bluuebunny/crossref_metadata_2025 huggingface dataset:
(Se) correspondre en ligne
Authors: Bergström Marie
Published: January 2017

Résumé Apparus en France au tournant du XXI e siècle, les sites de rencontres sur internet sont aujourd'hui largement fréquentés. Ils étendent la géographie des rencontres amoureuses et sexuelles mais introduisent aussi un nouveau scénario de mise en couple. Cette nouvelle organisation des rencontres rend difficile la mobilisation du modèle explicatif habituel de l'homogamie, et ce de deux manières. Socialement et spatialement peu ségrégés, les sites suspendent d'abord la médiation des cadres de sociabilité dans la formation des couples. Fréquentés par des personnes socialement hétérogènes, ils semblent ainsi désenclaver l'espace des rencontres amoureuses et sexuelles. Ensuite, l'absence de face-à-face et la communication écrite modifient profondément le mode d'évaluation des partenaires potentiels. Si les sites changent donc les conditions de rencontre, les partenaires qu'ils introduisent restent, eux, proches socialement. L'article montre la manière dont est produite cette homogamie en ligne. L'analyse révèle une auto-sélection sociale produite processuellement au cours de trois étapes : l'évaluation des profils d'utilisateurs, l'échange écrit et la rencontre en face-à-face. À chacun de ces moments interviennent des mécanismes de sélection spécifiques qui donnent lieu, mais par d'autres chemins, à un appariement toujours homogame.
D'un objet d'hommes à une responsabilité de femmes
Authors: Thomé Cécile
Published: January 2017

Résumé Cet article s'intéresse aux rapports de genre qui se jouent aujourd'hui autour de l'usage du préservatif masculin. Il s'appuie sur des entretiens auprès d'hommes et de femmes diplômé·e·s de 20 à 35 ans ayant des rapports hétérosexuels et sur des données quantitatives issues de l'enquête FECOND (2010, Inserm/Ined). L'article revient d'abord sur la diffusion progressive de « l'évidence du préservatif » dans la société française. Il montre ensuite que, dans la majorité des situations, les femmes ont aujourd'hui la charge aussi bien logistique que « mentale » du préservatif. Ainsi, c'est désormais aussi bien la contraception que la protection qui est du ressort féminin. Mais les rapports de genre transparaissent également lorsque l'on s'intéresse à l'utilisation même du préservatif au cours de l'acte sexuel (masculinité technique, féminité sanitaire). Cet objet semble ainsi être un bon révélateur des représentations genrées de la sexualité qui prévalent aujourd'hui encore, ainsi que des doubles injonctions faites aux femmes.
Occurrence of mycotoxins in aquaculture: preliminary overview of Asian and European plant ingredients and finished feeds
Authors: Gonçalves R.A. , Schatzmayr D. , Hofstetter U. , Santos G.A.
Published: January 2017

Concern about mycotoxins in aquaculture has been growing, partly due to the gradual replacement of animal-derived proteins, such as fish meal, by plant sources. Over a period of one year, 2,176 samples of different plant protein sources and 25 samples of finished aquaculture feeds were analysed. Samples were tested for aflatoxins (AF; sum of aflatoxin B1, B2, G1 and G2), zearalenone (ZEA), deoxynivalenol (DON), fumonisins (FB; sum of fumonisin B1 and B2), T-2 toxin and ochratoxin A (full toxin screen). The following plant-based meals were analysed: soybean meal (SBM), wheat (WH), wheat bran (WB), maize (C), corn gluten meal (CGM), cottonseed meal (CSM), rapeseed/canola meal (R/CM) and rice bran (RB). The plant raw materials and aquaculture finished feeds were obtained from Asia and Europe. Finished feed samples from Asia were acquired from Vietnam, Indonesia and Myanmar, while from Europe they were sampled from Denmark, Austria, the Netherlands and Germany. Mycotoxins were found in most of the commodities and finished feeds analysed, showing that mycotoxins represent a risk for the development of the aquaculture sector. Generally, in Asian samples we observed that SBM, WH, WB, C, CGM, R/CM and RB were mostly contaminated withFusarium mycotoxins (ZEA, DON and FB). CSM was contaminated primarily by AF andFusarium toxins (ZEA and DON) at lower concentrations. European samples were contaminated mainly byFusarium mycotoxins. The co-occurrence of mycotoxins in all commodities was high, raising the probability of co-occurrence in finished feeds. An accumulation of mycotoxins on the processed plant-based ingredients (e.g. CGM and WB) was observed when compared to the respective whole grains (C and WH, respectively). Compared to results obtained in 2014, finished feeds presented lower contamination levels, but the co-occurrence risk increased.
Professional Values Competency Evaluation for Students Enrolled in a Concept-Based Curriculum
Authors: Elliott Annette M.
Published: January 2017

Background:

Although many nursing programs have transitioned toward the use of concept-based curricula, the evaluation of student learning associated with the curricular approach has been limited. An evaluation of student learning related to professional values for programs offering concept-based curricula was not evident in the literature. The purpose was to determine how a course competency related to professional values was addressed by nursing students studying in a concept-based nursing curriculum.

Method:

The qualitative methodology of framework analysis was used to evaluate written assignments (
N
= 75).

Results:

The core concept appreciation for professional values and the core concept disillusionment with unprofessional behaviors were identified in students' written reflections.

