bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of Microcellular Injection Molding with Expandable Thermoplastic Microsphere
Authors: Peng J. , Yu E. , Sun X. , Turng L.-S. , Peng X.-F.
Published: June 2011

Injection molding with expandable thermoplastic microspheres (ETM) containing blowing chemicals is capable of fabricating lightweight, dimensionally stable plastic parts while using less material. This paper presents the study of microcellular injection molding of low density polyethylene (LDPE), polypropylene (PP), and polystyrene (PS) parts with various ETM contents. It was found that the molded parts exhibit relatively better surface quality than conventional foamed parts. The microcellular morphology and cell density of the fractured cross-sectional surfaces were characterized using a scanning electron microscope (SEM). As reflected by the testing results, the cell microstructure – such as cell size, cell density, and a layered structure with a foamed core sandwiched by skin layers – play an important role in the weight reduction, surface quality, and mechanical properties. A smaller cell diameter and a thicker skin layer help to improve the surface quality and tensile properties of the injection molded parts with ETM. Finally, an appropriate ETM content has a positive effect on cell microstructure and weight reduction, whereas too high a concentration of microspheres adversely affects the tensile properties and surface quality.
The Effects of Various Variotherm Processes and Their Mechanisms on Injection Molding
Authors: Huang C.-T. , Hsien I.-S. , Tsai C.-H. , Chiou Y.-C. , Tang C.-C.
Published: June 2011

To eliminate surface defects and improve the quality of molded parts, increasing the mold temperature is one of the solutions. Using high mold temperature can eliminate weld lines, reduce molding pressure, residual stress and clamping force and improve part surface quality. However, with the increasing of mold temperature, the cycle time will also be increased. Hence, people have paid the attention to mold temperature control technologies. Among them, the variotherm molding technologies, including Rapid Heat Cycle Molding (RHCM), Induction Heating Molding (IHM), and Electricity Heating Mold (E-mold), are some effective methods. Although those variotherm technologies have been proposed, how does the external or internal heating source affect the injection molding process and the final product? The true function and the efficiency study of each technology still remain vague. Hence, in this paper, we have systematically conducted various technologies, including Conventional Injection Molding (CIM), RHCM, IHM, and E-mold, by using true 3D transient cool technology. Through the inside mechanism investigation at various moments in time, the functions and the heating-cooling efficiency for each technology can be visualized. Besides, experimental study and verification of IHM are also performed.
Influence of Processing Parameters on the Fiber Length and Impact Properties of Injection Molded Long Glass Fiber Reinforced Polypropylene
Authors: Rohde M. , Ebel A. , Wolff-Fabris F. , Altstädt V.
Published: June 2011

Injection molding of long fiber-reinforced thermoplastics is a well-established method in automotive industry to produce high quality structural parts in mass production without the need of further finishing, where the performance is strongly dependent on the fiber length. It is known that the processing parameters have to be carefully chosen as they directly influence the final fiber length and can therefore have a negative effect on the resulting mechanical properties of the part. Particularly in terms of impact behavior, the fiber length is seen as a key factor. The aim of the present work is to quantify the effects of the injection molding parameters on the impact behavior of long fiber reinforced compounds. In a first step the resulting fiber length of injection molded glass fiber reinforced polypropylene is analyzed as a function of the injection velocity, holding pressure, revolution speed and back pressure. The single steps of fiber length analysis are carefully investigated in terms of feasibility and accuracy, in order to assure that a reproducible and reliable test method is employed. Subsequently, the impact behavior of the PP-GF compounds is quantified by falling dart experiments, and the results are then correlated to the fiber length and the processing parameters to establish a fundamental processing-structure-property relationship. The investigation of the fiber length analysis shows that a high pyrolysis temperature leads to embrittlement of the glass fibers and a decrease of tensile strength of the single fibers. This may consequently lead to incorrect characterization of the fiber length due to fiber breakage. The results of the statistical investigation of the processing parameters indicate a significant influence of the back pressure on both impact energy and fiber length.
Induction of Apoptosis in Human Promyelocytic Leukemia HL60 Cells by Panaxynol and Panaxydol
Authors: Yan Zhonghong , Yang Ruolin , Jiang Yi , Yang Zhihui , Yang Junrui , Zhao Qian , Lu Yang
Published: June 2011

Panaxynol and panaxydol are naturally occurring polyacetylenes, isolated from the lipophilic fractions of Panax notoginseng, that exert anti-proliferative effects against malignant cells. However, to the best of our knowledge, no study concerning the inhibitory effects of the two polyacetylenes on cell growth of human promyelocytic leukemia cells has been reported. In this paper, we examined the antiproliferation and proapoptotic effects of panaxynol and panaxydol on HL60 cells and investigated their mechanism of action. Cell growth inhibition of panaxynol and panaxydol were determined by trypan blue dye exclusion assays. Apoptosis of cells was revealed by morphological observation, analysis for nuclear DNA distribution and by annexin V-FITC/ PI staining using flow cytometry. It was found that panaxynol and panaxydol markedly inhibited proliferation of HL60 cells in a time- and dose-dependent manner via an apoptotic pathway. In concern with these ﬁndings, Western blot analysis showed proteolytic activation of PKCδ, caspase-3 activation and cleavage of poly (ADP [adenosine diphosphate]-ribose) polymerase in HL60 cells treated by panaxynol and panaxydol. In conclusion, panaxynol and panaxydol have profound effects on growth and apoptosis of HL60 cells, suggesting those substances are worthy of further exploration as potential anti-cancer agents.
Long‐distance dispersal and high genetic diversity are implicated in the invasive spread of the common reed, Phragmites australis (Poaceae), in northeastern North America
Authors: Kirk Heather , Paul Jennifer , Straka Jason , Freeland Joanna R.
Published: June 2011

