bluuebunny/crossref_metadata_2025 huggingface dataset:
Trophic State and Toxic Cyanobacteria Density in Optimization Modeling of Multi-Reservoir Water Resource Systems
Authors: Sulis Andrea , Buscarinu Paola , Soru Oriana , Sechi Giovanni
Published: April 2014

The definition of a synthetic index for classifying the quality of water bodies is a key aspect in integrated planning and management of water resource systems. In previous works [1,2], a water system optimization modeling approach that requires a single quality index for stored water in reservoirs has been applied to a complex multi-reservoir system. Considering the same modeling field, this paper presents an improved quality index estimated both on the basis of the overall trophic state of the water body and on the basis of the density values of the most potentially toxic Cyanobacteria. The implementation of the index into the optimization model makes it possible to reproduce the conditions limiting water use due to excessive nutrient enrichment in the water body and to the health hazard linked to toxic blooms. The analysis of an extended limnological database (1996–2012) in four reservoirs of the Flumendosa-Campidano system (Sardinia, Italy) provides useful insights into the strengths and limitations of the proposed synthetic index.
Recombinant Clostridium difficile Toxin Fragments as Carrier Protein for PSII Surface Polysaccharide Preserve Their Neutralizing Activity
Authors: Romano Maria , Leuzzi Rosanna , Cappelletti Emilia , Tontini Marta , Nilo Alberto , Proietti Daniela , Berti Francesco , Costantino Paolo , Adamo Roberto , Scarselli Maria
Published: April 2014

Clostridium difficile is a Gram-positive bacterium and is the most commonly diagnosed cause of hospital-associated and antimicrobial-associated diarrhea. Despite the emergence of epidemic C. difficile strains having led to an increase in the incidence of the disease, a vaccine against this pathogen is not currently available. C. difficile strains produce two main toxins (TcdA and TcdB) and express three highly complex cell-surface polysaccharides (PSI, PSII and PSIII). PSII is the more abundantly expressed by most C. difficile ribotypes offering the opportunity of the development of a carbohydrate-based vaccine. In this paper, we evaluate the efficacy, in naive mice model, of PSII glycoconjugates where recombinant toxins A and B fragments (TcdA_B2 and TcdB_GT respectively) have been used as carriers. Both glycoconjugates elicited IgG titers anti-PSII although only the TcdB_GT conjugate induced a response comparable to that obtained with CRM197. Moreover, TcdA_B2 and TcdB_GT conjugated to PSII retained the ability to elicit IgG with neutralizing activity against the respective toxins. These results are a crucial proof of concept for the development of glycoconjugate vaccines against C. difficile infection (CDI) that combine different C. difficile antigens to potentially prevent bacterial colonization of the gut and neutralize toxin activity.
Immunogenicity of a West Nile Virus DIII-Cholera Toxin A2/B Chimera after Intranasal Delivery
Authors: Tinker Juliette , Yan Jie , Knippel Reece , Panayiotou Panos , Cornell Kenneth
Published: April 2014

West Nile virus (WNV) causes potentially fatal neuroinvasive disease and persists at endemic levels in many parts of the world. Despite advances in our understanding of WNV pathogenesis, there remains a significant need for a human vaccine. The domain III (DIII) region of the WNV envelope protein contains epitopes that are the target of neutralizing antibodies. We have constructed a chimeric fusion of the non-toxic cholera toxin (CT) CTA2/B domains to DIII for investigation as a novel mucosally-delivered WNV vaccine. Purification and assembly of the chimera, as well as receptor-binding and antigen delivery, were verified by western blot, GM1 ELISA and confocal microscopy. Groups of BALB/c mice were immunized intranasally with DIII-CTA2/B, DIII, DIII mixed with CTA2/B, or CTA2/B control, and boosted at 10 days. Analysis of serum IgG after 14 and 45 days revealed that mucosal immunization with DIII-CTA2/B induced significant DIII-specific humoral immunity and drove isotype switching to IgG2a. The DIII-CTA2/B chimera also induced antigen-specific IgM and IgA responses. Bactericidal assays indicate that the DIII-CTA2/B immunized mice produced DIII-specific antibodies that can trigger complement-mediated killing. A dose escalation resulted in increased DIII-specific serum IgG titers on day 45. DIII antigen alone, in the absence of adjuvant, also induced significant systemic responses after intranasal delivery. Our results indicate that the DIII-CTA2/B chimera is immunogenic after intranasal delivery and merits further investigation as a novel WNV vaccine candidate.
Comments on Environmental and Sanitary Aspects of the Scorpionism by Tityus trivittatus in Buenos Aires City, Argentina
Authors: De Roodt Adolfo
Published: April 2014

Deaths by venomous animals are medical emergencies that can lead to death and thus constitute sanitary problems in some regions of the world. In the South of America, the accidents by these animals are a common sanitary problem especially in warm, tropical or subtropical regions, related with rural work in several countries. Argentina is located in the extreme South of South America and a minor part of the continental surface is in tropical or subtropical regions, where most of the accidents by venomous animals happen. However, in the big cities in the center and South of the country, with no relation to rural work, scorpionism, mostly due to the synanthropic and facultative parthenogenetic scorpion Tityus trivittatus, has become a sanitary problem in the last few decades. This scorpion is present in the biggest cities of Argentina and in the last decades has killed over 20 children in provinces of the center and north of the country, mostly in big cities. In addition, it seems that this species is growing and spreading in new regions of the cities. In this revision, some characteristics of this scorpion regarding its habitat, spreading in Buenos Aires city, combat measures and available treatments are discussed.
Quantifying Reaeration Rates in Alpine Streams Using Deliberate Gas Tracer Experiments
Authors: Benson Andrew , Zane Matthew , Becker Timothy , Visser Ate , Uriostegui Stephanie , DeRubeis Elizabeth , Moran Jean , Esser Bradley , Clark Jordan
Published: April 2014