Conclusion:

The core concept of appreciation for professional values contributes to an evidence base of contemporary professional values identified in nursing. The core concept of disillusionment with unprofessional behaviors can inform curricular planning and research on how to advocate for professional behaviors. [
J Nurs Educ.
2017;56(1):12–21.]
Blending Simulation-Based Learning and Interpretative Pedagogy for Undergraduate Leadership Competency Development
Authors: McPherson Charmaine , MacDonald Cathy
Published: January 2017

Background:

Effective leadership is an essential component guiding nursing activity and influencing health systems, health workers, and patient outcomes. Despite this evidence, undergraduate nursing programs may not be adequately preparing graduates to effectively engage in leadership practice.

Method:

This article describes an educational innovation designed to support prelicensure leadership competency development. The authors blended simulation-based learning (SBL) with an interpretative pedagogical frame in a senior nursing leadership course at a primarily undergraduate university.

Results:

The innovation involves a break from traditional nursing educational pedagogy by bringing SBL into the leadership classroom. Using interpretative pedagogy to purposefully create different relationships in the learning space supported deeper personal and professional transformation for the students.

Conclusion:

Nurse educators must purposefully design leadership curricula using active educational strategies that adequately prepare nurses for complex health systems. Integrating SBL within an interpretative pedagogy for leadership development moves students from merely knowing theory to informed and effective action. [
J Nurs Educ.
2017;56(1):49–54.]
Europa y América. Música litúrgica en ámbito hispánico. La catedral de Las Palmas de Gran Canaria y su maestro de capilla Diego Durón de Ortega (*1653; †1731) Documentación y marcas de agua
Authors: Romero Naranjo Francisco Javier
Published: January 2017

La Capilla Musical de la Catedral de Las Palmas de Gran Canaria posee una historia sumamente interesante al estar compuesta por músicos de diversas nacionalidades y localizarse geográficamente en un lugar estrategico debido a su conexión con el continente americano. Diego Durón de Ortega fue uno de los maestros de Capilla mas representativos y estables que supo afrontar las particularidades de la misma. En esta investigación presentamos una breve documentación sobre la Catedral de Las Palmas de Gran Canaria en relación a la figura de Diego Durón de Ortega y un resumido estudio sobre las marcas de agua de su producción litúrgica conservadas en el archivo de la mencionada catedral.
Proporciones, alegorías, ángeles músicos y ejecución históricamente informada en los órganos de la catedral de México
Authors: Guzmán Bravo José Antonio
Published: January 2017

Análisis estético de las cajas gemelas de los órganos de la Catedral de México. Correspondencia entre las proporciones arquitectónicas del barroco y las proporciones aritmético-musicales pitagóricas. La composición fónica de un retablo sonoro. Los cuerpos de flautados de fachada, los ecos internos, los flautados de nave y la trompetería horizontal. La expresión sonora de las calles, platabandas, cornisas y ventanas de las cajas de cedro y ayacahuite de los órganos de Catedral. Los dorados y rubicundos ángeles en instrumentos mudos. Iconografía organológica. Instrumentos prehispánicos, clásicos grecolatinos, góticos, renacentistas y barrocos; un despliegue enciclopédico. Disposición actual de los registros. Diseños de ambas fachadas.
La composición original de los tubos. Resultado lumínico y cromático. Restauración del brillo original y de los figurones pintados en las bocas de las flautas de fachada.
Documentos en que debe apoyarse toda restauración; mantenimiento y cuidado para que estando en uso no se deteriore. Preservación y promoción del archivo musical de catedral. Función social y sentido cultural al restaurar un instrumento patrimonial único.
Uso litúrgico y académico para preservar y promover la cultura organística.
El instrumento como fuente de investigación; la Ejecución Históricamente Informada (EHI).
Breve estudio y traducción española de Die Kunst das Clavier zu Spielen de Friedrich Wilhelm Marpurg (Berlín, Henning, 1750)
Authors: Pascual León María de las Nieves
Published: January 2017

El presente trabajo supone la primera versión en lengua castellana del tratado de F. W. Marpurg Die Kunst das Clavier zu spielen, que había estado restringido para el lector común de habla hispana desde su primera aparición en 1750. Acompaño esta traducción fi lológica del tratado (en la que se ofrece al lector la versión facsímil de la primera edición del original en páginas enfrentadas frente a la traducción española), de un breve estudio sobre las diversas ediciones de la obra que vieron la luz en vida del autor, se prentende ofrecer una primera aproximación al tratado, facilitando el acceso del gran público a la obra y contribuyendo a su máxima divulgación.
El comercio de partituras en Barcelona entre 1792 y 1834: De Antonio Chueca a Francisco Bernareggi
Authors: Brugarolas Bonet Oriol
Published: January 2017

Los datos que se presentan en este artículo suponen una primera contribución al estudio del comercio de partituras en Barcelona entre 1792 y 1834. Se dan a conocer los lugares donde se podían comprar partituras impresas y manuscritas y las personas relacionadas con ese comercio (libreros, constructores de instrumentos, músicos, copistas y pequeños comerciantes no especializados en música). También se detallan el sistema comercial mediante el cual se realizaba la venta (venta directa, por suscripción, intercambio, alquiler, en lotes, en cuadernos o mediante periódicos musicales), el repertorio y, en algunos casos, el precio de la partitura. La intensidad del comercio de partituras, sobre todo a partir de 1814, una vez acabada la guerra de la Independencia, evidencia el alto desarrollo de la actividad y la cultura musical de Barcelona y demuestra que España formaba parte de una red de distribución de partituras europea.
Rock permittivity characterization and application of electromagnetic mixing models for density/compactness assessment of HMA by means of step‐frequency radar
Authors: Araujo Steven , Delbreilh Laurent , Laguerre Laurent , Dumont Hervé , Dargent Éric , Fauchard Cyrille
Published: January 2017

