bluuebunny/crossref_metadata_2025 huggingface dataset:
Development and Comparative Analysis of Aluminosilicate Based Ceramic Filters for Ground Water Defluoridation
Authors: Efavi Johnson Kwame , Yaya Abu , Adeborna Solomon , Fobil Julius
Published: June 2014

Low levels of fluoride in drinking water is healthy for the teeth enamel, however, higher concentrations result in dental fluorosis with prolonged exposures leading to skeletal fluorosis. Fluoride removal capacities of ceramic filters using aluminosilicates (Anfoega clay, Kibi kaolin, Laterite soil and Termitaria earth) samples from Ghana Geological Survey Department have been investigated and analysed for possible application in the Bongo District of Ghana noted forhavinghigh fluoride concentration in its ground water. Batch sorption studies conducted revealed that the amount of fluoride ions removed increased proportionally with increasing filter thickness, temperature and contact time to an optimum value. Using particle size ranges of <355μm and 1cm filter thickness at room temperature, the percentage of fluoride removed by the samples reached an optimum value after 70mins. Increases in filter thickness, contact time or temperatureincreased the amount of fluoride ions removedand the time required to reach the optimum value reduced significantly.
Preparation of 5-Sulfosalicylic Acid Modified Silica Gel and its Adsorption Performances for Lead
Authors: Wu Xiong Zhi , Meng Jiao , Li Fei Ping , Luo Liang Liang
Published: June 2014

A new sorbent (SSA-SG) with 5-sulfosalicylic acid as functional group has been prepared and characterized with FTIR and then used as micro-column packing for enrichment of Pb (II). Enrichment conditions of lead were optimized. The enrichment factor reaches 200 and the dynamic sorption capacity was 15.46 mgg-1 for Pb (II). The proposed column enrichment procedure was applied for the preconcentration/separation and atomic absorption spectrometry (AAS) determination of Pb (II) in water samples successfully.
The Effect of Polyvinyl Pyrrolidone and Nickel Acetylacetonate on the Fabrication of Polyacrylonitrile Precursor Fiber
Authors: Wang Zhi Hui , Rong Hai Qin , Xu Ao Yun , Lin Hui Min , Zhao Shu Hui
Published: June 2014

The effect of polyvinyl pyrrolidone (K30) and nickel acetylacetonate (Ni (acac)2) on the fabrication of polyacrylonitrile (PAN) fiber was investigated. K30 and Ni (acac)2 were chosen as pore-forming agents to prepare mesoporous carbon fibers.Meanwhile, the concentration of K30 and Ni (acac)2, the mass ratio of pore-forming agent to PAN, the rheological properties of spinning dope, the mechanical properties, thermal performance of fiber precursor were also characterized. Furthermore, the precursor fibers and the carbon fibers were researched by FTIR analysis, TG analysis and static benzene adsorption. Based on the research, when the concentration of K30 and Ni (acac)2 was 5%, the mass ratio of K30/Ni (acac)2 to PAN was 7:3, the fiber precursors had excellent properties. Adding poreforming agent, the pore distribution was controlled.
Morphology and Conductivity of Self-Assembled Pyrene-Perylenetetracarboxylic Diimide Dyad
Authors: Shi Yan , Li Xi You
Published: June 2014

One perylenetetracarboxylic diimide (PDI) derivatives (PDI 1) linked with pyrene by flexible chain at the bay positions was synthesized and the molecular structure was characterized by 1H NMR, MALDI-TOF mass spectra as well as elemental analysis. The molecular self-assembly were prepared from solution via a slow evaporation of solvent. The properties of these molecular aggregates were studied by electronic absorption and fluorescence spectra. The morphologies and structures were examined by scanning electronic microscopy (SEM) and X-ray diffraction (XRD) techniques. The conducting properties were evaluated by currentvoltage (IV) measurements. The results revealed highly ordered structure for these molecular self-assembly. The thin solid film fabricated from these molecular self-assembly show an electric conductivity as high as 4.85 × 10-4 S cm-1 under the ambient light, which means this compound might be used as a semiconductor in nanoelectronics.
Effect of Solvent Properties on the Swelling Assisted with Protrusion of PS@TiO2
Authors: Chen Bao Ling , Zheng Long Hui , He Jun Hui , Chen Qin Hui , Lin Jin Huo
Published: June 2014

swelling; core-shell microspheres; Janus; solubility parameter; polar fraction Abstract. Janus particles have particular properties and potential application for their asymmetry dual-faced structure. In this report, we study the effect of the solubility parameter and the polar fraction of solvent on the swelling assisted with protrusion of polystyrene @ titanium dioxide (PS@TiO2) core-shell microspheres. The resultant titanium dioxide/polystyrene (TiO2/PS) Janus particles were characterized by scanning electron microscope. Results indicated that solvent with the solubility parameter of about 9.3 (cal/cm3)1/2 and with low polarity such as dimethylbenzene, carbon disulfide and methyl methacrylate exhibited the preferable swelling efficiency. Janus particles have particular properties and potential application for their asymmetry dual-faced structure. In this report, we study the effect of the solubility parameter and the polar fraction of solvent on the swelling assisted with protrusion of polystyrene @ titanium dioxide (PS@TiO2) core-shell microspheres. The resultant titanium dioxide/polystyrene (TiO2/PS) Janus particles were characterized by scanning electron microscope. Results indicated that solvent with the solubility parameter of about 9.3 (cal/cm3)1/2 and with low polarity such as dimethylbenzene, carbon disulfide and methyl methacrylate exhibited the preferable swelling efficiency.
Preparation of Zircon Whiskers via Non-Hydrolytic Sol-Gel Process Combined with Molten Salt Method
Authors: Wang Hong Da , Jiang Wei Hui , Feng Guo , Liu Jian Min , Wu Qian , Miao Li Feng
Published: June 2014

