bluuebunny/crossref_metadata_2025 huggingface dataset:
Solvothermal Synthsis of Nano-Sized Li4Ti5O12 Particles as Anode Material for Lithium Ion Batteries
Authors: Zhang Yue , Zhu Yu Jing , Gu Yuan Xiang , Chen Rui Xin
Published: August 2015

We synthesized nano-Li4Ti5O12particles by solvothermal method. The as-prepared materials were characterized by XRD, SEM, TEM and electrochemical measurements. The Li4Ti5O12Li4Ti5O12 showed excellent rate capability and cycle ability. The as-preparedLi4Ti5O12Li4Ti5O12 electrode exhibited highly initial discharge capacity 176 mAh/g at 0.1 C rate up to, which was slightly higher than its theoretical capacity (175 mAh/g). By increasing the C-rate, the cell showed 152, 143, 138 and 135 mAh/g at 0.5, 1, 1.5 and 2 C, respectively.
Research on the Surface of Nano H68 Alloy Surface Corro Sion Mechanism
Authors: Zhou Yi Ren , Qiu Xiao Lin
Published: August 2015

Based on nanometer related theory, this paper has used H68 alloy for power plant condensers alloy surface nano mechanical polishing method, combining the related theory of materials research, the use of metallographic microscopic analysis, XRD analysis, hardness test and electrochemical corrosion test method, the correlation properties of nano surface treatment of H68 test, around the related properties of nano surface treatment H68 experiment, theoretical analysis and normative analysis, combining qualitative analysis with quantitative analysis, it has concluded that the surface nano can improve the corrosion resistance of H68 alloy in ammonia solution.
PLA Nanofiber Formation during Solution Blowing
Authors: Wang Ru Piao , Han Wan Li , Gu Jian , Xing Cong Cong , Yang Li Hong
Published: August 2015

In this paper, PLA nanofibrous mats were obtained via solution blowing. PLA fibers diameter ranged from 400 to 1000 nm produced are that the solution concentration is 7%, air blowing pressure is 0.12MPa, the solution injecting rate is 0.9ml/h. Furthermore, the PLA nanofiber morphology and formation were investigated under different distance of collector. The results indicate that the distance of collector plays an important role for the PLA fiber formation during solution blowing.
Surface Morphology of AlN Nucleation Layer Grown on Si by MOCVD
Authors: Fan Shu , Yu Le , He Xiao Long , Han Ping , Wu Cai Chuan , Dai Jing Ping , Li Xue Fei , Liu Bin , Hu Li Qun , Xie Zi Li , Xiu Xiang Qian , Peng Chen , Chen Dun Jun , Zhao Hong , Hua Xue Mei , Zhang Rong , Zheng You Dou
Published: August 2015

The AlN nucleation layer (NL) has been deposited on Si (111) substrate by metal-organic chemical vapor deposition (MOCVD). The result indicates that the growth mode of the AlN NL is in the form of 2-dimensional plane and 3-dimensional island. The proportion of 3-dimensional region increases gradually and the 2-dimensional region reduces correspondingly with the increase of growth time. The decrease of the coverage ratio of AlN grains in the 2-dimensional growth region is due to the effect of etching. AlN film with the single crystal orientation has been deposited on the optimized AlN NL.
The Optical and Electrical Properties of Al and (Al, Cu) Doped ZnO Film
Authors: Wang Dan Dan , Fang Qing Qing , Yang Jing Jing
Published: August 2015

The optical and electric transport properties of the Al:ZnO(AZO) and (Cu, Al):ZnO (CAZO) films deposited by pulsed laser deposition (PLD) were investigated in this paper. The experiment found the optical band gap (OBG) of AZO films at room temperature increased from 3.378eV of ZnO to 3.446eV of ZnO:Al (2min) sample, but decreased as continue add Al to ZnO:Al (4min), which were attributes to the Burstein-Moss (B-M) effect. For CAZO films, there is obvious change about hall mobility,ν, and resistivity,ρ, after doped Cu. It can be found that theνdecreased from to and theρincreased from to for AZO and CAZO, respectively, which is due to the scattering increasing between donor carriers and grain boundary as Cu2+ions increase, meanwhile, it was also found the decrease of OBG, which are very help to further understand the electric transport properties and the OBG effect of AZO-based films as well as its devices potential application.
Synthesis Photosical Properties of Silicon-Containing Cross-Linked Polymer
Authors: Yang Bing Xue , Ma Qing Yu , Li Jian Quan
Published: August 2015

