bluuebunny/crossref_metadata_2025 huggingface dataset:
Intra-accumbens Raclopride Administration Prevents Behavioral Changes Induced by Intermittent Access to Sucrose Solution
Authors: Suárez-Ortiz Josué O. , Cortés-Salazar Felipe , Malagón-Carrillo Ariadna L. , López-Alonso Verónica E. , Mancilla-Díaz Juan M. , Tejas-Juárez Juan G. , Escartín-Pérez Rodrigo E.
Published: February 2018

Overeating is one of the most relevant clinical features in Binge Eating Disorder and in some obesity patients. According to several studies, alterations in the mesolimbic dopaminergic transmission produced by non-homeostatic feeding behavior may be associated with changes in the reward system similar to those produced by drugs of abuse. Although it is known that binge-eating is related with changes in dopaminergic transmission mediated by D2 receptors in the nucleus accumbens shell (NAcS), it has not been determined whether these receptors may be a potential target for the treatment of eating pathology with binge-eating. Accordingly, the aim of the present study was to evaluate whether sugar binging induced by intermittent access to a sucrose solution produced changes in the structure of feeding behavior and whether blocking D2 receptors prevented these changes. We used the intermittent access model to a 10% sucrose solution (2 h/day for 4 weeks) to induce sugar binging in Sprague Dawley female rats. Experimental subjects consumed in a 2-h period more than 50% of the caloric intake consumed by the subjects with ad-lib access to the sweetened solution without any increase in body weight or fat accumulation. Furthermore, we evaluated whether sugar binging was associated to the estrous cycle and we did not find differences in caloric intake (estrous vs. diestrus). Subsequently, we characterized the structure of feeding behavior (microstructural analysis) and the motivation for palatable food (breakpoints) of the subjects with sugar binging and found that feeding episodes had short latencies, high frequencies, as well as short durations and inter-episode intervals. The intermittent access model did not increase breakpoints, as occurred in subjects with ad-lib access to the sucrose. Finally, we evaluated the effects of D2 receptor blockade in the NAcS, and found that raclopride (18 nM) prevented the observed changes in the frequency and duration of episodes induced by intermittent access to the sucrose solution. Our results suggest that alterations in behavioral patterns associated with binge-eating behavior depend in part on the dopaminergic transmission in the NAcS and that the antagonism of D2 receptors may be a therapeutic tool for feeding pathology with binge-eating.
Recommendations and Choices for BRCA Mutation Carriers at Risk for Ovarian Cancer: A Complicated Decision
Authors: Lewis Kelsey E. , Lu Karen H. , Klimczak Amber M. , Mok Samuel C.
Published: February 2018

Current ovarian cancer screening guidelines in high-risk women vary according to different organizations. Risk reducing surgery remains the gold standard for definitive treatment in BRCA mutation carriers, but research advancements have created more short-term options for patients to consider. The decisions involved in how a woman manages her BRCA mutation status can cause a great deal of stress and worry due to the imperfect therapy options. The goal of this review was to critically analyze the screening recommendations and alternative options for high-risk ovarian cancer patients and evaluate how these discrepancies and choices affect a woman’s management decisions.
Improved Kinetic Data Acquisition Using An Optically Accessible Catalytic Plate Reactor with Spatially-Resolved Measurement Techniques. Case of Study: CO2 Methanation
Authors: Hernandez Lalinde Jose A. , Kofler Kevin , Huang Xuejie , Kopyscinski Jan
Published: February 2018

Modelling and optimization of chemical reactors require a good understanding of the reactions mechanism with the corresponding kinetic description. Therefore, high quality kinetic data are needed, which can be challenging to obtain, especially for fast and highly exothermic reactions such as the CO2 methanation. Traditionally, kinetic studies rely on measuring the exit gas composition (1 data point per species and experiment) using differential reactors with diluted catalyst beds and reactants to avoid temperature change. Therefore, an optically accessible catalytic channel reactor was designed, which allowed for the chance to gather spatially-resolved information on axial gas composition and catalyst surface temperature, specifically by means of a movable sampling capillary and shortwave infrared-thermography (SWIR), respectively. A catalyst coated plate was placed at the bottom of the channel, while a set of two quartz glass plates covers the top. In the current study 35 data points per gas species were collect for 1 experiment conducted under laminar flow conditions at 425 °C. Catalyst surface temperature determined via a SWIR camera was not influenced by polyatomic molecules partaking in the reaction and thus did not falsify the kinetic data. The catalyst mass distribution along the reactor axis was determined, enabling the development of a correct reactor model for kinetic parameter estimation and model discrimination.
Electrical Behavior and Microstructural Features of Electric Field-Assisted and Conventionally Sintered 3 mol% Yttria-Stabilized Zirconia
Authors: Carvalho Sabrina , Muccillo Eliana , Muccillo Reginaldo
Published: February 2018