This work aims to determine the compactness/density of hot mix asphalt by measuring its permittivity by means of step‐frequency radar. As hot mix asphalt (HMA) is mainly made of rocks; their dielectric properties are measured in the frequency range of 0.5 ‐ 4 Ghz with step‐frequency radar, using cylindrical cavities. The results show that the rocks can be considered as low‐loss dielectric. As electromagnetic mixing models are required to translate measured permittivity to the compactness, power law models and unified mixing rules are needed for laboratory experimental data. The slab permittivity of various compactness is determined with the help of the step‐frequency radar system. This study shows that: (i) the selection of the electromagnetic mixing model has a critical impact on the accuracy of the calculated compactness; (ii) the choice of the host matrix for a family of unified mixing rules has huge consequences; and (iii) the best assessment of compactness/density is given by the complex refractive index model and Rayleigh and Böttcher models with an aggregate matrix.
Behaviour and frequency characteristics of acoustic emissions from sandy ground under model pile penetration
Authors: Mao Wuwei , Aoyama Shogo , Goto Shigeru , Towhata Ikuo
Published: January 2017

Acoustic emission (AE) testing is regarded as an effective non‐destructive technique and is capable of detecting micro‐level defects inside a material. In the field of civil engineering, the acoustic emission technique has been widely applied to the studies of steelwork, concrete, and composite materials. However, the geophysical investigations of the application of acoustic emission, dealing with porous granular media, are comparatively limited. In this study, the acoustic emission testing is implemented in a model pile system to investigate subsoil behaviour subjected to pile penetration. The results reveal that the tendency of acoustic emission settlement and load settlement shows high similarity. In addition, the detected acoustic emission signals are studied in the frequency domain using fast Fourier transformation. Higher frequency acoustic emission signals (>100 kHz) are interpreted to be associated with sand particle crushing, which provides a new insight to evaluate the feature of sand grain crushing. Furthermore, the distinction of acoustic emission characteristics observed among different pile penetration sequences demonstrates the effect of ground density on the subsoil behaviour. The results obtained in this paper are beneficial to further clarify the bearing mechanism of pile foundations and also to provide useful information on the fundamental characteristics of acoustic emission signals originating from stressed granular soils, that can be extended to other acoustic emission‐based field investigations.
Spiritualité populaire versus religion bourgeoise
Authors: Peloso Luca
Published: January 2017

Même si Pasolini n’a presque jamais de « solutions » à proposer, la valeur citoyenne et constructive de son activité est présente dans toutes ses œuvres. Sa rébellion, en tant que critique inflexible et systématiquement anticonformiste contre la société, est indissolublement liée à son sentiment du sacré, tout comme à son interprétation du christianisme ; en particulier dans La religione del mio tempo, Il Vangelo secondo Matteo et Teorema. L’aspect religieux fait donc partie intégrante de la lutte pasolinienne pour un autre monde et une autre société.
Penser l’Église catholique avec l’émancipation politique du sous-prolétariat
Authors: Millot Loïc
Published: January 2017

Étroitement liée au pontificat de Jean XXIII et à l’ouverture conciliaire de Vatican II (1962-1965), la réalisation de L’Évangile selon Matthieu (Il Vangelo secondo Matteo, 1964) inaugure une période de conciliation au sein de la filmographie de Pier Paolo Pasolini [Joubert-Laurencin 1995, p. 397]. La carrière du cinéaste était en effet fortement compromise depuis l’« outrage à religion d’État » provoqué par la réalisation de La ricotta (1963). Le rapprochement de Pasolini avec la Pro Civitate Christiana fut déterminant, puisque cette organisation jésuite se porta garante auprès des banques pour assurer les capitaux nécessaires au financement de ce film. En mettant en tension l’analyse filmique avec leur contexte de production et de réception dans le champ catholique, nous examinerons la façon dont Pasolini a donné une inflexion marxiste au récit évangélique dans le but de restituer le drame chrétien aux paysans de l’Italie méridionale. À travers les oppositions de classes qu’il forge dans son film, un enjeu révolutionnaire reposerait stratégiquement sur le sous-prolétariat méridional, idéalement soutenu par une Église de la pauvreté et le parti communiste italien.
A Sleepless Dream
Authors: Kesel Marc De
Published: January 2017

Religion plays a crucial role in the critical dimension of Pasolini’s movies (The Gospel according to St-Matthew, Teorema, Medea, Notes for an African Oresteia, and others). Yet the religion performed there is a thoroughly ‘pagan’ religion, a religion that is itself not critical at all. The question to be raised is why Pasolini does not refer to the ‘monotheistic’ kind of religion, which is critical – and even religion critical – in its core. The article tries to develop an answer to that question by means of patient and profound reflection upon Pasolini’s definition of ‘God’ (in Teorema) as “a dream that allows no sleep and from which one cannot waken”.
Religion contre cinéma
Authors: Paris Antoine
Published: January 2017

En mettant en scène dans La Ricotta le tournage d’un film sur la Passion du Christ, Pier Paolo Pasolini présente une déconstruction du cinéma, dénonçant cet art comme complice d’une société qui assujettit les corps. Cette dénonciation coïncide avec une révélation religieuse : la présence du Christ dans toute chair exploitée.
L’exil, la quête et le refugié
Authors: Paquette Julie
Published: January 2017

