bluuebunny/crossref_metadata_2025 huggingface dataset:
Les journalistes des télévisions privées algériennes en 2015 : Nouvelles figures, nouvelles pratiques
Authors: Bouchaala Nabila Aldjia
Published: January 2017

Cet article interroge les conditions socioprofessionnelles des journalistes de l’audiovisuel privé en Algérie à l’aune des représentations qu’ils font de leurs pratiques professionnelles et à la lumière du développement que fait Bourdieu de la notion de champ journalistique. L’enquête menée auprès d’une vingtaine de journalistes, appartenant à six entreprises médiatiques, entendait situer leurs pratiques dans le contexte d’apparitions de ces chaînes de télévisions, si bien que l’objectif qui a sous-tendu ce travail est de comprendre la nouvelle configuration du paysage de l’audiovisuel et de voir le rôle conduit par les journalistes dans sa définition.
Effect of Temperature on Conductivity Performance of PEO-NaI Based Polymer Electrolytes
Authors: Muhammad F.H. , Saaid F.I. , Razamin N.A.Y. , Winie Tan
Published: January 2017

The polymer electrolyte composed of poly (ethylene oxide) (PEO) and sodium iodide (NaI) as dopant salt was prepared by using solution casting method. Effect of temperature on the conductivity performance was studied by impedance spectroscopy in the temperature range of 303 to 343K. The linear variation of conductivity with temperature suggests the Arrhenius type thermally activated process. The effect of temperature on the conductivity is discussed on the basis of number, n, mobility, μ and diffusion coefficient, D of free ions. In this paper, n, μ and D were determined using impedance spectroscopy method.
Pyrolysis Behaviour of Boron Phenolic Resin-Based Ceramicable Composites by Introducing of MgO-Al2O3-SiO2
Authors: Shi Min Xian , Fan Shan Shan , Luo Wen , Huang Zhi Xiong
Published: January 2017

Ceramifying composites based on boron phenolic resin (BPF) were prepared with the modification additives of nanoMgO-Al2O3-SiO2 (MAS). The effects of fillers on the thermal stability of BPF-based composites were investigated. MAS inorganic fillers could enhance the heat-resistance with a high residue yield and a near-net shape at elevated temperature. The effect of elevated temperature on microstructure and phase composition of composites was also characterized by scanning electron microscope (SEM) and X-ray diffraction analyses (XRD) when samples were heated at 600°C, 800°C, 1000°C and 1200°C respectively. SEM showed the presence of the skin and compact ceramic structure formation, more pronounced at higher temperature. XRD patterns manifested that the formation of new phases (main glass phase) in 1200°C stemmed mainly from the reaction between the porous activated carbon from the decomposed resin matrix and MAS fillers.
Preparation and Properties of Ethylene Propylene Diene Rubber/SiO2/Carbon Nanotubes Composites
Authors: Su Jun , Li Cai Hong
Published: January 2017

This paper studies how the addition of Carbon nanotubes (CNT) influencing the properties, especially the mechanical properties and colorimetry of ethylene propylene diene rubber (EPDM)/SiO2 composites. The results show that the increased content of CNT can turn EPDM/SiO2 composites from lighter, redder, and yellower to darker, greener and bluer, respectively. The total color change (ΔE) of EPDM/SiO2 composites would be acceptable when the CNT content is below 3%. When the CNTs content reaches 4%, the tensile strength of EPDM is the maximum.
Intercalation of Fenoprofen into Layered Double Hydroxide for the Formation of Controlled Release Anti-Inflammatory Drug
Authors: Sarijo Siti Halimah , Jadam Monica Limau , Md Saleh Faizah
Published: January 2017

Synthesis of a new hybrid nanocomposite materials, zinc-aluminium-fenoprofen, ZAF was successfully accomplished by self-assembly method with molar ratio of Zn to Al; R=2 at concentration of fenoprofen=0.3 M. As a result of the successful intercalation, the interlayer spacing expanded from 9.8 Å in the zinc-aluminium-layered double hydroxide, ZAL to 20.1 Å in the ZAF hybrid nanocomposite. The FTIR spectra of the ZAF show resemblance peaks of ZAL and fenoprofen indicating the inclusion of the organic compound into the LDH interlamellae. The percentage loading of the guest anion, fenoprofen in ZAL was estimated to be about 63.4% (w/w) calculated from the carbon content.
Cutting Performance of Fiber Laser Textured Tools in Face Milling of Titanium Alloys
Authors: WU Ze , Xing You Qiang , Huang Peng
Published: January 2017

Textured self-lubricating tools were fabricated by fiber laser machining. Dry milling of titanium alloys was carried out with these textured tools and conventional one for comparison. The cutting forces, cutting temperature, surface roughness of processed workpiece and tool flank wear were measured. Results show that the textured tools can reduce the cutting forces, cutting temperature and surface roughness of workpiece, as a result, present superior wear-resistance compared to the untextured tool.
Machining of SiCp/Al Composites: Effect of Tool Corner Radius on Residual Stresses, Cutting Force and Temperature
Authors: Tang De Weng , Zhang Wen Ming , Zhao Rui Lan , Lv Xi Jian
Published: January 2017

