bluuebunny/crossref_metadata_2025 huggingface dataset:
Le musée gallo-romain d'Aoste (Isère) : de l'histoire à l'archéologie
Authors: Jospin Jean-Pascal
Published: January 2018

C'est en 1987 que le Musée dauphinois est chargé de la conservation du musée d'Aoste, décision qui préfigure ainsi la mise en place du réseau départemental des musées associés.

Inauguré en 1988, le nouveau musée développe rapidement ses activités, des travaux de recherche permettant par ailleurs de renouveler les connaissances ainsi que les collections. Douze ans plus tard, un ambitieux projet de construction lui donne une nouvelle impulsion : agrandi, aménagé et doté d'une petite équipe, il remplit dès lors pleinement ses missions de conservation et d'animation.

Aujourd'hui, si le musée d'Aoste est le seul équipement culturel du département isérois (à l'exception de celui de Vienne) à présenter exclusivement des collections archéologiques de la période romaine, son avenir, inscrit dans une perspective patrimoniale globale, nécessite sans doute un soutien intercommunal.
La reconnaissance législative du domaine public fluvial de la Nouvelle-Calédonie, la fin d’une longue période d’insécurité juridique
Authors: Massenavette Céline
Published: January 2018

Depuis sa modification en août 2009, la loi organique du 19 mars 1999 affirme que les cours d’eau, les lacs, les eaux souterraines et les sources font partie du domaine fluvial de la Nouvelle-Calédonie. Cette évolution législative très attendue a mis fin à une longue période d’insécurité juridique durant laquelle les doutes liés à la propriété des ressources en eau sont venus s’ajouter à la complexité du partage des compétences prévu par le statut du territoire. Le droit de l’eau n’avait pas évolué depuis près de cinquante ans en Nouvelle-Calédonie. Le silence des textes statutaires sur la question de la propriété des ressources y est sans doute pour beaucoup. Cette carence désormais comblée, il reste maintenant à envisager, sur des bases nouvelles, les règles de droit qui permettront une gestion pérenne de l’ensemble des ressources en eau, y compris de celles situées dans les terres coutumières.
Développement récent du droit de l’environnement en Allemagne
Authors: Roller Gerhard
Published: January 2018

Cette chronique passe en revue les orientations du nouveau gouvernement en Allemagne, au pouvoir depuis novembre 2009, les conséquences pour les compétences législatives et institutionnelles de la réforme constitutionnelle de 2006, les lois et la jurisprudence récente dans plusieurs secteurs environnementaux et, enfin, la protection de l’environnement par les tribunaux administratifs allemands.
Lumières du principe de précaution. A propos de la résolution du 1er février 2012 de l’Assemblée nationale
Authors: Naim-Gesbert Éric
Published: January 2018

La résolution du 1er février 2012 de l’Assemblée nationale sur le principe de précaution ne doit pas passer inaperçue. Outre le fait qu’elle est le fruit d’une nouvelle procédure parlementaire – issue des travaux du Comité d’évaluation et de contrôle des politiques publiques (CEC) – elle met en lumière la dimension scientifique de ce principe. Elle en donne, en neuf points, les éléments constitutifs, dessinant ainsi son statut juridique comme expertise immergée dans les faits sociaux.
L’adoption de la Convention de Minamata, ou la longue marche vers un instrument international juridiquement contraignant sur le mercure
Authors: Vassallo Laurent
Published: January 2018

The legally constraining international instrument on mercury, known as convention of Minamata, was adopted in Geneva on January 19th, 2013. If the final text is not published yet, the reading of the debates and the articles approved by nearly 140 States shows the difficulty in drawing up an international convention to fight against the mercury emissions. However, the International community for several years has been alerted on the medical and environmental impacts of mercury and its compounds. International environmental law and health are then necessary to fight against this heavy metal. Will the convention of Minamata be effective ?
Optical Coronagraphic Spectroscopy of AU Mic: Evidence of Time Variable Colors?
Authors: Lomax Jamie R. , Wisniewski John P. , Roberge Aki , Donaldson Jessica K. , Debes John H. , Malumuth Eliot M. , Weinberger Alycia J.
Published: January 2018

We present coronagraphic long slit spectra of AU Mic’s debris disk taken with the STIS instrument aboard the Hubble Space Telescope. Our spectra are the first spatially-resolved, scattered light spectra of the system’s disk, which we detect at projected distances between approximately 10 and 45 au. Our spectra cover a wavelength range between 5200 and 10200 Å. We find that the color of AU Mic’s debris disk is bluest at small (12–17 au) projected separations. These results both confirm and quantify the findings qualitatively noted by Krist et al. and are different than IR observations that suggested a uniform blue or gray color as a function of projected separation in this region of the disk. Unlike previous literature, which reported that the color of AU Mic’s disk became increasingly more blue as a function of projected separation beyond ∼30 au, we find the disk’s optical color between 35 and 45 au to be uniformly blue on the southeast side of the disk and decreasingly blue on the northwest side. We note that this apparent change in disk color at larger projected separations coincides with several fast, outward moving “features” that are passing through this region of the southeast side of the disk. We speculate that these phenomenon might be related and that the fast moving features could be changing the localized distribution of sub-micron-sized grains as they pass by, thereby reducing the blue color of the disk in the process. We encourage follow-up optical spectroscopic observations of AU Mic to both confirm this result and search for further modifications of the disk color caused by additional fast moving features propagating through the disk.
Orbital Light Curves of UU Aquarii in Stunted Outburst
Authors: Robertson J. W. , Honeycutt R. K. , Henden A. A. , Campbell R. T.
Published: January 2018