In this article we will underline how the inactual work of Pier Paolo Pasolini and his thoughts on the European conscious from the ’50 to the ’70 can be use as a tool for a better understanding of the Refugees Crisis. In order to do so, we will return to the script of Porno-Teo-Kolossal as well as to the poem Ali dagli occhi azzurri. Within this voyage, we will underline the importance of a radical hospitality – with the work of René Schérer on Teorema, as well as the necessity to say no. Finally, we will point out how the refugee can be hear as the one who is revealing the paradox of our epoch (Wendy Brown) and how this situation is asking for the construction of an updated’ solidarity of the oppressed (Walter Benjamin).
Twice Optimized Evaporative Cooling System with Vortex Tube
Authors: Stanescu George
Published: January 2017

A new configuration of a hybrid system for cooling electronics using a Vortex Tube is presented. The optimization of the geometry and functional parameters is based on the assumption that the thermal interaction between the moist air stream and the heat-generating electronic board, and the phase change of liquid water vaporization occurs simultaneously. The first step of this analysis is focused on the optimal geometry of the system, while the second step identifies the Vortex Tube regime that maximizes its coefficient of performance. The cooling below the adiabatic air saturation temperature and the increase of moisture transport explain the high performance of the new device. Our results shed some light on the practical procedure for the optimal configuration of the new system.
Evaluation of the Seasonal Pattern of Wind-Driven Waves on the South-Southeastern Brazilian Shelf
Authors: Oleinik Phelype Haron , Marques Wiliam Correa , Kirinus Eduardo de Paula
Published: January 2017

The focus on renewable energy sources on the last few decades has pushed studies on wave energy availability. In this sense, this study aims to determine annual characteristics of the wave climate on the South-Southeastern Brazilian Shelf (SSBS) to improve the comprehension of the Brazilian wave climate, as well as, to give an insight on the more energetic coastal spots in this area. To accomplish that, the sea state model TOMAWAC was used to simulate 18 years of wave conditions on the SSBS which were later converted to a single year, representative of the Brazilian wave climate. The results showed a strong annual pattern of steadier sea state in summer and spring and a more agitated one in autumn and winter. The results also showed that in the Santa Marta cape, the seasonal wave power oscillates between 8 and 11 kW/m, and at Ilhabela, between 7 and 11 kW/m. At the Farol island, on the other hand, the seasonal wave power varies around 11 and 19 kW/m, yielding much more energy but, at the cost of an extremely higher variation throughout the year.
Thermal Fatigue Analysis in a High Pressure Cooling System (HPCS) Nozzle of a Boling Water Reactor
Authors: Hernández-Gómez Luis Héctor , Pérez-Escobar Brayan Leonardo , Beltrán-Fernández Juan Alfonso , Flores-Campos Juan Alejandro , Pérez-Montejo Salatiel , Jiménez-Santiago Krisselby Ivonne , Ruiz-López Pablo , Urriolagoitia-Calderón Guillermo Manuel
Published: January 2017

In this paper, the Cumulative Usage Factor (CUF) of a High Pressure Core Cooling System (HPCS) reactor nozzle of a Boiling Water Reactor was calculated. This fatigue damage has been caused by the sudden injection of cold water into the reactor vessel through such nozzle. For this purpose, a three-dimensional analysis was carried out. Accordingly, a transient heat transfer analysis was developed. The temperature distribution was determined. With this information, the stress analysis was carried out. The safe end was restricted to move along its axial direction and the forging end was free to expand axially and radially. The resultant stress field established the magnitude of the alternative stresses. In the last step, a fatigue analysis was developed. The most critical point is the junction of the nozzle with the thermal sleeve. The fatigue performance was evaluated during a period of sixty years. It was assumed that 1.5 cycles per year will take place. The fatigue curves of ASME code section III were used. The results showed that the Cumulative Usage Factor (CUF) vary with the temperature injection, being 0.4090 when the water injected was 4.44°C and 0.3797 when the water temperature was 37.77°C. Both of them were estimated for a period of 60 years of operation. Therefore, damage is reduced as the temperature of the injected water increases. Besides, it is advisable to at least follow the recommendations of the NUREG ́s 1800 and 1801 [1, 2]. In this way, the aging of the nozzle is adequately managed.
Experiments on Dissimilar Valve Lift (DVL) for Turbulence Increment on a Bi-Fuel Compressed Natural Gas (CNG) Engine
Authors: Ramasamy D. , Kadirgama K. , Noor M.M. , Rahman M.M.
Published: January 2017

Current engines are readily available for CNG bi-fuel conversions because it requires only minor engine modifications. However, CNG flame speed is lower than gasoline, therefore reducing the power and range of the vehicle when operating on CNG. This situation can be improved by increasing the flame speed via higher turbulence generated by swirl motion. A computational fluid dynamics (CFD) model was used to analyse the swirl generated by dissimilar valve lift (DVL) profiles on the intake valve. A 3D engine simulation shows differences in swirl motion and turbulence between the original symmetric valve lift profile and the DVL. The swirl before combustion was found to increase almost 25%. The higher swirl number can increase the turbulence kinetic energy (TKE) level which improves better fuel mixing. The 1 mm DVL proved to be the better choice from CFD analysis and later was tested on a K3-VE engine. Pressure analysis shows peak pressure increased by 5.6% and burn rate shows CNG had a slower burning speed on the small engine
Effects of Longitudinal Alignments on the Time-Mean Flow Structures of Side-by-Side Circular Cylinders of Diameter Ratio Two
Authors: Tseng Sheng Yung , Hsu Shang Wen , Kuo Cheng Hsiung
Published: January 2017