SiCp/Al composite is widely used in the aerospace, electronics and automobile industries due to its ultrahigh strength and wear resistance. Surface integrity in the machining process can be influenced by tool corner radius. A finite element model is developed by DEFORM-2D to study on the effect of tool corner radius on residual stresses, cutting force and temperature in machining SiCp/Al composite process. The results show the large corner radius can improve cutting force, but hardly influence cutting temperature. Meanwhile, value of residual stresses is influenced by tool corner radius, but distribution of residual stress is not. The larger corner radius is, the greater the curve fluctuation of residual stresses is. And the large tool corner radius can effectively improve surface residual compressive stress.
Stabilization of Cd in Ore Soil Using Modified Red Mud Materials
Authors: Luo Hui Li , Zhu Qing , Zhou Ying , Liu Zi Lin , Ou Wei Qi
Published: January 2017

Modifications of red mud for activating available silicon (Si) by phosphates were carried on in this paper. And then the modified red mud materials were used to stabilize Cd in an ore soil. Results indicated that phosphates efficiently increase the content of available Si in red mud. In the stabilization, exchange Cd was decreased by 90.97% when using 5% potassium dihydrogen phosphate modified red mud, which was better than using raw re mud as the decrease was 77.08%. In rice pot soil, increases of residue Cd were positively correlated with the increases of available Si (P<0.05, R=0.9965). Contents of Cd in root increased 53.87% while it in rice decreased 24.17% by adding 3% modified red mud.
Extended Constitutive Model for FRP-Confined Concrete in Circular Sections
Authors: Gholampour Aliakbar , Ozbakkloglu Togay
Published: January 2017

This study presents an extended finite element (FE) model based on concrete damage-plasticity approach for fiber-reinforced polymer (FRP)-confined normal-strength and high-strength concrete (NSC and HSC). The proposed model is based on Lubliner’s model and it accurately incorporates the effects of confinement level, concrete strength, and nonlinear dilation behavior. Failure surface and flow rule were established using an up-to-date database. In order to validate the extended damage-plasticity model, finite element (FE) model is developed for specimens under a wide range of confining pressures. The results indicate that the model predictions of FRP-confined NSC and HSC are in good agreement with the experimental results.
Magnetic Properties and Magnetocaloric Effect of Nd0.7Gd0.3Mn2Si2 Alloy
Authors: Lin Shi Dong , Chen Xiao Long , Wang Jiang , Zhu Chao Fan , Rong Mao Hua , Rao Guang Hui , Zhou Huai Ying
Published: January 2017

In this work, crystal structure, magnetic properties and magnetocaloric effect of Nd0.7Gd0.3Mn2Si2 alloy were studied by X-ray diffraction (XRD), Physical Property Measurement System (PPMS) and Differential Scanning Calorimetry (DSC). Nd0.7Gd0.3Mn2Si2 crystallizes in ThCr2Si2-typed structure with space group I4/mmm, in which the Nd, Gd, Mn and Si atoms occupy 2a (0, 0, 0), 2a (0, 0, 0), 4d (0, 1/2, 1/4) and 4e (0, 0, 0.38261) position, respectively. The Curie temperature (Tc) of Nd0.7Gd0.3Mn2Si2 alloy is 42 K, while the spin reorientation temperature (TSR) is 26 K and the Nel temperature (TN) is 410 K. The Tc and TN were determined using PPMS and DSC, respectively. The maximum value of the magnetic entropy change (-Smax) in the field change of 0-5 T is 11.862 J/kg K, while the value of relative cooling power (RCP) in Nd0.7Gd0.3Mn2Si2 alloy is 69.666 J/kg under the field change of 5 T.
Tin Selenide Quantum Dots Electrochemical Biotransducer for the Determination of Indinavir - A Protease Inhibitor Anti-Retroviral Drug
Authors: Feleni Usisipho , Ajayi Rachel Fanelwa , Jijana Abongile , Sidwaba Unathi , Douman Samantha , Baker Priscilla , Iwuoha Emmanuel
Published: January 2017

Biocompatibility of tin selenide quantum dots was achieved by the incorporation of 3-mercaptopropionic acid (3-MPA) as a capping agent, which also improved the stability and the solubility of the material. The UV-Vis spectrophotometric analysis of the quantum dots revealed a broad absorption band at ~ 330 nm (with a corresponding band gap, Eg, value of 3.75 eV), which is within the range of values expected for quantum dots materials. The 3-mercaptopropionic acid-capped tin selenide (3-MPA-SnSe) quantum dots were used to develop an electrochemical biosensor for indinavir, which is a protease inhibitor antiretroviral (ARV) drug. The biosensor was prepared by the self-assembly of L-cysteine on a gold electrode that was functionalised with 3-MPA-SnSe quantum dots, followed by cross-linking with cytochrome P450-3A4 (CYP3A4) using 1-ethyl-3(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). The electrocatalytic properties of the biosensor included a characteristic cyclic voltammetric reduction peak at-380 mV, which was used to detect the response of the biosensor to indinavir. The sensor performance parameters included response time and limit of detection (LOD) values of 11 s and 3.22 pg/mL, respectively. The test concentration range studied (0.014 – 0.066 ng/mL) gave a linear calibration plot for indinavir, and it was lower than the physiological plasma concentration index (i.e. maximum plasma concentrations, Cmax,) of indinavir (5 - 15 ng/mL) normally observed 8 h after intake. This indicates that the biosensor can be very useful in the case of ultra-rapid metabolisers where very low Cmax values are expected
Fabrication of PMMA Membranes with Nano-Pillars Array Using Template/Spin-Coating Method
Authors: Liu Hao , Zhu Li Li , Xu Yan Fang , Jie Xu , Cheng Bo Wen
Published: January 2017

