pinecone/core-2020-05-10-deduplication huggingface dataset:
Two Millisecond Pulsars Discovered by the PALFA Survey and a Shapiro Delay Measurement

International audienceWe present two millisecond pulsar discoveries from the PALFA survey of the Galactic plane with the Arecibo telescope. PSR J1955+2527 is an isolated pulsar with a period of 4.87 ms, and PSR J1949+3106 has a period of 13.14 ms and is in a 1.9 day binary system with a massive companion. Their timing solutions, based on 4 years of timing measurements with the Arecibo, Green Bank, Nançay , and Jodrell Bank telescopes, allow precise determination of spin and astrometric parameters, including precise determinations of their proper motions. For PSR J1949+3106, we can clearly detect the Shapiro delay. From this we measure the pulsar mass to be 1.47 +0.43 −0.31 M , the companion mass to be 0.85 +0.14 −0.11 M , and the orbital inclination to be i = 79.9 −1.9 +1.6 deg, where uncertainties correspond to ±1σ confidence levels. With continued timing, we expect to also be able to detect the advance of periastron for the J1949+3106 system. This effect, combined with the Shapiro delay, will eventually provide very precise mass measurements for this system and a test of general relativity
Assessment of a new fabrication route for Fe-9Cr-1W ODS cladding tubes

International audienceOxide Dispersion Strengthened ferritic/martensitic steels are developed as future cladding materials for Generation IV Sodium-Cooled Fast Reactors. ODS alloys are elaborated by powder metallurgy, consolidated by hot extrusion and manufactured into tube cladding using cold rolling process. ODS steels present low ductility and high hardness at room temperature which complicate their manufacturing. Cold working leads to the hardening of the tube which needs to be softened by heat treatment. A new high temperature fabrication route performed on a Fe-9Cr-1W-Ti-Y 2O 3-ODS martensitic steel has been designed by following the hardness values, the morphological and crystallographic anisotropy and the nano-precipitation size evolution at each step of the fabrication route. Observations show that phase transformation from ferrite (α) to austenite (γ) is crucial to reduce the morphological and the crystallographic anisotropy induced by the manufacturing processes. The high temperature heat treatments permit to make the austenitic grain grow leading to an improvement of the cold workability. Ultimate Tensile Strength values obtained in the hoop direction remain about 315 MPa at 650 °C which is slightly lower compared to other Fe-9Cr ODS tubes but the new microstructure could be more favorable for creep properties
New K–Ar age determinations of Kilimanjaro volcano in the North Tanzanian diverging rift, East Africa

International audienceThe Kilimanjaro is the African highest mountain and culminates at 5895 m high. This huge volcanic edifice is composed of three main centres along a N110°E-striking axis (Shira, Kibo and Mawenzi from W to E), and emplaced in a key area where a major N80°E-oriented volcanic lineament intersects a first-order NW–SE basement fault-like discontinuity. Seventeen K–Ar ages (on microcrystalline groundmass) acquired on lavas and intrusive facies from the three eruptive centres confirm that the Plio-Quaternary volcanicity of Kilimanjaro is clearly polyphased. The oldest phases of volcanic activity begun at ~ 2.5 Ma in the Shira vent and our data suggest that the latest important phases occurred around 1.9 Ma, just before the collapse of the Northern part of the edifice. Magmatic activity then shifted eastwards in the Mawenzi and Kibo twin centres where initial volcanism is dated at ~ 1 Ma. Two K–Ar ages obtained for the most recent Mawenzi rocks from the Neumann Tower-Mawenzi group (492 ka) and Mawenzi eruptive centre (448 ka), near the present summit, are linked to the final stage of edification for this centre. Whereas the eruptive activity ceased in the Mawenzi, it still continued on Kibo since sub-actual time. The oldest dated rocks from Kibo (482 ka) is obtained on a dyke from the Lava Tower group cropping out at 4600 m high. The main phase of magmatism on Kibo is recorded by two lava formations with a great spatial extension – the Rhomb Porphyry group and the Lent group – that have been emplaced in a short time interval at ~ 460–360 ka (including two erosive stages) and 359–337 ka, respectively. Based on the dating of Caldera rim group lavas, it is shown that the edification of the present cone was accomplished in a period ranging from 274 to 170 ka. The new ages obtained for the main episodes of volcanic activity on Kibo appear to roughly coincide with the oldest known Quaternary glaciations. The interaction between eruptive phenomena and the ice cover is assumed to have played an important role in triggering collapse processes and associated lahars deposits. The last volcanicity, around 200–150 ka, is marked by the formation of the present summit crater in Kibo and the development of linear parasitic volcanic belts, constituted by numerous Strombolian-type isolated cones on the NW and SE slopes of Kilimanjaro. These belts are likely to occur above deep-seated fractures that have guided the magma ascent, and the changes in their directions with time might be related to the rotation of recent local stress fiel
Properties of projectile-fragments in the $^{40}$Ar + $^{27}$Al reaction at 44 A MeV. Comparison with a multisequential decay model