• Premise of the study: The Eurasian subspecies of the common reed (Phragmites australis subsp. australis, hereafter abbreviated as P. a. australis) was introduced to North America in the late 18th century and rapidly expanded its range, posing an ecological threat to wetlands. In this study, we aimed to determine whether admixture among multiple lineages, dispersal mechanisms, and high genetic diversity have contributed to the invasion of P. a. australis in the northeastern part of its range. Understanding mechanisms of the P. a. australis invasion will 1) contribute to a broader understanding of the factors that facilitate plant invasion, and 2) help us to develop effective management strategies for wetlands threatened by P. a. australis invasion.

• Methods: We used a population genetics approach incorporating nine microsatellite loci to study genetic diversity and population structure in relation to biogeography of introduced North American Phragmites a. australis stands in the northeastern continental region.

• Key Results: Phragmites a. australis is genetically diverse in the region studied here. Significant population structure exists, and population structure is likely influenced by both long‐distance dispersal via major waterways, and short‐distance dispersal overland. Different lineages sometimes colonize geographically proximate locations leading to opportunities for admixture. Clonal reproduction likely exaggerates geographical structure among some stands, although high genetic and clonal diversity within some stands implies that sexual reproduction occurs frequently in P. a. australis.

• Conclusions: A variety of factors, including admixture among multiple lineages, multiple modes of dispersal, and plasticity in reproductive strategy promote the invasion success of Phragmites a. australis. Wetland managers in the St. Lawrence River/Great Lakes region should focus monitoring efforts on the shores of conservation lands to prevent the establishment of propagules from novel lineages.
Effect of Raltegravir on the Total and Unintegrated Proviral HIV Dna during Raltegravir-Based Haart
Authors: Nicastri Emanuele , Tommasi Chiara , Abbate Isabella , Bonora Stefano , Tempestilli Massimo , Bellagamba Rita , Viscione Magdalena , Rozera Gabriella , Gallo Anna L , Ivanovic Jelena , Amendola Alessandra , Pucillo Leopoldo , Perri Giovanni Di , Capobianchi Maria R , Narciso Pasquale
Published: June 2011

Background

Raltegravir is the first approved antiretroviral able to prevent HIV genome integration into the host chromosomes. The aim of the study is to test if raltegravir plasma concentrations can be associated with proviral DNA decline during raltegravir-based salvage therapy.

Methods

A total of 33 multidrug-resistant HIV-infected patients were enrolled in a longitudinal open-label pilot study and completed a 24-week follow-up. The CD4+ T-cell count, plasma viral load, proviral HIV DNA and two-long-terminal repeat (2-LTR) circular forms were assessed at baseline, day 14, 30, 60, 90 and 180. The raltegravir trough concentration (Ctrough) was measured by HPLC-ultraviolet and patients were divided into two groups according to the median raltegravir Ctrough.

Results

The mean ±sd values of baseline HIV RNA, CD4+ T-cell count and HIV DNA were 4.4 ±0.82 log copies/ml, 256 ±177 cells/mm3, and 2,668 ±4,721 copies/106 peripheral blood mononuclear cells, respectively. Despite a transient increase of total DNA at week 2, a marked proviral DNA decay ( P=0.01) with an increase of the 2-LTR unintegrated/total DNA ratio ( P=0.06) over time was observed. At univariate analysis, no correlation between raltegravir C and trough classical virological parameters was observed. Nevertheless, the decay of proviral HIV DNA was more pronounced in patients displaying Ctrough <158 ng/ml with respect to those with Ctrough>158 ng/ml ( P=0.046).

Conclusions

Successful raltegravir-based therapy produces a significant decline in proviral DNA and is associated with an increase of the unintegrated/total DNA ratio. Further studies are necessary to define the possible role of pharmacokinetic raltegravir monitoring and the biological meaning of unintegrated proviral DNA.
An Ex Vivo Platform to Simulate Cardiac Physiology: A New Dimension for Therapy Development and Assessment
Authors: de Hart Jurgen , de Weger Arend , van Tuijl Sjoerd , Stijnen Johannes M. A. , van den Broek Chantal N. , Rutten Marcel C. M. , de Mol Bas A.
Published: June 2011

Purpose

Cardiac research and development of therapies and devices is being done with in silico models, using computer simulations, in vitro models, for example using pulse duplicators or in vivo models using animal models. These platforms, however, still show essential gaps in the study of comprehensive cardiac mechanics, hemodynamics, and device interaction. The PhysioHeart platform was developed to overcome these gaps by the ability to study cardiac hemodynamic functioning and device interaction ex vivo under in vivo conditions.