Zircon whiskers were prepared via non-hydrolytic sol-gel process combined with molten salt method, using Si (OC2H5)4 (TEOS) and ZrCl4 as raw materials, LiF as mineralizer, and Na2WO4 as molten salt. The phase composition, morphology and microstructure of the samples were characterized by X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The influence of introducing molten salt and calcination temperature on the synthesis and morphology of zircon crystals was investigated. The results show that the introduction of Na2WO4 contributes to the one-dimensional preferential growth of zircon. Zircon whiskers elongated along the c-axis, with diameter of ~100nm and aspect ratio of more than 15, are achieved at the temperature of 850 °C, and neither over low nor over high calcination temperature is conducive to the growth of zircon whiskers.
Simulation of Characteristics of Debris Cloud Produced by Hypervelocity Impact
Authors: Ma Wen Lai , Zhang Wei , Pang Bao Jun
Published: June 2014

All spacecraft in low orbit are subject to hypervelocity impacts by meteoroids and space debris. These impacts can damage spacecraft flight-critical systems, which can in turn lead to catastrophic failure of the spacecraft. The numerical simulations of characteristics of debris cloud produced by an aluminum sphere projectile hypervelocity impact on different material bumpers at normal incidence have been carried out by using the SPH (smoothed particle hydrodynamics) technique. The effects of impact velocity, the ratio t/d of the bumper thickness to the projectile diameter and the bumper materials on the debris cloud characteristics are presented.
3D Printing Manufacture Micro-Channel Structure by Metal Micro Droplet-on-Demand Deposition
Authors: Chao Yan Pu
Published: June 2014

In order to realize the rapid-flexible manufacture of metal micro-channel radiator structure,metal micro-droplet deposition manufacture was proposed and an experimental setup was developed. The principle of pneumatic droplet-on-demand generator and the process of single droplet ejected from the nozzle were analyzed. The calculation model of forming wall thickness was established. On this basis, a micro-channel radiator structure was fabricated. The above research show that the manufacturing of micro-channel structure by micro-droplet deposition is feasible. This works offer a new manufacturing method for micro-channel radiator structure.
Optimization Design for the Stationary Platen Based on Uniform Design
Authors: Li Kai Ling , Qi Hua Long , Zhu Kang Jian , Zang Shu Hua
Published: June 2014

Design and analysis of computer experiments (DACE) can solve the optimization design problem for stationary platen effectively. In this paper the method of uniform design is applied to obtain the design of computer experiments which is employed in the optimization design of the stationary platen. 3 factors (11 levels for each factor) are selected. The approximate Kriging model is built on the basis of the FEA results. 10 design points are selected randomly to verify the prediction ability of the Kriging model. The results show that the maximum of the relative error is 2.53% and the minimum is 0.63%. The approximate model built in this paper is practical in the optimization design of the stationary platen. The steps proposed in this paper are also suitable for the optimization design problems with complicated geometry or finite element model.
Softening of High-Strength Steel for Laser Assisted Clinching
Authors: Osten Julia , Söllig Paul , Reich Michael , Kalich Jan , Füssel Uwe , Kessler Olaf
Published: June 2014

The conventional clinching of steels is currently limited to tensile strength less than 800 N/mm2 and to elongation at fracture more than 14 %. To realise the clinching of high-strength steels, the sheet can be heated locally at the joint, to improve ductility. Thereby the material characteristics outside the joint should be maintained. This could be achieved by means of short-time laser heating. The short-time tempering behaviour of press hardened steel 22MnB5 has been analysed. The mechanical properties during a short-time heat treatment were investigated by thermo-mechanical analysis in a deformation dilatometer. Thereby laser-assisted clinching shall be established and an efficient form-closed and force-closed connection shall be produced. As a result, the press hardened steel 22MnB5 could be clinched by laser assistance for the very first time.
Corrosion Resistance on the Interlayer of AISI 316L/AISI 304 Stainless Steels Joined with an Iron Based Metallic Glass Ribbon at 1000 °C by Induction Heating
Authors: Verduzco Jorge A. , Gonzalez Jorge A. , Verduzco Víctor H. , Borja Carlos E. , Quezada José Guadalupe , Figueroa Ignacio A.
Published: June 2014

This work presents a study of the corrosion resistance as a function of the holding time on the interface generated during the process of brazing an AISI 304 to AISI 316L stainless steels by using a non-commercial Fe60Ni12Cr8P13B7 metallic glass alloy ribbon by induction heating at 1000 °C into a chamber with an Ar controlled atmosphere. Samples of the austenitic stainless steels were joined in a sandwich-like arrangement using the Fe-based metallic glass ribbon. Corrosion experiments carried out in distilled water and 3.5 wt. % sodium chloride solution revealed that the corrosion resistance was higher for samples tested in the distilled water than the latest medium for all dwell joining times, since in the former medium the samples passivated. It was also found that the highest corrosion resistance was achieved for samples joined for a dwelling time of 4 minutes.
Precipitation Hardening Analysis of an Al-8%Ag Alloy
Authors: Hernández Martínez Sergio Eliseo , García Rocha Jorge , Cruz Rivera José de Jesús , Hernandez Rivera José Luis
Published: June 2014