Stunted outbursts are ∼0.ͫ6 eruptions, typically lasting 5–10 days, which are found in some novalike cataclysmic variables, including UU Aqr. The mechanism responsible for stunted outbursts is uncertain but is likely related to an accretion disk instability or to variations in the mass transfer rate. A campaign to monitor the eclipse light curves in UU Aqr has been conducted in order to detect any light curve distortions due to the appearance of a hot spot on the disk at the location of the impact point of the accretion stream. If stunted outbursts are due to a temporary mass transfer enhancement, then predictable deformations of the orbital light curve are expected to occur during such outbursts. This study used 156 eclipses on 135 nights during the years 2000–2012. During this interval, random samples found the system to be in stunted outbursts 4%–5% of the time, yielding ∼7 eclipses obtained during some stage of stunted outburst. About half of the eclipses obtained during stunted outbursts showed clear evidence for hot spot enhancement, providing strong evidence that the stunted outbursts in UU Aqr are associated with mass transfer variations. The other half of the eclipses during stunted outburst showed little or no evidence for hot spot enhancement. Furthermore, there were no systematic changes in the hot spot signature as stunted outbursts progressed. Therefore, we have tentatively attributed the changes in hot spot visibility during stunted outburst to random blobby accretion, which likely further modulates the strength of the accretion stream on orbital timescales.
Exo-Milankovitch Cycles. I. Orbits and Rotation States
Authors: Deitrick Russell , Barnes Rory , Quinn Thomas R. , Armstrong John , Charnay Benjamin , Wilhelm Caitlyn
Published: January 2018

The obliquity of the Earth, which controls our seasons, varies by only ∼2.°5 over ∼40,000 years, and its eccentricity varies by only ∼0.05 over 100,000 years. Nonetheless, these small variations influence Earth’s ice ages. For exoplanets, however, variations can be significantly larger. Previous studies of the habitability of moonless Earth-like exoplanets have found that high obliquities, high eccentricities, and dynamical variations can extend the outer edge of the habitable zone by preventing runaway glaciation (snowball states). We expand upon these studies by exploring the orbital dynamics with a semianalytic model that allows us to map broad regions of parameter space. We find that, in general, the largest drivers of obliquity variations are secular spin–orbit resonances. We show how the obliquity varies in several test cases, including Kepler-62 f, across a wide range of orbital and spin parameters. These obliquity variations, alongside orbital variations, will have a dramatic impact on the climates of such planets.
Heating and Cooling of Coronal Loops with Turbulent Suppression of Parallel Heat Conduction
Authors: Bian Nicolas , Emslie A. Gordon , Horne Duncan , Kontar Eduard P.
Published: January 2018

Using the “enthalpy-based thermal evolution of loops” (EBTEL) model, we investigate the hydrodynamics of the plasma in a flaring coronal loop in which heat conduction is limited by turbulent scattering of the electrons that transport the thermal heat flux. The EBTEL equations are solved analytically in each of the two (conduction-dominated and radiation-dominated) cooling phases. Comparison of the results with typical observed cooling times in solar flares shows that the turbulent mean free path

lies in a range corresponding to a regime in which classical (collision-dominated) conduction plays at most a limited role. We also consider the magnitude and duration of the heat input that is necessary to account for the enhanced values of temperature and density at the beginning of the cooling phase and for the observed cooling times. We find through numerical modeling that in order to produce a peak temperature

K and a 200 s cooling time consistent with observations, the flare-heating profile must extend over a significant period of time; in particular, its lingering role must be taken into consideration in any description of the cooling phase. Comparison with observationally inferred values of post-flare loop temperatures, densities, and cooling times thus leads to useful constraints on both the magnitude and duration of the magnetic energy release in the loop, as well as on the value of the turbulent mean free path

.
Helium Star Models with Optically Thick Winds: Implications for the Internal Structures and Mass-loss Rates of Wolf–Rayet Stars
Authors: Nakauchi Daisuke , Saio Hideyuki
Published: January 2018

We construct helium (He) star models with optically thick winds and compare them with the properties of Galactic Wolf–Rayet (WR) stars. Hydrostatic He-core solutions are connected smoothly to trans-sonic wind solutions that satisfy the regularity conditions at the sonic point. Velocity structures in the supersonic parts are assumed by a simple β-type law. By constructing a center-to-surface structure, a mass-loss rate

can be obtained as an eigenvalue of the equations. Sonic points appear at temperatures

below the Fe-group opacity peak, where the radiation force becomes comparable to the local gravity. Photospheres are located at radii 3–10 times larger than sonic points. The obtained mass-loss rates are comparable to those of WR stars. Our

–luminosity relation agrees well with the relation recently obtained by Gräfener et al. Photospheric temperatures of WR stars tend to be cooler than our predictions. We discuss the effects of stellar evolution, detailed radiation transfer, and wind clumping, which are ignored in this paper.
Resolved H i Observations of Local Analogs to z ∼ 1 Luminous Compact Blue Galaxies: Evidence for Rotation-supported Disks
Authors: Rabidoux Katie , Pisano D. J. , Garland C. A. , Guzmán Rafael , Castander Francisco J. , Wolfe Spencer A.
Published: January 2018