Methods

Slaughterhouse pig hearts (420 ± 30 g) were used for their morphological and physiological similarities to human hearts. Hearts were arrested, isolated and transported similar to transplantation protocols. After preparation, the hearts were connected to a special circulatory system that has been engineered using physical and medical principles. Through coronary reperfusion and controlled cardiac loading, physiological cardiac performance was achieved while hemodynamic parameters were continuously monitored.

Results

Normal cardiac hemodynamic performance was achieved both qualitatively, in terms of pulse waveforms, and quantitatively, in terms of average cardiac output (4 l/min) and pressures (110/75 mmHg). Cardiac performance was controlled and kept at normal levels for up to 4 hours, with only minor deterioration of hemodynamic performance.

Conclusions

With the PhysioHeart platform we were able to reproduce normal physiological cardiac conditions ex vivo. The platform enables us to study, under different but controlled physiological conditions, form, function, and device interaction through monitoring of performance parameters and intra-cardiac visualization. Although the platform has been used for pig hearts, application of the underlying physical and engineering principles to physiologically comparable hearts from different origin is rather straightforward.
Assessment of the Competitiveness of Ports as Bunkering Hubs: Empirical Studies on Singapore and Shanghai
Authors: Lam Jasmine Siu Lee , Chen Desiree , Cheng Fan , Wong Kevin
Published: June 2011

Bunkering, that is, supplying ships with fuel, has gained strategic importance in port and shipping businesses. This article formulates a framework and a method for assessing the competitiveness of ports as bunkering hubs and includes empirical studies on the ports of Singapore and Shanghai. Ten attributes for the selection of a bunkering port were identified based on interview with practitioners. Through surveys, ship operators and managers ranked the importance of these attributes. Bunker quality was found to be the most important attribute. The respondents also assessed Singapore and Shanghai ports based on the ten attributes. The performances of both ports were analyzed according to their score on each attribute and the total weighted scores. Singapore was rated a better performer in the assessment. Besides Singapore's naturally strategic location, which attracts large cargo volume, the fundamental reason for its excellent performance is its liberal market structure, which results in attractive pricing and efficient practices. In this study, recommendations are given to port authorities and operators, with special focus on ports of Singapore and Shanghai.
1-Algebra of a Locally Compact Groupoid
Authors: Amini Massoud , Medghalchi Alireza , Shirinkalam Ahmad
Published: June 2011

For a locally compact groupoid with a fixed Haar system and quasi-invariant measure ,
we introduce the notion of -measurability and construct the space 1(, , ) of absolutely integrable
functions on and show that it is a Banach -algebra and a two-sided ideal in the algebra ()
of complex Radon measures on . We find correspondences between representations of on Hilbert
bundles and certain class of nondegenerate representations of 1(, , ).
Hermeneutical discontinuity between Calvin and later Calvinism
Authors: Kennedy Kevin D.
Published: June 2011

The purpose of this article is to demonstrate that Calvin's interpretation of biblical passages related to the question of the extent of the atonement differed significantly from the later tradition. This difference in interpretation is explained by the fact that Calvin did not share certain hermeneutical presuppositions which were to become almost universal among theologians of the later Reformed tradition. This article will examine two hermeneutical ‘rules’ which Calvin frequently employed in his interpretation of scripture and will contrast his handling of scripture with the interpretative practices employed by the later Reformed tradition. The first hermeneutical ‘rule’ involves those passages in scripture which state that Christ came to give his life as a ransom for ‘many’, or that he shed his blood for ‘many’. Contrary to the later Reformed interpreters of scripture, Calvin understands these passages to mean that Christ died for all people rather than just some. The second hermeneutical ‘rule’ concerns Calvin's frequent appeal to the fact that the word ‘all’ does not always mean ‘all’ when it is used in scripture. Certain present-day Reformed theologians argue that since Calvin shares this second hermeneutical rule with the later Reformed tradition, then his reading of scripture must not have differed significantly from that of the later tradition. Therefore, Calvin must have held to a limited atonement. However, this article will show that this conclusion only holds true if we read Calvin's own writings by means of this hermeneutic.
Lagged Learning and the Response to Equilibrium Shock: The Global Financial Crisis and IMF Surveillance
Authors: Moschella Manuela
Published: June 2011

The paper investigates the changes to the Fund's bilateral surveillance policy in the wake of the global financial crisis of 2007–09 asking about the factors that caused the quick and deep shift to a systemic surveillance approach. In answering this question, the paper argues that the causes of the quick and deep transformation of IMF surveillance lie in the preceding two decades of incremental accumulation of knowledge and small transformations in policy instruments and organizational practices. In identifying the causes of present policy choices in the lessons drawn from past experience, the paper provides an example of lagged learning because the lessons drawn from the 1990s emerging market crises exerted their full impact only as a response to the global financial crisis. These findings therefore contribute to the literature that aims at showing the importance of temporality and process sequencing to explain policy change.
Welcome address
Authors: Erdelen Walter
Published: June 2011