Template/spin-coating method was presented for fabricating single-layer nano-pillar array polymethylmethacrylate (SL-PMMA) and double-layer nano-pillar array polymethylmethacrylate (DL-PMMA) membranes. The different mass ratio of PMMA/DiMethyl Formamide (DMF) solution was dripped on single-layer porous anodic alumina (SL-PAA) or double-layer porous anodic alumina (DL-PAA) membrane and spun at 4000rpm speed for 30 seconds. The SL-PAA and DL-PAA membranes had been put into vacuum oven at 150°C for 2 hours, before SL-PMMA and DL-PMMA were removed. Experimental results show that the regularity degree of PAA fabricated in OAS/PAS is higher than that of PAA fabricated in PAS by two-step anodization method. The ordered pores and clear double-layer outline can be observed from the surface and cross-section FESEM images of DL-PAA membranes. When the content of PMMA in mixture solution is 20 wt%, the top shape of nano-pillars is convex, because the solution was completely filled in the pore of SL-PAA, and the length of nano-pillars is equal to the height of pore of PAA. However, the top pore amount on nano-pillars at ascending speed 20°C per minute is more than that of at ascending speed 10°C per minute. The PMMA membranes with ordered mid-hollow and porous nano-pillars will have wide application prospect in biosensors, chemical sensors, microcapsules fabrication fields due to many advantages such as simple operation, low cost, high specific surface area, etc.
Measurement for Elastic Modulus of Ultra-Thin Glass by Cantilever Beam Method
Authors: Liu Xiao Gen , Bao Yi Wang , Wan De Tian
Published: January 2017

In order to overcome the limitations of common methods for measuring elastic modulus of the ultra-thin glass，a novel method is proposed for measuring the elastic modulus of the ultra-thin glass by cantilever beam vibration method．The measurement principle，apparatus，and manipulation were introduced. In this method, the measured ultra-thin glass is generated in the form of a cantilever beam, and the cantilever beam can be vibrated for a short time when transient excitation is applied. The natural frequency of the cantilever beam can be used to calculate the elastic modulus of the ultra-thin glass material. A series of ultra-thin glass samples with different thickness were tested in this work, the measured values are consistent with that given . The effect of beam length/thickness ratio on determination of elastic modulus of materials by means of cantilever method was analyzed, the result shows that the influence of the ratio can be neglected if the beam length is equal to or more than 10 times of the beam thickness.
Evaluating Thermal Expansion Coefficient of SiC Coatings by Relative Method
Authors: Pan Rui Na , Wei Chen Guang , Bao Yi Wang , Wan De Tian , Wang Yan Ping
Published: January 2017

A simple test approach named relative method is developed for determining the thermal expansion coefficient of ceramic coatings. Although ceramic coatings are hardly separated from the substrates, it was evaluated in this work simply by need only the measured thermal expansion coefficient of coated samples and substrates. This novel method was demonstrated to be valid for rectangular beam samples of two types of coating configurations: sandwich coating and around coating. The feasibility of this test method was confirmed by experimental results of SiC coating.
Patent Analysis of Concrete Testing Technology
Authors: Huang Peng Fei
Published: January 2017

Discover Patent existing concrete performance test technology at home and abroad in the field of analysis of the existing concrete performance test technical features, difficulties and trends, noted that the current domestic patent technology in concrete performance test encountered utilization, protection and disputes, high durability and lightweight concrete and avoid patent risk recommendations for the structure to adapt to the development of the next building needs and provide research and development of high strength.
Oxidation Behavior of Si-B-C-N Multiphase Ceramic
Authors: Chen Ming Wei , Qiu Hai Peng , Xie Wei Jie , Guan Hong
Published: January 2017

Si-B-C-N ceramics were synthesized by co-pyrolyzing hybrid polymeric precursors of polycarbosilane and polyborazine due to their mutual solubility. The pyrolysis behavior of Si-B-C-N precursor was analyzed by TG-DSC-FTIR-MS coupling technique. The oxidation behavior was studied through static oxidation test. Results showed that oxidation rate of Si-B-C-N multiphase ceramic was greater than that of SiC ceramic obviously, which promoted forming the liquid B2O3 or stable borosilicate glass. The generated glass state oxides acted as a protective layer which could heal the cracks and reduce oxidation rate due to lower vaporization rate and smaller oxygen diffusivity. Furthermore, Si-B-C-N multiphase ceramic shows excellent oxidation resistance and can be kept in service in a long time at 1200°C
Synthesis and Conductivity Investigation of Cu Doped Apatite Type Lanthanum Silicate Electrolyte
Authors: Li Wen Zhao , Huang Zhi Liang , Li Qian Zi , Chen Juan
Published: January 2017

In this paper, Cu-doped lanthanum silicate electrolyte (La9.33Si6-xCuxO26-x) precursor was synthesized by urea-nitrate combustion method using La2O3, CuO and TEOS as raw materials. The as-prepared precursor was lighted at 600 °C and sintered at 800 °C. The sintered powder samples were grinded and mixed absolutely by ball milled. Finally, we preformed and sintered powder samples to synthesis Cu-doped lanthanum silicate ceramics. Ac impedance method and analysis was used to test conductivity of as-prepared electrolyte, investigated the influence of balling time, sintering temperature and doping content on conductivity property of LSO sintered product. The final result shows that best balling time is 3 h, secondary sintering temperature is 1500 °C and the doping content is 0.3. Under this condition, the conductivity of Cu-doped lanthanum silicate electrolyte could reach 7.28×10-3 s/cm at 700 °C.
Photoluminescence Properties of SrSi2O2N2 Doped with Divalent Ytterbium Phosphor in Nitrogen-Rich Coordination
Authors: Gu Xi Guang , Fu Ren Li , Yang Fang
Published: January 2017