Gas exchange across the air-water interface is a critical process that maintains adequate dissolved oxygen (DO) in the water column to support life. Oxygen reaeration rates can be accurately measured using deliberate gas tracers, like sulfur hexafluoride (SF6) or xenon (Xe). Two continuous release experiments were conducted in different creeks in the Sierra Nevada of California: Sagehen Creek in September, 2009, using SF6 and Martis Creek in August, 2012, using both SF6 and Xe. Measuring gas loss along the creek, which was approximated with the one-dimensional advection-dispersion equation, allows for the estimation of the SF6 or Xe reaeration coefficient (KSF6, KXe), which is converted to DO reaeration (KDO or K2) using Schmidt numbers. Mean KSF6 for upper and lower Sagehen and Martis Creeks were, respectively, 34 day−1, 37 day−1 and 33 day−1, with corresponding KDOs of 61 day−1, 66 day−1 and 47 day−1. In Martis Creek, KXe was slightly higher (21%) than KSF6, but the calculated KDO from SF6 agreed with the calculated KDO from Xe within about 15%; this difference may be due to bubble-enhanced gas transfer. Established empirical equations of KDO using stream characteristics did a poor job predicting KDO for both creeks.
Phase II Study of Bevacizumab, Capecitabine, and Oxaliplatin Followed by Bevacizumab Plus Erlotinib as First-Line Therapy in Metastatic Colorectal Cancer
Authors: Muñoz Alberto , Pericay Carles , García-Girón Carlos , Alonso Vicente , Dueñas Rosario , Cirera Luis , Rivera Fernando , Falcó Esther , Bustos Iñaki Alvarez , Salud Antonieta
Published: April 2014

This phase II trial investigated the efficacy of an induction regimen of bevacizumab, capecitabine plus oxaliplatin (XELOX) followed by maintenance therapy with bevacizumab plus erlotinib as first-line therapy in patients with metastatic colorectal cancer. Patients with metastatic colorectal
cancer received intravenous bevacizumab 7.5 mg/kg plus oxaliplatin 130 mg/m2 on day 1 followed by oral capecitabine 1,000 mg/m2 twice daily on days 1‐14 every 3 weeks for six cycles. In the absence of disease progression, patients then received bevacizumab 7.5
mg/kg every 3 weeks plus oral erlotinib 150 mg once daily. The primary study endpoint was progression-free survival. In the intention-to-treat population (n = 90), the median progression-free survival was 9.2 [95% confidence interval (CI): 7.9‐11.9] months, and the median overall
survival was 25.8 (95% CI: 18.0‐30.9) months. In the patient subpopulation who received both induction and maintenance therapy (n = 52), median progression-free survival was 11.1 (95% CI: 9.0‐15.7) months, and the median overall survival was 29.5 (95% CI: 23.7‐36.7)
months. KRAS status did not predict efficacy. The most common grade 3/4 adverse events were diarrhea, asthenia, and neutropenia. XELOX‐bevacizumab for 6 cycles followed by bevacizumab‐erlotinib maintenance therapy has been shown to be a highly active and well-tolerated first-line regimen in patients with metastatic colorectal cancer.
Clean and fast cross-coupling of aryl halides in one-pot
Authors: Pandarus Valerica , Gingras Geneviève , Béland François , Ciriminna Rosaria , Pagliaro Mario
Published: April 2014

Unsymmetrically coupled biaryls are synthesized in high yield starting from different aryl bromides and bis(pinacolato)diboron by carrying out the Miyaura borylation reaction followed by the Suzuki–Miyaura reaction in the same reaction pot over 1–2 mol % SiliaCat DPP-Pd. The SiliaCat DPP-Pd catalyst is air-stable and the method does not require the use of inert conditions. The use of non-toxic isopropanol or 2-butanol as reaction solvent further adds to the environmental benefits of this new green synthetic methodology.
N-Alkylated dinitrones from isosorbide as cross-linkers for unsaturated bio-based polyesters
Authors: Goerz Oliver , Ritter Helmut
Published: April 2014

Isosorbide was esterified with acryloyl chloride and crotonic acid yielding isosorbide diacrylate (9a) and isosorbide dicrotonate (9b), which were reacted with benzaldehyde oxime in the presence of zinc(II) iodide and boron triflouride etherate as catalysts to obtain N-alkylated dinitrones 10a/b. Poly(isosorbide itaconite -co- succinate) 13 as a bio-based unsaturated polyester was cross-linked by a 1,3-dipolar cycloaddition with the received dinitrones 10a/b. The 1,3-dipolar cycloaddition led to a strong change of the mechanical properties which were investigated by rheological measurements. Nitrones derived from methyl acrylate (3a) and methyl crotonate (3b) were used as model systems and reacted with dimethyl itaconate to further characterize the 1,3-dipolaric cycloaddition.
Kinetics of Hydrogenolysis of Glycerol to Ethylene Glycol over Raney Ni Catalyst
Authors: Jiang Tao , Ren Mei Xuan , Chen Shi Shi , Huai Qiang , Ying Wei Yong , Cao Fa Hai
Published: April 2014

The rapid development of biodiesel production yields large amount of glycerol as a by-product. It is a resource-utilization efficient and biological technical process to employ hydrogenolysis of glycerol aqueous solution for ethylene glycol generation. In this work, Raney Ni catalyst was prepared through conventional means and tested for hydrogenolysis of glycerol to produce ethylene glycol. The experiments were performed by varying the reaction time and rotate speed at a hydrogen pressure of 6.0-10.0MPa over a temperature range of 453-493K using a batch reactor. The effect of reaction conditions on the conversion of glycerol and the product distribution were also investigated and discussed. The results indicated that with the increase of reaction time the conversion of glycerol and the selectivity of 1,2-PDO tended to rise but the concentration of ethylene glycol decreased after reaching a peak point. The conversion of glycerol reached as much as 100% and the selectivity of ethylene glycol reached a maximum of 40%. Based on the experimental data, the reaction kinetics was studied and the parameters involved a two-site Langmuir-Hinshelwood model were acquired by the parameter estimation method. In the end, residual error distribution and statistic test showed that the obtained kinetic model was suitable and acceptable.
Production of High-Purity Hydrogen and Carbon Dioxide Capture by Sorption Enhanced WGS Reaction Process
Authors: Chou Cheng Tung , Huang Yu Jie , Yang Hong Sung
Published: April 2014