GANIL-EXPResults on projectile fragment–fragment coincidences in the forward direction and for the reaction 40Ar + 27Al at 44 A MeV are presented and compared with the predictions of two different entrance channel models, a two-body and a three-body mechanism both followed by a binary multisequential decay including fission. This analysis shows that many features of the projectile decay products are well accounted for by the binary multisequential decay model. However the results depend critically upon the initial masses and excitation energies of the primary projectile fragments. In this respect, the three-body approach underestimates the excitation energy imparted to the primary fragments whereas the two-body scenario overestimates it. The present data put strong constraints on the initial excitation energy imparted to the primary fragments which appears to be intermediate between the predictions of the two models
Can natural disasters have positive consequences? Investigating the role of embodied technical change

International audienceIt has been suggested that disasters might have positive economic consequences, through the accelerated replacement of capital. This possibility is referred to as the productivity effect. This effect is investigated using a model with embodied technical change. in this framework, disasters can influence the production level but cannot influence the growth rate, in the same way than the saving ratio in a Solow-like model. Depending on reconstruction quality, indeed, accounting for embodied technical change can either decrease or increase disaster costs, but is never able to turn disasters into positive events. Moreover, a better but slower reconstruction amplifies the short-term consequences of disasters, but pays off over the long-term. Regardless, the productivity effect cannot prevent the existence of a bifurcation when disaster damages exceed the reconstruction capacity, potentially leading to poverty traps. (C) 2008 Elsevier B.V. All rights reserved
Dynamics of sheet nacre formation in bivalves

International audienceFormation of nacre (mother-of-pearl) is a biomineralization process of fundamental scientific as well as industrial importance. However, the dynamics of the formation process is still not understood. Here, we use scanning electron microscopy and high spatial resolution ion microprobe depth-profiling to image the full three-dimensional distribution of organic materials around individual tablets in the top-most layer of forming nacre in bivalves. Nacre formation proceeds by lateral, symmetric growth of individual tablets mediated by a growth-ring rich in organics, in which aragonite crystallizes from amorphous precursors. The pivotal role in nacre formation played by the growth-ring structure documented in this study adds further complexity to a highly dynamical biomineralization process
MAX: Development of a Laue diffraction lens for nuclear astrophysics

The next generation of instrumentation for nuclear astrophysics will have to achieve an improvement in sensitivity by a factor of 10-100 over present technologies. With the focusing gamma-ray telescope MAX we take up this challenge and propose to combine the required sensitivity with high spectral and angular resolution, and the capability to measure the polarization of the photons. MAX is a space-borne crystal diffraction telescope, featuring a broad-band Laue lens optimized for the observation of compact sources in two wide energy bands of high astrophysical relevance. Gamma rays will be focused from the large collecting area of a crystal diffraction lens onto a very small detector volume. As a consequence, the signal to background ratio is greatly enhanced, leading to unprecedented sensitivities
I.C.E.: a Transportable Atomic Inertial Sensor for Test in Microgravity

