractal dimension df = 3. This begs the question of whether the irregular surfaces of these compact rings may be characterized by a fractal surface dimension ds < 3. We revisit the scaling analysis of the form factor by Halverson et al. [J. Chem. Phys. 134, 204904 (2011)] implying ds ≈ 2.8. Our analysis suggests that this conclusion might be due to the application of the Generalized Porod Law at large wavevectors where length scales other than the total chain size do matter. We present an alternative “decorated Gaussian loop” model which does not require ds < 3.
In-beam Mössbauer spectroscopy of 57Fe/57Mn in MgO and NaF at Heavy-Ion Medical Accelerator in Chiba
Authors: Kubo M. K. , Kobayashi Y. , Yamada Y. , Mihara M. , Nagatomo T. , Sato W. , Miyazaki J. , Sato S. , Kitagawa A.
Published: December 2013

Development of efficient ion supply of 58Fe from 58Fe(C5H5)2, and quick switching between therapy and material science at the Heavy-Ion Medical Accelerator in Chiba realized a new 57Mn in-beam emission Mössbauer spectroscopy measurement system. Application to simple binary chemical compounds, MgO and NaF, proved the usefulness of the system to probe chemical and physical behaviors of trace impurities in solids. Annealing of lattice defects produced by the implantation and β-decay of 57Mn and/or γ-ray emission recoil was observed by a local probe.
Numerical study of the inductive plasma coupling to ramp up the plasma density for the Linac4 H− ion source
Authors: Ohta M. , Mattei S. , Yasumoto M. , Hatayama A. , Lettry J.
Published: December 2013

In the Linac4 H− ion source, the plasma is generated by an RF antenna operated at 2 MHz. In order to investigate the conditions necessary for ramping up the plasma density of the Linac4 H− ion source in the low plasma density, a numerical study has been performed for a wide range of parameter space of RF coil current and initial pressure from H2 gas injection. We have employed an Electromagnetic Particle in Cell model, in which the collision processes have been calculated by a Monte Carlo method. The results have shown that the range of initial gas pressure from 2 to 3 Pa is suitable for ramping up plasma density via inductive coupling.
Handling radiation generated during an ion source commissioning
Authors: Ren H. T. , Zhao J. , Peng S. X. , Lu P. N. , Zhou Q. F. , Xu Y. , Chen J. , Zhang T. , Zhang A. L. , Guo Z. Y. , Chen J. E.
Published: December 2013

Radiation is an important issue, which should be carefully treated during the design and commissioning of an ion source. Measurements show that X-rays are generated around the ceramics column of an extraction system when the source is powered up to 30 kV. The X-ray dose increases greatly when a beam is extracted. Inserting the ceramic column into a metal vacuum box is a good way to block X-ray emission for those cases. Moreover, this makes the online test of an intense H+ ion beam with energy up to 100 keV possible. However, for deuteron ion source commissioning, neutron and gamma-ray radiation become a serious topic. In this paper, we will describe the design of the extraction system and the radiation doses of neutrons and gamma-rays measured at different D+ beam energy during our 2.45 GHz deuteron electron cyclotron resonance ion source commissioning for PKUNIFTY (PeKing University Neutron Imaging FaciliTY) project at Peking University.
Application of polynomial su(1, 1) algebra to Pöschl-Teller potentials
Authors: Zhang Hong-Biao , Lu Lu
Published: December 2013

Two novel polynomial su(1, 1) algebras for the physical systems with the first and second Pöschl-Teller (PT) potentials are constructed, and their specific representations are presented. Meanwhile, these polynomial su(1, 1) algebras are used as an algebraic technique to solve eigenvalues and eigenfunctions of the Hamiltonians associated with the first and second PT potentials. The algebraic approach explores an appropriate new pair of raising and lowing operators \documentclass[12pt]{minimal}\begin{document}$\hat{K}_\pm$\end{document}K̂± of polynomial su(1, 1) algebra as a pair of shift operators of our Hamiltonians. In addition, two usual su(1, 1) algebras associated with the first and second PT potentials are derived naturally from the polynomial su(1, 1) algebras built by us.
Hamilton-Jacobi method for molecular distribution function in a chemical oscillator
Authors: Nakanishi Hiizu , Sakaue Takahiro , Wakou Jun'ichi
Published: December 2013