Global warming has become more and more serious, which is caused by greenhouse gases. Cutting down the emission of CO2 has already become one of the major research target in the world. This study is numerically investigating Thermal Swing Sorption Enhanced Reaction Process on water gas shift (WGS) reaction by Na2O-promoted alumina. According to Le Chateliers law, the forward reaction rates and conversion can be increased by removing some products selected. Therefore, this concept can be used to generate product of high-purity hydrogen. The purified H2 can be sent to gas turbine for generating electrical power or can be used for other energy source. Carbon dioxide can also be recovered and sequestrated to reduce greenhouse gas effects. The method of lines is utilized in simulation, combined with upwind differences, cubic spline approximation and LSODE of ODEPACK software to solve the problem. The concentration, temperature, and adsorption quantity in the bed are integrated with respect to time by LSODE of ODEPACK software. The simulation is stopped when the system reaches a cyclic steady state. In this study, we first simulate breakthrough curve of Na2O-promoted alumina cited from literatures to prove the accuracy of simulation program. The optimal operating conditions of the WGS TSA (temperature swing adsorption) single-bed six-process is obtained by varying operating variables, such as feed time and rinse time. Furthermore, WGS TSA single-bed six-process could achieve 99.89% purity of H2 (dry-basis) as the top product and 90.95% purity and 98.22% recovery of CO2 (dry-basis) as the bottom product.
Dielectric Properties and Microstructure of BaO-Nd2O3-Bi2O3-TiO2 Microwave Ceramics with Li2O-B2O3-SiO2
Authors: Zhang Yong Gang , Wu Xiao Gang
Published: April 2014

Low temperature co-fired ceramics (LTCC) technology becomes crucial in the development of various modules and substrates in electronic packaging, especially in wireless and microwave applications [. With this technology, passive components (such as capacitors and inductors) can be embedded into substrates, and co-fired with high-conductive metals (such as silver and copper) below 900°C. Therefore, the shringkage and dielectric properties of LTCC are of great importance to the performance of components. So far, ceramic/glass composites have been widely researched for LTCC application due to tailored physical properties and low sintering temperature [2-3].
Thermal Behaviour of Slurry Prepared from Clermont Bituminous Coal and Oil Palm Empty Fruit Bunch Bio-Oil
Authors: Hamdan Hazlin , Shahruddin Munawar Zaman , Mohamad Daud Ahmad Rafizan , Syed-Hassan Syed Shatir A.
Published: April 2014

Investigation on the pyrolysis behaviour of coal-biooil slurry (CBS) fuel prepared at different ratios (100:0; 70:30; 60:40;0: 100) were conducted using a Thermogravimetric Analyzer (TGA). The selected coal sample was Clermont bituminous coal (Australia), while Empty Fruit Bunch (EFB) was used as source of bio-oil that was thermally converted by means of pyrolysis. Thermal degradation of CBS fuel was performed in an inert atmosphere (50mL/min nitrogen) under non-isothermal conditions from room temperature to 1000°C at heating rate of 10°C/min. The proportions of CBS fuel at 70:30 and 60:40 blends were observed to have influenced the fuel properties of the slurry. The addition of bio-oil will shift the temperature region towards early devolatilization. Meanwhile, the thermal profiles of the blends, showed potential trends that followed the characteristics of an ideal slurry fuel where highest degradation rate was found at the blend ratio of 60:40 biooil/coal. These findings can be useful to the development of a slurry fuel technology for application in the vast existing conventional power plants.
Regeneration of Activated Carbon Using Photo-Oxidation Process
Authors: Al-Dawery Salam K.
Published: April 2014

Activated carbon has been used as an adsorbent for centuries. For purpose of regeneration, advanced oxidation processes is sugested, this approcah could be viable from the econmic and environmental point of view, and appears as an alternative to the many of inefficient single-step processes actaully applied for the regeneration process.
The results showed that the Titanium dioxide can easily regenerate the AC by oxidizing the organic compounds adsorbed on the surface of AC. The increase of UV light intensity has a positive effect on the adsorption capacity. However, the increase of TiO2 concentrations have a small negative effect on the adsorption capacity of the AC.
Keywords: regeneration, activated carbon, photo-catalyst
The Effect of Preparation Method of Precursor on Synthesis of BiFeO3 by a Hydrothermal Method
Authors: Xiao Yang , Cao Zhen Zhu , Shao Ru Yi , He Wei Yan , Gao Yan Fang , Liu Jin Rong
Published: April 2014

The precursor of bismuth ferrite BiFeO3 powders were prepared by the normal co-precipitation and reversed co-precipitation method. The key influencing factors including the reaction time, the concentration of mineralizer and the molar ratio of raw materials in the normal co-precipitation are systematically studied. Pure BiFeO3 powder has been obtained by adjusting the molar ratio of raw materials. Based on the results of the normal co-precipitation, a simple reversed co-precipitation process has been developed.
Curvature Elastic Energy Model for Carbon Nanotubes
Authors: Yao Wen Wei
Published: April 2014