ZrO2: 3 mol% Y2O3 (3YSZ) polycrystalline pellets were sintered at 1400 °C and by applying an alternating current (AC) electric field at 1000 °C. An alumina sample holder with platinum wires for connecting the sample to a power supply was designed for the electric field-assisted sintering experiments. The apparent density was evaluated with the Archimedes technique, the grain size distribution by analysis of scanning electron microscopy images, and the electrical behavior by the impedance spectroscopy technique. Sintering with the application of AC electric fields to 3YSZ enhances its ionic conductivity. An explanation is proposed, based on the dissolution back to the bulk of chemical species, which are depleted at the grain boundaries, leading to an increase in the oxygen vacancy concentration. For the enhancement of the grain boundary conductivity, an explanation is given based on the diminution of the concentration of depleted chemical species, which migrate to the bulk. This migration leads to a decrease of the potential barrier of the space charge region, known to be responsible for blocking the oxide ions through the intergranular region. Moreover, the heterogeneity of the distribution of the grain sizes is ascribed to the skin effect, the tendency of the AC current density to be largest near the surface, decreasing towards the bulk.
“All that Matter … in One Big Bang …”, &Other Cosmological Singularities
Authors: Elizalde Emilio
Published: February 2018

The first part of this paper contains a brief description of the beginnings of modern cosmology, which, the author will argue, was most likely born in the year 1912. Some of the pieces of evidence presented here have emerged from recent research in the history of science and are not usually shared with the general audiences in popular science books. In particular, the issue of the correct formulation of the original Big Bang concept, according to the precise words of Fred Hoyle, is discussed. Too often, this point is very deficiently explained (when not just misleadingly) in most of the available generalist literature. Other frequent uses of the same words, Big Bang, as to name the initial singularity of the cosmos, and also whole cosmological models, are then addressed, as evolutions of its original meaning. Quantum and inflationary additions to the celebrated singularity theorems by Penrose, Geroch, Hawking and others led to subsequent results by Borde, Guth and Vilenkin. Additionally, corresponding corrections to the Einstein field equations have originated, in particular,

R
2

,

f
(
R
)

, and scalar-tensor gravities, giving rise to a plethora of new singularities. For completeness, an updated table with a classification of the same is given.
Whole-Transcriptome Sequencing: A Powerful Tool for Vascular Tissue Engineering and Endothelial Mechanobiology
Authors: Kutikhin Anton G. , Sinitsky Maxim Yu. , Yuzhalin Arseniy E. , Velikanova Elena A.
Published: February 2018

Among applicable high-throughput techniques in cardiovascular biology, whole-transcriptome sequencing is of particular use. By utilizing RNA that is isolated from virtually all cells and tissues, the entire transcriptome can be evaluated. In comparison with other high-throughput approaches, RNA sequencing is characterized by a relatively low-cost and large data output, which permits a comprehensive analysis of spatiotemporal variation in the gene expression profile. Both shear stress and cyclic strain exert hemodynamic force upon the arterial endothelium and are considered to be crucial determinants of endothelial physiology. Laminar blood flow results in a high shear stress that promotes atheroresistant endothelial phenotype, while a turbulent, oscillatory flow yields a pathologically low shear stress that disturbs endothelial homeostasis, making respective arterial segments prone to atherosclerosis. Severe atherosclerosis significantly impairs blood supply to the organs and frequently requires bypass surgery or an arterial replacement surgery that requires tissue-engineered vascular grafts. To provide insight into patterns of gene expression in endothelial cells in native or bioartificial arteries under different biomechanical conditions, this article discusses applications of whole-transcriptome sequencing in endothelial mechanobiology and vascular tissue engineering.
The Impact of Brain Breaks Classroom-Based Physical Activities on Attitudes toward Physical Activity in Polish School Children in Third to Fifth Grade
Authors: Glapa Agata , Grzesiak Joanna , Laudanska-Krzeminska Ida , Chin Ming-Kai , Edginton Christopher R. , Mok Magdalena Mo Ching , Bronikowski Michal
Published: February 2018

The purpose of this study was to examine the effectiveness of the Brain Breaks® Physical Activity Solutions in changing attitudes toward physical activity of school children in a community in Poland. In 2015, a sample of 326 pupils aged 9–11 years old from 19 classes at three selected primary schools were randomly assigned to control and experimental groups within the study. During the classes, children in the experimental group performed physical activities two times per day in three to five minutes using Brain Breaks® videos for four months, while the control group did not use the videos during the test period. Students’ attitudes toward physical activities were assessed before and after the intervention using the “Attitudes toward Physical Activity Scale”. Repeated measures of ANOVA were used to examine the change from pre- to post-intervention. Overall, a repeated measures ANOVA indicated time-by-group interaction effects in ‘Self-efficacy on learning with video exercises’, F(1.32) = 75.28, p = 0.00, η2 = 0.19. Although the changes are minor, there were benefits of the intervention. It may be concluded that HOPSports Brain Breaks® Physical Activity Program contributes to better self-efficacy on learning while using video exercise of primary school children.
Integrated Participatory and Collaborative Risk Mapping for Enhancing Disaster Resilience
Authors: Liu Wei , Dugar Sumit , McCallum Ian , Thapa Gaurav , See Linda , Khadka Prakash , Budhathoki Nama , Brown Sarah , Mechler Reinhard , Fritz Steffen , Shakya Puja
Published: February 2018