Yb2+ -doped SrSi2O2N2 had been successfully synthesized using a conventional solid-state reaction method under reducing atmosphere. The phase and luminescence properties of the SrSi2O2N2 phosphors were investigated. Being an orange-red emitting phosphors, SrSi2O2N2:Yb was an emission peaking at 605 nm. With the increasing amount of Yb2+, the optical band gap of SrSi2O2N2 was decreased. The optical band gap of SrSi2O2N2 is decreased by Yb2+ increasing. The luminescence spectra of the nitrogen-rich coordination of Yb2+ in SrSi2O2N2 can be promoted. The concentration quenching mechanism of Yb2+ emission was responsible for the electric dipole–dipole interaction.
Characterization of Test Methods of Capillary Pressure of Cement-Based Materials
Authors: Zhang Jian Liang , Tian Qian , Wang Yu Jiang , Li Ming
Published: January 2017

A Negative pressure sensing set-up for capillary pressure test was designed and used for testing the capillary pressure of cement-based materials, cement pastes of water-cement ratio 0.30 was adopted, and the factors that may affect the measured values such as hardness of water tube, gas volume in the set-up, gas content in water, test depth, bleeding of cement pastes was studied. The results shows that the accuracy of the measured value is very large impacted by the air volume in the set-up and by the hardness of water tube, the capillary pressure at different depths could be affected by the external environment and the bleeding of cement pastes. According to the test results, methods for measuring the capillary pressure of cement-based materials were proposed, and some other recommendations that help to improve the test accuracy were given.
Determination of Formaldehyde in Water-Borne Coatings by HPLC
Authors: Wang Ming Yu , Guo Zhong Bao , Guan Hong Yan , Li Man
Published: January 2017

A method for determination of formaldehyde in water-borne coatings by high-performance liquid chromatographic was proposed. Ultrasonic water extraction method was used instead of the traditional steam distillation method can be more rapid and efficient extraction of target, filtered and derivatived with DNPH. The extract was separated by C18 column with an elution composed of acetonitrile and water, and detected at 352nm. The detection limit was 0.1mg/L. The method showed good linear correlation, R2 was 0.9997 at the range of 0.1mg/L ~ 20 mg/L. Recovery was 95% ～105%. This method is simple, effective and sensitive.
Effect of Reaction Time on the Morphology and Photocatalytic Property of ZnO Nanoparticles
Authors: Kong Xia , Hu Ya Wei , Pan Wei
Published: January 2017

Abstract. ZnO nanoparticles with different morphology were synthesized through a one-step and low temperature hydrothermal method with different reaction time. The prepared ZnO nanoparticles have been used as photocatalysts for the degradation of methylene blue (MB) aqueous solution under UV irradiation to study the relationship between the morphology and photocatalytic performance. The phase, crystallographic structure and morphology of synthesised ZnO nanoparticles were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD). The photocatalytic activity of ZnO nanoparticles were carried out by UV-visible spectroscopy (UV-vis). SEM results showed that different particle sizes and morphologies of flower-like, elliptical-shape and rod-shapes were obtained at 60 °C for 1 h, 4 h, 8 h and 12 h, which promoted photodegradation of methylene blue (MB) aqueous solution under UV light irradiation. Especially, elliptical-shape ZnOnanoparticles with reaction time of 4 h were most efficient, and the degradation rate was up to 98.2% after 20 min UV irradiation.
Deep Wet Etching Uniformity of Polished Fused Silica Glass
Authors: Du Xiu Rong , Song Xue Fu , Sun Yuan Cheng , Zhang Xiao Qiang , Wang Hui , Yang Xiao Hui
Published: January 2017

Deep wet etching for polished fused silica glass in HF solutions was investigated to manufacture quartz pendulous reed with better surface quality and higher size precision. It is widely believed that etching rate was mostly decided by the temperature and concentration of HF solutions. But, in the beginning it was found difficult to control the uniformity of etching depth when the glass was etched for 0.3 ~ 0.5 mm each side. Now, it is detected with help from new designed etching machine that depth of 0.5mm or more can be achieved very easily. And the uniformity about ±0.002 mm would also be realized easily by keeping the sample glass at same depth and moving all the time in HF solution with the temperature and concentration are 45°C and 40% HF
Influence of Ionizing Gas Flow on Structural Homogeneity of Type IV Silica Glass
Authors: Sun Yuan Cheng , Song Xue Fu , Du Xiu Rong , Zhang Xiao Qiang , Wang Hui , Yang Xiao Hui
Published: January 2017

Type IV silica glass is the key material in inertial navigation and optical field due to its high purity and unbroken structural network. Structural homogeneity of type IV silica glass, which is mainly affected by producing process, is one of the most important properties and determines its usability. The influence of ionizing gas flow of plasma was studied in this paper. Flow rate of working gas and protecting gas was changed and the depositing temperature field was measured. Structural homogeneity of deposited silica glass was discussed by optical homogeneity, fictive temperature and stress birefringence. Results show that more uniform temperature field can be obtained with higher working gas flow and lower protecting gas flow, and the structural homogeneity of type IV silica glass is better. But the proportion of working gas and protecting gas should not be larger than 2. When the working gas and protecting gas are 5 m3/h and 2.5 m3/h respectively, the structural homogeneity of type IV silica glass is the best.
Determination of Chemical Composition in Zircon-Refractory Material by MLD Method
Authors: Han Wei , Liu Yu Bing , Ren Jian Xing , Lu Juan Juan
Published: January 2017