Since carbon nanotubes (CNTs) were discovered, due to their unique and novel physical and chemical characteristics, many studies focus on them. In this article, a two-dimensional (2D) curvature elastic energy model for isotropic tube is presented, and reduced to a one-dimensional (1D) continuous model which is in accordance with Kirchhoff elastic rod theory. The problems remaining to be solved are discussed.
Micro-Structural Properties of Zinc Oxide Nano-Particles Synthesized by Bio-Polymeric Templates
Authors: Mandal Sujata , Savio Dominic , Selvaraj S.J. , Natarajan S. , Mandal Asit Baran
Published: April 2014

Zinc and iron oxide nanoparticles were synthesized using natural bio-polymeric templates viz. cellulose and sodium alginate. Cellulose fibres from different sources viz. filter-and blot-papers, were used as templates for this purpose. The synthesized Zinc oxide nanoparticles were characterized by X-ray diffraction (XRD), fourier transform infra-red spectra (FT-IR), UV-Visible spectrophotomer (UV-Vis) and scanning electron microscopic (SEM) studies. XRD studied confirmed the formation of highly crystalline hexagonal wurtzite phase of ZnO in all the synthesized nanoparticles. The average crystallite sizes of the nanoparticles obtained using different templates, were well below 50 nm. Characteristics of the zinc oxide nanoparticles obtained by template-based techniques were compared with those obtained by co-precipitation technique. Influence of various templates on the characteristics of metal oxide nanoparticles was studied.
Preparation and In Vitro Degradation of PDO Intravascular Stents with Braided Structure
Authors: Wang Cong R. , Xu Hui Jun , Zhang Pei Hua
Published: April 2014

In this paper, in vitro degradation behaviors of the PDO monofilaments and the stents were studied. The mechanical properties,morphology observation and Differential Scanning Calorimeter (DSC) of PDO monofilaments were determined, as well as the compression strength of the stents. The experimental results showed that the PDO monofilaments contained half of its original strength after 6 weeks degradation and lost its strength in the 10thweek. DSC outcomes showed that the crystalline regions of PDO havent been hydrolyzed after 16 weeks of degradation. The stents demonstrated good compression behaviors for 12 weeks and therefore can be utilized in short-term application.
The Change of Processing Maps in Hot Compression Procession for Ti-6.0Al-7.0Nb Biomedical Titanium Alloy
Authors: Liu Yan Hui , Yao Ze Kun , Ning Yong Quan , Guo Hong Zhen , Zhao Zhang Long
Published: April 2014

Isothermal compression tests were carried out on Ti-6.0Al-7.0Nb biomedical titanium alloy at the temperatures of 750900°C (all below β phase transition temperature about 1010°C) and strain rates of 0.0011.0s-1. The processing maps were constructed to evaluate the efficiency of power dissipation (η) and recognize the flow instability regimes. True strain takes great effect on the efficiency of power dissipation η under the different temperatures and strain rates. The value of power dissipation η increases from 0.1 to 0.7 in most areas. When the strain is 0.9, the value of power dissipation η in most regimes is from 30% to 40%. There are two instability regimes respectively located around 780°C/1.0s-1 and 860-900°C/0.001-0.01s-1 when the strains are below 0.5. One of the instability regimes disappears when the strains are 0.5-0.7. When the strain is 0.9, there are still two instability regimes. The safe regime located around 780-840°C/0.1-0.01s-1, and hot deformation can be carried out in this area.
Electrochemical Corrosion Behavior of Different Graphite Shapes Cast Irons in Acidic Solution
Authors: Yu Zhu Huan , Qiang Jun Feng , Li Hui Lu
Published: April 2014

The effect of graphite shapes on the electrochemical corrosion behavior of cast iron was studied by means of weight loss tests, electrochemical measurements and electron microscopy. It was found that the electrochemical corrosion behavior of graphite is significantly different from one other, and the corrosive potential difference between carbide ad the matrix is the main driving force of the different phase corrosions. Among them, the center A type and edge D type graphite exhibited the highest corrosion resistance. The corrosion of white iron is worst, because there are so many type carbides in white iron and so there is an obvious tendency to produce micro-cell in white iron.
The Extrusion Behavior of Mg Alloys Interpenetrating with Stainless Steel Wire
Authors: Li Ping , Wang Shou Ren , Wang Yong , Xue Guang Ji
Published: April 2014

The interpenetrating magnesium composites reinforced by three-dimensional braided stainless steel wire reinforcement were fabricated. And, the deformation behavior of materials was analyzed in four extrusion velocities by DEFORM-3D software. The results show that with the increases of extrusion velocities, the equivalent stress values exhibit a gradually increasing and then decreasing trend. Owing to the effect of three dimensional reinforcement, the basal plane orientation occur tilt. And, the microstructure turns refined.
Flexural Toughness of Hybrid Fiber Reinforced Concrete under Notched Beam Three-Point Bending
Authors: Xiong Si Hui , Xia Dong Tao , Liu Xiang Kun
Published: April 2014

In order to focus on hybrid fiber reinforced concrete flexural toughness,mixed 0.7% steel fiber/0.3% modified polypropylene fiber reinforced concrete, mixed 0.89% steel fiber/0.11% Dura fiber reinforced concrete were chosen to perform flexural toughness test. The test method is giving a central point load to the notched beam specimens (H*B*L1:150mm*150mm*550mm, h1*B1:2mm*25mm) with a 0.2 mm/min loading rate. The load we carry out should not stop until the mid span deflection is more than 3mm.Based on calculating the contribution of the fiber to the energy absorption value Dcr when the concrete cracking,the contribution of the fiber to the energy absorption value D1f when mid-span deflection is δ1,the contribution of the fiber to the energy absorption value D2f when mid-span deflection isδ2 and the equivalent flexural tensile strength feq1,feq2,the effect of the way use to hybrid fiber on the flexural toughness of concrete were investigated. The results shows that the hybrid fiber can significantly improve the flexural toughness of concrete, have favorable deformability and the ability to control crack. The result of 0.7% steel fiber/0.3% modified polypropylene fiber reinforced concrete is shown: Dcr=2185 Nmm,D1f=7634.26 Nmm,D2f=2198.67 Nmm, feq1=4.89 MPa,feq2=2.83 MPa, hence it shows the positive enhancement effect of hybrid fiber and flexural toughness increase significantly.
Research on the Longitudinal Displacement between Track Plate and Filling Layer under the Influence of Temperature
Authors: Zhang Zhi Chao , Zeng Zhi Ping , Liu Fu Shan , Zhang Yi Ming , Zeng Da Peng
Published: April 2014