Critical knowledge gaps seriously hinder efforts for building disaster resilience at all levels, especially in disaster-prone least developed countries. Information deficiency is most serious at local levels, especially in terms of spatial information on risk, resources, and capacities of communities. To tackle this challenge, we develop a general methodological approach that integrates community-based participatory mapping processes, one that has been widely used by governments and non-government organizations in the fields of natural resources management, disaster risk reduction and rural development, with emerging collaborative digital mapping techniques. We demonstrate the value and potential of this integrated participatory and collaborative mapping approach by conducting a pilot study in the flood-prone lower Karnali river basin in Western Nepal. The process engaged a wide range of stakeholders and non-stakeholder citizens to co-produce locally relevant geographic information on resources, capacities, and flood risks of selected communities. The new digital community maps are richer in content, more accurate, and easier to update and share than those produced by conventional Vulnerability and Capacity Assessments (VCAs), a variant of Participatory Rural Appraisal (PRA), that is widely used by various government and non-government organizations. We discuss how this integrated mapping approach may provide an effective link between coordinating and implementing local disaster risk reduction and resilience building interventions to designing and informing regional development plans, as well as its limitations in terms of technological barrier, map ownership, and empowerment potential.
Synthesis Target Structures for Alkaline Earth Oxide Clusters
Authors: Escher Susanne G. E. T. , Lazauskas Tomas , Zwijnenburg Martijn A. , Woodley Scott M.
Published: February 2018

Knowing the possible structures of individual clusters in nanostructured materials is an important first step in their design. With previous structure prediction data for BaO nanoclusters as a basis, data mining techniques were used to investigate candidate structures for magnesium oxide, calcium oxide and strontium oxide clusters. The lowest-energy structures and analysis of some of their structural properties are presented here. Clusters that are predicted to be ideal targets for synthesis, based on being both the only thermally accessible minimum for their size, and a size that is thermally accessible with respect to neighbouring sizes, include global minima for: sizes

n
=
9
,
15
,
16
,
18

and 24 for (MgO)

n

; sizes

n
=
8
,
9
,
12
,
16
,
18

and 24 for (CaO)

n

; the greatest number of sizes of (SrO)

n

clusters (

n
=
8
,
9
,
10
,
12
,
13
,
15
,
16
,
18

and 24); and for (BaO)

n

sizes of

n
=
8
,
10

and 16.
Further Theoretical Insight into the Mechanical Properties of Polycaprolactone Loaded with Organic–Inorganic Hybrid Fillers
Authors: Maietta Saverio , Russo Teresa , De Santis Roberto , Ronca Dante , Riccardi Filomena , Catauro Michelina , Martorelli Massimo , Gloria Antonio
Published: February 2018

Experimental/theoretical analyses have already been performed on poly(ε-caprolactone) (PCL) loaded with organic–inorganic fillers (PCL/TiO2 and PCL/ZrO2) to find a correlation between the results from the small punch test and Young’s modulus of the materials. PCL loaded with Ti2 (PCL = 12, TiO2 = 88 wt %) and Zr2 (PCL = 12, ZrO2 = 88 wt %) hybrid fillers showed better performances than those obtained for the other particle composition. In this context, the aim of current research is to provide further insight into the mechanical properties of PCL loaded with sol–gel-synthesized organic–inorganic hybrid fillers for bone tissue engineering. For this reason, theoretical analyses were performed by the finite element method. The results from the small punch test and Young’s modulus of the materials were newly correlated. The obtained values of Young’s modulus (193 MPa for PCL, 378 MPa for PCL/Ti2 and 415 MPa for PCL/Zr2) were higher than those obtained from a previous theoretical modelling (144 MPa for PCL, 282 MPa for PCL/Ti2 and 310 MPa for PCL/Zr2). This correlation will be an important step for the evaluation of Young’s modulus, starting from the small punch test data.
A Hexahomotrioxacalix[3]arene-Based Ditopic Receptor for Alkylammonium Ions Controlled by Ag+ Ions
Authors: Jiang Xue-Kai , Ikejiri Yusuke , Wu Chong , Rahman Shofiur , Georghiou Paris , Zeng Xi , Elsegood Mark , Redshaw Carl , Teat Simon , Yamato Takehiko
Published: February 2018

A receptor cone-1 based on a hexahomotrioxacalix[3]arene bearing three pyridyl groups was successfully synthesized, which has a C3-symmetric conformation and is capable of binding alkylammonium and metal ions simultaneously in a cooperative fashion. It can bind alkylammonium ions through the -cavity formed by three aryl rings. This behaviour is consistent with the cone-in/cone-out conformational rearrangement needed to reorganize the cavity for endo-complexation. As a C3-symmetrical pyridyl-substituted calixarene, receptor cone-1 can also bind an Ag+ ion, and the nitrogen atoms are turned towards the inside of the cavity and interact with Ag+. After complexation of tris(2-pyridylamide) derivative receptor cone-1 with Ag+, the original C3-symmetry was retained and higher complexation selectivity for n-BuNH3+ versus t-BuNH3+ was observed. Thus, it is believed that this receptor will have a role to play in the sensing, detection, and recognition of Ag+ and n-BuNH3+ ions.
Modeling of Alpine Grassland Cover Based on Unmanned Aerial Vehicle Technology and Multi-Factor Methods: A Case Study in the East of Tibetan Plateau, China
Authors: Meng Baoping , Gao Jinlong , Liang Tiangang , Cui Xia , Ge Jing , Yin Jianpeng , Feng Qisheng , Xie Hongjie
Published: February 2018