It is a great pleasure for me to open the IAU-UNESCO Symposium on The Role of Astronomy in Society and Culture which is taking place at the UNESCO Headquarters this week.
Orientations of dolmens in Western Europe
Authors: Hoskin Michael
Published: June 2011

The communal tombs (‘dolmens’) constructed through Europe and the Mediterranean region in the late Neolithic nearly always had an entrance to permit the introduction of further bodies, and hence an orientation. Extensive fieldwork shows that the builders always felt constrained to observe a custom of orientation, and in most of Western Europe the custom may well have been to face the rising Sun at some time of year, or the Sun after it had risen. But at Fontvieille near Arles the local custom was quite different, with tombs facing sunset or the Sun when descending. In southwest France and neighbouring parts of Cataluña the two customs are in conflict.
Sky observation and mythology: paths to an astronomical culture
Authors: Alencar Victor Alves
Published: June 2011

The teaching and the popularization of Astronomy, nowadays, suffers from the absence of attractiveness. It's, somehow, consensual that the most efficient approach to attract the general public or even an uninterested student to the Astronomy is the sky observation. With the help of instruments like telescopes or binoculars, the observation of aesthetical impressive objects such as galactic clusters, approaching planets and many others may have a great impact upon those people. We have been executing an efficient and attractive didactic method which has been evaluated permanently for more than two years and has shown great efficiency that consists in the utilization of legends and myths from different cultures (including Brazilian Indians myths, in an etnoastronomical approach) about the constellations and their dispositions in the sky. The objective of this panel is to show the efficiency of the method and some of its teaching routines always beginning with myths or legends involving a great number of constellations (using, preferentially, most of the watchable sky in a certain time of year), using asterisms for identification and then following to a certain constellation from which it is possible to extract the information required for the studied subject.
The question “Are we alone ?” in different cultures
Authors: Schneider Jean
Published: June 2011

A survey of the worldwide litterature reveals that the question “Are we alone in the Universe?” has been formulated only in the “western” litterature. Here I try to understand why it is so. To investigate this problem it is first necessary to clarify what western culture means.
Hobbits, Hogwarts, and the Heavens: The use of fantasy literature and film in astronomy outreach and education
Authors: Larsen Kristine
Published: June 2011

Due in part to recent (and ongoing) film adaptations, the fantasy series of C.S. Lewis (The Chronicles of Narnia), J.K. Rowling (Harry Potter), Philip Pullman (His Dark Materials), and J.R.R. Tolkien (The Silmarillion, The Hobbit, and The Lord of the Rings) are being introduced to a new audience. Many astronomers and astronomy educators are unaware of the wide variety of astronomical references contained in each series, and the myriad possible uses of these works in astronomy education and outreach. This paper highlights activities which educators, planetariums, and science centers have already developed to utilise these works in their education and outreach programs.
Astronomy and astronomers in Jules Verne's novels
Authors: Crovisier Jacques
Published: June 2011

Almost all the Voyages Extraordinaires written by Jules Verne refer to astronomy. In some of them, astronomy is even the leading theme. However, Jules Verne was basically not learned in science. His knowledge of astronomy came from contemporaneous popular publications and discussions with specialists among his friends or his family. In this article, I examine, from the text and illustrations of his novels, how astronomy was perceived and conveyed by Jules Verne, with errors and limitations on the one hand, with great respect and enthusiasm on the other hand. This informs us on how astronomy was understood by an “honnête homme” in the late 19th century.
TWAN: The World at Night
Authors: Tafreshi Babak A.
Published: June 2011

The World at Night (TWAN) is a global program to produce, collect, and present stunning photographs and time-lapse videos of the world's most beautiful and historic sites against the night-time backdrop of stars, planets, and celestial events. TWAN is a bridge between art, science and humanity to bring the message of peace, concealed in the sky. Organised by “Astronomers Without Borders”, the project consist of world's best night sky photographers in over countries and coordinators, regional event organisers, and consultants. TWAN was also designated as a Special Project of the International Year of Astronomy 2009. While the project's global exhibitions and educational events peaked during IYA2009, TWAN is planned for long term in several phases and will continue to create and exhibit images in the next years.
Dispelling superstitions in Nepalese society with astronomy
Authors: Shah Rishi
Published: June 2011

Throughout human history, astronomy has played crucial rôle in the development of our civilization, culture and daily chores of lives that have been influenced by observations of Sun, moon, planets, stars and other cosmic entities. Our ancestors who were hunting and gathering and foraging food while living in caves learned to think logically by gazing at the twinkling stars in the heavens. Seasons for crops plantation were determined, time concept was introduced, entire sky was charted and the motions of celestial objects were meaningfully understood. With the advent of telescopes, the geocentric model of universe was replaced by the revolutionary heliocentric concept of our Solar System. Astronomy dispelled superstitious beliefs strongly prevailing in societies. Closely associated with numerous disciplines of science astronomy is still flourishing worldwide and is attempting to fly us away to those habitable cosmic bodies of our universe. By establishing well-equipped observational infrastructure local and international astronomy research and development could be enhanced. Introduction of astronomy in education system right from school would attract and encourage students to pursue higher studies for enabling them for participating in future international scientific and exploration programmes. Astronomy has helped our society to progress peacefully and efficiently.
Astronomers without borders
Authors: Simmons Mike
Published: June 2011