Aluminum alloys are important in aerospace industry, due to their mechanical properties, low specific weight and good corrosion resistance. Such properties are achieved due to a heat treatment of solubilization, quenching and aging, in order to precipitate metastables phases, which act as dislocation obstacles, increasing the strength of the alloy. In the present study, the precipitation sequence of Al-8%Ag alloy was analyzed via Vickers hardness and Transmission Electron Microscopy. The size and morphology of the precipitated particles, involved in the stages of precipitation process was characterized. It was determined the microstructure at the peak hardness, which is mainly composed of spherical GP zones with about 6 nm average diameter, which are responsible for the alloy achieve a value of 72 HVN. It was observed that this hardness value does not compete with others well known alloys, like AA 6061 and AA 2024, which can be precipitation hardened. The main reason for the low values of HVN, is because of there is no enough difference between the matrix and the precipitated particles lattice parameters, and dont cause a significant elastic strain by coherence in the matrix lattice, that could produce a substantial hardening. To ascertain this assumption, the aged material was severely plastic deformed, achieving 94 HVN, and the grain refinement and high dislocations density were the major hardening mechanisms, since the precipitates behavior was similar as the matrix, because particles were distorted instead of acting as impediment to material flow.
Study of Cantilever Structures Based on Piezoelectric Materials for Energy Harvesting at Low Frequency of Vibration
Authors: Ambrosio Roberto , Gonzalez Hector , Moreno Mario , Torres Alfonso , Martinez Rafael , Robles Efren , Sauceda Angel , Hurtado Abel , Heredia Aurelio
Published: June 2014

In this work is presented a study of a piezoelectric energy harvesting device used for low power consumption applications operating at relative low frequency. The structure consists of a cantilever beam made by Lead Zirconate Titanate (PZT) layer with two gold electrodes for electrical contacts. The piezoelectric material was selected taking into account its high coupling coefficients. Different structures were analyzed with variations in its dimensions and shape of the cantilever. The devices were designed to operate at the resonance frequency to get maximum electrical power output. The structures were simulated using finite element (FE) software. The analysis of the harvesting devices was performed in order to investigate the influence of the geometric parameters on the output power and the natural frequency. To validate the simulation results, an experiment with a PZT cantilever with brass substrate was carried out. The experimental data was found to be very close to simulation data. The results indicate that large structures, in the order of millimeters, are the ideal for piezoelectric energy harvesting devices providing a maximum output power in the range of mW
Immobilization of SA-α-2,6-Gal Receptors Related to Influenza on Magnetic Nanoparticles Coated with Chitosan
Authors: Gregorio-Jauregui Karla M. , Carrizales-Alvarez Susana A. , Rivera-Salinas Jorge E. , Saade Hened , Martinez Jose L. , Lopez Raul G. , Ilyina Anna
Published: June 2014

Influenza infection is carried out due to the virus hemagglutinin recognizes host cell surface with terminal sialic acid (SA) linked receptors SA-α-2,6-Gal for human strain. Sambucus nigra lectin has structural similarity to the viral hemagglutinin. Magnetic nanoparticles (MNP) coated with chitosan can be used as support for the study of these receptors. The goal of this study was to extract the SA-α-2,6-Gal receptors of porcine trachea for their immobilization on magnetic nanoparticles coated with chitosan. The extraction was carried out based on affinity of Sambucus nigra lectin to SA-α-2,6-Gal receptors. It was possible to immobilize up to 76% of SA-α-2,6-Gal receptors, with a molecular weight at 88.4 kDa for more representative protein. The presence of the receptors was confirmed trough FTIR analysis. Magnetic functionalized nanoparticles showed superparamagnetic properties and an average diameter around 10 nm. These results may be used to evaluate the interaction between functionalized nanoparticles and specific lectin or hemagglutinin of influenza virus as model of study virus-receptor.
Anisotropic Emission in Strain-Balanced Quantum Well Solar Cells
Authors: Cabrera C. Ivan , Rimada J.C. , Hernandez Luis , Enciso Agustin , Contreras-Solorio David Armando
Published: June 2014

Strain-balanced quantum well solar cells (SB-QWSC) extend the photon absorption edge beyond that of bulk GaAs by incorporation of quantum wells in the i-region of a pin device. The strain-balanced quantum well solar cell benefits from a fundamental efficiency enhancement due to anisotropic emission from the quantum wells. This anisotropy arises from a splitting of the valence band due to compressive strain in the quantum wells, suppressing a transition which contributes to emission from the edge of the quantum wells. We have studied both the emission light polarized in the plane perpendicular (TM) to the quantum well which couples exclusively to the light hole transition and the emission polarized in the plane of the quantum wells (TE) which couples mainly to the heavy hole transition. It was found that the spontaneous emission rates TM and TE increase when the quantum wells are deeper. We have also demonstrated that the photo-generated carriers can escape from the QWs with near unity efficiency, via a thermally-assisted tunneling process, because gain is several orders greater than radiative recombination.
Development and Characterization of Cementing Composites with Blast Furnace Slag Replacement
Authors: Sánchez-Ramírez Reyna , Diaz-Cruz Manuela , Díaz de La Torre Sebastían , Rocha-Rangel Enrique
Published: June 2014