The time-averaged flow characteristics in the regions upstream and downstream of the side-by-side cylinders of diameter ratio two, arranged at different longitudinal alignments and two gap ratios, are studied via particle image velocimetry (PIV). It is found that the locations of forward stagnation point of the large and the small cylinders do change with the longitudinal alignments. Upstream of the large cylinder, the streamwise variations of U* are nearly independent of the longitudinal alignment for both T*=1.5 and 1.0. However, upstream of the small cylinder, the streamwise variations of U* indeed depend on T*. Upstream of the small cylinder, the streamwise variations of V* are strongly affected by T* and, the largest magnitude of V* occurs at CLA for both T*=1.5 and T*=1.0. Also, the locations of the largest magnitude of V* move closer to the small cylinder as the T* reduces. For different T* and L*, the flow rate (or the averaged velocity through the gap) and the gap orientation will be changed at the same Reynolds number (Re=1000). The effect of pressure difference across the gap may be overwhelmed or be counterbalanced by that of the gap orientation leading to quite different flow structures in the downstream region of the cylinder couples. The effects of longitudinal alignment are to (1) change the forward stagnation points of the large and the small cylinders; (2) modify the region of mutual interaction between two wakes. (3) As S* reduces, the gap orientation takes the dominance over the pressure difference across the gap to switch the gap flow so that the wide-wake is formed behind the small cylinder especially for T*=1.0 and TEA.
Optimized Pressure Determined in Accordance with Variable Plunger Stroke of Internal Injector NGV
Authors: Kim Kwon Se , Choi Doo Seuk
Published: January 2017

Using an analytical model, a clear investigation was performed into the phenomenon of decreasing overall pressure and velocity of a plunger when its stroke within a natural gas injector changes. The results indicated the following mesh sizes from the mesh matrix: 0.0005 mm minimum, 12.7 mm maximum, 1,107,420 nodes, and 5,856,567 elements. Consequently, the pressure was affected by the stroke height from the designed plunger shape, and although the height of the plunger stroke changes over 0.150 mm, the absence of the phenomenon of pressure drop was noticeable.
Dynamic Phenomena in Laser Processing - The Generation of the Surface Heat-Spot in the Sheet High-Speed Cutting with the Fiber Laser and Change of the Heating Domain
Authors: Arai Takeji
Published: January 2017

A laser beam with a fixed diameter emitted from an oscillator acts as a heat-spot (or hot-spot by the heat source) on the surface of the material that irradiates. The shape of the heat-spot on the material has been treated as constant for a long time, regardless of the speed of the material to be processed. In fact, on the surface of the material the light and the material mutually act on each other, so the shape of the heat-spot which appears on the surface many vary depending on the processing speed. In order to confirm this, an experiment was performed using infrared sensors sheet, and using a galvanized steel sheet. The experiment confirmed that the shape of the heat-spot on the material surface depends on the processing speed. The decreasing ratio of deformation with respect to the speed was determined, and it was applied to high-speed cutting processing with a fiber laser. We also studied the rate of change of the preheating-area and the removal-area in the heat-spot which is an important domain when performing high-speed cutting.
Measuring the Thermal Characteristics of Concretes Exposed to Extreme Conditions
Authors: Kušnerová Milena , Kopal Ivan , Václavík Vojtěch , Gola Lukáš , Dvorský Tomáš , Valíček Jan , Harničárová Marta , Šimíček Vojtěch
Published: January 2017

This article presents the results of an experimental research dealing with the measurement of the thermal characteristics of concretes based on natural and artificial aggregates (steel slag). The samples of concrete composites were prepared on the basis of natural aggregate fractions 0/4, 4/8 and 8/16 mm and on the basis of steel slag fr. 4/8 mm. The volume ratio of the individual aggregate fractions in all experimental mixtures used for the production of concrete composites was 40:30:30 (fr. 0/4: 4/8: 8/16). The prepared samples of concrete composites based on natural aggregate and natural aggregate combined with steel slag were subjected to the tests of strength characteristics, water-tightness, thermal characteristics using a commercial device ISOMET 2104 (measurement of the coefficient of thermal conductivity λ, specific heat capacity c, and the coefficient of thermal diffusivity a), and heating in a prototype calorimetric computer-controlled chamber. The main attention was focused on the testing of the value changes of the coefficients of thermal conductivity λ depending on the changes of temperatures within the range of -5 °C to + 40 °C. The measurements of these thermal characteristics have very high informative value, especially because these material parameters are not tabulated for the newly designed building materials, and that is why they are not examined at extreme temperatures. This is a reason why they cannot be used as important data during the thermal calculations of a non-insulated concrete structure (e.g. using polystyrene and / or glass wool).
Analysis of Physical-Mechanical and Surface Properties of Wood Plastic Composite Materials to Determine the Energy Balance
Authors: Harničárová Marta , Mitaľová Zuzana , Kušnerová Milena , Valíček Jan , Mitaľ Dušan , Kopal Ivan , Václavík Vojtěch
Published: January 2017

Wood plastic composite (WPC) materials represent modern materials that are attracting interest worldwide. WPC are composite materials and they have properties of both components – plastic and wood. WPC materials are formed by combining two substances – discontinuous reinforcements (wood particles or cellulose microfibers) and a continuous binder (plastic matrix), in a certain proportion. The authors describe WPC machined surfaces after turning. On the basis of a set of experimental data collected by surface and mechanical tests obtained from the WPC materials, the mechanical deformation work was evaluated, the value of which presents specific information about the material as a specific material coefficient.
Research on the Foamed Concrete with High Volume Fly Ash
Authors: Chu Hui Chao , Lyu Xian Jun , Zhang Yan
Published: January 2017