Using the Hamilton-Jacobi method, we solve chemical Fokker-Planck equations within the Gaussian approximation and obtain a simple and compact formula for a conditional probability distribution. The formula holds in general transient situations, and can be applied not only to a steady state but also to an oscillatory state. By analyzing the long time behavior of the solution in the oscillatory case, we obtain the phase diffusion constant along the periodic orbit and the steady distribution perpendicular to it. A simple method for numerical evaluation of these formulas are devised, and they are compared with Monte Carlo simulations in the case of Brusselator as an example. Some results are shown to be identical to previously obtained expressions.
Six-flow operations for catalyst development in Fischer-Tropsch synthesis: Bridging the gap between high-throughput experimentation and extensive product evaluation
Authors: Sartipi Sina , Jansma Harrie , Bosma Duco , Boshuizen Bart , Makkee Michiel , Gascon Jorge , Kapteijn Freek
Published: December 2013

Design and operation of a “six-flow fixed-bed microreactor” setup for Fischer-Tropsch synthesis (FTS) is described. The unit consists of feed and mixing, flow division, reaction, separation, and analysis sections. The reactor system is made of five heating blocks with individual temperature controllers, assuring an identical isothermal zone of at least 10 cm along six fixed-bed microreactor inserts (4 mm inner diameter). Such a lab-scale setup allows running six experiments in parallel, under equal feed composition, reaction temperature, and conditions of separation and analysis equipment. It permits separate collection of wax and liquid samples (from each flow line), allowing operation with high productivities of C5+ hydrocarbons. The latter is crucial for a complete understanding of FTS product compositions and will represent an advantage over high-throughput setups with more than ten flows where such instrumental considerations lead to elevated equipment volume, cost, and operation complexity. The identical performance (of the six flows) under similar reaction conditions was assured by testing a same catalyst batch, loaded in all microreactors.
Growth direction of oblique angle electron beam deposited silicon monoxide thin films identified by optical second-harmonic generation
Authors: Vejling Andersen Søren , Lund Trolle Mads , Pedersen Kjeld
Published: December 2013

Oblique angle deposited (OAD) silicon monoxide (SiO) thin films forming tilted columnar structures have been characterized by second-harmonic generation. It was found that OAD SiO leads to a rotationally anisotropic second-harmonic response, depending on the optical angle of incidence. A model for the observed dependence of the second-harmonic signal on optical angle of incidence allows extraction of the growth direction of OAD films. The optically determined growth directions show convincing agreement with cross-sectional scanning electron microscopy images. In addition to a powerful characterization tool, these results demonstrate the possibilities for designing nonlinear optical devices through SiO OAD.
Independent bases on the spatial wavefunction of four-identical-particle systems
Authors: Xiao Shuyuan , Deng Zhixuan , Chen Hong
Published: December 2013

We construct the independent bases on the spatial wavefunction of four-identical-particle systems classified under the rotational group SO(3) and the permutation group S4 with the usage of transformation coefficients that relate wavefunctions described in one set of internal coordinates with those in another. The basis functions for N ⩽ 2 are presented in the explicit expressions based on the harmonic oscillator model. Such independent bases are supposed to play a key role in the construction of the wavefunctions of the five-quark states and the variation calculation of four-body systems. Our prescription avoids the spurious states and can be programmed for arbitrary N.
Elastic properties of B-C-N films grown by N2-reactive sputtering from boron carbide targets
Authors: Salas E. , Jiménez Riobóo R. J. , Sánchez-Marcos J. , Jiménez-Villacorta F. , Muñoz-Martín A. , Prieto J. E. , Joco V. , Prieto C.
Published: December 2013