The contents of each element in the melting glass samples of zircon-refractory material were measured by X-ray fluorescence spectrometry. The samples were melted completely with uniform intensity. Then the incident ray absorption coefficient and the MLD coefficient of the solvents and samples were extracted by using the method of equivalent wavelength. Finally the chemical composition of zircon-refractory material was determined by MLD coefficient and normalization calculation method. The results are consistent with those obtained with the national standard method and the absolute value of error is less than 0.1%. The precision is comparative with the counting error of XRF analysis and the absolute value of the standard deviation is less than 0.05%, being much higher than national standard method. At the same time, this method is simple, easy to be operated.
Water Absorption and Hydration Products of Metakaolin Modified Mortar
Authors: Geng Hai Ning , Li Qiu
Published: January 2017

The compressive strength, water absorption and hydration products of mortar with metakaolin addition were characterized by a range of techniques to evaluate the effect of metakaolin on the properties and hydration of mortar. Metakaolin is more effective on the improvement of compressive strength of mortar after curing for 7 days, due to the refinement of pore structure and pozzolanic reaction between metakaolin and calcium hydroxide. Water absorption of mortar was reduced by introducing metakaolin, especially in the very early age, due to the optimization of packing density of mortar by superfine metakaolin particles. There is no correlation between compressive strength and water absorption of mortar due to the differences between mechanisms affecting the compressive strength and water absorption of mortar by metakaolin. The hydration products of mortar without metakaolin were Portlandite and ettringite. Additional hemicarboaluminate and monocarboaluminate were identified in mortar with metakaolin addition. Metakaolin addition reduced the calcium hydroxide content due to the pozzolanic reaction.
Activity Evaluation of a Tailing in a Cementitious System
Authors: Li Bing Hao , Xiao Lian Zhen , Fu Ya Qing
Published: January 2017

Hydration activity of a tailing is evaluated by the hydration rate obtained from the electrical resistivity measurement and compressive strength in a cementitious hydration system as a mineral admixture. A plain paste and the pastes with tailing or fly ash by replacement of cement at water-binder ratio of 0.4 are prepared. The electrical resistivity of the paste samples was measured in 168h(7d) by a non-contact resistivity technique. Hydration activity of the tailing was also evaluated by measuring the compressive strength at the curing ages of 3d~90d to confirm the results from the electrical resistivity. It is found that the addition of a mineral admixture delays the occurrence of two peaks on the electrical resistivity differential curve and the delayed times are 3.32h and 6.10h for the sample with tailing, and 0.78h, 3.49h for the sample with fly ash. The rate values on the two peaks are decreased with incorporation of the tailing or fly ash. The activity evaluation results on the mineral admixtures from the resistivity measurement are consistent with the strength results before 7d. The resistivity as an activity index can provide a simple and fast way to evaluate mineral material activity at early ages. The effect of tailing and fly ash on compressive strength for a long term was also analyzed and the micro-structure of the pastes at 7d and 28d were observed by SEM.
Shrinkage Properties of Cement-Silica Fume Blended Pastes in Early Age
Authors: Zou Di , Xiao Lian Zhen , Shi Wen Chong
Published: January 2017

The cement-silica fume blended pastes were prepared with different silica fume (SF) dosages of 0%, 5%, 10%, and 15% at different water-binder ratios (W/B) of 0.4 and 0.5. The autogenous shrinkage (AS) and the drying shrinkage (DS) of the paste samples in the hydration period of 7d (168 hours) were measured by a new measurement technique to explore the influence of W/B and silica fume incorporation on the shrinkage in early age. The study results can provide reference for high performance concrete mix design.It is found that ether the AS or the DS of the paste samples shows a similar pattern, and the AS development with hydration time appeared a temporary expansion period after a rapid growth, especially in the samples at a higher W/B or with a lower SF content. However, the DS development did not occur obvious expansion period.Three development trends were obtained for the factors of W/B and SF content. 1) the AS and DS of the pastes mainly occurred in early ages. The lower W/B, the shorter the rapid growth periods, and the higher the shrinkage ratio of 1d to 7d. For the pastes with W/B of 0.4, the AS grew rapidly in 1d and the DS grew rapidly in the first 10h, and the AS value in 1d reached to 63.6% of 7d, and the DS value reached to 62.1% of 7d in the paste with SF of 10%. For the pastes with W/B of 0.5, the rapid growth periods of the AS and DS respectively extended to 30~33h and 12h, and the AS value in 1d reached to 60.0% of 7d, and the DS value reached to 57.2% of 7d in the paste with SF of 10%. 2) The lower W/B, the higher the shrinkage ratio of the AS to the DS. When the SF dosage is 10%, the ratio of the AS value to the DS value of 7d is 21.66%~21.15% for W/B of 0.4, and only 6.06%~5.78% for the W/B of 0.5. 3) the higher SF content results in the higher AS in cement-SF blended pastes. For the pastes with W/B of 0.4, the ratio of the AS to the DS increased from 6.98% to 30.16% with the increase of content of SF from 5% to 15% in 1d, from 15.1% to 28.19% in 3d, from 16.78% to 26.16% in 7d.
Study on the Reduction of Radon Exhalation Rates of Concrete with Different Activated Carbon
Authors: Zhang Yong Gui , Wang Yang , Yang Chun Yong , Li Gui Qiang , Yan Hao Chun
Published: January 2017