While bright, blue, compact galaxies are common at

, they are relatively rare in the local universe, and their evolutionary paths are uncertain. We have obtained resolved H i observations of nine

luminous compact blue galaxies (LCBGs) using the Giant Metrewave Radio Telescope and Very Large Array in order to measure their kinematic and dynamical properties and better constrain their evolutionary possibilities. We find that the LCBGs in our sample are rotating galaxies that tend to have nearby companions, relatively high central velocity dispersions, and can have disturbed velocity fields. We calculate rotation velocities for each galaxy by measuring half of the velocity gradient along their major axes and correcting for inclination using axis ratios derived from SDSS images of each galaxy. We compare our measurements to those previously made with single dishes and find that single-dish measurements tend to overestimate LCBGs’ rotation velocities and H i masses. We also compare the ratio of LCBGs’ rotation velocities and velocity dispersions to those of other types of galaxies and find that LCBGs are strongly rotationally supported at large radii, similar to other disk galaxies, though within their half-light radii the

values of their H i are comparable to stellar

values of dwarf elliptical galaxies. We find that LCBGs’ disks on average are gravitationally stable, though conditions may be conducive to local gravitational instabilities at the largest radii. Such instabilities could lead to the formation of star-forming gas clumps in the disk, resulting eventually in a small central bulge or bar.
Neutrino Oscillations within the Induced Gravitational Collapse Paradigm of Long Gamma-Ray Bursts
Authors: Becerra L. , Guzzo M. M. , Rossi-Torres F. , Rueda J. A. , Ruffini R. , Uribe J. D.
Published: January 2018

The induced gravitational collapse paradigm of long gamma-ray bursts associated with supernovae (SNe) predicts a copious neutrino–antineutrino (

) emission owing to the hypercritical accretion process of SN ejecta onto a neutron star (NS) binary companion. The neutrino emission can reach luminosities of up to 1057 MeV s−1, mean neutrino energies of 20 MeV, and neutrino densities of 1031 cm−3. Along their path from the vicinity of the NS surface outward, such neutrinos experience flavor transformations dictated by the neutrino-to-electron-density ratio. We determine the neutrino and electron on the accretion zone and use them to compute the neutrino flavor evolution. For normal and inverted neutrino mass hierarchies and within the two-flavor formalism (

), we estimate the final electronic and nonelectronic neutrino content after two oscillation processes: (1) neutrino collective effects due to neutrino self-interactions where the neutrino density dominates, and (2) the Mikheyev–Smirnov–Wolfenstein effect, where the electron density dominates. We find that the final neutrino content is composed by ∼55% (∼62%) of electronic neutrinos, i.e.,

, for the normal (inverted) neutrino mass hierarchy. The results of this work are the first step toward the characterization of a novel source of astrophysical MeV neutrinos in addition to core-collapse SNe and, as such, deserve further attention.
Using DNA metabarcoding for assessing chironomid diversity and community change in mosquito controlled temporary wetlands
Authors: Theissinger Kathrin , Kästel Anna , Elbrecht Vasco , Makkonen Jenny , Michiels Susanne , Schmidt Susanne , Allgeier Stefanie , Leese Florian , Brühl Carsten
Published: January 2018

The biocide Bacillus thuringiensis var. israelensis (Bti) is widely applied for mosquito control in temporary wetlands of the German Upper Rhine Valley. Even though Bti is considered environmentally friendly, several studies have shown non-target effects on chironomids, a key food resource in wetland ecosystems. Chironomids have been proposed as important indicators for monitoring freshwater ecosystems, however, morphological determination is very challenging. In this study, we investigated the effectiveness of metabarcoding for chironomid diversity assessment and tested the retrieved chironomid operational taxonomic units (OTUs) for possible changes in relative abundance and species diversity in relation to mosquito control actions in four temporary wetlands. Three of these wetlands were, for the first year after 20 years of Bti treatment, partly left Bti-untreated in a split field design, and one wetland has never been treated with Bti. Our metabarcoding approach detected 54 chironomid OTUs across all study sites, of which almost 70% could be identified to species level comparisons against the BOLD database. We showed that metabarcoding increased chironomid species determination by 70%. However, we found only minor significant effects of Bti on the chironomid community composition, even though Bti reduced chironomid emergence by 65%. This could be due to a time lag of chironomid recolonization, since the study year was the first year of Bti intermittence after about 20 years of Bti application in the study area. Subsequent studies will have to address if and how the chironomid community composition will recover further in the now Bti-untreated temporary wetlands to assess effects of Bti.
The Dorsal 4-finger Technique: A Novel Method to Examine Metacarpophalangeal Joints in Patients with Rheumatoid Arthritis
Authors: Omair Mohammed A. , Akhavan Pooneh , Naraghi Ali , Mittoo Shikha , Xiong Juan , Weber Deborah , Lin Daming , Weber Melissa , Keystone Edward C.
Published: January 2018

Objective.

To describe the dorsal 4-finger technique (DFFT) in examining metacarpophalangeal (MCP) joints of patients with rheumatoid arthritis (RA) and compare it to the traditional 2-finger technique (TFT) using ultrasound (US) as a gold standard.

Methods.

Four rheumatologists evaluated 180 MCP joints of 18 patients with RA. All patients underwent US for greyscale (GSUS) and power Doppler US (PDUS). Agreements between rheumatologists, the 2 techniques, and US were evaluated using Cohen κ and the first-order agreement coefficient (AC1) κ methods.