Organic light-emitting materials in Organic Light-emitting Diodes(OLED) reserch in a very important posotion, the quality of materials directly affect the level of luminous efficiency of the device. We chose benzene 2,6-alkynyl, respectively, and tetrakis (4-bromophenyl) silane, tetrakis (3-bromophenyl) silane synthesis of new cross-linked polymer, the structure was characterized by solid NMR, by fluorescence chromatography UV crosslinking compound characterization of chromatographic performance in photophysical aspects may choose to add a new organic light-emitting material.
Investigation of Ni-Microalloyed Sn-0.5Cu Lead-Free Solders
Authors: Gyenes Anett , Nagy Erzsébet , Lanszki Péter , Gácsi Zoltán
Published: August 2015

In this study the effects of small amounts of nickel addition (0-2000 ppm) on the microstructure, on Cu6Sn5 intermetallic compound formation and the mechanical properties of a Sn-0.5Cu lead-free solder were investigated. It is known that even ppm level additions of Ni have significant effects on the microstructure of Sn-Cu solder alloys. Ni suppresses the growth of β-Sn dendrites in favour of eutectic formation. As the nickel content increases, the microstructure undergoes a morphology evolution from hypoeutectic through fully eutectic to hypereutectic. Furthermore, the presence of Ni in the Cu6Sn5 intermetallic compound phase stabilises its high-temperature allotrope η-Cu6Sn5.
Making Thermoelectric Materials SnxGa1−xNx Alloys by Magnetron Sputtering Technology
Authors: Guo Xing Long
Published: August 2015

Thermoelectric materials are of interest for applications as heat pumps and power generators. Thermoelectric properties of SnxGa1−xN alloys have been investigated. It was found that as Sn concentration increases, the thermal conductivity decreases and power factor increases, which leads to an increase in the TE figure of ZT. The valuge of ZT was found to be 0.07 at 300 K for Sn0.38Ga0.64N alloy. The results indicate that SnGaN alloys could be potentially important TE materials for many applications, especially for prolonged TE device operation at high temperatures, such as for recovery of waste heat from automobile, aircrafts, and power plants due to their superior physical properties, including the ability of operating at high temperature/high power conditions, high mechanical strength and stability, and radiation hardness.
Preparation and Performance of Super-Absorbent Resin Using Polyacrylonitrile Fiber Wastes
Authors: Wang Kun Yan , Cen Ru Feng , Shu Wen Wen
Published: August 2015

In order to develop a new way for utilizing Polyacrylonitril (PAN) fiber wastes, a super-absorbent resin was prepared using the waste of PAN fibers at alkaline hydrolysis condition with Al3+ as cross-linker. The molecular structure of the super-absorbent resin was confirmed by FTIR. The thermal degradation of super-absorbent resin consisted of one main weight loss step. Factors that can influence absorbencies of the super-absorbent resin were investigated, such as the amount of cross-linker. The super-absorbent resin has the water absorbency of 131g/g in distilled water. The super-absorbent resin can be used as a new material to water retention from the soil in agriculture.
Flame-Retardant Properties of Polyester Fabrics Reinforced Phenolic Resin Modified with Silazanes Composites
Authors: Ren Xiao Wen , Zhu Ya Ping , Wang Fan , Qi Hui Min
Published: August 2015

Phenolic resin modified with methylvinylcyclosilazanes (MVSZ) were prepared and their flame-retardant properties were investigated, and results exhibited that the Limited Oxygen Index (LOI) values increased with the content increasing of MVSZ, and the LOI reach to 40.8, when the content of MVSZ was 26.0%. The flame-retardant and mechanical properties of polyester fabrics reinforced phenolic resin modified with silazanes (PFMS) composites were measured, the results indicated that the LOI and flexural strength were enhanced compared with those of phenolic resins composites.
Preparation of Modified Urea-Formaldehyde/Phosphate Foamed Thermal Insulation Material
Authors: Huang Xin Zuo , Huang Long Nan , Wang Xin Bo
Published: August 2015