Boron-carbon-nitrogen films were grown by RF reactive sputtering from a B4C target and N2 as reactive gas. The films present phase segregation and are mechanically softer than boron carbide films (a factor of more than 2 in Young's modulus). This fact can turn out as an advantage in order to select buffer layers to better anchor boron carbide films on substrates eliminating thermally induced mechanical tensions.
Spectroscopy of snake states using a graphene Hall bar
Authors: Milovanović S. P. , Ramezani Masir M. , Peeters F. M.
Published: December 2013

An approach to observe snake states in a graphene Hall bar containing a pn-junction is proposed. The magnetic field dependence of the bend resistance in a ballistic graphene Hall bar structure containing a tilted pn-junction oscillates as a function of applied magnetic field. We show that each oscillation is due to a specific snake state that moves along the pn-interface. Furthermore, depending on the value of the magnetic field and applied potential, we can control the lead in which the electrons will end up and hence control the response of the system.
Carrier-number fluctuations in the 2-dimensional electron gas at the LaAlO3/SrTiO3 interface
Authors: Barone C. , Romeo F. , Pagano S. , Di Gennaro E. , Miletto Granozio F. , Pallecchi I. , Marrè D. , Scotti di Uccio U.
Published: December 2013

The voltage-spectral density SV (f) of the 2-dimensional electron gas formed at the interface of LaAlO3/SrTiO3 has been thoroughly investigated. The low-frequency component has a clear 1/f behavior with a quadratic bias current dependence, attributed to resistance fluctuations. However, its temperature dependence is inconsistent with the classical Hooge model, based on carrier-mobility fluctuations. The experimental results are, instead, explained in terms of carrier-number fluctuations, due to an excitation-trapping mechanism of the 2-dimensional electron gas.
High performance raised source/drain InAs/In0.53Ga0.47As channel metal-oxide-semiconductor field-effect-transistors with reduced leakage using a vertical spacer
Authors: Lee Sanghoon , Huang Cheng-Ying , Cohen-Elias Doron , Law Jeremy J. M. , Chobpattanna Varistha , Krämer Stephan , Thibeault Brian J. , Mitchell William , Stemmer Susanne , Gossard Arthur C. , Rodwell Mark J. W.
Published: December 2013

We demonstrate raised source/drain InAs/In0.53Ga0.47As metal-oxide-semiconductor field-effect-transistors incorporating a vertical spacer in the high-field region between the channel and the drain. The spacer significantly reduces off-state leakage at a high drain bias (VDS) without increasing the source/drain contact pitch. Subsequently, thinning the InAs layer within the channel further reduces the off-state leakage and subthreshold swing (SS). At ∼60 nm gate length and VDS = 0.5 V, devices with a 6 nm/3 nm InAs/In0.53Ga0.47As channel show 2.7 mS/μm peak transconductance (gm) and 125 mV/dec SS, while devices with a 4.5 nm/3 nm InAs/In0.53Ga0.47As channel show 2.4 mS/μm peak gm and 96 mV/dec SS.
Ultrasensitive mass sensing with nonlinear optics in a doubly clamped suspended carbon nanotube resonator
Authors: Chen Hua-Jun , Zhu Ka-Di
Published: December 2013

Nanomechanical resonator makes itself as an ideal system for ultrasensitive mass sensing due to its ultralow mass and high vibrational frequency. The mass sensing principle is due to the linear relationship of the frequency-shift and mass-variation. In this work, we will propose a nonlinear optical mass sensor based on a doubly clamped suspended carbon nanotube resonator in all-optical domain. The masses of external particles (such as nitric oxide molecules) landing onto the surface of carbon nanotube can be determined directly and accurately via using the nonlinear optical spectroscopy. This mass sensing proposed here may provide a nonlinear optical measurement technique in quantum measurements and environmental science.
Omnidirectional broadband insulating device for flexural waves in thin plates
Authors: Climente Alfonso , Torrent Daniel , Sánchez-Dehesa José
Published: December 2013