A study has been undertaken to investigate the effects, on the properties of foamed concrete, of replacing large volumes of cement with fly ash. This paper reports the results of the properties of foamed concrete and shows that up to 55% of the cement could be replaced without any significant reduction in compressive strength. Foamed concrete with 55% fly ash and good performance were obtained by optimizing the process parameters. The results showed that the compressive strength, dry density, water absorption and thermal conductivity of foamed concrete with 55% fly ash were 0.71MPa, 244kg/m3, 33%, and 0.045 W/mK respectively.
Influence of Physical Strengthening Technology on the Properties of Recycled Coarse Aggregate
Authors: Yue Gong Bing , Li Qiu Yi , Song Gao
Published: January 2017

This paper studied the properties improvement of recycled coarse aggregate by the physical strengthening technology (particle-shaping method). Through the analysis for obtained properties which consist of density, crush index, bulk density and water absorption. etc of recycled coarse aggregates in different strengthening technologies, the categories of recycled coarse aggregate could be assessed and determined. The results showed that ordinary recycled coarse aggregates that was handled twice by using particle shaping equipment can achieve the standard of class Iaggregates and its water absorption ratio at 24h was 1.2%, the apparent density reached 2575kg/m3, crush index value was 9%, the void ratio was 45%, all property parameters were close to those of natural coarse aggregate.
Research Status and Development Trend of High Sand Filling Materials
Authors: Liu Yong , Chen Jie
Published: January 2017

The coal is main energy in our country, it takes many economy and environment problems in the process of exploitation process.With the development of large-scale mining area, mining of rock fracture field and the change of the terrain, vegetation and ecological environmental impact of surface water, ground seriously. This paper introduces about goaf paste filling mining which is the important part of coal green mining technology, it is an effective method to solve subsidence and the problem of coal mining surface ecological environment. Occurrence of aeolian sand and flexible strip filling control effect on the stability of water-resisting layer create conditions for the development of the local water filling mining.The paste filling material prepared with cemented Filling materials has the advantages of low cost and environment protection, which can take the various benefits such as economy, society and environment to diggings.
Numerical Study on the Impact of Cooling Rate on the Solidification of Al-Bi Hypermonotectic Alloys
Authors: Kang Zhi Qiang , Yang Xue , Feng Guo Hui , Zhang Lin
Published: January 2017

A numerical model describing the liquid-liquid phase transformation of the nucleation, the diffusional growth, Ostwald coarsening and macro-transport phenomena was established based on Euler-Euler method. The microstructure development of Al-Bi alloys in different solidification rate has been simulated by coupling the calculated temperature and velocity fields with the kinetic equation which controls the microstructure evolution. The results showed that average diameter difference of L2 phase droplets between top and bottom of samples in low cooling rate increased by 151 % than in high cooling speed and the maximum volume fraction of the droplets at the bottom of the sample in low cooling rate much higher than in high cooling rate. Analysis that the bigger cooling rate can shorten the action time which caused by gravity settling and collisions coagulation of the droplets, and then improves the macrosegregation of solidification structure in favor of uniform distribution of the solidification structure.
Effect of Ti Content on Microwave Absorbing Properties of Nd-Fe Alloys
Authors: Luo Jia Liang , Pan Shun Kang , Wang Zhen Zhong , Qiao Zi Qiang , Cheng Li Chun
Published: January 2017

The Nd7.69Fe92.31-xTix (x = 0, 4, 8, 12) alloy were prepared by arc smelting and high energy ball milling method. The morphology and phase structure of the powders were analyzed by Scanning Electron Microscope (SEM), X-ray diffraction (XRD) and the effect of the Ti content on microwave absorbing properties of the powders were measured by a vector network analyzer (VNA). The results reveal that the samples mainly consisted of Nd2Fe17 and α-Fe crystal structure. The minimum absorption peak frequency shifts to lower frequency region firstly and then shifts to higher frequency region with the increasing amount of Ti content. The minimum reflection loss of Nd7.69Fe84.31Ti8 powder is-31.35 dB and the bandwidth of R < -5 dB reach 3.6 GHz when the coating thickness is 2.0 mm. With the increasing of the coating thickness, the minimum reflectivity peak value of the Nd7.69Fe84.31Ti8 moves to lower frequency region and the minimum reflection loss increase firstly and then decrease. And the minimum reflection value of Nd7.69Fe84.31Ti8 alloy can reach to-38.74 dB (microwave absorption rate 99.99%) at 5.68 GHz, and the bandwidth of R < -10 dB reach 1.12 GHz with the best matching thickness of 2.2 mm.
Numerical Simulation of Stress Distribution of AZ31B Magnesium Alloy/LY12 Aluminum Alloy Diffusion Welded Joint
Authors: Kong Ling Ming , Du Shuang Ming , Xia Yu Jie , Li Jun Hui
Published: January 2017