Thermal insulation materials are the most crucial composition in the external wall insulation technology. For the poor fireproofing of organic thermal insulation material, the inorganic/organic composite foamed thermal insulation material is prepared by optimizing inorganic foaming reaction. Inorganic polymer cross-linking system is used as the skeletal structure of foamed composite material and the modified urea-formaldehyde resin with excellent fire resistance is used as toughening material. The analysis results indicate that the composite structure with metal phosphate as skeleton and modified urea-formaldehyde resin as toughened-membrane is formed during the preparation process of the composite foamed material. The property test shows that the thermal conductivity is 0.0389W/m·K, the compressive strength is 180kPa, temperature rise in furnace is less than 20°C and the mass-loss rate is less than 50%. What is more there is no obvious flame appeared in the building materials incombustibility test. Therefore the composite foamed material can be judged to be A-grade incombustible thermal insulation material.
Structure and Properties of Hydrolyzed Cyclization-Crosslinking Flame-Retardant Polyacrylonitrile Fiber
Authors: Kang Yong Qiang , Yang Yan Gong , Li Li Jing , Jia Zhao , Ma Ai Rong
Published: August 2015

As flame-retardant Polyacrylonitrile (PAN) fibers was one of the most important differential fibers, it was of great importance to make research on the modification of flame-retardant PAN fibers to improve its characteristics. In this present study, the flame-retardant PAN fiber with good moisture absorption and mechanical properties has been prepared treated by blending solution of sodium hydroxide and hydrazine hydrate. FTIR spectra presented that new amide and cyclization-crosslinking pyridine group band peaks appeared. X-ray diffraction showed that the crystal structure of PAN fibers has been converted from quasi-crystalline structure into partially crystallized structure after modification treatment. SEM micrographs indicated that the original longitudinal surface microgroove has changed to layered structure by surficial etchant.
Microwave Synthesis of the Composites (α-Al2O3+TiB2)/NiAl from Al-TiO-B-Ni System
Authors: Guo Guan Hong , Zhu He Guo
Published: August 2015

NiAl matrix composites reinforced with a-Al2O3 and TiB2 were fabricated by microwave synthesis from Al-TiO2-B-Ni system. The reaction process and microstructures were analyzed by using differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM).The results showed that the ignition temperatures of the reaction heating by microwave and conventional method were approximately 556°C and 592°C respectively. Furthermore, the fabrication time by microwave synthesis was about several minutes, which was much shorter than two hours spent usually in conventional heating method. The a-Al2O3 phase aggregated at the trigonal grain boundary of the NiAl matrix, and the TiB2 phase distributed uniformly in the NiAl matrix.
Preparation and Swelling Properties of Organoclay/Super-Absorbent Resin Using Polyacrylonitrile Fiber Wastes
Authors: Cen Ru Feng , Wang Kun Yan , Shu Wen Wen
Published: August 2015

A series of novel organoclay(OMMT)/super-absorbent resin composites were prepared using the waste of PAN fibers at alkaline hydrolysis condition with Al2(SO4)3 as cross-linker. The effects of OMMT content on the chemical structure and degradation of the super-absorbent resin were investigated. The swelling behavior was also evaluated. The swelling rates of super-absorbent resin went up with increasing OMMT loading to 3wt% and then decreased with further increasing OMMT loadings. OMMT-based super-absorbent resin might have potential applications in many areas, such as construction engineering and hygienic products.
Preparation and Properties of Kevlar or Polysulfonamide Pulp Reinforced Activated Carbon Fiber Paper
Authors: Liu Qi Xia , Ji Tao , Gao Qiang , Yao Li Rong , Wang Fei Yan , Qiu Qun Ren
Published: August 2015

In this paper, Kevlar or Polysulfonamide (PSA) pulp were used to replace plant fiber pulp partially or completely and by adjusting their ratios and a variety of Kevlar or PSA pulp reinforced activated carbon fiber paper (ACFP) were prepared via wet-laid paper making technology. The influences of addition of Kevlar or PSA pulp on the permeability, mechanical property, filtration performance, adsorption property of ACFP were discussed by maintaining the addition content of activated carbon fiber unchanged. Results showed that with the addition content of Kevlar or PSA pulp increased, the permeability and filtration performance of ACFP decreased obviously, while the bursting strength and the static CCl4 adsorption performances were firstly increased and then decreased. Generally, the permeability and filtration performance of Kevlar pulp reinforced ACFP were slightly worse than that of PSA pulp reinforced ACFP, while the bursting strength as well as the static CCl4 adsorption properties of Kevlar pulp reinforced ACFP were better than that of PSA pulp reinforced ACFP.
Experimental Study of Nano-Al2O3 Particles Reinforced Fe-Based Composite Coating Made by Laser Cladding
Authors: Zhang Wei
Published: August 2015