Results.

The population comprised 17 females (94.4%) with a mean (SD) age and disease duration of 56.8 (14.4) and 21.8 (12.9) years, respectively. Eight patients (44.4%) were taking methotrexate monotherapy, while 10 patients (55.6%) were receiving biologics. US evaluation revealed 69 (38.3%) and 30 (16.7%) joints exhibited synovitis grade 2–3 by GSUS and PDUS, respectively. Effusion was documented in 30 joints (16.7%). The mean intraobserver agreement using the DFFT and TFT were 80.5% and 86%, respectively. The mean interobserver agreements using the DFFT and TFT were 84% and 74%, respectively. κ agreement with US findings was similar for both techniques in tender joints but was higher for the DFFT in nontender joints (0.33 vs 0.07, p = 0.015 for GSUS) and (0.48 vs 0.11, p = 0.002 for PDUS). The DFFT had a higher sensitivity in detecting ballottement by GSUS (0.47 vs 0.2, p < 0.001) and PDUS (0.60 vs 0.27, p < 0.001).

Conclusion.

The DFFT is a novel, reproducible, and reliable method to examine MCP joints, and it has a better correlation with US than the traditional TFT.
Association Between Glucocorticoid Exposure and Healthcare Expenditures for Potential Glucocorticoid-related Adverse Events in Patients with Rheumatoid Arthritis
Authors: Best Jennie H. , Kong Amanda M. , Lenhart Gregory M. , Sarsour Khaled , Stott-Miller Marni , Hwang Yong
Published: January 2018

Objective.

Oral glucocorticoid (OGC) use for rheumatoid arthritis (RA) is debated because of the adverse event (AE) profile of OGC. We evaluated the associations between cumulative doses of OGC and potential OGC-related AE, and quantified the associated healthcare expenditures.

Methods.

Using the MarketScan databases, patients ≥ 18 years old who have RA with continuous enrollment from January 1 to December 31, 2012 (baseline), and from January 1 to December 31, 2013 (evaluation period), were identified. Cumulative OGC dose was measured using prescription claims during the baseline period. Potential OGC-related AE (osteoporosis, fracture, aseptic necrosis of the bone, type 2 diabetes, ulcer/gastrointestinal bleeding, cataract, hospitalization for opportunistic infection, myocardial infarction, or stroke) and AE-related expenditures (2013 US$) were gathered during the evaluation period. Multivariable regression models were fitted to estimate OR of AE and incremental costs for patients with AE.

Results.

There were 84,357 patients analyzed, of whom 48% used OGC during the baseline period and 26% had an AE during the evaluation period. A cumulative OGC dose > 1800 mg was associated with an increased risk of any AE compared with no OGC exposure (OR 1.19, 99.65% CI 1.09–1.30). Incremental costs per patient with any AE were significantly greater for cumulative OGC dose > 1800 mg compared with no OGC exposure (incremental cost = $3528, 99.65% CI $2402–$4793).

Conclusion.

Chronic exposure to low to medium doses of OGC was associated with significantly increased risk of potential OGC-related AE in patients with RA, and greater cumulative OGC dose was associated with substantially higher AE-related healthcare expenditures among patients with AE.
S100A12 Is Associated with Response to Therapy in Juvenile Idiopathic Arthritis
Authors: Gohar Faekah , Anink Janneke , Moncrieffe Halima , Van Suijlekom-Smit Lisette W.A. , Prince Femke H.M. , van Rossum Marion A.J. , Dolman Koert M. , Hoppenreijs Esther P.A.H. , ten Cate Rebecca , Ursu Simona , Wedderburn Lucy R. , Horneff Gerd , Frosch Michael , Foell Dirk , Holzinger Dirk
Published: January 2018

Objective.

Around one-third of patients with juvenile idiopathic arthritis (JIA) fail to respond to first-line methotrexate (MTX) or anti-tumor necrosis factor (TNF) therapy, with even fewer achieving ≥ American College of Rheumatology Pediatric 70% criteria for response (ACRpedi70), though individual responses cannot yet be accurately predicted. Because change in serum S100-protein myeloid-related protein complex 8/14 (MRP8/14) is associated with therapeutic response, we tested granulocyte-specific S100-protein S100A12 as a potential biomarker for treatment response.

Methods.

S100A12 serum concentration was determined by ELISA in patients treated with MTX (n = 75) and anti-TNF (n = 88) at baseline and followup. Treatment response (≥ ACRpedi50 score), achievement of inactive disease, and improvement in Juvenile Arthritis Disease Activity Score (JADAS)-10 score were recorded.

Results.

Baseline S100A12 concentration was measured in patients treated with anti-TNF [etanercept n = 81, adalimumab n = 7; median 200, interquartile range (IQR) 133–440 ng/ml] and MTX (median 220, IQR 100–440 ng/ml). Of the patients in the anti-TNF therapy group, 74 (84%) were also receiving MTX. Responders to MTX (n = 57/75) and anti-TNF (n = 66/88) therapy had higher baseline S100A12 concentration compared to nonresponders: median 240 (IQR 125–615) ng/ml versus 150 (IQR 87–233) ng/ml, p = 0.021 for MTX, and median 308 (IQR 150–624) ng/ml versus 151 (IQR 83–201) ng/ml, p = 0.002, for anti-TNF therapy. Followup S100A12 could be measured in 44/75 MTX-treated patients (34/44 responders) and 39/88 anti-TNF-treated patients (26/39 responders). Responders had significantly reduced S100A12 concentration (MTX: p = 0.031, anti-TNF: p < 0.001) at followup versus baseline. Baseline serum S100A12 in both univariate and multivariate regression models for anti-TNF therapy and univariate analysis alone for MTX therapy was significantly associated with change in JADAS-10.