In this work, they were produced and characterized cementing composites made with blast furnace slag replacement, for their use in the construction of oil wells. To this, slurries were prepared with a replacement of 20 and 30% slag, as well as a slurry with 100 % slag and a slurry with 100% H-cement were prepared. Starting materials were characterized by chemical analysis, X-ray diffraction and Fourier Transformed Infra Red. Slurries also were activated with sodium silicate in order to study theirs hydration kinetics, driving by isothermal calorimetry. These studies were complemented by the preparation of specimens of 4 X 4 X 16 cm to which they determine its compressive and bending strength during 2 and 28 days of curing. From the results it can be concluded that it was obtained a product that can be effectively used in the construction of oil wells.
Solid Solutions Study of BaTiO3 Doped on B Site by Electronic Compensation
Authors: Barrientos-Hernández Francisco Raúl , Arenas-Flores Alberto , Lira Hernández Iván Alonso , Gómez-Yáñez Carlos , Pérez Labra Miguel
Published: June 2014

Several compositions of BaTiO:Nb5+ were made by conventional solid-state method in air atmosphere, according to the general formula BaTi1-xNbxO3; (x= 0.005, 0.04, 0.08, 0.20, and 0.25). The crystal structure, microstructure, dielectric and ferroelectric properties of samples were investigated by XRD, Raman Spectroscopy, Electrical Measurements and SEM. X-ray diffraction results clearly indicated that when x ≥ 0.25 was prepared; the hexagonal phase Ba8Ti3Nb4O24 appeared. Electrical measurements at 1 kHz were carried out and several pellets were made, the relative permittivity was calculated. The dielectric constant of the pristine BaTiO3 is about 7000, and the Curie temperature is ≈120°C at room temperature, decreasing to 90°C with Nb5+ addition (x = 0.005).
Synthesis Method for Obtaining Anode-Supported Tubular Solid Oxide Fuel Cells by Slip Casting
Authors: Samperio-Gómez Iván L. , Cortés-Escobedo Claudia A. , Bolarín-Miró A.M. , Sánchez de Jesús Félix
Published: June 2014

Several methods for processing tubular anodes for solid oxide fuel cells have been developed, but many of them are expensive and sophisticated, therefore, there is a great interest in researching the use of a simple process to produce them. In this paper, the results of using slip casting for processing minitubes of NiO-8YSZ with the dimensions of 100x5x1 mm are presented. This is a versatile method for obtaining complex geometries with a suitable surface finish and dimensional precision at low cost compared with ceramic processing which uses high energy consumption and/or has high startup costs. In order to carry out this study, an aqueous slurry of an oxide mixture of NiO-8YSZ with poly-etilenglycol as a dispersant agent was used. The modification of the ratio of water:ceramic powders, the composition NiO:x8YSZ (30, 50 and 70 in wt.) and the casting time (3 to 30 min) were also applied. The minitubes obtained were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and spectroscopy of dispersive energy (EDS). The results show that slip casting is an appropriate method to obtain NiO-8YSZ minitubes. Minitubes of varying composition (30, 50 and 70% in wt. of NiO) with dimensions of 100x5x1 mm were obtained showing an excellent porosity (higher than 96% in v/v) and a homogeneous distribution of NiO and 8YSZ particles. XRD analysis confirms the presence of starting oxides before and after the casting process.
Synthesis, Characterization and Mesomorphic Properties of N,N'-(1,4-Phenylene(methanylylidene))bis(4-(hexyloxy)aniline)
Authors: Caldera Villalobos Martín , García Serrano Jesús , Herrera González Ana María
Published: June 2014

Liquid crystals (LCs) are compounds that have properties between isotropic liquids and solid crystal materials. Although there is not a parameter to predict this behavior, the liquid crystals reported until now have common characteristics, for example rigid groups such as columns or rods within its structures, and long hydrocarbon chains that give flexibility. In this work we report the synthesis and characterization of LC N,N'-(1,4-phenylene bis (methanylylidene)) bis (4-(hexyloxy) aniline). The compound was characterized by infrared (IR), raman and 1H-nuclear magnetic resonance (1H-NMR) spectroscopies. The mesomorphic properties were determined by Differential Scanning Calorimetry (DSC) and Polarized Optical Microscopy (POM). The compound N,N'-(1,4-phenylene bis (methanylylidene)) bis (4-(hexyloxy) aniline) was obtained with a yield of 87 % and purity of 99.9 % determined by elementary analysis. The POM study revealed that this compound have a typical low molecular weight liquid crystal behavior. At temperatures of 157 and 174 °C typical mesophases of liquid crystals were observed; the phase transitions were analyzed by DSC. The POM images reveal the typical birefringence of liquid crystal behavior and different anisotropic textures of smectic and nematic mesophases, these textures are characteristic of the benzylideneanilines or Schiff bases.
Applied-Information Technology with Different Sub-Grid Models in Large Eddy Simulation
Authors: Chen Xin , Wu Yuan Qiang , Wang Huai Yu , Ning Hou Yu
Published: June 2014

Aiming at different sub-grid models of large eddy simulation, numerical simulation of aerodynamic noise caused by rearview mirror was conducted by the large eddy simulation. Compared with experimental data, the results of four sub-grid models on rearview mirror simulation have the difference respectively. Studies have shown that simulation result using the Dynamic Stress Smagorinsky-Lilly model is closest to the experimental data, and the other three models have larger error. Using the Dynamic Stress Smagorinsky-Lilly model in large eddy simulation for predicting aerodynamic noise of rearview mirror is effective and feasible, which can be used as reference for subsequent rearview mirror wind noise prediction.
Performance Evaluations of Carbon/Glass Hybrid Polymer Composites
Authors: Tan Chye Lih , Azmi Azwan Iskandar , Muhammad Noorhafiza
Published: June 2014