The experiment of laser cladding on the surface of Cr12 mold steel was made. Ni-coated nano-Al2O3 particles powder was used as cladding material. The microstructure and hardness of laser cladding layer were tested. The research showed that the compact cladding layer without crack, gas hole and other defects could be made by laser cladding. The cladding layer was made up of three phases, Fe-Ni solid solution, Fe-Cr solid solution and nano-Al2O3 particle. nano-Al2O3 particles enhanced the inhomogeneous nucleation of Fe-based alloy, refined the crystal grains and strengthened the mechanical properties of cladding layer. The average hardness of cladding zone was 900 HV0.2 which was 2.2 times higher than that of substrate.
The Effect of Graphite Content on the Wear Behavior of Ni/WC/G Composite Coating
Authors: Yang Gui Rong , Huang Chao Peng , Song Wen Ming , Ma Ying , Hao Yuan
Published: August 2015

The Ni/WC/G composite coating was fabricated through vacuum cladding. The effect of graphite content on the wear behavior was investigated, and the worn surface was observed through scanning electron microscopy (SEM). The friction coefficient decreased with the increasing graphite content until the graphite content was 6%, and then increased when the graphite content was 8%. The wear rate decreased with the increasing graphite content for all graphite content. The wear loss of GCr15plate decreased with the increasing graphite content until the graphite content was 6%, and the wear loss of plate was rising when graphite was 8%. There was a layer composed of wear debris that containing oxides and graphite. The covering area increased with the increasing graphite content, which agreed with the changing trend of friction coefficient and wear rate. The net texture-like structure was formed among the composite coating, which could be the main support for load during wear process. There was little single WC particle protruding for support the wear load. Therefore, the Ni-based substrate was not easily to be worn.
Corrosion of 50%(Ni-22%Cr-10%Al-1%Y)-50%(ZrO2-8%Y2O3) Coatings in Na2SO4 and 75%NaCl-25%Na2SO4 Salts
Authors: Lee Dong Bok
Published: August 2015

The composite coating that consisted of 50%(Ni-22%Cr-10%Al-1%Y) and 50%(ZrO2-8%Y2O3) was fabricated by air plasma spraying, and corroded at 800 and 900°C for 50 h in Na2SO4 or 75%NaCl-25%Na2SO4 salt. The scales consisted primarily of Cr2O3, NiO and α-Al2O3. However, most of them continuously dissolved off as complex ions into the salt during hot corrosion.
Influence of Passivation Coatings Synthesized by Atomic Layer Deposition on Li-Ion Batteries Cathode Cycle Life
Authors: Maximov M.Yu. , Popovich A.A. , Rumyantsev A.M.
Published: August 2015

In this work, we investigated the influence of passivation coating of aluminum oxide on cycle life of lithium-ion batteries. Al2O3 was synthesized by atomic layer deposition directly on the porous electrodes based on LiCoO2. More than 800 charge-discharge cycles were done. No increase of internal resistance due to Al2O3 coating was observed. According to the results, electrodes coated by aluminum oxide have better cycle life.
Study on Microstructure and Fracture Toughness of TaC Ceramic Coating on HT300
Authors: Wang Jie Fang , Shao Tian Tian , Cai Xiao Long , Zhong Li Sheng , Zhao Na Na , Xu Yun Hua
Published: August 2015

Tantalum carbide (TaC) ceramic coating was produced on grey cast iron by the combined process of casting and heat treatment. The microstructure, micro-hardness, and fracture toughness of the TaC ceramic coating were investigated by scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and indentation technique. The results show that TaC ceramic coating can be divided into two apparent regions, and the density of products gradually decrease from the surface to the matrix. The main phases of the ceramic coating are only TaC, α-Fe, and Fe3C. TEM examination revealed a nanostructure ceramic, in which 200~300 nm TaC grains are cemented by iron binder. The nanoindentation hardness of TaC ceramic coating vary in the range of 14~21 GPa. A close examination of the indentation crack paths of TaC samples revealed that the TaC ceramic coating have extensive crack deflection with a great amount of intergranular fracture.
Preparation of Aspirin-β-Cyclodextrin Inclusion Complex by Grinding Method
Authors: Xu Xiang Qun , Hong Nian , Zheng Jing Wen , Guo Bing Bing , Cheng Lin
Published: August 2015