Conclusion.

Responders to MTX or anti-TNF treatment can be identified by higher pretreatment S100A12 serum concentration levels.
Smoking Is the Most Significant Modifiable Lung Cancer Risk Factor in Systemic Lupus Erythematosus
Authors: Bernatsky Sasha , Ramsey-Goldman Rosalind , Petri Michelle , Urowitz Murray B. , Gladman Dafna D. , Fortin Paul R. , Yelin Edward H. , Ginzler Ellen , Hanly John G. , Peschken Christine , Gordon Caroline , Nived Ola , Aranow Cynthia , Bae Sang-Cheol , Isenberg David , Rahman Anisur , Hansen James E. , Pierre Yvan St. , Clarke Ann E.
Published: January 2018

Objective.

To assess lung cancer risk in systemic lupus erythematosus (SLE), relative to demographics, drug exposures, smoking, and disease activity.

Methods.

We analyzed data from 14 SLE cohorts. We calculated adjusted HR estimates for lung cancer in SLE, relative to demographics, smoking, time-dependent medication exposures, and cumulative disease activity [mean adjusted SLE Disease Activity Index (SLEDAI) scores]. This project was approved by the ethics boards of all participating institutions, including the Institutional Review Board of the McGill University Health Centre. The ethics approval number for the Cancer Risk study is GEN-06-031.

Results.

Within these 14 SLE cohorts, 49 incident lung cancers occurred. Among lung cancer cases, 59.0% were in the highest SLEDAI quartile at baseline versus 40.8% of lung cancer–free SLE controls. The vast majority (84.2%) of SLE lung cancer cases were ever-smokers at baseline, versus 40.1% of those without lung cancer. In adjusted models, the principal factors associated with lung cancer were ever smoking (at cohort entry) and current age. Estimated adjusted effects of all drugs were relatively imprecise, but did not point toward any drug exposures as strong lung cancer risk factors.

Conclusion.

We saw no clear evidence for drugs as a trigger for lung cancer risk in SLE, although drug risk estimates were relatively imprecise. Smoking may be the most significant modifiable lung cancer risk factor in SLE.
Efficiency of Crystalline Coating Measured by Contact Angle Method
Authors: Pazderka Jiří , Purkrtová Magdalena , Hecht Clemens
Published: January 2018

The paper deals with two problems in the field of cement-based crystalline coating: The uncertainties about the depth effect of crystalline coating and the influence of curing on resulting waterproofing effect. For coating depth effect investigation the authors used a method based on the analysis of surface hydrophobicity (contact angle method). The depth effect of crystalline coating can be detected on the basis of the different surface hydrophobicity in various distances from the coated surface. The results of measurement showed that the tested crystalline coatings affect concrete microstructure to depth of approximately 50 - 60 mm (measured 4 months after the coating application). But it turned out that used method is not appropriate for this purpose because the results can be affected by a lot of influences and it is necessary be cautious about the conclusions. Another part of experimental program showed that the curing of crystalline coating during its ageing is absolutely necessary for the consequent waterproofing effect. This fact is also the risk factor for the using of crystalline coatings because the waterproofing effect is dependent on a consistent technological discipline.
The Influence of High Temperatures and Time on the Material and Mechanical Properties of Cement Binder with Fly Ash
Authors: Zobal Ondřej , Padevět Pavel
Published: January 2018

The paper deals with the use of fly ash in cement and concrete. Fly ash, primarily waste material, can be used as a binder because of pozzolanic properties. This fact positively influences the economic and ecological part of the construction. At present, also in the context of higher fire protection requirements fly ash, it is mentioned as a possible material for the protection of structures from fire. The article presents and discusses the results of destructive tests of tensile strength and compressive strength and non-destructive verification of dynamic modulus of elasticity of cement pastes with fly ash after high temperature load. The test samples were almost six years old.
Prefabrication of the Thin-Walled U-Profile UHPFRC Footbridge
Authors: Citek David , Kolisko Jiří , Tej Petr , Mandlík Tomáš , Rehacek Stanislav
Published: January 2018

This article presents a mix design, preparation and production of thin-walled footbridge made from UHPFRC. Optimization of UHPFRC matrix and parameters of this material leads to the design of very thin structures. In this case an experimental pedestrian bridge was designed and prepared. Single-span bridge with span of 10 m and the clear width of 1.50 m with the total thickness of shell structure 30 - 45 mm was cast as a prefabricated element in one piece. Self-compacting character of UHPFRC with high flowability allows the production of the final structure. Extensive research was done before production of footbridge. Two versions of large scale mock-ups were casted and tested. According to the complexity of whole experiment a casting technology and production of formwork were tested and optimized many times. Experimental reached data were compared with extensive numerical analysis and the final design of structure and UHPFRC matrix were optimized in many details.
Influence of Plasticizers on Properties of Anhydrite Binder
Authors: Gazdič Dominik , Mokrá Jana , Hanáček Jan
Published: January 2018