In the construction process, it is not a one-time work to complete the track plates overall longitudinal connection of the CRTSII ballastless track structure. Moreover, due to the tracks longitudinal connection, temperature difference can form displacement accumulation in the whole structure. Under some serious circumstances, it may even produce excessive longitudinal displacement between track plate and mortar layer, and make mortar layer void. Based on the finite element method, a finite element model is built on the track plate and mortar layer. By targeting at the free end of the track plate, carry on a stress displacement analysis; study the influence of changeable temperature on motor layers relative displacement with track plate,the reasonable construction temperaturefor construction is put forward. The research results provide references for the ongoing ballastless track construction on the passenger dedicated line.
Experimental Study on Axial Tensile Strength of Low Volume Fraction of Ternary Hybrid Fiber Reinforced Concrete
Authors: Zhu Yu Ting , Xia Dong Tao , Zhou Bo Ru
Published: April 2014

In this paper, according to the national standard and testing methods,the direct tension strength,splitting tensile strength and cubic compressive strength test were carried out for 8 different groups of hybrid fiber (containing steel fiber, macro-polypropylene fiber and dura fiber) reinforced HPC specimens.The results showed that when the volume proportion of ternary hybrid fiber was less than 1%, there was not obvious influence for the concrete compressive strength, but the splitting tensile strength increased by 26% ~ 69%; the ratio between splitting tensile strength and compressive strength for HFRC increased to 1/12~1/9. When added 0.7% steel fiber, 0.19% macro-polypropylene fiber and 0.11% dura fiber, the confounding effect was the best. Based on the advantages and disadvantages of tensile splitting strength and direct tensile strength test and the results of tests, the concept of equivalent tensile strength and calculative formula was put forward .
Processing Effect on the Compressive Strength and Bioactivity of Ti-Based Composites Produced with TiH2 and Calcium Phosphate
Authors: Gemelli Enori , Nery Fabio , Camargo Nelson Heriberto Almeida , Rodrigues Henriques Vinicius André , da Silva Daiara Floriano
Published: April 2014

Titanium-based composites with bioactive phases were produced with TiH2and 10% in volume of calcium phosphate. The mixtures were prepared either by conventional powder metallurgy processing or by ultrasound, dried in a rotary evaporator, pressed at 600 MPa and vacuum-sintered at 1200 °C for 2 hours. Crystal phases of the as-fabricated composites are found to be α-Ti, CaTiO3and TixPyphase (s). The TixPyand CaTiO3phases resulted from the reaction between titanium and tricalcium phosphate at about 1130 °C. Calcium phosphate was better dispersed by ultrasound leading to a higher compressive strength of the composite and a more uniform Ca-P deposition in simulated body fluid solution.
Performance Improvement of Dye-Sensitized Solar Cell by Optimizing TiO2-Photoanode Structure
Authors: Yang Fei , Liu Li Feng , Wang Xu , Kang Jin Feng
Published: April 2014

A composite TiO2 photoelectrode structure is explored to optimize the dye-sensitized solar cell (DSSC) properties. The composite TiO2 photoanodes consist of two nanoparticular TiO2 layers with different size and thickness. The impact of film thickness on the performance of DSSCs was also investigated. In the optimized composite photoelectrode structure with large sized TiO2 nanoparticle as light scattering layer, the significantly improved performance of DSSC with 25% increase of current density and 13.1% increase of conversion efficiency was experimentally demonstrated.
Synthesis and Luminescence Properties of Ba3Y1-xEuxB3O9 (0.05≤x≤0.35) under UV Excitation
Authors: Li Xiao Xia
Published: April 2014

Single phase of Ba3Y1-xEuxB3O9 (0.05 ≤ x≤ 0.35)samples was prepared by the solid state reaction. The crystal structure, the surface, the particle size and luminescence properties were characterized by X-ray diffractometer, scanning electron microscopy and spectrophotometer. The results showed that the obtained samples with the particle size from 0.3 to 1.5 um were hexagonal structure. Monitored by 592 nm emission, the excitation spectra of Ba3Y1-xEuxB3O9were dominated by the charge transfer band of O2-→Eu3+ peaking at about 259 nm until x= 0.15; the transition from 7F0 to 5L6 level of Eu3+ at about 395 nm was maximum after x> 0.15. The strongest emission peak due to the 5D0→7F1transition of Eu3+ was all located at about 592 nm in the emission spectra of Ba3Y1-xEuxB3O9, and the maximum emission was obtained at x= 0.15 and 0.3 under 254 and 395 nm excitation, respectively. The excitationprocess under the two excitation energies was analyzed. It indicated that only the centrosymmetric lattices could be excited under 254 nm excitation; both the centrosymmetric and noncentrosymmetric positions could be excited by 395 nm, accordingly, the ratio of the red emission (5D0→7F2) to the orange one (5D0→7F1) increased, leading to a better chromaticity of the phosphors.
Sol-Gel Synthesis and Characterization of Ultrafine ZrSiO4 Powder
Authors: Li Zhen Quan , Zhen Qiang , Wang Ya Li
Published: April 2014