“Astronomers Without Borders” is a new global organisational dedicated to furthering understanding and goodwill across national and cultural boundaries using the universal appeal of astronomy and space science. A growing network of affiliate organisations brings together clubs, magazines and other organizations involved in astronomy and space science. Forums, galleries, video conferences and other interactive technologies are used to connect participants around the world. Sharing of resources and direct connections through travel programs are also planned. One project, “The World at Night” (TWAN), has become an Special Project of IYA2009. TWAN creates wide-angle images of the night sky in important natural and historic settings around the world, dramatically demonstrating the universal nature and appeal of the night sky. “Astronomers Without Borders” is also a leader of the 100 Hours of Astronomy IYA2009 Global Cornerstone Project.
Reconstructing the astronomical heritage
Authors: Planesas Pere
Published: June 2011

Studies of the astronomical heritage can deal with the ancient astronomical knowledge, traditions and myths, as well as with old instruments and observatories. It is urgent to work for their recovery, before they are definitely forgoten, lost or destroyed. On the cultural side, the Joint ALMA Observatory is sponsoring the study of the local cosmology and sky of the indigenous people living in the region where ALMA is currently being build. In the case of ancient instruments, several success stories already exist, the most recent one being the reconstruction of the Madrid 25ft Herschel telescope. Examples of notable instruments pending reconstruction are listed.
Techies, thinkers and tinkerers: Why CFHT became a world-class telescope
Authors: Bryson Liz
Published: June 2011

Following the celebrated DVD, Gathering the Forgotten Voices, we have embarked on new interviews of the men and women whose hard work and ingenuity forged the technological breakthroughs that maintained CFHT's preeminence as a world-class observatory. While Gathering the Forgotten Voices emphasized the personal history of those involved with the first decade of deep-space observing, the new DVD explores the CFHT innovation in instrumentation from vision through design to construction. It will chronicle the breakthroughs of the observatory's staff so that that record may serve as a prototype for qualitative research at other technological centers.
Astronomy education and scientific schools in Ukraine
Authors: Yatskiv Yaroslav S. , Vavilova Iryna B.
Published: June 2011

We describe briefly the current state of astronomical education in Ukraine, namely the secondary, higher, and post-graduating education systems. A special attention is paid to so called “scientific schools”, non-formal groups of scientists formed by recognised astronomers, which have played and continue to play an important rôle in development of the astronomy education system. Among the founders of scientific schools were the well-known professors Alexander Ya. Orlov (Odessa University), Nikolai P. Barabashov (Kharkiv University), Sergei K. Vsekhsvyatsky (Kyiv University), Semen Ya. Braude (Kharkiv Polytechnical Institute), and Vladimir P. Tsesevich (Odessa University). We also give a general review on the history of astronomy education during the 16th-18th centuries. In 2000 astronomy was reinstated into the current 12-year secondary education curriculum of Ukraine. At present, some elements of astronomical knowledge are included in the lessons of “Natural Sciences” for pupils in the 5th – 10th grades. Astronomy is included as a basic course both in general (non-specialised) schools (17 academic hours in the last 11th or 12th grade) and in lyceums of the natural sciences (34 academic hours in the 12th grade). It is included also as an optional course in the educational program of gymnasiums in humanities. Every year about 75 young persons enter the Ukrainian universities to become astronomers. Results of our monitoring of the efficiency of astronomical higher educational system indicate that about 80% of the entered university students finish their education in 5 years; 50% of those who finished the cursus were working in astronomy. Since 1992 more then 100 astronomers defend Theses of Cand. Sci. (similar to Ph.D) and about 40 astronomers defend Theses of Dr. Sci. (topmost scientific degree, similar to Dr. Hab.). One of our present-day problems is a brain drain of young scientists. About 50% of those who obtained Cand. Sci. degree work outside Ukraine. At the same time in Ukraine we have a lack of experienced persons to work in astronomical instrumentation and observations.
The Observatorio Astronómico Nacional - Tonantzintla: Site Evaluation
Authors: Hernández-Toledo H.M. , Martínez-Vázquez L.A. , Pani-Cielo A.
Published: June 2011

The objective of this contribution is to present some results of an evaluation on the local conditions at the site that were considered in order to propose that the Observatorio Astronómico Nacional, Tonantzintla, (OAN-Tonantzintla) become a National Facility for Astronomy Education. The evaluation included a quantitative diagnostic (CCD photometry) on the quality of the local sky. The attributes of the 1-m telescope, the current instrumentation and a well planned upgrading that includes new instrumentation is considered at the basis for a successful transition maintaining the attractiveness of the site for astronomy education. A 3-year upgrading program actually in progress at UNAM is providing funding for that purpose. Physics and astronomy programs at college and graduated levels at UNAM will benefit from this, yielding clear connections among astronomy researchers and educators and students at various levels. Although the OAN-Tonantzintla faces the danger of deteriorating its sky conditions, we are maintaining awareness of the night sky characteristics in long-term monitoring campaigns and encouraging the local authorities to find alternative solutions to this problem.
Motivating the study of astronomy
Authors: Poveda Finita
Published: June 2011