This paper deals with the development and research of sulphate binder based on anhydrite for the industrial production of dry mortar self-leveling mixtures. As part of the experimental activity, selected plasticizers for the sulphate binders were tested. These additives were added in various weight ranges. The tests were carried out first on anhydrite pastes and then on anhydrite mortars of standard composition. Their influence was mainly observed on the achieved basic technological properties, such as the consistency, the initial setting time and the achieved strength.
Application of Granulated Cable Plastic Waste for Soil Stabilization
Authors: Lidmila Martin , Jogl Marcel , Kubissa Wojciech , Jaskulski Roman , Reiterman Pavel
Published: January 2018

Paper deals with the assessment of practical utilization of granulated cable plastic waste (GCPW) for the production of stabilized soil layers in transport engineering. The main goal of the experimental work was the evaluation of the influence of GCPW on mechanical properties of soil stabilization based on the fluidized fly ash. Mechanical properties were investigated using standard procedures in soil mechanics. GCPW was dosed as a partial replacement of fluidized fly ash up to 30 %. It was concluded, that the studied level of replacement performs critical level, additional increasing of GCPW would lead to a decline of required mechanical properties. Besides, replacement by studied waste material caused lower values of the bulk density.
The Comparison of Properties of Fine Recycled Aggregate Concrete from Different Sources of Recycled Aggregate
Authors: Pavlů Tereza
Published: January 2018

The main aim of this contribution is comparison the properties of fine aggregate concrete with partial replacement of sand by fine recycled aggregate. The fine recycled aggregate originated from two different sources. The main topic of this article is the study of influence of the origin of FRA to fine aggregate concrete properties. The compressive strength, flexural strength and freeze-thaw resistance were tested. The mechanical properties and weight were examined after 28 and 60 days and after 25, 50, 75 and 100 cycles of freeze-thaw. Partial replacement of sand was 25 and 50 % for all these tests. The properties were investigated by using prismatic specimens.
The Properties of Fine Recycled Aggregate Concrete Containing Recycled Bricks from Construction and Demolition Waste
Authors: Fořtová Kristina , Pavlů Tereza
Published: January 2018

This paper presents research results of recycled fine aggregate concrete testing. The main aim of this contribution is verification of properties of fine aggregate concrete with partial replacement of fine natural aggregate by recycled masonry aggregate originated from construction and demolition waste. The influence of partial replacement of natural sand to mechanical properties and freeze-thaw resistance is described. The compressive strength and flexural strength were tested at the age of 28 and 60 days and after 25, 50, 75 and 100 freeze-thaw cycles. Partial replacement of natural sand was 0, 25 and 50 % for all these tests. Prismatic specimens were examined.
Influence of Guar Gum Derivatives on Hardened Properties of Aerial Lime-Based Mortars
Authors: Žižlavský Tomáš , Vyšvařil Martin , Bayer Patrik , Rovnaníková Pavla
Published: January 2018

This paper studies the possibility of usage of the guar gum and its derivatives (carboxymethylhydroxypropyl guar (CMHPG) and hydroxypropyl guar (HPG)) as admixtures for aerial lime-based mortars. The influence on the properties of mortars was studied on the aerial lime –based mortars prepared with quartz fine grained sand and doses of admixtures ranging between 0,5 and 10‰. The hardened bulk densities, flexural and compressive strength, porosity, water absorption coefficient due to capillarity action and carbonation rate were studied. The addition of the hydroxypropyl guar lowered the bulk density (due to an air intake), improved workability, slightly increased the strength, slowed carbonation rate, and nobbled the water transport in the mortar. The addition of carboxymethylhydroxypropyl guar does not impact the bulk density, the strengths were increased similarly to HPG: it does not impact carbonation rate significantly, so the long term strengths were comparative with the HPG. The water transport was slightly better in lower doses and slightly worse in larger doses in comparison with the reference mortar. The pure guaran was found not to be beneficial for the lime mortars for its only advantage is in the water transport, where in any dose the transport was better than any other mortar, but the benefit of this is questionable.
Microscale Tests of Cement Paste Performed with FIB and Nanoindentation
Authors: Němeček Jiří , Němeček Jiří
Published: January 2018

This study deals with experimental determination of tensile properties of cement paste hydration products at micro-scale. Cantilever micro-beams with length of about 16 µm and pentagon cross section with micrometer dimensions were fabricated by focused ion beam milling on hydrated cement paste samples. Nanoindentation was used for evaluating elastic properties while tensile properties were derived from beam bending tests. Displacement controlled micro-scale tests give access to both tensile strength and estimates of fracture energy based on the load-displacement curves measured with the nanoindenter. The mean tensile strength and the fracture energy of inner hydration product were assessed as 791 MPa and 16.7 J/m2, respectively. The huge difference of the micro-scale properties when compared to macroscopic values comes from the scaling properties of concrete.
Nanoparticles in Concrete: Application in Fresh and Hardened State
Authors: Němeček Jiří , Šulc Rostislav , Němečková Jitka , Kruis Jaroslav
Published: January 2018