International audienceWe present our the construction of an atom interferometer for inertial sensing in microgravity, as part of the I.C.E. (\textit{Interf\'{e}rom\'{e}trie Coh\'{e}rente pour l'Espace}) collaboration. On-board laser systems have been developed based on fibre-optic components, which are insensitive to mechanical vibrations and acoustic noise, have sub-MHz linewidth, and remain frequency stabilised for weeks at a time. A compact, transportable vacuum system has been built, and used for laser cooling and magneto-optical trapping. We will use a mixture of quantum degenerate gases, bosonic $^{87}$Rb and fermionic $^{40}$K, in order to find the optimal conditions for precision and sensitivity of inertial measurements. Microgravity will be realised in parabolic flights lasting up to 20s in an Airbus. We show that the factors limiting the sensitivity of a long-interrogation-time atomic inertial sensor are the phase noise in reference frequency generation for Raman-pulse atomic beam-splitters and acceleration fluctuations during free fall
Land Use Changes in Europe. Processes of Change, Environmental Transformations and Future Patterns

Patterns of land use in Europe owe much to the boundaries set by the natural environment. The alterations imposed by man are still ultimately constrained by natural limitations of which climate pays a major role. Possible global climatic change, therefore, is likely to have a major effect on land use patterns and this is the first volume to describe the potential changes against the background of historical land use changes in Europe, the likely future land use patterns and the policy implications that are becoming evident in relation to feasible land use management strategies. \ud
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This book covers a wide spectrum of issues: How will the characteristics of the land resource change? What are the implications of these changes on the environment? What policies need to be introduced to encourage sensitivity to environmental supply limitations? What is the scale of response that is needed to address these issues? \ud
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The workshop that addressed these topics was sponsored by IIASA in association with the Institute of Geography and Spatial Organization of the Polish Academy of Sciences. The Stockholm Environment Institute collaborated in this and took on the main responsibility of producing this volume from the range of contributions at the workshop
The dynamics of plate boundaries over a convecting mantle

International audienceTrench motion and upper plate deformation ultimately respond to mantle flow. Herein I build upon the mantle flow model results of Conrad and Behn (2010) and compute the drag forces underneath all plates, and show that they control the dynamics of plates and plate boundaries. The small misfit angle between between the traction azimuths of mantle traction and absolute plate motion corroborates the idea that convective mantle drag is a prominent driver of plate tectonics. Less intuitive is the fact that the interplay between the drag forces from the upper and lower plates, that amounts to 5 to 8.5 1012Nm 1 (per unit trench length), dictates both trench migration rates and upper plate deformation. At odds with the classic view that assigns the prime role to the idiosyncrasies of subduction zones (slab age, interplate friction, water content etc), I find that the intrinsic properties of subduction zones in fact only modulate this behavior. More specifically, the mean value of the integrated trenchward mantle drag force from the lower and upper plates (from 2 to 6.5 1012Nm 1) controls upper plate deformation. Conversely, it is the difference between the lower and upper plates mantle drag forces (from 3 to 10 1012Nm 1) that controls trench migration rates. In addition, I find that a minimum trenchward force of 2.5 1012Nm 1 must be supplied by mantle drag before trenches can actually advance, and before upper plates undergo compression. This force results from the default tendency of slabs to rollback when solely excited by their own buoyancy, and is thus the effective tensional force that slab pull exerts on the plate interface
On Pole Assignment and Stabilizability of Neutral Type Systems

In this note we present a systematic approach to the stabilizability problem of linear infinite-dimensional dynamical systems whose infinitesimal generator has an infinite number of instable eigenvalues. We are interested in strong non-exponential stabilizability by a linear feed-back control. The study is based on our recent results on the Riesz basis property and a careful selection of the control laws which preserve this property. The investigation may be applied to wave equations and neutral type delay equations
Active Light Noise Filter by a Differential Operation