In this work, the influence of hybrid effect on carbon and glass fiber reinforced polymer (FRP) on the mechanical performance for structural application was studied. The hybrid fiber reinforced polymer (FRP) composites made from woven E-glass and carbon fibers with epoxy resin. The FRP hybrid composites were fabricated using vacuum-assisted resin transfer moulding process, which is capable of producing constant thickness with high volume fractions of composite panels compared to that of traditional wet hand lay-up method. Mechanical performance of the FRP hybrid composites were evaluated against full carbon or glass fiber reinforced polymer composites. Important properties such as tensile strength, flexural strength and volume fraction of reinforcement were determined according to the ASTM standards. It was found that the mechanical properties of carbon-glass hybrid composites exhibited significant improvement in term of strength and strain respectively compared to that of full glass FRP composites and full carbon FRP composites.
Preparation of Nano Ni2P/TiO2-Al2O3 Catalyst and Catalytic Activity for Hydrodesulfurization
Authors: Song Hua , Wang Zi Dong , Jin Zai Shun , Li Feng , Wang Huai Yuan , Song Hua Lin
Published: June 2014

nanonickel phosphide Ni2P catalysts supported on TiO2-Al2O3 support were prepared by impregnation. The catalysts were characterized by XRD, BET, and XPS. The effects of impregnation method,Ni2P loading on catalyst structure and HDS activity were studied. The results indicated that co-impregnation method is beneficial to the formation of Ni2P and can avoid the formation of Ni12P5. The catalyst prepared with co-impregnation method, Ni2P loading of 30% exhibited the best performance. At a reaction temperature of 606 K, a pressure of 3.0 MPa, a hydrogen/oil ratio of 500 (V/V), and a weight hourly space velocity (WHSV) of 2.0 h-1, the conversion of DBT HDS was 96.0%.
The Green Preparation of Nano-Silver Particle by Reductive Polysaccharide
Authors: Yang Ming Shan , Wen Xin Pin , Li Lin Kai
Published: June 2014

Silver nanoparticles have been prepared using reductive polysaccharides (glucan) as protecting agents and silver nitrate as precursor via a facile green approach, and possible formation mechanism of silver nanoparticle was proposed in this paper. Silver nanoparticles appearance, size and size distribution were controlled by different synthesis technologies and reaction conditions. By changing the reaction conditions such as AgNO3 solution concentration, glucan dosage, reaction temperature, reaction time, the parameters affecting the product shape, particle size and size distribution were investigated. The samples synthesized were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis spectrophotometer (UV-vis) methods. The results have showed that nanosilver particle with different shapes such as rod-like, sheet-like or flake and tree-like etc. can be prepared by reductive polysaccharides, and it is a green preparation technology.
Surface Quality Improvement and Tool Footprint Analysis in a Robotic Grinding Cell
Authors: Dieste José Antonio , Fernández Angel , Roba David
Published: June 2014

Finishing process (Grinding and Polishing), is still manually performed, specially in free form surface parts. This involves a series of remaining problems, mainly related with the geometrical shape of the finished part.
In traditional manually finishing task, the final quality aspect of the part is the only parameter to be controlled. This supposes a lack in the quality parameter control, mainly in high level parts, as in automotive, aeronautics or mould making parts. Manual finishing has not any control about the amount of material removed, during finishing process, affecting this way to the final geometrical shape of the product.
This is the reason why this investigation proposes an exhaustive research of the parameter influencing the finishing tasks, and defining a finishing methodology adapted for an automatic process executed by a spherical robot. Making it an automatic way, and controlling paths, tool, abrasive, and defining a mathematical model for the finishing process, final quality of the part and product will be optimized, from a quality point of view, at the same time process time and cost is reduced.
A Tool Wear Monitoring System for Steel and Aluminium Alloys Based on the same Sensor Signals and Decision Strategy
Authors: Salgado D.R. , Cambero I. , Herrera J.M. , García-Sanz-Calcedo J. , González González Alfonso , Núñez López Pedro Jose , García Plaza Eustaquio
Published: June 2014

This paper presents a tool wear monitoring system that uses the same signals and prediction strategy for monitoring the machining process of different materials, i.e., a steel and an aluminium alloy. It is an important requirement for a monitoring system to be applied in real applications. Experiments have been performed on a lathe over a range of different cutting conditions, and TiN coated tools were used. The monitoring signals used are the AC feed drive motor current and the cutting vibrations. The geometry tool parameters used as inputs are the tool angle and the radius. The performance of the proposed system was validated against different experiments. In particular, different tests were performed using different numbers of experiments obtaining a rmse for tool wear estimation of 17.63 μm and 13.45 μm for steel and aluminium alloys respectively.
Analysis of Color of the Ceramic Coatings Submitted to Different Processing Conditions
Authors: de Oliveira Feitosa Alan , Filho José Elson Soares , dos Santos Leonardo Leandro , Menezes Romualdo Rodrigues , Dutra Ricardo Peixoto Suassuna
Published: June 2014

Color is a very important characteristic in ceramic products. In ceramic coatings, the basis of ceramic is normally classified as red or white basis. Another relevant factor for color variation is the processing to which the material is submitted. In this sense, this work aims to analyze and quantify the color of ceramic pieces used as coatings, which were developed from a formulation of masses, using raw materials such as clay, feldspar, kaolin and quartz. Each raw material was analyzed separately and then a standard formulation was made, involving all of them, and these ones were submitted to different processing temperatures. All the samples were quantified regarding the color, by using the tridimensional colorimetric space by CIELAB method. Results point out that each raw material has an own value regarding color and the temperature has contributed directly to the color variation of the ceramic pieces.
Evolution of aerosol chemistry in Xi'an, inland China during the dust storm period of 2013 – Part 1: Sources, chemical forms and formation mechanisms of nitrate and sulfate
Authors: Wang G. H. , Huang Y. , Tao J. , Ren Y. Q. , Wu F. , Cheng C. L. , Meng J. J. , Li J. J. , Cheng Y. T. , Cao J. J. , Liu S. X. , Zhang T. , Zhang R.
Published: June 2014