Four different material of activated carbon, i.e., coconut shell, fruit shell, wood and coal, were used to be mixed with concrete, the radon exhalation rates of concrete then was measured. At the same time, the pore distribution of activated carbon and some performances of concrete were tested. The results show that coconut shell carbon has the best effect for reduction radon exhalation rates of concrete, fruit shell carbon comes second. The adsorption mechanisms of activated carbon towards the radon gas in the solid and in the air are similar. Activated carbon have less effect on the strength of concrete, however, they have greater influence on the constructability and durability.
Dynamic Hydrothermal Synthesis of Super-Low Density Xonotlite Thermal Insulation Materials from Industrial Quartz Powder
Authors: Yue Hong Zhi , Wang Xin , Yang Zan Zhong , Wei Chun Cheng
Published: January 2017

Xonotlite was synthesized by dynamic hydrothermal methode with industrial quartz powder as the siliceous materials and calcium hydroxide derived from hydration of calcined calcium carbonate as calcareous material.This paper focused on the influence of particle size of the industrial quartz powder, the mass ratio of water and solid reactants (W/S) and additives on the product composition, apparent density and crystal morphology. The products were characterized by X-ray powder diffraction (XRD), scanning eletron microscope (SEM) and other analysis methodes. Results indicated that in a certain range to decrease particle sizes of quartz powder could improve the content of xonotlite under the help of potassium hydroxide and zirconium oxychloride, the content of xonotlite could reach 99.5% when the particle size of quartz powder decrease to 4.65um no need to the common level of below 1 um in some literature. The product had a very high xonotlite content and perfect particle morphology when the ratio of W/S was controled over 30%; under the help of strontium ions and zirconium ions xonotlite fiber became significantly slimmer with a greater ratio of length to diameter,which was easier to obtain super-low density xonotlite thermal insulation materials.
Static Modulus of Ettringite in Different Environment
Authors: Chen Peng , Jin Zu Quan , Fan Jun Feng
Published: January 2017

The pure ettringite, (Ca6Al2(OH)12(SO4)3· 32H2O), was synthesized by chemical reaction with saturation calcium hydroxide and aluminum sulfate. The ettringite in different environments including various concentration of sodium chloride, 5% magnesium sulfate and carbonation for 3 days were synthesized. And then these ettringtie specimens were prepared under different pre-loads. The static modulus and phase composites were tested. The experimental result shown that the influence of chloride ions concentration on the static modulus of ettringite could be ignored. And the magnesium ion reduced the generation of ettringite, and promoted the formation of gypsum. The static modulus of ettringite increased with carbonation time due to the formation of calcium carbonate.
Extended High-Temperature Operation of Silicon Carbide CMOS Circuits for Venus Surface Application
Authors: Holmes Jim , Francis A. Matthew , Getreu Ian , Barlow Matthew , Abbasi Affan , Mantooth H. Alan
Published: January 2017

In the last decade, significant effort has been expended toward the development of reliable, high-temperature integrated circuits. Designs based on a variety of active semiconductor devices including junction field-effect transistors and metal-oxide-semiconductor (MOS) field-effect transistors have been pursued and demonstrated. More recently, advances in low-power complementary MOS (CMOS) devices have enabled the development of highly integrated digital, analog, and mixed-signal integrated circuits. The results of elevated temperature testing (as high as 500°C) of several building block circuits for extended periods (up to 100 h) are presented. These designs, created using the Raytheon UK's HiTSiC® CMOS process, present the densest, lowest-power integrated circuit technology capable of operating at extreme temperatures for any period. Based on these results, Venus nominal temperature (470°C) transistor models and gate-level timing models were created using parasitic extracted simulations. The complete CMOS digital gate library is suitable for logic synthesis and lays the foundation for complex integrated circuits, such as a microcontroller. A 16-bit microcontroller, based on the OpenMSP 16-bit core, is demonstrated through physical design and simulation in SiC-CMOS, with an eye for Venus as well as terrestrial applications.
Influence of bottleneck lengths and position on simulated pedestrian egress
Authors: Parisi Daniel R. , Patterson Germán A.
Published: January 2017

In this paper, the problem of pedestrian egress under different geometries is studied by means of two numerical models. The length of the bottleneck after the exit and the distance of the exit to the lateral wall of a squared room are investigated. Both models show that an increase in the bottleneck length increases the evacuation time by more than 20 %, for any exit position. Hence, a bottleneck length tending to zero is the best choice. On the contrary, the results of moving the exit closer to the lateral wall are different in both models and, thus, its convenience cannot be stated. To unveil whether this layout modification is favorable, experimental data are required. Moreover, the discrepancy between models indicates that they should be validated considering several scenarios.
Received: 25 August 2016,  Accepted: 3 January 2017; Edited by: G. C. Barker;  Reviewed by: A. Seyfried, Institute for Advanced Simulation Julich Supercomputing Centre, Germany; DOI: http://dx.doi.org/10.4279/PIP.090001
Cite as: D R Parisi, G A Patterson, Papers in Physics 9, 090001 (2017)
This paper, by D R Parisi, G A Patterson, is licensed under the Creative Commons Attribution License 3.0.
Mesembe Edet’s conversation with Innocent Onyewuenyi: an exposition of the significance of the method and canons of conversational philosophy
Authors: Nweke Clement Victor
Published: January 2017