To study the process conditions for preparing aspirin β-cyclodextrin inclusion.Method: Choose the usage ration of aspirin with β-cyclodextrin and the time of reaction as the main factors, and use the inclusion yield as evaluated indicators and the process condition to conduct orthogonal experiment Optimization Pack aspirin.Outcome: The optimum inclusion process condition: molar ratio of the aspirin with β-cyclodextrin is 1:3, inclusion time is 60 minutes.Conclusion: The process condition of using β-cyclodextrin inclusion to inconcluse aspirin is feasible, effective, and of applicative value.
Effect of Mn on the Microstructure and Hardness of Gear Steel Treated by Quenching and Partitioning Process
Authors: Chen Yi Fei , Zhang Heng Hua
Published: August 2015

By adding Mn into SAE8620 gear steel, the effect of Mn on the microstructure and hardness of steel treated by quenching and partitioning process is investigated in this research. Microstructure is observed. Hardness is measured, after that it is converted into tensile strength. And the content of austenite is determined by X-ray diffraction analysis. It is found that higher content of Mn increases the content of martensite and reduces that of blocky ferrite and also leads to higher hardness of steel. In addition, XRD pattern shows obvious existence and enhancement of retained austenite.
Piezoelectric and Ferroelectric Properties of KNN-LS-BF1-xCx Ceramics
Authors: Wang Hua , Zhao Xia Yan , Xu Ji Wen , Yang Ling
Published: August 2015

0.998[(0.95(K0.5Na0.5)NbO3-0.05LiSbO3]-0.002BiFe1-xCoxO3 (KNN-LS-BF1-xCx, x=0-0.8) piezoelectric ceramics were prepared by solid-state reaction method. The influences of Co content on piezoelectric and ferroelectric properties were investigated. The results reveal that the substitution of Co significantly affects the piezoelectric and ferroelectric properties of KNN-LS-BF1-xCx ceramics. All samples with various Co contents show a pure perovskite structure. With increasing x from 0 to 0.8, the depolarization temperature Td of KNN-LS-BF1-xCx ceramics increase with increasing x, and the piezoelectric constant d33of KNN-LS-BF1-xCx specimen with x=0.2 is larger than those of other KNN-LS-BF1-xCx specimens in the investigated range when the temperature is lower than Td. The remnant polarization Pr decrease with x in the investigated range, but the coercive field Ec increase to 1.78kV/mm with x up to 0.6, and then decrease with further increase of Co contents x.
Effect of Inclusion on Pitting Corrosion of X80 Pipeline Steel
Authors: Lang Feng Jun , Huang Xian Qiu , Pang Tao , Ma Ying , Cheng Peng , He Rui
Published: August 2015

The influence of inclusion on pitting corrosion of X80 pipeline steel was investigated by using electrochemical test and atomic force microscope. The results indicated that corrosion potential of X80 pipeline steel sample with higher grade inclusion was lower, and decreased significantly with chloride ion concentration increasing. Inclusion was not conducive to corrosion resistance of X80 pipeline steel. The way of X80 pipeline steel pitting corrosion was that pit formed at the inclusion dissolution, and grew to pitting. There were less corrosion products near the pit hole, forming a cathode ring.
Influence of Temperature on Structure Formation Processes Geocements for Rehabilitation of Concrete
Authors: Kyrychok Volodymyr , Drochytka Rostislav , Kryvenko Pavlo V.
Published: August 2015

When using geocements composition (xNa2O+yK2O)·Al2O3·(2÷4)SiO2·10H2O for protective coating of concrete from aggressive environments, the main problem is to determine the optimal treatment temperature, which depends on the ratio of basic oxides structural formula. In this work, using two-factor three level method of experiment planning determined that when the content as a part geocement (0,8÷0,9Na2O+0,2÷0,1K2O) and the ratio of SiO2/Al2O3=2,5÷3,5 achieved the necessary water resistance - Cr>0,8 at 40°C. When the ratio of SiO2/Al2O3>3,5 physico-mechanical properties geocement growing and processing temperature also increases to 50÷60°C. In subsequent researches will explore the possibility of reducing the processing temperature by modifying the geocement in the direction of accelerating processes of structure formation.
The Suitability of Sealants for Use with Concrete Structures
Authors: Šlanhof Jiří , Liška Pavel , Nečasová Barbora , Šimáčková Martina
Published: August 2015