A method for an active light noise filter is proposed by using two identical light receivers.  They work as a differential electrometer by a common mode connection.  Therefore, only an output of a laser light incident upon one receiver can be obtained as a signal.  It was found from the experiment that the light noise was reduced to about 0.6% in the usual light room and further the signal to noise ratio was improved up to 30 times at least as compared to a usual light shielding method.  The method can then be effectively used under a well-lighted room such as a factory without noise light shielding cover
Molecular dynamical modelling of endohedral fullerenes formation in plasma

The initial stages of fullerene and endohedral metallofullerene (EMF) synthesis in 
carbon-helium plasma at 1500 K and 2500 K have been simulated with quantum chemical 
molecular dynamics (MD) based on density-functional tight-binding (DFTB). The cases of 
formation of large (>100 atoms) sp2-carbon clusters with scandium atoms inside were 
observed. These clusters are considered as precursors of fullerenes or EMFs, and thus it is 
shown that formation of EMFs can be explained within the framework of "shrinking hot giant" 
mechanism. Also, the dependence of formation rates on plasma parameters, including 
temperature, buffer gas and metal atoms concentrations, has been studied
Perception of climate change and farm level adaptation choices in central Kenya

This article addresses: The need for adaptation which is highly justified at political level have to be considered at local level also ? Studies concerning adaptation choices at local levels particularly in the coffee agroforestry systems of east Africa are insufficient ? Local people are affected by the changes in climate and the economic pressure; their perception and adaptation depends on the effects from the climate and the economic pressure as well ? Coffee and food crops farmers perceive and respond to climate change differently ? Farmers who implemented multiple adaptation strategies have higher payoff/return compare to farmers who implement single strategies or never implement strategies at all ? Adaptation to climate change depends on different determinant factors such as household characteristics, resource constraint, institutional variables, and farming system ? The determinants for adaptation to climate change are also different for coffee and food crops farmer
Developing motivation to teach elementary science: Effect of collaborative and authentic learning practices in preservice education

The rapid growth in knowledge over recent times has meant that teachers have to be responsive to new and ever changing demands of society.  Science is among those key areas of knowledge that has experienced overwhelming growth and thus developing scientific literacy is a priority if citizens are to participate effectively in society.  Failure to develop children’s interest in science will disempower a generation of children in an era when scientific knowledge is at the foundation of our culture.  Unfortunately, many elementary teachers express a lack of confidence in their ability to teach science with dire consequences for the quality of teaching.  This paper reports a study involving a cohort of 161 elementary preservice teachers in the third year of a four-year Bachelor of Education program enrolled in a core science education (methods) course.  An instructional program that addressed five essential dimensions of meaningful learning – the knowledge base, metacognition, motivation, individual differences and context – was implemented.  Quantitative and qualitative data obtained through surveys, observations and focus session reviews revealed that a learning environment based on social constructivist perspectives was effective in developing students’ conceptual and pedagogical knowledge, and most importantly enhanced students’ sense of science teaching self-efficacy.  Particular initiatives that were identified by students as being of value were collaborative learning and associated strategies, reflective journal writing, and assignment tasks that adopted principles of problem based learning.  While statistically significant gains in science teaching self-efficacy (p < .001) were observed overall, qualitative data enabled a more detailed analysis of the changes in motivations and goals of individual student teachers.  The paper explores how the experiences developed their confidence and will to teach science in elementary school and how opportunities were provided that empowered the student teachers to be proactive seekers of knowledge and become lifelong learners
Synthesis of TiN Reinforced Aluminium Metal Matrix\ud
Composites Through Microwave Sintering