Grassland cover and its temporal changes are key parameters in the estimation and monitoring of ecosystems and their functions, especially via remote sensing. However, the most suitable model for estimating grassland cover and the differences between models has rarely been studied in alpine meadow grasslands. In this study, field measurements of grassland cover in Gannan Prefecture, from 2014 to 2016, were acquired using unmanned aerial vehicle (UAV) technology. Single-factor parametric and multi-factor parametric/non-parametric cover inversion models were then constructed based on 14 factors related to grassland cover, and the dynamic variation of the annual maximum cover was analyzed. The results show that (1) nine out of 14 factors (longitude, latitude, elevation, the concentrations of clay and sand in the surface and bottom soils, temperature, precipitation, enhanced vegetation index (EVI) and normalized difference vegetation index (NDVI)) exert a significant effect on grassland cover in the study area. The logarithmic model based on EVI presents the best performance, with an R2 and RMSE of 0.52 and 16.96%, respectively. Single-factor grassland cover inversion models account for only 1–49% of the variation in cover during the growth season. (2) The optimum grassland cover inversion model is the artificial neural network (BP-ANN), with an R2 and RMSE of 0.72 and 13.38%, and SDs of 0.062% and 1.615%, respectively. Both the accuracy and the stability of the BP-ANN model are higher than those of the single-factor parametric models and multi-factor parametric/non-parametric models. (3) The annual maximum cover in Gannan Prefecture presents an increasing trend over 60.60% of the entire study area, while 36.54% is presently stable and 2.86% exhibits a decreasing trend.
Approach for the Development of a Framework for the Identification of Activities of Daily Living Using Sensors in Mobile Devices
Authors: Pires Ivan Miguel , Garcia Nuno M. , Pombo Nuno , Flórez-Revuelta Francisco , Spinsante Susanna
Published: February 2018

Sensors available on mobile devices allow the automatic identification of Activities of Daily Living (ADL). This paper describes an approach for the creation of a framework for the identification of ADL, taking into account several concepts, including data acquisition, data processing, data fusion, and pattern recognition. These concepts can be mapped onto different modules of the framework. The proposed framework should perform the identification of ADL without Internet connection, performing these tasks locally on the mobile device, taking in account the hardware and software limitations of these devices. The main purpose of this paper is to present a new approach for the creation of a framework for the recognition of ADL, analyzing the allowed sensors available in the mobile devices, and the existing methods available in the literature.
Regional Cooperation for the Sustainable Development and Management in Northeast Asia
Authors: Choi Yongrok
Published: February 2018

The Northeast Asian countries are the most pro-active regions in the world to take on the challenges of sustainable development. With this background, there has been an annual series of Sustainable Asia Conferences (SAC) which date back to the first inaugural meeting in 2009. This special issue consists of selected papers from the SAC 2017, held in Nanjing, China, from 23–25 June. With ten years of accumulated experience, SAC became one of the leading international conferences for presenting innovative or fundamental advances in sustainable development issues for Asia. Over time, SAC introduced more performance-oriented approaches to handle the feasibility of the sustainable development solutions. In this special issue, most of the papers focused on the precise and accurate sustainable governance mechanism in harmonizing economic development with a healthier life, while enhancing the quality of all standards of living. The majority of papers in this special issue also deal with two important pillars of the sustainable development: regional cooperation and regulatory effectiveness. This special edition will propose unique implications and feasible or workable suggestions against global warming and environmental degradation.
Challenges in measuring interprofessional–interorganisational collaboration with a questionnaire
Authors: Meijer Loes J , de Groot Esther , van Smeden Maarten , Schellevis François G , Damoiseaux Roger AMJ
Published: February 2018

Background

Collaboration between medical professionals from separate organisations is necessary to deliver good patient care. This care is influenced by professionals’ perceptions about their collaboration. Until now, no instrument to measure such perceptions was available in the Netherlands. A questionnaire developed and validated in Spain was translated to assess perceptions about clinicians’ collaboration in primary and secondary care in the Dutch setting.

Aim

Validation in the Dutch setting of a Spanish questionnaire that aimed to assess perceptions of clinicians about interorganisational collaboration.

Design & setting

After translation, cultural adaptation, and pre-testing, the questionnaire was sent to GPs and secondary care clinicians (SCCs) in three regions in the Netherlands. The responses of 445 responders were used to assess the validity and reliability of the questionnaire.

Method

A confirmatory factor analysis (CFA) and an exploratory factor analysis (EFA) were performed to study the construct validity of the hypothesised factor model underlying the questionnaire. Test-retest reliability was evaluated using weighted Kappa statistics.

Results

Results of the CFA indicated poor fit of the hypothesised factor structure. EFA, executed separately for each region, showed a highly unstable factor structure. The test-retest reliability analysis demonstrated low re-test reliability.

Conclusion

The underlying factor structure of a Spanish questionnaire could not be reproduced. The construct validity and reliability of this questionnaire were insufficient to warrant use in the Dutch setting. This study demonstrates the need for evaluating validity and reliability of questionnaires in local settings.
Magneto-optical Effects in the Scattering Polarization Wings of the Ca i 4227 Å Resonance Line
Authors: Alsina Ballester E. , Belluzzi L. , Trujillo Bueno J.
Published: February 2018