Building reconstruction is rather a broad term encapsulating the implementation of solutions to the unsatisfactory condition of various parts of a built structure, which includes the solution of issues concerning the penetration of undesired humidity in the liquid state through leaks in the building’s outer shell. This contribution deals with issues involved in the sealing of concrete elements in the outer shell structures of buildings using modern sealants. It involves the experimental testing of sealed joints using test samples fabricated from glass fibre reinforced concrete and fibre-cement facade cladding panels in combination with various commonly accessible sealants. The sealants were exposed to tensile stress under various environmental conditions, as well as cyclic stress. The results of the tests provide a comprehensive picture of sealants’ adhesion and cohesion with the test substrates and clearly show the suitability or unsuitability of their application on substrates with cement content.
Comparison of Standardized Test Methods for Determining the Permeability of the Surface Layer of Concrete
Authors: Komárková Tereza , Králíková Monika , Kocáb Dalibor , Misák Petr , Stavař Tomáš
Published: August 2015

The durability of concrete can be assessed based on the quality of the surface layer of concrete, for which there are a few standardized assessment test methods. Usually, the quality of the surface layer of concrete is evaluated based on its air and water permeability. The aim of this experiment was to compare the outputs which provide some methods for determining the permeability of the surface layer of concrete (GWT, ISAT, TPT, the depth of penetration of water under pressure). The measured values using the individual methods of assessing the permeability of the surface layer of concrete very closely correspond.
Enhancing the Wood Glue Bond Using Cellulose Modified Epoxy
Authors: Vanerek Jan , Drochytka Rostislav , Benešová Anna
Published: August 2015

The paper deals with the possibilities of enhancing the durability of wood bonds using the epoxy resin. These types of resin very often failed while exposing the water uptake when wood adherend swells and the bonds failed in bonding interface layer. Using the nanocellulose fibers in epoxy resin leads to higher fracture toughness while the interphase could better accommodate the large dimensional changes of the wood. That was the reason, why the different amount of nanocellulose fibers in epoxy resin were applied and the durability test of single-lap wood joints were performed. The higher percentage of cohesive failure in wood adherend and higher shear strengths after exposing the hygrothermal exposures were achieved.
Experimental Comparison of Air Pore Content of Concrete with Different Dosage of Cement by Microscopic Analysis
Authors: Moravcová Bronislava , Blažek Michal , Pőssl Petr , Misák Petr
Published: August 2015

The pore structure of concrete is a very important material property influencing the durability of concrete. Concrete pore structure is influenced, among others, by the composition of concrete, water/cement ratio, aeration or cracking [1]. The experiment described in this paper understands concrete cover to be 40 – 60 mm from the surface of the specimen.The paper focuses on the determination of air void content in different concrete mixtures by means of microscopic analysis. Mixtures differ in the amount of cement and plastifying agent added while maintaining the consistency of the fresh concrete. In order to determine the air void characteristics, the experiment used manual and automated microscopic analysis.
Mineralization Influence on the Strength Parameter of Solid Wood
Authors: Murínová Tereza , Mec Pavel , Daňková Jana , Rezek Petr
Published: August 2015

Moisture characteristics, related durability and especially strength parameters are observed for wood (solid, treated, or modified), which is used in building constructions. Material modification by siliceous substances reduces intake of liquid water, but solution exposition and subsequent deposition of mineral particles may also affect the physico - mechanical properties of the material. In this work, longitudinal compressive strength was determined for the samples treated by dipping in aqueous solution of organosilane. The results confirm the correlation between the length of dipping and the change of tested strength parameter.
Influence of Firing Temperature on the Quality of Fly Ash Body
Authors: Černý Vit
Published: August 2015

Nowadays, over 95 % of fly ash is used as construction products in the Czech Republic. However, around 80 % of fly ash is used for renovation of open-pit quarries and areas affected by human activity. Production of artificial aggregate is the way to use over 90 % of energy by-products in the building material industry. It is necessary to find appropriate combination of parameters of input materials and conditions of production to get optimal properties of aggregate. The paper gives an account of the influence of parameters of fly ash and conditions of firing on the quality of ceramic body made from fly ash. Temperatures of 1050 °C, 1150 °C and 1200 °C were examined. The research focused on the structure of the ceramic body as well as its physico-mechanical parameters.
Single-Sided Nuclear Magnetic Resonance as a Non-Invasive Tool to Evaluate Sprayed Polymer Concrete
Authors: Schulte Holthausen Robert , Weichold Oliver
Published: August 2015