High purity ZrSiO4 powder were synthesized using Si (C2H5O)4 and ZrOCl2·8H2O as raw materials by the sol-gel method, LiCl was added as mineralizer to promote crystallization of zircon. The influences of molar ratio of Zr:Si, calcined time and calcined temperature on the synthesis of ZrSiO4 powder were investigated. XRD, SEM and TEM were used to characterize the powders. It was found that when the molar ratio of Zr:Si was 1:1.2, the calcined temperature was 1600°C and the calcined time was 4h, the high purity ZrSiO4 ultrafine powder was obtained. The ZrSiO4 formation began at 1300°C and when the gel was calcined at 1600°Cfor 4 h, the formation rate of ZrSiO4 was up to 95%. SEM and TEM studies reveal a homogeneous product with particle sizes on the order of 0.1-1μm. The IR emissivity of ultrafine ZrSiO4 is 0.892 at the whole wavelength range, and that is up to 0.951 at the wavelength range of 8-14 μm.
Lithium Storage Property of MoS2 with Mechanical Alloying Treatment
Authors: Han Xue Song , Jiang Xun Yong , Yin Shou Gen
Published: April 2014

MoS2 is a candidate for new generation lithium ion battery anode. In this paper, two groups of materials, pure MoS2 and MoS2/graphite composite, were treated by mechanical alloying (MA). The results showed that MA treatment did not change the phase structure of MoS2, but MA will reduce the particle size of MoS2. For MoS2/graphite composite, MA makes graphite distributing homogeneous on the surface of MoS2. After MA, MoS2 keeps the character of 100% columbic efficiency during charging and discharging process. With the increase in cycle number, capacity of MoS2 decays. MA treatment on MoS2 accelerates the decay of capacity. The addition of graphite in MoS2 reduces the harmful effect of MA treatment on cycling property.
Effects of Preparation of Cement Raw Meal with Carbide Slag on the Environment and Equipments
Authors: Wang Ya Li , Cui Su Ping , Wang Hui , Dong Shi Jie , Yao Yan
Published: April 2014

Based on the physical and chemical properties of carbide slag, the contents of heavy metals in effluent came from carbide slag drying process were studied, and then the composition of exhaust gas emitted from the carbide slag drying process and calcinations process of raw materials prepared with carbide slag was detected, in order to know whether there are harmful or corrosive gases released and the effect of the emissions on the environment and related equipments. The results indicate that the exhaust gases emitted from the calcination process of raw meal prepared with carbide slag is mainly composed of CO2 and water vapor, and is free from harmful gases. However, a lot of water in carbide slag during the pre-heat and decomposition process under high temperature would accelerate the corrosion of equipments. Simultaneously, a small number of heavy metal ions contained in the carbide slag can cause environmental pollution and sulfides would be adverse to the cement calcination process resulting in the crust blockage of kiln.
Equilibrium and Kinetics Studies of Phosphate Removal from Solution onto a Hydrothermally Modified Al-Si-Fe-Ca Composite Adsorbent
Authors: Wu Qiong , You Rui Rong , Wu Qiu Ping , Chen Fei Yun , Yu Yan
Published: April 2014

A novel Al–Si–Fe–Ca composite material for phosphate removal in wastewater treatment was made by using Al (OH)3,Fe2O3,CaO and silica powder as raw materials. Sorption data modelling with a pH range of 3–12, P concentrations of 3,5,7,9, 11,13, 15mg L−1, and an ambient temperature of 23°C indicated that an optimal removal of P occurred at pH 6.0. A maximum removal of 99.68% was found for 11mg L−1(pH of 6). Langmuir isotherm best described theadsorption processwith a maximumadsorption capacity of 8.60mg g−1. Three kinetic models (apseudo-first-order, a pseudo-second-order (PSO) and Elovich) were also applied,and the results showed that the PSOmodel best described the data. SEM and EDAX analysis confirmed that P was adsorbed to the surface of the composite material. This study demonstrates that the composite adsorbent is suitable for use in wastewater treatment, with P removal of the solids being preferential and spontaneous.
Environment Impact of Freight Transportation in China
Authors: Zhang Yu Feng , Gong Xian Zheng , Wang Zhi Hong , Liu Yu
Published: April 2014

Transportation is an important part of industrial production systems, with serious energy consumption and environmental pollution. In this study, environment impact of road transportation, river freight in the Yangtze River, and railway transportation was established and analyzed by life cycle assessment method. The analysis results show that CO2 is the largest emission of pollutants for freight transport in China. abiotic depletion potential (ADP) of electric locomotives significantly lower than the other five kinds of shipping methods, only 3.2% of diesel locomotive, 3.9% of the Yangtze barges fleet; 1.2% of the Yangtze Cargo vessel, 0.2% of heavy-duty trucks and 0.1% of light-duty trucks. The results show that accomplishing the same cargo turnover, light-duty truck has the largest environmental impact, while the Electric locomotive freight has the minimum environmental impact. Although the environmental impact of river freight transport is greater than rail transport, but it is far less than road transport.
Environmental Coordinated Analysis of Corrugated Box Based on LCA
Authors: Li Xiao Peng , Wang Wei , Jiang Bin , Jian Yu Ping
Published: April 2014

Corrugated box, as a kind of packaging product in the paper packing industry, fulfills the requirements on China’s circular economy development, and has become one of the most widely adopted containers for modern packing.
The analysis of corrugated box has shown that the main affection of corrugated box were respiratory inorganics, climate change and acidification/eutrophication. The critical point has been found in respiratory inorganics which normalization result is 50.64, and the impact categories showed climate change was 898793.5 kg CO2-eq in the system. The serious life cycle stages were the manufacture of base paper and cardboard/corrugated box.
A Recyclable Method for Preparation of Hydrochars and Silica from Rice Husk
Authors: Ma Xiao Yu , Wang Li Li , Cui Su Ping , Wang Ya Li
Published: April 2014