The linear polarization pattern produced by scattering processes in the Ca i 4227 Å resonance line is a valuable observable for probing the solar atmosphere. Via the Hanle effect, the very significant Q/I and U/I line-center signals are sensitive to the presence of magnetic fields in the lower chromosphere with strengths between 5 and 125 G, approximately. On the other hand, partial frequency redistribution (PRD) produces sizable signals in the wings of the Q/I profile, which have always been thought to be insensitive to the presence of magnetic fields. Interestingly, novel observations of this line revealed a surprising behavior: fully unexpected signals in the wings of the U/I profile and spatial variability in the wings of both Q/I and U/I. We show that the magneto-optical (MO) terms of the Stokes-vector transfer equation produce sizable signals in the wings of U/I and a clear sensitivity of the Q/I and U/I wings to the presence of photospheric magnetic fields with strengths similar to those that produce the Hanle effect in the line core. This radiative transfer investigation on the joint action of scattering processes and the Hanle and Zeeman effects in the Ca i 4227 Å line should facilitate the development of more reliable techniques for exploring the magnetism of stellar atmospheres. To this end, we can now exploit the circular polarization produced by the Zeeman effect, the magnetic sensitivity caused by the above-mentioned MO effects in the Q/I and U/I wings, and the Hanle effect in the line core.
The Effects of Barycentric and Asymmetric Transverse Velocities on Eclipse and Transit Times
Authors: Conroy Kyle E. , Prša Andrej , Horvat Martin , Stassun Keivan G.
Published: February 2018

It has long been recognized that the finite speed of light can affect the observed time of an event. For example, as a source moves radially toward or away from an observer, the path length and therefore the light travel time to the observer decreases or increases, causing the event to appear earlier or later than otherwise expected, respectively. This light travel time effect has been applied to transits and eclipses for a variety of purposes, including studies of eclipse timing variations and transit timing variations that reveal the presence of additional bodies in the system. Here we highlight another non-relativistic effect on eclipse or transit times arising from the finite speed of light—caused by an asymmetry in the transverse velocity of the two eclipsing objects, relative to the observer. This asymmetry can be due to a non-unity mass ratio or to the presence of external barycentric motion. Although usually constant, this barycentric and asymmetric transverse velocity (BATV) effect can vary between sequential eclipses if either the path length between the two objects or the barycentric transverse velocity varies in time. We discuss this BATV effect and estimate its magnitude for both time-dependent and time-independent cases. For the time-dependent cases, we consider binaries that experience a change in orbital inclination, eccentric systems with and without apsidal motion, and hierarchical triple systems. We also consider the time-independent case which, by affecting the primary and secondary eclipses differently, can influence the inferred system parameters, such as the orbital eccentricity.
Probing the Small-scale Structure in Strongly Lensed Systems via Transdimensional Inference
Authors: Daylan Tansu , Cyr-Racine Francis-Yan , Rivero Ana Diaz , Dvorkin Cora , Finkbeiner Douglas P.
Published: February 2018

Strong lensing is a sensitive probe of the small-scale density fluctuations in the Universe. We implement a pipeline to model strongly lensed systems using probabilistic cataloging, which is a transdimensional, hierarchical, and Bayesian framework to sample from a metamodel (union of models with different dimensionality) consistent with observed photon count maps. Probabilistic cataloging allows one to robustly characterize modeling covariances within and across lens models with different numbers of subhalos. Unlike traditional cataloging of subhalos, it does not require model subhalos to improve the goodness of fit above the detection threshold. Instead, it allows the exploitation of all information contained in the photon count maps—for instance, when constraining the subhalo mass function. We further show that, by not including these small subhalos in the lens model, fixed-dimensional inference methods can significantly mismodel the data. Using a simulated Hubble Space Telescope data set, we show that the subhalo mass function can be probed even when many subhalos in the sample catalogs are individually below the detection threshold and would be absent in a traditional catalog. The implemented software, Probabilistic Cataloger (PCAT) is made publicly available at https://github.com/tdaylan/pcat.
Metal-rich, Metal-poor: Updated Stellar Population Models for Old Stellar Systems
Authors: Conroy Charlie , Villaume Alexa , Dokkum Pieter G. van , Lind Karin
Published: February 2018

We present updated stellar population models appropriate for old ages (>1 Gyr) and covering a wide range in metallicities (−1.5 ≲ [Fe/H] ≲ 0.3). These models predict the full spectral variation associated with individual element abundance variation as a function of metallicity and age. The models span the optical–NIR wavelength range (0.37–2.4 μm), include a range of initial mass functions, and contain the flexibility to vary 18 individual elements including C, N, O, Mg, Si, Ca, Ti, and Fe. To test the fidelity of the models, we fit them to integrated light optical spectra of 41 Galactic globular clusters (GCs). The value of testing models against GCs is that their ages, metallicities, and detailed abundance patterns have been derived from the Hertzsprung–Russell diagram in combination with high-resolution spectroscopy of individual stars. We determine stellar population parameters from fits to all wavelengths simultaneously (“full spectrum fitting”), and demonstrate explicitly with mock tests that this approach produces smaller uncertainties at fixed signal-to-noise ratio than fitting a standard set of 14 line indices. Comparison of our integrated-light results to literature values reveals good agreement in metallicity, [Fe/H]. When restricting to GCs without prominent blue horizontal branch populations, we also find good agreement with literature values for ages, [Mg/Fe], [Si/Fe], and [Ti/Fe].
Molecular Cloud Structures and Massive Star Formation in N159
Authors: Nayak O. , Meixner M. , Fukui Y. , Tachihara K. , Onishi T. , Saigo K. , Tokuda K. , Harada R.
Published: February 2018