One of the reasons for which this symposium has been organised is to seek answers to several questions, one of which being: Can Astronomy help reducing the waning interest that the younger generations of students feel about science studies? My personal opinion is that it is indeed the case. In fact, I claim that astronomy can be very effective for this aim. The present situation of pupil shortages in scientific studies is a complex problem because there are multiple and diverse variables influencing this situation. One of them is that the contents are not introduced in the most appropriate form, because the methods used in teaching scientific disciplines are not appropriate. This paper relates my personal experience; first as a teacher and then as a student at the Faculty of Sciences in the University of Alicante.
Light pollution around Tonantzintla Observatory
Authors: Vázquez-Mata José A. , Hernández-Toledo Héctor M. , Martínez-Vázquez Luis A. , Pani-Cielo Atanacio
Published: June 2011

Being close to the cities of Puebla to east and Cholula to the north, both having potential for large growth, the National Astronomical Observatory in Tonantzintla (OAN-Tonantzintla) faces the danger of deteriorating its sky conditions even more. In order to maintain competitiveness for education and scientific programs, it is important to preserve the sky brightness conditions. through: 1) our awareness of the night sky characteristics in continuous monitoring campaigns, doing more measurements over the next years to monitor changes and 2) encouraging local authorities about the need to regulate public lighting at the same time, showing them the benefits of such initiatives when well planed and correctly implemented.
IYA and astronomy education in China
Authors: Zhu Jin , Wan Haoyi
Published: June 2011

The current situation on astronomy education in mainland China is introduced. IYA 2009 was a great opportunity for promotion of astronomy education and some basic ideas and plans in mainland China are presented.
The universe is here
Authors: Antiche Garzón Erika L.
Published: June 2011

Astronomy is a science devoted to the study of what existed, exists and will exist, from the most elemental particle to the most massive and powerful galaxy one observes. The study of the universe is not only meant to be to achieve an important understanding about it, but also in other fields of science and technology. The most important contribution from astronomy is perhaps social: it fascinates millions of people along the globe. The history of astronomy carries along the very history of humankind.
Flow at ice‐divide triple junctions: 1. Three‐dimensional full‐Stokes modeling
Authors: Gillet‐Chaulet Fabien , Hindmarsh Richard C. A.
Published: June 2011

Ice domes are either axisymmetric, high points along ridges, or ridge triple junctions. We model time‐dependent isothermal flow near triple junctions, solving the full set of mechanical equations with a nonlinear power law rheology. Forcing is applied through the boundary conditions, which affect flow patterns at outlets. Where such forcing is purely axisymmetric, an axisymmetric dome is formed. If a threefold symmetry in the forcing is applied, the axisymmetric dome breaks up into three ridges subtending angles of 120°. Sets of experiments where the forcing was not exactly threefold symmetric by angle or by amplitude caused the triple junction to migrate to a new steady state. Here, in steady state, the ridges join the triple junction at nearly 120°, but one ridge curves to satisfy the boundary forcing. The slope pattern in the immediate dome vicinity depends only on a dimensionless parameter, which is a function of the ice consistency, the accumulation, and the rheological power law index. Attempts to replicate the topography around Summit, Greenland, obtained a good fit with n = 3. At a triple junction the dome is really distinct from the surrounding ridges, contrary to the highest point of a single ridge divide. As a consequence, the Raymond effect is at its strongest at the dome and weakens considerably over one ice thickness as one moves away from the flow center. Along the ridges leaving the dome, the Raymond effect is still present and decreases with the ratio of the flow across and along the ridge. In the vicinity of the dome, horizontal strain rates vary strongly from uniaxial to biaxial. Large‐scale effects, represented in our model as fluxes at boundaries, seem to be the primary controls on dome position and shape.
A scaffold of accessory subunits links the peripheral arm and the distal proton-pumping module of mitochondrial complex I
Authors: Angerer Heike , Zwicker Klaus , Wumaier Zibiernisha , Sokolova Lucie , Heide Heinrich , Steger Mirco , Kaiser Silke , Nübel Esther , Brutschy Bernhard , Radermacher Michael , Brandt Ulrich , Zickermann Volker
Published: June 2011

Mitochondrial NADH:ubiquinone oxidoreductase (complex I) is a very large membrane protein complex with a central function in energy metabolism. Complex I from the aerobic yeast Yarrowia lipolytica comprises 14 central subunits that harbour the bioenergetic core functions and at least 28 accessory subunits. Despite progress in structure determination, the position of individual accessory subunits in the enzyme complex remains largely unknown. Proteomic analysis of subcomplex Iδ revealed that it lacked eleven subunits, including the central subunits ND1 and ND3 forming the interface between the peripheral and the membrane arm in bacterial complex I. This unexpected observation provided insight into the structural organization of the connection between the two major parts of mitochondrial complex I. Combining recent structural information, biochemical evidence on the assignment of individual subunits to the subdomains of complex I and sequence-based predictions for the targeting of subunits to different mitochondrial compartments, we derived a model for the arrangement of the subunits in the membrane arm of mitochondrial complex I.
A strong analogy between the dielectric breakdown of high-K gate stacks and the progressive breakdown of ultrathin oxides
Authors: Tous Santi , Wu Ernest Y. , Miranda Enrique , Suñé Jordi
Published: June 2011