This work presents a gradient index device for insulating from vibrations a circular area of a thin plate. The gradient of the refractive index is achieved exploiting the thickness-dependence of the dispersion relation of flexural waves in thin plates. A well-like thickness profile in an annular region of the plate is used to mimic the combination of an attractive and repulsive potentials, focusing waves at its bottom and dissipating them by means of an absorptive layer placed on top. The central area is therefore isolated from vibrations, while they are dissipated at the bottom of the well. Simulations have been done using the multilayer multiple scattering method and the results prove their broadband efficiency and omnidirectional properties.
Detection and measurement of electroreflectance on quantum cascade laser device using Fourier transform infrared microscope
Authors: Enobio Eli Christopher I. , Ohtani Keita , Ohno Yuzo , Ohno Hideo
Published: December 2013

We demonstrate the use of a Fourier Transform Infrared microscope system to detect and measure electroreflectance (ER) from mid-infrared quantum cascade laser (QCL) device. To characterize intersubband transition (ISBT) energies in a functioning QCL device, a microscope is used to focus the probe on the QCL cleaved mirror. The measured ER spectra exhibit resonance features associated to ISBTs under applied electric field in agreement with the numerical calculations and comparable to observed photocurrent, and emission peaks. The method demonstrates the potential as a characterization tool for QCL devices.
Enhanced sensitivity and contrast with bimodal atomic force microscopy with small and ultra-small amplitudes in ambient conditions
Authors: Santos Sergio
Published: December 2013

Here, we introduce bimodal atomic force microscopy operated with sub-nm and ultra-small, i.e., sub-angstrom, first and second mode amplitudes in ambient conditions. We show how the tip can be made to oscillate in the proximity of the surface and in perpetual contact with the adsorbed water layers while the second mode amplitude and phase provide enhanced contrast and sensitivity. Nonlinear and nonmonotonic behavior of the experimental observables is discussed theoretically with a view to high resolution, enhanced contrast, and minimally invasive mapping. Fractions of meV of energy dissipation are shown to provide contrast above the noise level.
Stimulated electroluminescence emission from n-ZnO/p-GaAs:Zn heterojunctions fabricated by electro-deposition
Authors: Köç P. , Tekmen S. , Baltakesmez A. , Tüzemen S. , Meral K. , Onganer Y.
Published: December 2013

In this study, n-ZnO thin films were electrochemically deposited on p-GaAs:Zn substrates. The XRD results of ZnO thin films deposited on p-GaAs:Zn substrates at potentials varied from −0.9 V to −1.2 V show a strong c-axis (002) orientation and homogeneity. The current-voltage characteristics exhibit rectification, proving a low turn-on voltage and an ideality factor of 4.71. The n-ZnO/p-GaAs heterostructures show blue-white electroluminescence (EL) emission, which is composed of broad emission bands. In addition to these broad peaks, stimulated emission also appear on the top of the spectra due to the multiple reflections from the mirror like surfaces of ZnO-ZnO and ZnO-GaAs interfaces. Besides, three broad photoluminescence (PL) emission peaks have also been observed peaking at respectively around 3.36 eV, 3.28 eV and 3.07 eV generally attributed to the near bandedge emission, the residual donor level and deep level emission due to the localized defects, respectively.
Polymorphisms of LHβ and GnRHR genes and their association with the number of embryos recovered in goats
Authors: Fu M. Z. , Li G. , Zhou Z. Q.
Published: December 2013