Single-sided nuclear magnetic resonance (NMR) is a powerful tool to evaluate building-material properties such as layer thickness, moisture content, and ageing. Due to its simple setup, it is potentially applicable on site. It is non-invasive with a high depth resolution and makes a number of parameters for planning and executing the rehabilitation of buildings as well as for quality assurance easy accessible. In this paper, we focus on the quality assurance of a sprayed polymer-concrete (SPC), which was recently developed by Massenberg GmbH and the Institute of Building Materials Research (ibac) for the repair of sewage systems. Single-sided NMR was used to access curing time of the epoxy binder, binder content, layer thickness, and diffusion of acids through the SPC. However, single-sided NMR measurements only give relative values, so calibrations are given where required. While single-sided NMR shows great potential and can be used in various further applications, limitations of resolution, depth and measurement time need to be considered.
The Effect of Long Term Storage on Properties and Stability of Dry Mixture
Authors: Tumova Eva , Mészárosová Lenka , Drochytka Rostislav
Published: August 2015

This paper focuses on the stability of dry ready to made mixture for use on the construction site from bags or silos. It is also dedicated to development of those mixtures and to the description of the impact of long term storage on the properties of the product.
Thermotechnical Calculation of Air Cavities by Rehabilitation of Wet Brickworks
Authors: Solař Jaroslav
Published: August 2015

For excessive wet masonry rehabilitation, except for other methods, the method of air cavities is used. These can be wall or floor cavities. The wall cavities may be situated either on the internal or the external side of the wall. From the height point of view, internal side cavities can be located under the floor or above the floor level. This contribution only deals with the cavities above the floor level. In the projection practice, the air cavities usually are designed only empirically. But it is necessary to carry out their thermal technical evaluation for their correct capacity. The matter of the evaluation is the topic of the following contribution.
Use of Separated Dust from the Formatting and Grinding Cement-Bonded Chipboards to Modify their Composition
Authors: Melichar Tomáš , Konečný Dalibor , Bydžovský Jiří , Vacula Miroslav
Published: August 2015

The article presents results of the research focused on suitability assessment of separated dust from formatting and grinding of cement-bonded chipboards to modify their composition. The attention was paid to dust treatment, i.e. milling and sorting. The dust was applied to chipboards in amounts of 5 and 10%. Formulas with water-cement ratio 0.60 and 0.65 were prepared. The influence of sorted dust was subsequently evaluated using setting of selected material properties. In particular the bending strength and tensile strength perpendicular to plate plane were monitored including the influence of frost on these characteristics.
Comparison of Two Medieval Trusses from the Viewpoint of Geometric and Static Analysis
Authors: Krušinský Peter , Capková Eva , Gocál Jozef
Published: August 2015

The subject of article is a comparison of two load bearing structures of medieval trusses in terms of their original design, based on the geometrical concept, as well as from the perspective of their current static analysis, based on modern, standardized calculation procedures. It is a roof above the sanctuary of the Roman Catholic Church in the village of Bela-Dulice from 1409d, and a roof above the sanctuary of the Church of St. Peter of Alcantara in the Franciscan monastery in Okolicne from 1499d. From a typological point of view, both the trusses have a similar rafter collar-beam construction with longitudinal stiffening frame truss and with approximately the same span. In the case of the monastery church in Okolicne, the construction of main cross truss is supplemented by the spike struts. From the geometric analysis of trusses there are obvious different geometric proportional relationships that have been applied in the original design. The aim of static analysis of the load bearing structures using current advanced computing resources is to clarify and compare the static behaviour of the both roof structures.
Flexural Buckling of Columns Strengthened under Load
Authors: Vild Martin , Bajer Miroslav
Published: August 2015

This paper refers to behaviour and capacity of axially loaded columns strengthened under load using welded steel plates. This method of strengthening is fast, simple and widely used but no universal and reliable analytical solution has been presented yet. In the paper, focus is put on flexural buckling. The approach using cross-section properties of strengthened member and the modified buckling reduction factor was used to calculate the ultimate resistance. In buckling theory, the resistance of column subjected to compression load is reached when the most stressed fibres start to yield. However, some researchers allow certain amount of yielding for base material of columns strengthened under load. In the paper, the new modified buckling reduction factor based on Eurocodes is derived. Two types of column strengthening under various preload magnitudes are investigated using finite element study in ANSYS code and transient analysis type. Birth and death of elements is used to simulate strengthening welded plates. The results are compared with analytical solutions.
Application of Colored Impregnating Glazes on Wood and Color Changes due to Artificial Aging
Authors: Slunská Sylvie
Published: August 2015