The breakdown of high-K (HK) stack gate dielectrics is shown to be analogous to the failure of ultrathin SiO2-based oxides showing progressive breakdown. The breakdown of a HK stack is shown to occur in two phases. First, one or several percolation paths are formed in the SiO2-based interfacial layer. Then, these partial breakdowns propagate into the HK through defect generation in this layer. This propagation phase is equivalent to the progressive breakdown local degradation phenomenon. As a consequence of this analogy, the reliability assessment tools developed for ultrathin single-layer oxides can also be used without significant changes to assess the reliability of HK stacks. This analogy is so strong that the experimental distinction between HK propagation and conventional progressive breakdown appears to be rather difficult. However, the residual time distribution from first breakdown to final oxide failure is shown to be significantly different for both processes at low failure percentiles. This has allowed us to obtain experimental evidence of HK propagation (as opposed to conventional progressive breakdown effects) in relatively thick Hf-based gate stacks where the detection of first BD appears to be feasible.
An ice lithography instrument
Authors: Han Anpan , Chervinsky John , Branton Daniel , Golovchenko J. A.
Published: June 2011

We describe the design of an instrument that can fully implement a new nanopatterning method called ice lithography, where ice is used as the resist. Water vapor is introduced into a scanning electron microscope (SEM) vacuum chamber above a sample cooled down to 110 K. The vapor condenses, covering the sample with an amorphous layer of ice. To form a lift-off mask, ice is removed by the SEM electron beam (e-beam) guided by an e-beam lithography system. Without breaking vacuum, the sample with the ice mask is then transferred into a metal deposition chamber where metals are deposited by sputtering. The cold sample is then unloaded from the vacuum system and immersed in isopropanol at room temperature. As the ice melts, metal deposited on the ice disperses while the metals deposited on the sample where the ice had been removed by the e-beam remains. The instrument combines a high beam-current thermal field emission SEM fitted with an e-beam lithography system, cryogenic systems, and a high vacuum metal deposition system in a design that optimizes ice lithography for high throughput nanodevice fabrication. The nanoscale capability of the instrument is demonstrated with the fabrication of nanoscale metal lines.
Discontinuous Galerkin particle-in-cell simulation of longitudinal plasma wave damping and comparison to the Landau approximation and the exact solution of the dispersion relation
Authors: Foust F. R. , Bell T. F. , Spasojevic M. , Inan U. S.
Published: June 2011

We present results showing the measured Landau damping rate using a high-order discontinuous Galerkin particle-in-cell (DG-PIC) [G. B. Jacobs and J. S. Hesthaven, J. Comput. Phys. 214, 96 (2006)] method. We show that typical damping rates measured in particle-in-cell (PIC) simulations can differ significantly from the linearized Landau damping coefficient and propose a simple numerical method to solve the plasma dispersion function exactly for moderate to high damping rates. Simulation results show a high degree of agreement between the high-order PIC results and this calculated theoretical damping rate.
Thin viscous sheets with inhomogeneous viscosity
Authors: Pfingstag G. , Audoly B. , Boudaoud A.
Published: June 2011

We derive the equations governing the dynamics of thin viscous sheets having non-homogeneous viscosity, via asymptotic expansion methods. We consider distributions of viscosity that are inhomogeneous in the longitudinal and transverse directions and arbitrary (bulk and surface) external forces. Two specific problems are solved as an illustration. In a first example, we study the effects of purely in-plane variations of viscosity, which lead to thickness modulations when the sheet is stretched or compressed. In a second example, we study a stretched viscous sheet whose viscosity varies both across thickness and in-plane; in that case, we find that in-plane strain leads to out-of-plane displacement as the in-plane forces become coupled to transverse ones.
Benchmark of density functional theory methods on the prediction of bond energies and bond distances of noble-gas containing molecules
Authors: Lai Tai-Yuan , Yang Chun-Yu , Lin Hsiao-Jing , Yang Chang-Yu , Hu Wei-Ping
Published: June 2011