The finite element model of diffusion bonding was established based on the analysis software of ANSYS, and the stress distribution characteristics of AZ31B/LY12 vacuum diffusion welded joint using Cu foil as the intermediate layer were analyzed. The effects of three factors, the welding temperature, the thickness of the intermediate layer Cu foil and the welding pressure, on the stress distribution of the AZ31B/Cu/LY12 joint were studied. The simulation results show that, when diffusion bonding of AZ31B and LY12 with intermediate layer Cu, the stress located on the center area of joint distribution is uniform, while the edge stress value is larger; welding parts along the axial stress distribution does not change significantly, while the maximum axial stress increases slightly when the temperature increases from 520 to 540 °C; when the thickness of intermediate layer Cu foil changes from 50 to 100 μm, the maximum shear stress value increases, while the position of that has no significant change; The stress distribution does not change, while the region of high stress increases when the welding pressure changes from 1 to 3 MPa.
In Situ Investigations of Structures Evolution of Mg Doped Zn4Sb3
Authors: Wang Yu , Li Hong , Yang Ying Guo , Ji Geng Wu , Shen Kong Chao , Sun Hao Liang , Li Jiong , Jiang Zheng , Song Fei
Published: January 2017

The beta-phase of Zn4Sb3 has been regarded as a very promising thermoelectric material since middle nineties, owing to its unique merit: intermediate temperature region (200-400 °C), made of cheap, non-toxic and abundant elements and high thermoelectric property. However, the thermal stability of Zn4Sb3 seems to be an inherent obstacle for the practical application during the working temperatures. Herein, magnesium doped Zn-Sb semiconductor (Mg0.04Zn3.96Sb3) was investigated thoroughly in-situ during thermal annealing up to 600 K, whilst both microstructure and electronic structures were recorded via the combination of synchrotron-based two dimensional X-ray diffraction techniques and the X-ray photoemission spectroscopy. While the time-resolved grazing incidence XRD reveals the preserved crystal structures during thermal annealing to 600 K, XPS measurement demonstrate the robustness of electronic structures. On basis of these findings, it was concluded in the end that the doping of magnesium significantly improves the thermal stability of zinc-antimonite compounds and introduces minor influence on the electronic structure of Zn-Sb alloy. Our study may propose an effective approach towards the wild application of Zn4Sb3 related thermoelectric materials.
Structure and Performances of 7075 Aluminum Alloy Surface Subject to Hot-Dip Zinc
Authors: Xu Na , Qiao Xiao Yang , Yang Xu , Li Yong Cun , Li Hai Zhi , Tong Wei Ping
Published: January 2017

The hot-dip galvanized coating was produced on the 7075 aluminum alloy plate by immersion in a pure zinc bath at different temperature from 440°C to 470°C for different modification time (between 1 min and 10 min). The hot-dip galvanized of the treated and un-treated samples were investigated by using scanning electron microscopy (SEM) with EDX analysis, X-ray diffraction (XRD), hardness measurements and potentiodynamic polarization curves. There were three layers fabricated on the 7075 substrate surface, specifically, zinc-rich layer, two-phase mixed layer Al-Zn and interdiffusion layer. Moreover, the 7075 aluminum alloy with the hot-dip galvanized coating exhibit higher hardness and better anti-corrosion properties in comparison with the 7075 substrate.
Thermal Analysis Kinetics of Pd-Doped SiO2 Organic-Inorganic Hybrid Material
Authors: Yang Jing , Li Hong Jun , Mu Rui Hua , Zhao Ya Mei , Tong Zhi
Published: January 2017

Pd-doped SiO2 organic-inorganic hybrid material (Pd/M-SiO2) was prepared by sol-gel method and characterized by XRD, FTIR spectra and TG/DTG analysis. The most probable kinetic mechanism function, apparent activation energy and pre-exponential factor of the thermal decomposition for Pd/M-SiO2 material were calculated using the combined Coast-Redfern intergral and Αchar differential methods. Pd element in noncalcined Pd/M-SiO2 materials exists in PdCl2 form. FTIR spectroscopy confirmed the existence of hydrophobic Si−CH3 groups. The thermal decomposition process of Pd/M-SiO2 materials can be divided into four stages, with different mechanism functions. The activation energies are 76.37, 146.85, 208.90 and 413.89 kJ·mol−1 for the four stages, respectively, and the pre-exponential factors are 5.04×1012, 7.14×1013, 2.93×1012 and 6.56×1019 s−1, respectively. There is no obvious influence of the existence of metallic Pd0 on the thermal decomposition of methyl.
The Tight-Binding Calculation Research of the Silicene Structure
Authors: Song Gen Zong , Zhang Lin
Published: January 2017

Silicene is a single atomic layer of silicon thin film structure, its structure is similar to the graphene, the hexagonal lattice structure with pleats. In recent years it has aroused widespread concern because of its unique physical properties. In this paper, use the tight-binding method (DFTB) of density functional theory calculation of the variation of silicene structure and structural changes in the bond lengths and bond angles. The results show that for small sized silicene its structure is unstable and relatively large changes. With the increase of the size of silicene, the structure tends to be stable and some structures appear symmetric. When the difference between the X coordinate values of the left and right borders silicene initial structure reaches 38 Å, the structure is completely symmetrical on both sides.
Effect of Heat Treatment on Microstructural Evolution of 13Cr Martensitic Stainless Steel
Authors: Ma Hou Yu , He Yin Sheng , Lee Kwon Yeong , Shin Kee Sam
Published: January 2017