Abstract. In the current work TSP sample was hourly collected in Xi'an, an inland mega-city of China near the Loess Plateau, during a dust storm event of 2013 (9 March 18:00–12 March 10:00 LT), along with a size-resolved aerosol sampling and an online measurement of PM2.5. The TSP and size-resolved samples were determined for EC, OC, water-soluble organic carbon (WSOC) and nitrogen (WSON), inorganic ions and elements to investigate aerosol chemistry evolution. Hourly concentrations of Cl−, NO3−, SO42−, Na+ and Ca2+ in the TSP samples reached up to 34, 12, 180, 72 and 28 μg m−3, respectively, when dust peak arrived over Xi'an. Chemical compositions of the TSP samples showed that NH4+ and NO3− strongly correlated each other in the whole observation period (r2=0.76), while SO42− and Cl− well correlated with Na+, Ca2+, Mg2+ and K+ (r2>0.85). Size distributions of NH4+ and NO3− presented a same pattern, which dominated in the coarse mode (>2.1 μm during the event and predominated in the fine mode (<2.1 μm) during the non-event. SO42− and Cl− also dominated in the coarse mode during the event, but both exhibited two equivalent peaks in the fine and coarse modes during the non-event, respectively, due to the fine mode accumulations of secondarily produced SO42− and biomass burning emitted Cl− and the coarse mode enrichments of urban soil-derived SO42− and Cl−. Linear fit regression analysis further indicated that SO42− and Cl− in the dust samples possibly exist as Na2SO4, CaSO4 and NaCl, which directly originated from Gobi desert surface soil, while NH4+ and NO3− in the dust samples exist as NH4NO3. We propose a mechanism to explain these observations in which aqueous phase of dust particle surface is formed via uptake of water vapor by hygroscopic Na2SO4, CaSO4 and NaCl, followed by heterogeneous formation of nitrate on the liquid phase and subsequent absorption of ammonia. Our data indicate that 54 ± 20% and 60 ± 23% of NH4+ and NO3− during the dust period were secondarily produced via this pathway with the remaining derived from Gobi desert and Loess Plateau while SO42− in the event almost entirely originated from the source regions. To the best of our knowledge, the current work for the first time revealed an infant state of dust ageing process in the regions near the source, which is helpful for researchers to understand the panorama of dust ageing process from the source area to the downwind region.
Carbon storage versus albedo change: Radiative Forcing of forest expansion in temperate mountainous regions of Switzerland
Authors: Schwaab J. , Bavay M. , Davin E. , Hagedorn F. , Hüsler F. , Lehning M. , Schneebeli M. , Thürig E. , Bebi P.
Published: June 2014

Abstract. Forestation is seen as a possible option to counter climate change by sequestering carbon in forests and thus reducing the atmospheric concentration of carbon dioxide. However, previous studies suggest that the Radiative Forcing (RF) caused by forestation-induced albedo change in snow-rich boreal regions may offset the carbon sequestration effect. The Swiss mountains are characterized by snow-rich areas with strongly varying environmental conditions and forest expansion is currently the dominant land-use change process. Thus, quantifying both carbon sequestration and albedo change on appropriately high resolution in this region will improve our understanding of the forests potential for climate mitigation. We calculated the albedo RF based on remotely sensed datasets of albedo, global radiation and snow cover. Carbon sequestration was estimated from changes in carbon stocks based on National Inventories. Our results show that the net RF of forest expansion ranges from −24 W m−2 at low elevations of the Northern Prealps to 2 W m−2 at high elevations of the Central Alps. The albedo RF increases with increasing altitude, which offsets the CO2 RF at high elevations with long snow-covered periods, high global radiation and low carbon sequestration. Results indicate that the albedo RF is particularly relevant during transitions from open land to open forest and not in later stages of forest development. The albedo RF offsets the CO2 RF by an average of 40% between 1985 and 1997 when overall forest expansion in Switzerland was approximately 4%. We conclude that the albedo RF should be considered at an appropriately high resolution when estimating the climatic effect of forestation in temperate mountainous regions.
Gravitational and capillary soil moisture dynamics for hillslope-resolving models
Authors: Castillo A. , Castelli F. , Entekhabi D.
Published: June 2014

Abstract. Distributed and continuous catchment models are used to simulate water and energy balance and fluxes across varied topography and landscape. The landscape is discretized into plan computational elements at resolutions of 101–103 m, and soil moisture is the hydrologic state variable. At the local scale, the vertical soil moisture dynamics link hydrologic fluxes and provide continuity in time. In catchment models these local scale processes are modeled using one-dimensional soil columns that are discretized into layers that are usually 10−3–10−1 m in thickness. This creates a mismatch between the horizontal and vertical scales. For applications across large domains and in ensemble mode, this treatment can be a limiting factor due to its high computational demand. This study compares continuous multi-year simulations of soil moisture at the local scale using (i) a 1-D version of a distributed catchment hydrologic model; and (ii) a benchmark detailed soil water physics solver. The distributed model uses a single soil layer with a novel dual-pore structure, and employs linear parameterization of infiltration and some other fluxes. The detailed solver uses multiple soil layers and employs nonlinear soil physics relations to model flow in unsaturated soils. Using two sites with different climates (semiarid and sub-humid), it is shown that the efficient parameterization in the distributed model captures the essential dynamics of the detailed solver.
Quantification of octacalcium phosphate, authigenic apatite and detrital apatite in coastal sediments using differential dissolution and standard addition
Authors: Oxmann J. F. , Schwendenmann L.
Published: June 2014