In the present work, a green and sustainable route for preparation of hydrochars and silica from a bio-resource (rice husk) under low temperature and atmospheric pressure was described. This route was achieved with the catalysis of sulfuric acid and NH4F. The sphere-like carbon materials with regular size of about 500nm were obtained at 95°C for 6 h when the acid concentration was 42% and 52%. The obtained yield of silica reached up to 94.6% and the particle size was 50-60nm. The morphology of the hydrochars was controllable by changing the concentration of sulfuric acid. Microstructure of the precipitated silica powder was carried out using transmission electron microscopy (TEM). The preparation conditions were determined and the recyclability of the process was confirmed experimentally. All the reactants and byproducts were recyclable in this process, without the waste emissions.
Molecular Dynamics Study on Shear Property of Single-Crystal Bi2Te3
Authors: Huang Ben , Zhai Peng Cheng , Liu Li Sheng
Published: April 2014

The shear property of the thermoelectric material Bi2Te3is inextricably linked with its layer structure. By the molecular dynamics method, the mechanism of shearing deformation was studied in this paper. In the simulation, cubic single-crystal simulation cells with different layer directions inside were adopted, ensuring that thecaxis of crystal lattice can be along, across and 45odeviated from the shear stress. Compared with all the calculation models, the results show that when the shear stress increases, slip occurs along the Te1-Te1 adjacent layers which are connected by the weak van der Waals bonding, and ultimately leads to structural fracture. Furthermore, size effect and loading modes can also impact the behavior of shearing deformation, however, in very different ways. Future efforts should be focused on the influence of the creation and motion of defects during the deformation as well as temperature effect and strain rate effect.
Preparation and Characterization of Electrodeposited CuxBi2Te3 Thermoelectric Films
Authors: Hu Yue Chao , Zou Zhi Gang , Cai Ke Feng
Published: April 2014

CuxBi2Te3films were prepared by chronopotentiometry electro-deposition on indium tin oxide (ITO)-coated glass substrates from an aqueous acidic electrolyte at room temperature. The films were deposited at the same current density but in electrolyte with different Cu2+concentrations: 0.1, 0.25, 0.5, 0.75 or 1mM. The phase composition and morphology of the films were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and field emission scanning electron microscope, respectively. The electrical conductivity and Seebeck coefficient of the CuxBi2Te3films were measured after being transferred onto a non-conductive rubberized fabric support. All the films showed n-type conduction with Seebeck coefficient in the range of-63 to-84μV/K, and the electrical conductivity in the range of 90 to 185S/cm. The film deposited from an electrolyte with 0.5mM Cu2+showed higher power factor ~130 μW/K-2m-1.
Thermal Aging Behavior of CoSb3 with Protective Mo Coating
Authors: Zhao De Gang , Zuo Min , Teng Xin Ying , Geng Hao Ran
Published: April 2014

In order to prevent the sublimation of Sb, protective Mo coatings were deposited on the CoSb3 substrate by DC magnetron sputtering. Thermal aging behavior of CoSb3 with Mo coating was investigated by accelerated experiment at 650oC for 24h. The results indicated that Mo coatings exhibit columnar crystal and body-centered cubic structure. It was found that the weight loss decreases with the increasing thickness of Mo coating. In comparison with naked CoSb3 material, the degradation of thermoelectric properties of CoSb3 with Mo coatings decreases under accelerated thermal aging test.
Evaluation and Optimization of Ba0.2Sr0.8Co0.9Nb0.1O3-δ-Gd0.1Ce0.9O1.95 Composite Cathodes for IT-SOFCs
Authors: Zhang Lei Lei , Huang Jin Hua , Song Zhao Yuan , Fu Yi Dan , Liu Mo , He Tian Min
Published: April 2014

Ba0.2Sr0.8Co0.9Nb0.1O3-δ(BSCN0.2)-xGd0.1Ce0.9O1.95(GDC) (x = 10, 20, 30 and 40 wt.%) composite cathodes were investigated for the potential application in the IT-SOFCs. The results of chemical compatibility measurement show that a small number of Gd and/or Ce ions may melt into the lattice of BSCN0.2 to form BSCN0.2-GDC solid solution. Thermal expansion coefficients effectively reduced by the incorporation of GDC. The electrochemical performance of BSCN0.2-xGDC composite cathodes increased with increasing x from 10 to 30 wt.%. When x = 30 wt.%, the area specific resistances were only 0.040 and 0.017 Ω cm2at 750 and 800oC, respectively. This improved electrochemical performance is attributed to the good thermal expansion match between BSCN0.2-xGDC composite cathode and GDC electrolyte, and the increased oxygen vacancy concentration. With further increasing x, the electrochemical performance of the composite cathode decreased. This result may be due to the ambipolar resistance model of porous composite cathode and the poor electrical conductivity of BSCN-40GDC. The maximum power densities of a BSCN0.2-30GDC/La0.9Sr0.1Ga0.8Mg0.2O3-δ/NiO-Sm0.2Ce0.8O1.9single-cell achieve 537 and 722 mW cm-2at 750oC and 800oC, respectively. These results indicate that the BSCN0.2-30GDC composite cathode is a promising candidate for IT-SOFC.
Facile Solution-Grown Mo-Doped Vanadium Dioxide Thermochromic Films with Decreased Phase Transition Temperature and Narrowed Hysteresis Loop Width
Authors: Zhao Li Li , Miao Lei , Liu Cheng Yan , Li Chao , Cheng Hao Liang
Published: April 2014