The paper summarizes utilization of nanoparticles (NP) in concrete for enhancing its mechanical, transport or other properties. The first part is devoted to review of NPs used in fresh concrete mixtures that have been reported previously in the literature while the second part shows original results from utilization of nanoparticles as healing agents for reparing of existing concrete structures. In the second case, nanoparticles are delivered to concrete via electrokinetic principle by using their surface charge provided in colloidal solutions. Particles are transported in the pore liquid of concrete due to electric field applied between the concrete surface and steel reinforcement. In this way, distressed concrete can be repaired, cracks sealed and risk of corrosion diminished. The injection of NPs can be complemented with extraction of chlorides that are the main deteriorating chemicals in reinforced concrete structures. Finally, the paper shows a framework developed for the electrokinetic transport of ionic species in concrete applied to chloride extraction from concrete and how it can be modified also for transport of nanoparticles.
Influence of Milling on some Chemical Properties and Reactivity of CFBC Fly Ash
Authors: Váchal Tomáš , Šulc Rostislav , Janků Tereza , Svoboda Pavel
Published: January 2018

This paper describes influence of milling on chemical properties of fly ash from Circulating fluidized Bed Combustion (CFBC). Specific properties of fly ash was determined using calorimetric measurement. It was determined heat properties and total content of calcium oxide CaO. The following methods of measurement were also performed: granulometric measurement and chemical analysis. The ash properties of non-milled and milled ashes were also described and evaluated and the ash reactivity was compared.
Influence of Biocorrosion on Concrete Properties
Authors: Chromková Ivana , Čechmánek René
Published: January 2018

The paper brings current results of a project that places emphasis on comparison of different fine-grained concrete resistance to influence of aggressive solutions of biogenic or biological origin. For laboratory testing, there were preferentially selected aggressive environments, to which concrete constructions of agricultural structures or sewage networks are exposed. Basic physical-mechanical parameters of concrete samples exposed to aggressive solutions for 1 year are stated in the paper.
The Effective Thermal Conductivity (ETC) of Spherical Packed-Bed Porous Media for Modification of the Color Surface as Black Color
Authors: Krittacom Bundit , Tongbai Pornsawan
Published: January 2018

The effective thermal conductivity (ETC) of the spherical packed-bed porous media in stagnant fluid case is estimated by modifying the color surface of the porous media as black surface. The Alumina-Cordierite (Al-Co) ceramic balls having average diameter (d) of 5.0 cm is constructed as the porous media and, then, a porosity (f) has 0.398. For development of the porous media as black surface, the Al-Co ceramic balls are painted by black color and then it is composed of 600 °C × 8 hr. The experimental procedure to evaluate the ECT is based on ASTM E1225. A higher temperature (TH) is investigated in the range of 400 to 800 K at the constant power of 350 W. The ETC of three surfaces of the Al-Co ceramics ball, i.e., original surface (λorg), combined black-painted and original surface (λcom) and black surface (λblk), are examined. From experiment, it is found that all ETC of three surfaces decrease with increasing TH. The value of three ETCs are in the range of 6.2 to 27.1 W/(m K). The lblk gives highest for the present research and, exactly, the worst case is obtained by λorg. Thus, the ETC of spherical packed-bed porous media with stagnant fluid can be improved by developing the color surface as black color.
Optimal Parameter Design of Rice Milling Machine Using Design of Experiment
Authors: Ruekkasaem Lakkana , Sasananan Montalee
Published: January 2018

This study was aimed at finding appropriate levels of machine set up for small-sized rice milling machine in order to improve rice milling effectiveness. Small rice milling machines are used by farmers to reduce the reliance on commercial rice mill. However, they are found to produce greater quantities of broken rice grains than large-sized rice milling machine. This study investigated three factors of machine setup that would lead to smallest percentage of broken rice grains, i.e. size of hopper feed, gap adjuster, and outlet regulator. Each factor had three levels thus 3 x 3 factorial design was used to investigate the factors. It was found that all the three factors had significant impact on the number of broken grains. The optimum parameter settings that led to the smallest percentage of broken rice grains were as follows: size of hopper feed at 12 cm2, gap adjuster at 5 mm, and outlet regulator at 5 cm.
Comparative Micro-EDM Studies on Ni Based X-Alloy Using Coated and Uncoated Tools
Authors: Perveen Asma , Jahan M.P.
Published: January 2018

Nickel based alloys have found their wide range of applications in the automotive, oil and gas, and aerospace industries due to their excellent mechanical and thermal properties. However, these alloys impose greater challenges to conventional machining techniques due to their extreme hardness. Therefore, non-traditional machining process like micro-electro discharge machining, which is a non–contact machining process, comes into consideration. In this study, the machinability of Ni based X-alloy was investigated using micro-EDM process with the aid of coated and uncoated tools. From the experimental results, it was evident that the machining time was reduced with the increase of discharge energy for both the coated and uncoated tools. Increase in discharge energy also resulted in enlargement of entrance diameter and overcut. However, the non-conductive nature of coating caused in the reduction of overcut for machining using coated tools. The tool wear was found to reduce with the increase of discharge energy due to shorter machining time at higher discharge energy. Finally, crater size also increased with the increased discharge energy. The coated tools resulted in bigger crater sizes than uncoated tools at 1000 rpm, however, for higher tool rotation the difference was not significant.
Development of Parameters Optimization Technology for Obtaining Composite Materials and Coatings with Shape Memory Effect
Authors: Rusinov Peter Olegovich , Blednova Zhesfina Michailovna
Published: January 2018