Abstract. Knowledge of calcium phosphate (Ca-P) solubility is crucial for understanding temporal and spatial variations of phosphorus (P) concentrations in water bodies and sedimentary reservoirs. In situ relationships between liquid- and solid-phase levels cannot be fully explained by dissolved analytes alone and need to be verified by determining particular sediment P species. Lack of quantification methods for these species limits the knowledge of the P cycle. To address this issue, we (i) optimized a specifically developed conversion–extraction (CONVEX) method for P species quantification using standard additions, and (ii) simultaneously determined solubilities of Ca-P standards by measuring their pH-dependent contents in the sediment matrix. Ca-P minerals including various carbonate fluorapatite (CFAP) specimens from different localities, fluorapatite (FAP), fish bone apatite, synthetic hydroxylapatite (HAP) and octacalcium phosphate (OCP) were characterized by XRD, Raman, FTIR and elemental analysis. Sediment samples were incubated with and without these reference minerals and then sequentially extracted to quantify Ca-P species by their differential dissolution at pH values between 3 and 8. The quantification of solid-phase phosphates at varying pH revealed solubilities in the following order: OCP > HAP > CFAP (4.5% CO3) > CFAP (3.4% CO3) > CFAP (2.2% CO3) > FAP. Thus, CFAP was less soluble in sediment than HAP, and CFAP solubility increased with carbonate content. Unspiked sediment analyses together with standard addition analyses indicated consistent differential dissolution of natural sediment species vs. added reference species and therefore verified the applicability of the CONVEX method in separately determining the most prevalent Ca-P minerals. We found surprisingly high OCP contents in the coastal sediments analyzed, which supports the hypothesis of apatite formation by an OCP precursor mechanism.
Factors driving the carbon mineralization priming effect in a sandy loam soil amended with different types of biochar
Authors: Cely P. , Tarquis A. M. , Paz-Ferreiro J. , Méndez A. , Gascó G.
Published: June 2014

Abstract. The effect of biochar on the soil carbon mineralization priming effect depends on the characteristics of the raw materials, production method and pyrolysis conditions. The goal of the present study is to evaluate the impact of three different types of biochar on physicochemical properties and CO2 emissions of a sandy loam soil. For this purpose, soil was amended with three different biochars (BI, BII and BIII) at a rate of 8 wt% and soil CO2 emissions were measured for 45 days. BI is produced from a mixed wood sieving from wood chip production, BII from a mixture of paper sludge and wheat husks and BIII from sewage sludge. Cumulative CO2 emissions of biochars, soil and amended soil were well fit to a simple first-order kinetic model with correlation coefficients (r2) greater than 0.97. Results show a negative priming effect in the soil after addition of BI and a positive priming effect in the case of soil amended with BII and BIII. These results can be related to different biochar properties such as carbon content, carbon aromaticity, volatile matter, fixed carbon, easily oxidized organic carbon or metal and phenolic substance content in addition to surface biochar properties. Three biochars increased the values of soil field capacity and wilting point, while effects over pH and cation exchange capacity were not observed.
Análisis de Retorno Social de la Inversión en dos sistemas de apoyo a personas con gran discapacidad: asistencia personal y servicio residencial. Un estudio de caso
Authors: Huete García Agustín , Quezada García Martha Yolanda
Published: June 2014

En la actualidad existen diferentes alternativas orientadas a proporcionar apoyos a las personas con discapacidad en su vida diaria, que requieren distintos despliegues y esquemas de aplicación de recursos. Estas alternativas, además, suponen diferentes impactos tanto en la vida de la misma persona con discapacidad como en su entorno próximo y en la sociedad. En este artículo se realiza un estudio de caso de una persona usuaria de asistencia personal en el Programa de Apoyo a la Vida Independiente (PAVI) a través de la Oficina de Vida Independiente (OVI) de la Comunidad de Madrid, en comparación con otro caso análogo en el ámbito residencial. El método de análisis utilizado se basa en el enfoque de Retorno Social de la Inversión (SROI, por sus siglas en inglés). Se especifican, asimismo, las decisiones adoptadas para la selección de los casos, los interlocutores consultados para recabar los conceptos y valores, las técnicas de recogida de información, las variables y fórmulas para el cálculo y la monetización. A pesar de su alcance limitado, es posible extraer conclusiones acerca del retorno social de la inversión en un “perfil tipo” que recibe servicios de asistencia personal frente a otro que recibe servicios en un entorno residencial.
Esthétique relationnelle
Authors: Spettel Elisabeth
Published: June 2014

S’il peut sembler paradoxal de parler de manifeste aujourd’hui, dans un contexte d’éclatement des pratiques artistiques et de disparition des mouvements, l’on observe pourtant un retour aux manifestes à la fin du XXe siècle, à l’époque de la « crise de l’art contemporain ». À titre d’exemple, le critique d’art Nicolas Bourriaud publie, en 1995, le livre Esthétique relationnelle : l’ouvrage expose une nouvelle théorie, rassemblant a posteriori des oeuvres très diverses sur le plan des sujets abordés et des styles. Nous constaterons ici que l’entreprise de légitimation par un appui théorique rapproche, dans un premier temps, l’Esthétique relationnelle du manifeste avant-gardiste. Cependant, nous verrons par la suite que l’approche quasi sociologique de Bourriaud et sa revendication d’un héritage s’opposent au ton polémique et à la tabula rasa propres aux avant-gardes. Nous expliquerons ces différences majeures en nous appuyant sur le changement de contexte historique : à l’ère de la globalisation, les artistes contemporains élaborent de nouvelles formes d’engagement et d’utopies, très éloignées de celles de leurs aînés, modifiant, par là même, les modalités et les finalités du manifeste.
Circunstancia familiar y entrada en la vida política del joven poeta valenciano Joan Escrivà (1461-1462)
Authors: Rubio Vela Agustín
Published: June 2014