13Cr martensitic stainless steels are widely used in gas industry, which are usually manufactured by quenching-tempering treatment. Microstructural study of 13Cr steel through various heat treatments was carried out for determining the optimum parameters for industry manufacture. After quenching treatment at 975 °C for 20 min, precipitation-free martensitic structures were formed. During tempering, recovery of martensite through grain boundaries migration and dislocations annihilation was found to soften the steel. In addition, transformation of needle-like Cr7C3 carbides to the irregular shaped Cr23C6 carbides was observed when tempering temperature is above 710 °C. The phase transformation induced precipitation strengthening is discussed. The optimum heat treatment parameters of 13Cr steel for avoiding over tempering and the precipitation hardening are found.
Preparation and Optical Properties Research on Graphene Quantum Dots
Authors: Shang Yu Dong , Chen Xiu Hua , Ma Wen Hui , Li Shao Yuan , Wang Yue Chun , Xiang Fu Wei
Published: January 2017

In this work, graphene quantum dots were simply and rapidly prepared by thermal decomposition of citric acid. The resulting graphene quantum dots shows good dispersion and high crystallinity, the sizes can be effectively adjusted by controlling the temperature of decomposition. The results indicate that with the increase of temperature, the size of GQDs increased from 2 nm to 12 nm. The effect of the size of graphene quantum dots on the optical properties were carefully studied. Based on the optical properties and electrochemical results, the HOMO and LUMO value of GQDs with different sizes were obtained and the band gap becomes smaller from 3.36 eV to 2.87 eV with the increase of size of GQDs, which provides a potential application in the field of optoelectronic devices.
Preparation and Properties of β/α SiC Composite Ceramics
Authors: Cheng Xu , Wang Xiao Gang
Published: January 2017

In this paper, the production of high-performance β/α SiC composite ceramics technology as the goal, by measuring density, we can optimize and determine the best technical ceramic formulations. Because a small amount of β-SiC in α-SiC,the sintered ceramic appeared long axis-like crystals, indicating fracture mode changes from the original transgranular fracture to transgranular fracture mainly and intergranular fracture supplement. The results show that, when added in an amount of 10% β-SiC, SiC ceramics having the best performance.
A Facial Route for Preparation of Hydrophobic Nano-Silica Modified by Silane Coupling Agents
Authors: Luo Jian Hui , Li Yuan Yang , Wang Ping Mei , Xia Bi Bo , He Li Peng , Yang Bo Wen , Jiang Bo
Published: January 2017

Nano-silica was prepared using tetraethylorthosilicate (TEOS) as precursor by sol-gel technology based on stÖber method. These silica nanoparticals were further modified with silane coupling agents, i.e., Hexadecyltrimethoxysilane (HDTMS), dimethoxydiphenylsilane (DMMPS), to introduce organic functional groups on the surface of SiO2 nanoparticles. The Fourier transform-infrared (FTIR) spectra indicated that these silane coupling agents were anchored on the surface of silica particles. And the obtained organic–inorganic hybrid SiO2 particles showed an improvement in hydrophobicity, which can effectively inhibit these silica particles from aggregating.
Microstructural Evolution of Super304H Steel upon Long-Term Aging
Authors: Nam Kyeon Gae , He Yin Sheng , Chang Jung Chel , Shin Kee Sam
Published: January 2017

The Nb-stabilized and Cu-strengthened austenitic stainless steel Super304H was aged at 600~700°C up to 20,000 hrs. Scanning electron microscope (SEM), and transmission electron microscope (TEM) were used to study the effect of aging on the microstructural evolution of the specimen, with focus on the precipitation behavior in relation to the temperature and time. Only NbCs in size range 2 μm ~ 50 nm were observed to be scarcely distributed in matrix in the as-received specimen. Upon aging, precipitation of σ-phase (~5 μm) and Cr-rich M23C6 (~1 μm) along grain boundary, and nanosized Cu precipitates (~65 nm) in the grain interior were formed. The size and fraction of the σ-phase and M23C6 increased with the increase of aging temperature and/or aging time, with higher sensitivity to the temperature. The size of Cu precipitates was relatively stable, while the fraction and number density increased with the aging temperature/time. The microhardness upon aging increased with increase of aging temperature/time, due to the precipitation of the nanosized Cu precipitates.
Density Functional Study on the Configurations of Nen (n=2~36) Clusters
Authors: Peng Chang Ning , Zheng Xing Rong
Published: January 2017

Based on the First-principles and the method of quantum chemistry calculations, using the B3LYP method and 6-31G basis set of the density functional theory (DFT), the configurations and binding energy of Nen (n=2~36) clusters are calculated and studied theoretically after the calculation of geometry optimization. By changing the atomic number n of the Nen (n=2~36) clusters, it obtained that the stable structures, the binding energy and HOMO - LUMO energy gap of the Nen (n=2~36) clusters under the same ideal conditions, and summarizes the change rule of the stable configurations, the binding energy and the average bond length of the Nen (n=2~36) clusters.
Synthesis and Characterization of Nd-Doped ZSM-5 Zeolite from Diatom Mud
Authors: Cheng Yue , He Lin
Published: January 2017

ZSM-5 zeolite was synthesized using diatom mud as the raw material, and then doped with different amounts of Nd2O3. Nd/ ZSM-5 zeolite was synthesized at °C for 24 h after stirring at high speed and aging in the synthesis mixture with the molar composition of 1.5 Nd2O3:25Na2O:150SiO2:1Al2O3:10TPABr:2500H2O.XRD confirmed Nd/ZSM-5 crystal phase. TEM showed that Nd/ZSM-5 zeolite crystal sizes are about 2-4μm. EDS shows Nd/ ZSM-5 zeolites chemical element compound. FT-IR analysis further showed that they are pentacyclic with typical absorption summit of ZSM-5 at about 547 cm-1.