The N159 star-forming region is one of the most massive giant molecular clouds (GMCs) in the Large Magellanic Cloud (LMC). We show the 12CO, 13CO, CS molecular gas lines observed with ALMA in N159 west (N159W) and N159 east (N159E). We relate the structure of the gas clumps to the properties of 24 massive young stellar objects (YSOs) that include 10 newly identified YSOs based on our search. We use dendrogram analysis to identify properties of the molecular clumps, such as flux, mass, linewidth, size, and virial parameter. We relate the YSO properties to the molecular gas properties. We find that the CS gas clumps have a steeper size–linewidth relation than the 12CO or 13CO gas clumps. This larger slope could potentially occur if the CS gas is tracing shocks. The virial parameters of the 13CO gas clumps in N159W and N159E are low (<1). The threshold for massive star formation in N159W is 501 M
⊙ pc−2, and the threshold for massive star formation in N159E is 794 M
⊙ pc−2. We find that 13CO is more photodissociated in N159E than N159W. The most massive YSO in N159E has cleared out a molecular gas hole in its vicinity. All the massive YSO candidates in N159E have a more evolved spectral energy distribution type in comparison to the YSO candidates in N159W. These differences lead us to conclude that the giant molecular cloud complex in N159E is more evolved than the giant molecular cloud complex in N159W.
Dielectronic and Trielectronic Recombination Rate Coefficients of Be-like Ar14+
Authors: Huang Z. K. , Wen W. Q. , Xu X. , Mahmood S. , Wang S. X. , Wang H. B. , Dou L. J. , Khan N. , Badnell N. R. , Preval S. P. , Schippers S. , Xu T. H. , Yang Y. , Yao K. , Xu W. Q. , Chuai X. Y. , Zhu X. L. , Zhao D. M. , Mao L. J. , Ma X. M. , Li J. , Mao R. S. , Yuan Y. J. , Wu B. , Sheng L. N. , Yang J. C. , Xu H. S. , Zhu L. F. , Ma X.
Published: February 2018

Electron–ion recombination of Be-like 40Ar14+ has been measured by employing the electron–ion merged-beams method at the cooler storage ring CSRm. The measured absolute recombination rate coefficients for collision energies from 0 to 60 eV are presented, covering all dielectronic recombination (DR) resonances associated with 2s
2 → 2s2p core transitions. In addition, strong trielectronic recombination (TR) resonances associated with 2s
2 → 2p
2 core transitions were observed. Both DR and TR processes lead to series of peaks in the measured recombination spectrum, which have been identified by the Rydberg formula. Theoretical calculations of recombination rate coefficients were performed using the state-of-the-art multi-configuration Breit–Pauli atomic structure code AUTOSTRUCTURE to compare with the experimental results. The plasma rate coefficients for DR+TR of Ar14+ were deduced from the measured electron–ion recombination rate coefficients in the temperature range from 103 to 107 K, and compared with calculated data from the literature. The experimentally derived plasma rate coefficients are 60% larger and 30% lower than the previously recommended atomic data for the temperature ranges of photoionized plasmas and collisionally ionized plasmas, respectively. However, good agreement was found between experimental results and the calculations by Gu and Colgan et al. The plasma rate coefficients deduced from experiment and calculated by the current AUTOSTRUCTURE code show agreement that is better than 30% from 104 to 107 K. The present results constitute a set of benchmark data for use in astrophysical modeling.
Comparative Life Cycle Assessment of Autoclaved Concrete Blocks and Fired Blocks in China
Authors: Sun Yan Qiong , Liu Yu , Cui Su Ping
Published: February 2018

In this paper, a variety of blocks were grouped into the autoclaved blocks and fired blocks as far as the productive technology is concerned. In order to compare the life cycle impacts of the two kinds of the blocks, a life cycle assessment of two products on the functional unit 1m3 was carried out through the exploitation of mineral stage, transportation stage and the production of the blocks stage on the considering of the resource and energy consumption and the pollutant discharges. The results demonstrated that the fired blocks appeared to have less impact than autoclaved concrete blocks on human health, marine ecotoxicity toxicity and terrestrial ecotoxicity toxicity nearly 30%. The raw coal led to the serious impacts on the fossil depletion through the cement production stage of the autoclaved concrete blocks accounting for 45.86% and the gangue exploitation stage of the fired blocks accounting for 42.5%. Assessment of the data quality that the data was of pretty high or within the permission. The sensitivity analysis and contribution analysis assessment showed that the conclusion were robust.
Effect of Layered Double Hydroxides with Different Particle Size on Properties of Bitumen
Authors: Wu Min , Li Lian , He Bian Yang , Yu Jian Ying
Published: February 2018

The crystal structure, microscopic morphology, particle size distribution and UV shielding properties of layered double hydroxides (LDHs) with different particle size were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), laser particle size analysis and ultraviolet and visible (UV-vis) spectrophotometer. The effects of LDHs with different particle size on the physical, rheological properties and UV aging resistance of bitumen were investigated by conventional physical properties and dynamic rheological characteristics. The results indicated that the particle size of LDHs had a little effect on the physical properties, and it had some influence on rheological properties of bitumen, but its influence on the UV aging resistance of bitumen was different significantly. When UV aging time was 9d, the viscosity aging indexes of bitumen modified by LDHs with different particle size (80nm, 115nm and 180nm) decreased by 48.2%, 58.1% and 63.8% compared with the pristine bitumen, respectively. LDHs with the particle size of 180 nm showed better improvement than other two kinds of LDHs on UV aging resistance of bitumen.
On the Partial Pressure Measurement and Activity Calculation of Mn in the Ni-Cr-Co-Mo Alloy Melt
Authors: Yang Ya Qian , Chen Bo , Zhang Meng Shu , Ma Ying Che , Liu Kui
Published: February 2018