Al-TiN (10, 20, 30 wt.%) composites were fabricated by using microwave radiation. Al and TiN powders\ud
were selected as starting materials, mixed in a ball mill for �10 min and sintered for various times. Results\ud
indicate that an optimum microwave sintering time of 2 min was essential and responsible for the improved\ud
densification and mechanical properties. The presence of TiN particles at grain boundaries plays a\ud
significant role in improving the densification and hardness values. Dry sliding wear results show the\ud
improved wear resistance of the composite (Al-TiN) due to the presence of TiN particles and the wear\ud
results are superior to the Al-TiN samples made by hot pressing techniqu
Selection Models for the Internal Quality of Fruit, based on Time Domain Laser Reflectance Spectroscopy

Time domain laser reflectance spectroscopy (TRS) was applied for the first time to evaluate internal fruit quality. This technique, known in medicine-related knowledge areas, has not been used before in agricultural or food research. It allows the simultaneous measurement of two optical characteristics of the sample: light scattering inside the tissues and light absorption. Models to estimate non-destructively firmness, soluble solids and acid contents in tomato, apple, peach and nectarine were developed using sequential statistical techniques: principal component analysis, multiple stepwise linear regression, clustering and discriminant analysis. Consistent correlations were established between the two parameters measured with TRS, i.e. absorption and transport scattering coefficients, with chemical constituents (soluble solids and acids) and firmness, respectively. Classification models were created to sort fruits into three quality grades (‘low’, ‘medium’ and ‘high’), according to their firmness, soluble solids and acidity
Distribution of subchondral bone density and cartilage thickness in the human patella

Subchondral bone density (by means of CT osteoabsorptiometry), and cartilage thickness (directly measured on photocopies of frozen sections), were examined in 30 human patellae, with an age range from 47 to 90 y. A surface demonstration of the distribution was prepared, and representative pictures produced by summation with a computer. Subchondral bone-density maxima were found in the proximal part of the lateral facet, and the density pattern interpreted as the expression of the long-term distribution of stress in the joint. It is reasonable to assume that cartilage thickness, of which two-thirds of the maximum values occupy a lateral position, is also dependent on the local stress. The 2 distributions show correlation coefficients > 0.5 in approximately a third of the cases we examined. Displacement of the higher values of cartilage thickness relative to the subchondral density maxima is attributed to incongruence in the medial part of the joint.
Geometrical analysis of thread milling – Part 1: Evaluation of tool angles

Thread milling is a method which is increasingly used for machining thread. For
this operation, a helical interpolation is required. Furthermore, the thread mill is a tool
whose geometry is rather complex. Its envelope profile is linked to the thread profile and
a single tooth of the thread mill is composed of three continuous cutting edges. The
present study proposes a geometrical model and an analytical formulation to define the
rake face and the cutting edge. Further, the calculations of cutting planes and cutting
angles are explained. The analysis shows specific aspects of thread mills, in particular
the fact that the flute angle may lead to a negative rake angle. This study is a contribution
to cutting geometry aspect and constitutes a step for cutting force model in thread milling
A multi-scale approach for the optimum design of sandwich plates with honeycomb core. Part I: homogenisation of core properties

This work deals with the problem of the optimum design of a sandwich panel. The design process is based on a general two-level optimisation strategy involving different scales: the meso-scale for both the unit cell of the core and the constitutive layer of the laminated skins and the macro-scale for the whole panel. Concerning the meso-scale of the honeycomb core, an appropriate model of the unit cell able to properly provide its effective elastic properties (to be used at the macro-scale) must be conceived. To this purpose, in this first paper, we present the numerical homogenisation technique as well as the related finite element model of the unit cell which makes use of solid elements instead of the usual shell ones. A numerical study to determine the effective properties of the honeycomb along with a comparison with existing models and a sensitive analysis in terms of the geometric parameters of the unit cell have been conducted. Numerical results show that shell-based models are no longer adapted to evaluate the core properties, mostly in the context of an optimisation procedure where the parameters of the unit cell can get values that go beyond the limits imposed by a 2D model