The paper studies the technology of producing composite materials and coatings by means of high-velocity oxygen-fuel spraying (HVOF) in a protective atmosphere. We have developed technologies for the formation of nanostructured surface layers made of multicomponent materials in the conditions of high-velocity oxygen-fuel spraying in order to improve operational properties and expand functional capabilities of engineering products. We optimized technological parameters and constructed nomograph of the process. We described a modernized GLC-720 unit which implements the resource-saving technology for the formation of nanostructured surface layers on cylindrical details, and makes it possible to produce HVOF in a protective atmosphere and thermomechanical processing in a single technological cycle.
Surface Hardening of AISI 420 Stainless Steel by Using a Nanosecond Pulse Laser
Authors: Netprasert Ornsurang , Tangwarodomnukun Viboon , Dumkum Chaiya
Published: January 2018

Unlike the conventional heat treatments, laser hardening process can selectively and locally harden the workpiece surface with minimum part distortion, thus making the process suitable for small or thin workpieces. To elucidate a better understanding of process performance, this paper presents an investigation of laser hardening process for AISI 420 martensitic stainless steel. A nanosecond pulse laser was used as a heat source to harden the metal surface. The effects of laser power scan overlap and scan speed on micro-hardness and case depth were experimentally examined. The results revealed that the micro-hardness of stainless steel surface increased from 242 HV to 1700 HV without any sign of surface melting. The depth of hardened layer was found to be 60-80 µm depending on laser power, scan speed and scan overlap applied. In addition, the scan overlap of 50% was recommended to lessen the deviation of micro-hardness across the laser-scanned area.
Research on Sound Insulation Performance of Poroelastic Material in Complex Structure
Authors: Zhang Jun , Yu Yi Hang , Zhao Wen Zhong
Published: January 2018

A finite element model of the double-wall acoustic insulation structure with a air layer and an acoustic absorbent layer made of the poroelastic materials is set up, the responses of this acoustic-vibration system are calculated by using of the direct finite element method when having a diffuse incident acoustic field acting on the incident surface, the radiant acoustic power from the another surface are achieved, then the Transmission Loss(TL) are formulated using the incident acoustic power and the radiant acoustic power. The effects of the thicknesses, elastic modulus, flow resistivity and viscous lengths of the poroelastic materials on TL are analyzed. The results show that the thicknesses and elastic modulus have a significant effects on TL, TL are enhanced with the thicknesses increasing of the poroelastic materials layers, a 4.9dB addition of TL is achieved when thickness is added from 2cm to 3cm; TL are enhanced with the reduction of the elastic modulus in considered frequency range, and TL are reduced with the declining of viscous lengths and with the addition of the flow resistivity when the frequencies are higher than 600Hz.
Fabrication and Properties of Glass Fibre Reinforced Fly Ash-Cement Roofing Tiles
Authors: Ariyadasa G.L.M. , Adikary S. Upali , Muthuratne S.S.K.
Published: January 2018

In this study Glass fibre reinforced fly ash -cement roofing tiles were fabricated using three different forms of coal fly ash (CFA) such as CFA as it is, CFA particle sizes below 75μm and below 45μm.The separated CFA was used to replace cement 30% by the weight and those matrices were reinforced by Alkali Resistant (AR) glass fibres adding 1% and 2% by weight.The corrugated roof tiles have dimensions of 490×250×8mm and they were hand cast using ordinary vibration. Physical and mechanical tests were performed after 28 days of aging. The tiles were tested in accordance with SLS 1189. Transverse strength increased with increasing fibre percentage. Further, the transverse strength decreased with decreasing CFA particle size. Highest characteristic transverse strength was observed in the CFA as it is sample which is 1650N and the lowest from CFA below 45µm particle size sample which is 1240N. However, all the samples satisfy the strength requirement which is 230N. High water absorption was observed in all the samples which is around 20%.The dry density was ranged in between 1.62-1.68g/cm3 .The lowest average dry density was observed in CFA as it is samples whereas CFA below 75μm particle size and CFA below 45μm particle size samples showed similar density values. The dry density of tile samples is in comparable with the dry density of asbestos cement sheets (≈1.63g/cm3) and the characteristic transverse strength is in comparable with Calicut clay tiles (1000-2000N) in Sri Lanka. Therefore, glass fibre reinforced fly ash-cement roofing tiles are promising substitute for asbestos roofing sheets.
Staphylococcal Superantigens Use LAMA2 as a Coreceptor To Activate T Cells
Authors: Li Zhigang , Zeppa Joseph J. , Hancock Mark A. , McCormick John K. , Doherty Terence M. , Hendy Geoffrey N. , Madrenas Joaquín
Published: January 2018

Canonical Ag-dependent TCR signaling relies on activation of the src-family tyrosine kinase LCK. However, staphylococcal superantigens can trigger TCR signaling by activating an alternative pathway that is independent of LCK and utilizes a Gα11-containing G protein–coupled receptor (GPCR) leading to PLCβ activation. The molecules linking the superantigen to GPCR signaling are unknown. Using the ligand-receptor capture technology LRC-TriCEPS, we identified LAMA2, the α2 subunit of the extracellular matrix protein laminin, as the coreceptor for staphylococcal superantigens. Complementary binding assays (ELISA, pull-downs, and surface plasmon resonance) provided direct evidence of the interaction between staphylococcal enterotoxin E and LAMA2. Through its G4 domain, LAMA2 mediated the LCK-independent T cell activation by these toxins. Such a coreceptor role of LAMA2 involved a GPCR of the calcium-sensing receptor type because the selective antagonist NPS 2143 inhibited superantigen-induced T cell activation in vitro and delayed the effects of toxic shock syndrome in vivo. Collectively, our data identify LAMA2 as a target of antagonists of staphylococcal superantigens to treat toxic shock syndrome.