In metallurgical production processes, the vapor pressures and activity coefficients of impurity elements areconsidered as importantparameters in thermodynamic calculation. A saturated flow method was used to measure the dissolution equilibrium of Mn vapour over the surface of liquid Ni-Cr-Co-Mo alloys from 1773 to 1923K, and the measured results were employed in the calculation of the activities andactivity coefficients of Mn in liquid Ni-Cr-Co-Mo alloys. It is found that Mn showed a strong positive deviation from the Henry’s law, and the relationship between temperature and the standard free energy of dissolution reaction Mn(g)=[Mn]Ni-Cr-Co-Mowas determined to be . At 1873 and 1923K , the activity coefficient ƒof Mn in the Ni-Cr-Co-Mo alloymelt with 0.2wt.%Mn addition were calculated to be 1.065 and 1.068, respectively. According to the results mentioned above,the volatile lower limit of Mn can be up to 2.14 ppm in conventional vacuum melting production.
Effect of Copper and Annealing Dew Point on Oxidation Behavior of C-Si-Mn Steels
Authors: Jiang Guang Rui , Wang Hai Quan , Liu Li Bin
Published: February 2018

The effect of copper on oxidation behavior of a C-Si-Mn steel was investigated. The samples were heated to 820°C and held for 75s under four different dew points with 5vol% hydrogen. The results of glow discharge optical emission spectrometry (GDOES), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) analysis techniques revealed the differences in oxidation. It is proposed that the steel containing 0.3 wt.% copper has less external oxidation of silicon and manganese compared to the steel containing no copper for all different dew points. As researched in this paper the external oxidation of C-Si-Mn steels would be suppressed by adding copper.
Microstructure and Properties of HAZ in Low-Carbon Bainite E550 Steel during Double-Pass Welding Thermal Cycle
Authors: Zong Yun , Liu Chun Ming
Published: February 2018

Investigations on the microstructure and properties of the Coarse-Grained Heat-Affected Zone (CGHAZ) and intercritical reheated Coarse-Grained Heat-Affected Zone (ICCGHAZ) of a low-carbon bainite E550 steel were carried out using thermal simulation technology in this paper.Double-pass welding thermal cycle were performed on Gleeble-3800 thermal simulator, tempering heat treatment of the critical coarse crystal zone carried out in a box resistance furnace, low impact energies at -40 °C and Vickers hardness determined, and the microstructure were observed. The experimental results show that the microstructure of CGHAZ (Tp1 is 1320 °C) was dominated by coarse granular bainite and Lath bainite Ferrite, the impact toughness of CGHAZ was poor. The toughness of the CGHAZ was improved after second welding heat cycle except intercritical two-phase heating. When the peak temperature of the second thermal cycle(Tp2) was 650 °C, martensite-austenite (M-A) constituent of original CGHAZ wasdecomposed and refined, impact toughness and hardness were all higher than that of CGHAZ; When Tp2 is 750 °C, there was a ” necklace” distribution of massive M-A constituent in this ICCGHAZ, the impact energy at -40 °C prominently decreased and Hardness went up; When Tp2 was in the temperature range of 850 °C ~1100 °C, the microstructure was mainly finer granular bainite, the toughness of CGHAZ could be effectively improved; When Tp2 was over 1100 °C, M-A constituents become coarse, the toughness declined slightly . The changing of hardness was the opposite of toughness but the hardness fluctuation was comparatively small. After tempering at different temperature (520 °C~640 °C) , the grain boundary "necklace" structure of ICCGHAZ was still obvious, some of the M-A constituent were decomposed, the hardness decreased, the lowest hardness was obtained in 610 °C.
Development of Domestic CT80S Sulfur Resistance Coiled Tubing
Authors: Yang Zhong Wen , Li Hong Bin , Wang Jing Li , Bi Zong Yue
Published: February 2018

According to the demand of oil and gas field development with a small amount of hydrogen sulfide, CT80S sulfur resistance coiled tubing was developed through the raw materials and manufacturing technology. The microstructure, mechanical properties, fatigue life and corrosion resistance of the CT80S sulfur resistant coiled tubing were analyzed. The results showed that the microstructure of CT80S sulfur resistant coiled tubing was consisted of the ferrite and pearlite with the grain size of 12, banded structure of 1.0, and the inclusions was less than 1.0. The strength and hardness of the pipe meet the requirements of API Spec 5ST, and the hardness control was less than 18HRC. The pipe had excellent low cycle fatigue property, the mean fatigue life of Φ31.8 × 3.18mm tube was 1055 cycles when the internal pressure was 34.47MPa and the bending radius was 1219mm. According to NACE TM 0284 and NACE TM 0177 standard, the HIC and SCC performance tests were carried out in same solution. The results show that the developed tubing is insensitive to HIC and the resistance to sulfide stress corrosion is good, under 90%σs stress loading not break.
A Thick Al-Based Composite Coating Cladded by the Amorphous Powder
Authors: Wang Yong Tian , Tao Lu Lu , Mo Jia Wei
Published: February 2018