The basic thesis of this essay is that the progressive development of any discipline is propelled by incessant constructive criticisms, creative emendation and articulate reconstruction of established positions and received opinions in the discipline. Accordingly, the essay argues that the method and canons of Conversational Philosophy (CP) are very significant to the progressive development of African philosophy. This is because they are fundamentally articulated to promote the constructive criticism, creative emendation, and articulate reconstruction of established positions or received opinions in African philosophy. It buttresses this point using Mesembe Edet’s conversation with Innocent Onyewuenyi on the question of the African belief on reincarnation. This choice stems from the explicit admittance of Edet that his conversation with Onyewuenyi adopts the method of conversationalism and the method of conversationalism is undergirded by the canons of CP. Specifically, this essay explicates how the conscious adoption of conversationalism and adherence to the canons of CP enabled Edet to engage Onyewuenyi in a very critical and creative conversation on the African belief in reincarnation which eventually led to a novel reconceptualization of reincarnation in African philosophy. It unveils the significance of conversationalism and the canons of CP in practice. It is therefore a conversational, expository and argumentative essay.Keywords: Conversationlism, Conversational Philosophy, Interrogative theory, Onyewuenyi, Reincarnation.
Beyond Irredentism and Jingoism: reflections on the nature of logic and the quest for (an) African logic
Authors: Uduma Uduma Oji
Published: January 2017

In this article, I attempt once more to revisit the subject of logic in African philosophy or as some would have it, African logic. I discuss the views of those I call jingoists and irredentists and distance myself from them. I argue that there is logic in every human culture and language. I argue also that even the ancient Africans had logic in their languages. My goal is to show that logic as the tool of thought is universal and not culture-bound. To do this, I will investigate the nature of logic and then examine again the notion of (an) African logic before showing the relevance of logic to life. My method will be descriptive, prescriptive and analytical.Keywords: Logic, African logic, Irredentism, Afrocentrism, jingoism, African philosophy
Sensitivity model study of regional mercury dispersion in the atmosphere
Authors: Gencarelli Christian N. , Bieser Johannes , Carbone Francesco , De Simone Francesco , Hedgecock Ian M. , Matthias Volker , Travnikov Oleg , Yang Xin , Pirrone Nicola
Published: January 2017

Abstract. Atmospheric deposition is the most important pathway by which Hg reaches marine ecosystems, where it can be methylated and enter the base of food chain. The deposition, transport and chemical interactions of atmospheric Hg have been simulated over Europe for the year 2013 in the framework of the Global Mercury Observation System (GMOS) project, performing 14 different model sensitivity tests using two high-resolution three-dimensional chemical transport models (CTMs), varying the anthropogenic emission datasets, atmospheric Br input fields, Hg oxidation schemes and modelling domain boundary condition input. Sensitivity simulation results were compared with observations from 28 monitoring sites in Europe to assess model performance and particularly to analyse the influence of anthropogenic emission speciation and the Hg0(g) atmospheric oxidation mechanism. The contribution of anthropogenic Hg emissions, their speciation and vertical distribution are crucial to the simulated concentration and deposition fields, as is also the choice of Hg0(g) oxidation pathway. The areas most sensitive to changes in Hg emission speciation and the emission vertical distribution are those near major sources, but also the Aegean and the Black seas, the English Channel, the Skagerrak Strait and the northern German coast. Considerable influence was found also evident over the Mediterranean, the North Sea and Baltic Sea and some influence is seen over continental Europe, while this difference is least over the north-western part of the modelling domain, which includes the Norwegian Sea and Iceland. The Br oxidation pathway produces more HgII(g) in the lower model levels, but overall wet deposition is lower in comparison to the simulations which employ an O3 ∕ OH oxidation mechanism. The necessity to perform continuous measurements of speciated Hg and to investigate the local impacts of Hg emissions and deposition, as well as interactions dependent on land use and vegetation, forests, peat bogs, etc., is highlighted in this study.
OH reactivity at a rural site (Wangdu) in the North China Plain: contributions from OH reactants and experimental OH budget
Authors: Fuchs Hendrik , Tan Zhaofeng , Lu Keding , Bohn Birger , Broch Sebastian , Brown Steven S. , Dong Huabin , Gomm Sebastian , Häseler Rolf , He Lingyan , Hofzumahaus Andreas , Holland Frank , Li Xin , Liu Ying , Lu Sihua , Min Kyung-Eun , Rohrer Franz , Shao Min , Wang Baolin , Wang Ming , Wu Yusheng , Zeng Limin , Zhang Yinson , Wahner Andreas , Zhang Yuanhang
Published: January 2017

Abstract. In 2014, a large, comprehensive field campaign was conducted in the densely populated North China Plain. The measurement site was located in a botanic garden close to the small town Wangdu, without major industry but influenced by regional transportation of air pollution. The loss rate coefficient of atmospheric hydroxyl radicals (OH) was quantified by direct measurements of the OH reactivity. Values ranged between 10 and 20 s−1 for most of the daytime. Highest values were reached in the late night with maximum values of around 40 s−1. OH reactants mainly originated from anthropogenic activities as indicated (1) by a good correlation between measured OH reactivity and carbon monoxide (linear correlation coefficient R2 = 0.33) and (2) by a high contribution of nitrogen oxide species to the OH reactivity (up to 30 % in the morning). Total OH reactivity was measured by a laser flash photolysis–laser-induced fluorescence instrument (LP-LIF). Measured values can be explained well by measured trace gas concentrations including organic compounds, oxygenated organic compounds, CO and nitrogen oxides. Significant, unexplained OH reactivity was only observed during nights, when biomass burning of agricultural waste occurred on surrounding fields. OH reactivity measurements also allow investigating the chemical OH budget. During this campaign, the OH destruction rate calculated from measured OH reactivity and measured OH concentration was balanced by the sum of OH production from ozone and nitrous acid photolysis and OH regeneration from hydroperoxy radicals within the uncertainty of measurements. However, a tendency for higher OH destruction compared to OH production at lower concentrations of nitric oxide is also observed, consistent with previous findings in field campaigns in China.
Climate engineering by mimicking natural dust climate control: the iron salt aerosol method
Authors: Oeste Franz Dietrich , de Richter Renaud , Ming Tingzhen , Caillol Sylvain
Published: January 2017