Resumen: El presente estudio aporta referencias documentales sobre la vida del poeta valenciano Joan Escrivà y, especialemte, sobre su trayectoria vital en los años 1461 y 1462, período en que entró en la vida política.Palabras clave: Joan Escrivà, poesia, Valencia, siglo XV, políticaAbstract: The present study provides documentary references to the life of the valencian poet Joan Escrivà and specially on his own life in the year 1461 and 1462, period in which he entered in his political lifeKeywords: Joan Escrivà, poetry, Valencia, 15th century, politics
Ressenya a Nancy di Benedeto, Libri dal mare di fronte. Lecce: Pensa Multimedia, 2012.
Authors: Perugini Carla
Published: June 2014

Ressenya a Nancy De Benedetto, Libri dal mare di fronte, Lecce, Pensa Multimedia, 2012, pp. 136, ISBN: 978-88-6760-040-3
Solar radiation management impacts on agriculture in China: A case study in the Geoengineering Model Intercomparison Project (GeoMIP)
Authors: Xia Lili , Robock Alan , Cole Jason , Curry Charles L. , Ji Duoying , Jones Andy , Kravitz Ben , Moore John C. , Muri Helene , Niemeier Ulrike , Singh Balwinder , Tilmes Simone , Watanabe Shingo , Yoon Jin‐Ho
Published: June 2014

Geoengineering via solar radiation management could affect agricultural productivity due to changes in temperature, precipitation, and solar radiation. To study rice and maize production changes in China, we used results from 10 climate models participating in the Geoengineering Model Intercomparison Project (GeoMIP) G2 scenario to force the Decision Support System for Agrotechnology Transfer (DSSAT) crop model. G2 prescribes an insolation reduction to balance a 1% a−1 increase in CO2 concentration (1pctCO2) for 50 years. We first evaluated the DSSAT model using 30 years (1978–2007) of daily observed weather records and agriculture practices for 25 major agriculture provinces in China and compared the results to observations of yield. We then created three sets of climate forcing for 42 locations in China for DSSAT from each climate model experiment: (1) 1pctCO2, (2) G2, and (3) G2 with constant CO2 concentration (409 ppm) and compared the resulting agricultural responses. In the DSSAT simulations: (1) Without changing management practices, the combined effect of simulated climate changes due to geoengineering and CO2 fertilization during the last 15 years of solar reduction would change rice production in China by −3.0 ± 4.0 megaton (Mt) (2.4 ± 4.0%) as compared with 1pctCO2 and increase Chinese maize production by 18.1 ± 6.0 Mt (13.9 ± 5.9%). (2) The termination of geoengineering shows negligible impacts on rice production but a 19.6 Mt (11.9%) reduction of maize production as compared to the last 15 years of geoengineering. (3) The CO2 fertilization effect compensates for the deleterious impacts of changes in temperature, precipitation, and solar radiation due to geoengineering on rice production, increasing rice production by 8.6 Mt. The elevated CO2 concentration enhances maize production in G2, contributing 7.7 Mt (42.4%) to the total increase. Using the DSSAT crop model, virtually all of the climate models agree on the sign of the responses, even though the spread across models is large. This suggests that solar radiation management would have little impact on rice production in China but could increase maize production.
Water‐Soluble Luminescent Cyclometalated Gold(III) Complexes with cis‐Chelating Bis(N‐Heterocyclic Carbene) Ligands: Synthesis and Photophysical Properties
Authors: Hung Faan‐Fung , To Wai‐Pong , Zhang Jing‐Jing , Ma Chensheng , Wong Wai‐Yeung , Che Chi‐Ming
Published: June 2014

A new class of cyclometalated AuIII complexes containing various bidentate C‐deprotonated C^N and cis‐chelating bis(N‐heterocyclic carbene) (bis‐NHC) ligands has been synthesized and characterized. These are the first examples of AuIII complexes supported by cis‐chelating bis‐NHC ligands. [Au(C^N)(bis‐NHC)] complexes display emission in solutions under degassed condition at room temperature with emission maxima (λmax) at 498–633 nm and emission quantum yields of up to 10.1 %. The emissions are assigned to triplet intraligand (IL) π→π* transitions of C^N ligands. The AuIII complex containing a C^N (C‐deprotonated naphthalene‐substituted quinoline) ligand with extended π‐conjugation exhibits prompt fluorescence and phosphorescence of comparable intensity with λmax at 454 and 611 nm respectively. With sulfonate‐functionalized bis‐NHC ligand, four water‐soluble luminescent AuIII complexes, including those displaying both fluorescence and phosphorescence, were prepared. They show similar photophysical properties in water when compared with their counterparts in acetonitrile. The long phosphorescence lifetime of the water‐soluble AuIII complex with C‐deprotonated naphthalene‐substituted quinoline ligand renders it to function as ratiometric sensor for oxygen. Inhibitory activity of one of these water‐soluble AuIII complexes towards deubiquitinase (DUB) UCHL3 has been investigated; this complex also displayed a significant inhibitory activity with IC50 value of 0.15 μM.