A 1mm thick Al-based composite coating was fabricated on the TC4 Ti-based substrate by using the amorphous powder and the pulse laser cladding technology. The microstructure, phase composition, hardness and friction of the coating were characterized by SEM, DSC, XRD and frictional wear tester, respectively. The results showed that the coating was composed of the micron-sized crystal phases and small amounts of amorphous matrix; the coating has the dense structure and metallurgically bonds with the substrate. The microhardness of the coating was up to 500-600 HV0.2, which was about two times of that of the TC4 Ti-based substrate. The friction coefficient of the coating was lower than that of the TC4 alloy, which improved the friction and wear properties of the TC4 substrate obviously.
Effects of Lanthanum Substitution on Dielectric, Ferroelectric and Electro-Optic Properties of Slim-Loop PLZT Ceramics
Authors: Zeng Xia , Cheng Wen Xiu , Qiu Ping Sun , He Xi Yun
Published: February 2018

Highly transparent lead lanthanum zirconate titanate (Pb1−xLax)(Zr0.65Ti0.35)1-x/4O3(x=0.096-0.1) electro-optic ceramics were prepared by the hot pressing method. The ceramics exhibited transparency as high as 67% at 632.8nm (close to the theoretical value). The effects of lanthanum substitution on the phase structure, microstructure, dielectric, ferroelectric, optical and electro-optic properties of PLZT were examined systematically. The XRD results indicated that all the compositions were single perovskite phases, and La substitution decreased the lattice constant and unit-cell volume. The dielectric results showed that the Tmaxand εmaxdecreased with La content increasing. The hysteresis loops showed that the La content reduced saturate polarization (Ps), remnant polarization (Pr) and coercive ﬁeld (Ec). Moreover, the half-wave voltage and EO coefficient R was enhanced and reduced respectively with increasing La.
Microstructure and Mechanical Properties of AlN Particle Reinforced Mg-Al Matrix Composites with Different Particle Contents
Authors: Wang Yong , Cheng Kai Ming , Zhou Ji Xue , Li Wei Hong , Xia Jin Huan
Published: February 2018

In this paper, magnesium matrix composite with different AlN particles content were fabricated by powder metallurgy. The microstructure of composites was investigated by scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS) and transmission electron microscopy (TEM). The mechanical properties of composites were measured by electronic universal testing machine. The results show that the best densification and the highest mechanical properties of composites reached when the addition of 6wt.% reinforcement at 620 °C for 1 hour. Additionally, the compressive strength and bending strength of composites were 217.06 MPa and 207.40 MPa respectively, increased by 79.2% and 91.12% compared with matrix alloy, and the reinforcement particles uniformly distributed in the matrix alloy. It may be concluded that the strengthening mechanism of composites is mainly attributed to grain refinement, load transfer, and dislocation strengthening.
Magnetic Properties of Pure Iron with Respect to Different C/Si Ratios and Grain Sizes
Authors: Liu Qing , Chen Zheng Yang , Yang Shu Feng , Li Jing She
Published: February 2018

Pure iron with C/Si > 1 and C/Si < 1 was smelted by a vacuum arc furnace, and the grain size was controlled through different heat treatments. The microstructure of pure iron was observed by using an optical microscope, and the grain size was subsequently measured and calculated. Finally, the coercive force, saturation magnetic induction, and permeability were measured using a vibrating sample magnetometer. The results indicate that the coercive force increases with decreases in the average grain diagonal size. An increase in the uniformity of the grain increases the saturation magnetic induction. The permeability depends on the average grain diagonal size and the uniformity of the grain as well as the chemical composition of pure iron.
Effect of Service Environment on Mechanical Properties of FeCoNiCrAl0.1 Alloy
Authors: Chen Ye Xin , Qiang Xiao Ni
Published: February 2018

The effect of service environment on mechanical properties of recrystallizedFeCoNiCrAl0.1 alloy when tested in vacuum, air and gaseous hydrogen was studied in this paper. The results show that the elongations of FeCoNiCrAl0.1 alloy tested in air and gaseous hydrogen are higher than that tested in vacuum. But the tensile strengths of the alloy tested in air and gaseous hydrogen decrease appreciably comparing with that tested in vacuum. With the increase of the hydrogen pressure in the environment, the elongation of the alloy first increases quickly, but the increasing ratio of the elongation decreases obviously when the hydrogen pressure is more than 10 kPa, and the elongation gradually tends to a constant. The fracture modes of FeCoNiCrAl0.1 alloy are all ductile fractures when tested in vacuum, air and gaseous hydrogen, and there are some micro-voids on the fracture surfaces.
Y-Ray Shielding Performance and Mechanical Properties of Mortar Strengthened by Amorphous Alloy Fibers
Authors: Cao P.H. , Wang Hui , Wu Yuan , Liu X.J. , Lu Zhao Ping
Published: February 2018

The γ-ray shielding performance of the mortar reinforced by zirconium-based amorphous alloy fibers was studied. Meanwhile, the mechanical properties of mortar blocks with two kinds of reinforcement addition phases, i.e. amorphous alloy fibers and steel fibers were tested. The results show that the linear attenuation coefficient to γ-ray increases and the thickness of half-value layer (HVL) decreases with the increasing of volume fraction of reinforcing fibers. The shielding results were simulated by Xcom software, and proven consistent with the experimental results. The compressive strength of mortar block reinforce with fibers of 0.4% volume fraction is 5% higher than that of pure mortar, the flexural strength of mortar block reinforced with fibers of 1.2% volume fraction is 57% higher than that of pure mortar, and 33.4% higher than that of mortar block added with steel fibers.