Abstract. Power stations, ships and air traffic are among the most potent greenhouse gas emitters and are primarily responsible for global warming. Iron salt aerosols (ISAs), composed partly of iron and chloride, exert a cooling effect on climate in several ways. This article aims firstly to examine all direct and indirect natural climate cooling mechanisms driven by ISA tropospheric aerosol particles, showing their cooperation and interaction within the different environmental compartments. Secondly, it looks at a proposal to enhance the cooling effects of ISA in order to reach the optimistic target of the Paris climate agreement to limit the global temperature increase between 1.5 and 2 °C. Mineral dust played an important role during the glacial periods; by using mineral dust as a natural analogue tool and by mimicking the same method used in nature, the proposed ISA method might be able to reduce and stop climate warming. The first estimations made in this article show that by doubling the current natural iron emissions by ISA into the troposphere, i.e., by about 0.3 Tg Fe yr−1, artificial ISA would enable the prevention or even reversal of global warming. The ISA method proposed integrates technical and economically feasible tools.
Propiedades psicométricas del cuestionario de afrontamiento al estrés para pacientes oncológicos (CAEPO)
Authors: Miaja Avila Melina , Romero Retes Rocío , Ibáñez Guerra Elena , Soriano Pastor José , García-Conde Ana
Published: January 2017

Los objetivos del estudio fueron: 1) analizar la estructura factorial de la escala CAEPO mediante análisis factorial exploratorio y confirmatorio; 2) estimar la consistencia interna de los factores; 3) describir la distribución de los factores; 4) analizar las diferencias de medias de las estrategias de afrontamiento entre hombres y mujeres. El Cuestionario de Afrontamiento al Estrés para Pacientes Oncológicos (CAEPO) de González (2004) fue aplicado a 148 pacientes oncológicos. Se sugiere reducir la escala a 35 ítems. Se encontró una estructura de cuatro factores correlacionados con consistencias internas de adecuadas a altas. La distribución de los factores se ajustó a una curva normal y no se encontraron diferencias significativas entre hombre y mujeres. En futuras investigaciones, se sugiere su empleo en muestras clínicas de España y otros países hispanoparlantes.
Cancer information for children: effect on adherence to intramuscular chemotherapy
Authors: Amaral Mariana , Zoéga Soares Maria Rita , Gioia Paula Suzana
Published: January 2017

Objetivo. Evaluar los efectos de una intervención para informar a los niños sobre el cáncer. Se pretendió mejorar la adhesión al tratamiento y conductas concurrentes que interfieren con la quimioterapia.Método. Participaron una niña y un niño de 9 y 4 años respectivamente, diagnosticados con leucemia linfoblastica aguda y en tratamiento en el ambulatorio de quimioterapia. Los participantes fueron filmados antes, durante y después de la intervención, en un total de 16 sesiones. La intervención psicológica ha sido realizada con cada participante en tres sesiones individualmente, basada en el libro Estou doente e agora? Orientacoes para criancas com cancer (Estoy enfermo y ahora? Orientaciones para niños con cáncer), organizada en 24 fichas conteniendo información, actividades recreativas y otros ejercicios de expresión de sentimientos sobre la enfermedad y el tratamiento. El registro filmado fue analizado por observadores ciegos que identificaron la ocurrencia de respuestas de adhesión y concurrentes, definidos de acuerdo con una version adaptada de la Observation Scale of Behavioral Distress (OSBD).Resultados. Los resultados muestran que la intervención fue efectiva. Durante la intervención la frecuencia de comportamientos de adhesión, se ha incrementado y la de comportamientos concurrentes, ha disminuido. No obstante tales efectos no se mantuvieron en las sesiones pos intervención.Conclusiones. Este es um modelo de intervención que debe ser analizado en otros estudios que busquen mejorar las contingencias para el desarrollo de un repertorio conductual que auxilie en la adaptación a esa condición. Los estudios futuros deberían usar un mayor número de sesiones, de participantes y grupos de control.
Cuestionarios de atención espiritual en cuidados paliativos: revisión de la evidencia para su aplicación clínica
Authors: Oliver Amparo , Benito Enric , Sansó Noemí , Galiana Laura
Published: January 2017

Objetivo: Revisar los cuestionarios de evaluación de necesidades y recursos espirituales en cuidados paliativos más recientes y evaluar su aplicabilidad clínica en nuestro entorno.Método: Revisión sistemática, siguiendo las guías PRISMA de las publicaciones realizadas durante 2015-2016 de trabajos sobre espiritualidad. Los artículos debían estar centrados en el cuidado espiritual o la evaluación de la espiritualidad, basados en población de cuidados paliativos; y sometidos a revisión por pares.Resultado: de los 42 artículos identificados, tras evaluación independiente de dos observadores, 15 cumplieron criterios de selección. Estos se analizan respecto sus características, propiedades psicométricas y aplicabilidad.Conclusiones: La necesidad de mejorar la atención espiritual en el proceso de morir ha llevado a la aparición de múltiples herramientas de evaluación y acompañamiento espiritual. Su uso debe ponderarse con la experiencia del clínico y su aplicabilidad según el entorno cultural en el que se ha construido y sus propiedades psicométrica