The objective of the present study was to explore a predictor of superovulation response on the basis of associations between the number of embryos recovered and gene polymorphism. Variation in the goat LHβ and GnRHR genes was investigated using polymerase chain reaction–single-strand conformational polymorphism and DNA sequencing. Two single nucleotide polymorphisms (SNPs) were identified in the 5′-UTR of LHβ gene (A59C, P1 locus) and in the Exon 2 of GnRHR gene (T177A, P6 locus). At the P1 locus in both breeds, the frequencies of one allele were 0.46 and 0.51, respectively. At the P6 locus, the minor allele frequency was 0.23. Associations of both SNPs with the number of embryos recovered and the corpus luteum number were evaluated in Boer and Shaanbei goat breeds. Association analysis showed that both SNPs had significant (P < 0.05) effects on the number of embryos recovered and corpus luteum number. These results indicate that LHβ and GnRHR genes are potential markers for the number of embryos recovered.
Molecular signatures of bovine embryo developmental competence
Authors: Hoelker M. , Held E. , Salilew-Wondim D. , Schellander K. , Tesfaye D.
Published: December 2013

Assessment of the developmental capacity of early bovine embryos is still an obstacle. Therefore, the present paper reviews all current knowledge with respect to morphological criteria and environmental factors that affect embryo quality. The molecular signature of an oocyte or embryo is considered to reflect its quality and to predict its subsequent developmental capacity. Therefore, the primary aim of the present review is to provide an overview of reported correlations between molecular signatures and developmental competence. A secondary aim of this paper is to present some new strategies to enable concomitant evaluation of the molecular signatures of specific embryos and individual developmental capacity.
Editing livestock genomes with site-specific nucleases
Authors: Carlson Daniel F. , Tan Wenfang , Hackett Perry B. , Fahrenkrug Scott C.
Published: December 2013

Over the past 5 years there has been a major transformation in our ability to precisely manipulate the genomes of animals. Efficiencies of introducing precise genetic alterations in large animal genomes have improved 100 000-fold due to a succession of site-specific nucleases that introduce double-strand DNA breaks with a specificity of 10–9. Herein we describe our applications of site-specific nucleases, especially transcription activator-like effector nucleases, to engineer specific alterations in the genomes of pigs and cows. We can introduce variable changes mediated by non-homologous end joining of DNA breaks to inactive genes. Alternatively, using homology-directed repair, we have introduced specific changes that support either precise alterations in a gene’s encoded polypeptide, elimination of the gene or replacement by another unrelated DNA sequence. Depending on the gene and the mutation, we can achieve 10%–50% effective rates of precise mutations. Applications of the new precision genetics are extensive. Livestock now can be engineered with selected phenotypes that will augment their value and adaption to variable ecosystems. In addition, animals can be engineered to specifically mimic human diseases and disorders, which will accelerate the production of reliable drugs and devices. Moreover, animals can be engineered to become better providers of biomaterials used in the medical treatment of diseases and disorders.
Parental diet, pregnancy outcomes and offspring health: metabolic determinants in developing oocytes and embryos
Authors: Sinclair Kevin D. , Watkins Adam J.
Published: December 2013

The periconceptional period, embracing the terminal stages of oocyte growth and post-fertilisation development up to implantation, is sensitive to parental nutrition. Deficiencies or excesses in a range of macro- and micronutrients during this period can lead to impairments in fertility, fetal development and long-term offspring health. Obesity and genotype-related differences in regional adiposity are associated with impaired liver function and insulin resistance, and contribute to fatty acid-mediated impairments in sperm viability and oocyte and embryo quality, all of which are associated with endoplasmic reticulum stress and compromised fertility. Disturbances to maternal protein metabolism can elevate ammonium concentrations in reproductive tissues and disturb embryo and fetal development. Associated with this are disturbances to one-carbon metabolism, which can lead to epigenetic modifications to DNA and associated proteins in offspring that are both insulin resistant and hypertensive. Many enzymes involved in epigenetic gene regulation use metabolic cosubstrates (e.g. acetyl CoA and S-adenosyl methionine) to modify DNA and associated proteins, and so act as ‘metabolic sensors’ providing a link between parental nutritional status and gene regulation. Separate to their genomic contribution, spermatozoa can also influence embryo development via direct interactions with the egg and by seminal plasma components that act on oviductal and uterine tissues.