We have tested three pure density functional theory (DFT) functionals, BLYP, MPWPW91, MPWB95, and ten hybrid DFT functionals, B3LYP, B3P86, B98, MPW1B95, MPW1PW91, BMK, M05-2X, M06-2X, B2GP-PLYP, and DSD-BLYP with a series of commonly used basis sets on the performance of predicting the bond energies and bond distances of 31 small neutral noble-gas containing molecules. The reference structures were obtained using the CCSD(T)/aug-cc-pVTZ theory and the reference energies were based on the calculation at the CCSD(T)/CBS level. While in general the hybrid functionals performed significantly better than the pure functionals, our tests showed a range of performance by these hybrid functionals. For the bond energies, the MPW1B95/6-311+G(2df,2pd), BMK/aug-cc-pVTZ, B2GP-PLYP/aug-cc-pVTZ, and DSD-BLYP/aug-cc-pVTZ methods stood out with mean unsigned errors of 2.0−2.3 kcal/mol per molecule. For the bond distances, the MPW1B95/6-311+G(2df,2pd), MPW1PW91/6-311+G(2df,2pd), and B3P86/6-311+G(2df,2pd), DSD-BLYP/6-311+G(2df,2pd), and DSD-BLYP/aug-cc-pVTZ methods stood out with mean unsigned errors of 0.008−0.013 Å per bond. The current study showed that a careful selection of DFT functionals is very important in the study of noble-gas chemistry, and the most recommended methods are MPW1B95/6-311+G(2df,2pd) and DSD-BLYP/aug-cc-pVTZ.
First-principles study of Ti intercalation between graphene and Au surface
Authors: Kaneko T. , Imamura H.
Published: June 2011

We investigate the effects of Ti intercalation between graphene and Au surface on binding energy and charge doping by using the first-principles calculations. We show that the largest binding energy is realized by the intercalation of single mono-layer of Ti. We also show that electronic structure is very sensitive to the arrangement of metal atoms at the interface. If the composition of the interface layer is Ti0.33Au0.67 and the Ti is located at the top site, the Fermi level lies closely at the Dirac point, i.e., the Dirac cone of the ideal free-standing graphene is recovered.
Autoclaving as a chemical-free process to stabilize recombinant silk-elastinlike protein polymer nanofibers
Authors: Qiu Weiguo , Cappello Joseph , Wu Xiaoyi
Published: June 2011

We report here that autoclaving is a chemical-free, physical crosslinking strategy capable of stabilizing electrospun recombinant silk-elastinlike protein (SELP) polymer nanofibers. Fourier transform infrared spectroscopy showed that the autoclaving of SELP nanofibers induced a conformational conversion of β-turns and unordered structures to ordered β-sheets. Tensile stress-strain analysis of the autoclaved SELP nanofibrous scaffolds in phosphate buffered saline at 37 °C revealed a Young’s modulus of 1.02 ± 0.28 MPa, an ultimate tensile strength of 0.34 ± 0.04 MPa, and a strain at failure of 29% ± 3%.
Stimulated emission of near-infrared radiation in silicon fin light-emitting diode
Authors: Saito S. , Takahama T. , Tani K. , Takahashi M. , Mine T. , Suwa Y. , Hisamoto D.
Published: June 2011

We propose top-down processes to make silicon multiple quantum wells called fins for a light-emitting diode. The silicon fins are formed vertically to a substrate and embedded in a Si3N4 waveguide. By current injections into silicon fins, we have observed stimulated emission spectra peaked at the wavelengths corresponding to the periodic structures of fins. The near-field mode profiles obtained at the edge of the waveguide qualitatively agreed with theoretical calculations. It has been turned out that both transverse-electric and transverse-magnetic fields can contribute to the optical gain.
A uniform Fourier restriction theorem for surfaces in ℝ^{𝕕}
Authors: Oberlin Daniel
Published: June 2011

We prove a Fourier restriction result, uniform over a certain collection of reference measures, for some indices in the Stein-Tomas range.
Generalized Ehrhart polynomials
Authors: Chen Sheng , Li Nan , Sam Steven
Published: June 2011

Let

P
P

be a polytope with rational vertices. A classical theorem of Ehrhart states that the number of lattice points in the dilations

P
(
n
)
=
n
P

P(n) = nP

is a quasi-polynomial in

n
n

. We generalize this theorem by allowing the vertices of

P
(
n
)

P(n)

to be arbitrary rational functions in

n
n

. In this case we prove that the number of lattice points in

P
(
n
)

P(n)

is a quasi-polynomial for

n
n

sufficiently large. Our work was motivated by a conjecture of Ehrhart on the number of solutions to parametrized linear Diophantine equations whose coefficients are polynomials in

n
n

, and we explain how these two problems are related.
Complex dynamics of semantic memory access in reading
Authors: Baggio Giosué , Fonseca André
Published: June 2011

Understanding a word in context relies on a cascade of perceptual and conceptual processes, starting with modality-specific input decoding, and leading to the unification of the word's meaning into a discourse model. One critical cognitive event, turning a sensory stimulus into a meaningful linguistic sign, is the access of a semantic representation from memory. Little is known about the changes that activating a word's meaning brings about in cortical dynamics. We recorded the electroencephalogram (EEG) while participants read sentences that could contain a contextually unexpected word, such as ‘cold’ in ‘In July it is very cold outside’. We reconstructed trajectories in phase space from single-trial EEG time series, and we applied three nonlinear measures of predictability and complexity to each side of the semantic access boundary, estimated as the onset time of the N400 effect evoked by critical words. Relative to controls, unexpected words were associated with larger prediction errors preceding the onset of the N400. Accessing the meaning of such words produced a phase transition to lower entropy states, in which cortical processing becomes more predictable and more regular. Our study sheds new light on the dynamics of information flow through interfaces between sensory and memory systems during language processing.