Molybdenum (Mo) doped vanadium dioxide (VO2) (V1-xMoxO2) thermochromic thin films with different Mo concentrations on borosilicate glasses were successfully synthesized via a facile and economic solution-based deposition method. The influences of substitutional doping with Mo dopants on the crystal structure and film morphology of VO2 were evaluated. All of the films were confirmed to be pure monoclinic crystalline phase of VO2 and no molybdenum oxides formed, suggesting the formation of a homogeneously dispersed solid-solution. The particle sizes and root-mean-square (RMS) roughness level obviously decreased upon Mo doping. V1-xMoxO2 films exhibited low metal-semiconductor transition (MST) temperature (Tc) and retained the excellent switching property at near-infrared region simultaneously. The rate of change of Tc with Mo doping reached as high as ~10°C/at.%. The reduced Tc may be attributed to the disruption of homo-polar V4+-V4+ bonding after the incorporation of Mo atoms in VO2 octahedron configuration. V1-xMoxO2 thin films exhibited narrower hysteresis loop width compared to undoped VO2, which show the promise for promoting practical implementation of VO2-based thermochromic fenestration.
Influence of RTA Treatment on the Properties of ZnO-CeO2 Dielectric Films
Authors: Tseng Ching Fang , Yang Ren Ya , Chen Chien Hua
Published: April 2014

The electrical and physical properties of ZnO-CeO2 thin films on n-type Si (100) substrates have been examined by sol-gel method. In addition, the structures were heat treated at different temperatures from 600 to 700oC using the RTA (Rapid Thermal Annealing) process and investigated the influence of RTA effect on their properties. The diffraction pattern showed that the deposited films exhibited a polycrystalline microstructure. All films exhibited ZnO-CeO2 peaks orientation perpendicular to the substrate surface and the grain size with the dependent on annealing temperature. The dependence of the physical and electrical characteristics on various annealing temperatures was investigated.
Investigation of the Morphotropic Phase Boundary (MPB) of (1-x-y)BaZrO3-x(K0.45Na0.5Li0.05)NbO3-yBi (Mg0.5Ti0.5)O3
Authors: Wu Rui Lin , Karaki Tomoaki , Zeng Jiang Tao , Zheng Liao Ying , Ruan Wei , Ruan Xue Zheng , Li Guo Rong
Published: April 2014

Lead-based piezoelectric ceramics have excellent piezoelectric properties with the compositions near the rhombohedral-tetragonal morphotropic phase boundary (MPB)[1,2]. In these materials, the dielectric and piezoelectric properties show the maximal values at MPB. For lead-free piezoelectric ceramics, finding the MPB area is a promising way to improve their properties. In this paper, the (1-x-y)BaZrO3-x(K0.45Na0.5Li0.05)NbO3-yBi (Mg0.5Ti0.5)O3 lead-free piezoelectric ceramics were prepared by solid-state reaction method, and their piezoelectric properties and dielectric properties were investigated. With the increase of KNLN content, the crystal structure changed from rombohedral phase to tetragonal phase, thus existed a MPB[3,4] between rombohedral and tetragonal phase. At room temperature, the specimen with the composition at MPB (x=0.93, y=0.01) shows the optimal piezoelectric properties (d33=225pC/N and kp=45%), which indicates that this material is a potential lead-free piezoceramic.
Structural and Dielectric Properties of XBaZr0.2Ti0.8O3-(1-x)BiFeO3 Solid Solution Ceramics
Authors: Cai Wei , Zhong Shi Xing , Fu Chun Lin , Chen Gang , Deng Xiao Ling
Published: April 2014

xBaZr0.2Ti0.8O3-(1-x)BiFeO3(x=0, 0.3, 0.5, 0.7) solid solution ceramics were prepared by conventional solid-state reaction method. The crystal structure and dielectric properties ofxBaZr0.2Ti0.8O3-(1-x)BiFeO3ceramics have been investigated. The result indicates that the crystal structure of solid solution ceramics changes from rhobohedral to pseudocubic structure with the increase of barium zirconate titanate content. The room temperature dielectric constant of all samples decreases with the increasing of frequency. When the temperature is in the range of 30oC~150oC, the dielectric constant of all samples increases as temperature rises. In the same temperature range, the dielectric loss of BiFeO3ceramics increases with the rise of temperature and the dielectric loss ofxBaZr0.2Ti0.8O3-(1-x)BiFeO3(x=0.3~0.7) changes a little. The addition of barium zirconate titanate leads to the decrease of dielectric loss and leakage current for BiFeO3ceramics.
Application Temperature Range of Temperature Memory Effect in Deformed TiNi Alloys
Authors: Liu Tian Wei , Zheng Yan Jun , Cui Li Shan
Published: April 2014

The application temperature range of temperature memory effect (TME) in deformed TiNi alloys was studied in this paper. The TME could be used in a wider temperature range when the specimen cold-rolled in a high deformation. And, the “highest” application temperature of TME could increase with the deformation, and finally rise to 573K with deformed 30%. This temperature no longer changes in higher deformations, while the characteristic of TME still increase with the deformation below 573K. This is due to the dislocation texture and deform-induced martensite structures restrain the reverse martensite transformation. And the restraint disappears when specimens are annealed more than 573K.
Effect of Sintering Behavior on Microwave Properties of (Ca0.8Sr0.2)ZrO3 Ceramics for Resonators
Authors: Hsu Cheng Hsing , Chang Chia Hao , Chen Wen Shiush , Lin Jenn Sen , Lai Chun Hung
Published: April 2014

Microwave dielectric properties and microstructures of (Ca0.8Sr0.2)ZrO3 ceramics prepared by the conventional solid-state route have been studied. The values of the dielectric constant (εr) were 22-26. The Q×f values of 10400–11500 GHz were obtained when the sintering temperatures were in the range of 1400–1490°C. The temperature coefficient of the resonant frequency τf was not sensitive to the sintering temperature. The εr value of 26, the Q×f value of 11500 GHz, and the τf value of-9 ppm/°C were obtained for (Ca0.8Sr0.2)ZrO3 ceramics sintering at 1490°C. The ceramic, (Ca0.8Sr0.2)ZrO3 is proposed as a suitable candidate material for application in highly selective microwave ceramic passive components.