Wood as organic material is extremely stressed and it is surface may be damaged over time due to atmospheric effects, mainly due to solar radiation and exposure to water. The purpose of this experiment is to compare colour changes of selected impregnation stain the wood, which in practice is primarily used for facade systems. These are among some of the most stressed parts of the building and construction, they must be paid great attention. Wood samples were painted with a colour glaze impregnation and subsequently subjected to artificial aging. The results show that the type of selected species, but also finish before applying a waterproofing glaze can affect subsequent changes light fastness whether, it is a lightening or darkening.
Determination of Compressive Strength of Cement and Polymer-Modified Cement Pastes with Pozzolans
Authors: Žižková Nikol , Bayer Patrik
Published: August 2015

The article focuses on the use of tree types of pozzolanic materials in the production of cement pastes and polymer-modified cement pastes. The determined physical-mechanical parameters of the pastes with pozzolanic materials were compared with a pure cement paste. For polymeric modification, ethylene/vinyl acetate copolymer (EVA) was used, which was added to the mortar and concrete during the preparation to improve some properties such as fracture toughness, impermeability and bond strength to various substrates.
Formation of Efflorescence on the Surface of Construction Products in the Process of their Operation
Authors: Yakovlev Grigory , Politaeva Alena , Shaybadullina Arina Valentinovna , Gordina Anastasiya Fedorovna , Buryanov Аleksandr F.
Published: August 2015

The factors influencing the formation of efflorescence of construction materials are connected with the increased solubility of the ingredients of construction materials. Efflorescence may accumulate under some less permeable decorative paint layers and cause their peeling from the surface of a building structure, its decorative properties being completely lost. At the same time, the formation of efflorescence not only as white bloom, but also as "blooming" of the surfaces of materials due to the formation of new chemical compounds is possible. Similar processes occur in the process of operation of coloured pavers manufactured wth vibrocompression of cement and sand mortars with the addition of colouring pigments. The main source of efflorescence is calcium hydroxide Ca (OH)2 which is formed in hardening cement. The alkaline nature leads to its intensive interaction with carbon dioxide CO2. This efflorescence in the second year of operation, as a rule, does not resume due to the carbonation of calcium hydroxide in the structure of set cement.
A Survey of Historic Galleries in the Area of the Prague Castle
Authors: Burgetová Eva , Michalová Kristýna
Published: August 2015

The paper deals with the historical and structural survey of house “At the Three Axis” and drainage and ventilation systems discovered in the Prague Castle area. Failures and deterioration processes of these historical structures are described. The important achievements of in-situ inspection and laboratory analysis are presented, interventions and maintenance of systems proposed.
Special Mortars for Repair Masonry: The Problem of the Optimization
Authors: Kharitonov Aleksey , Smirnova Olga
Published: August 2015

Destruction masonry is a common problem. The nature of the material of masonry and the degree of preservation offers different combinations of technological methods of repair. In this regard it has formulated one of the main tasks of restoration materials science - finding the optimal composition of a material with a large number of variables in the presence of rigid boundary conditions in a short time. The solution to this problem lies in the area of mathematical modeling using the methods of planning of experiments. In this regard the aim of this study is the development of methods for optimization of mortars that allows getting the desired result in a relatively short period of time.
Development of Repair Mortars Based on Alkali Activated Materials for Application in Chemically Aggressive Surroundings
Authors: Dufka Ámos , Brožovský Jiří , Melichar Tomáš
Published: August 2015

The paper analyses the possibility of alkali activated materials utilization as matrix for repair mortars, determined for rehabilitation of reinforced concrete structures, exposed to chemically aggressive surroundings. alcali activated materials have owing to their specific properties a high potential especially for utilization in materials determined for specific applications. Materials showing in comparison with the cement matrix significantly higher resistance against the effect of chemical substances are the so-called alkali activated materials. The rehabilitation of reinforced concrete structures exposed to extreme conditions is the area for effective utilization of the alkali activated extraordinary properties.
Effect of Grain Boundary State on Diffusion and Diffusion-Controlled Processes in Ultrafine-Grained Materials Processed by Severe Plastic Deformation
Authors: Naydenkin Evgeny V. , Grabovetskaya Galina P. , Mishin I.P.
Published: August 2015

Experimental studies on the grain boundary diffusion and processes controlled by it in the ultrafine-grained metallic materials produced by various methods of severe plastic deformation are reviewed. Correlation between the increased diffusion permeability of grain boundaries and features of recrystallization and deformation development in these materials possessing the non-equilibrium state of grain boundaries formed during severe plastic deformation in the temperature range of T < 0.35Tm is demonstrated and analyzed.
Morphology and Structure of Diffusion Layers in Nb3Sn-Based Superconductors of Different Geometry
Authors: Popova E.N. , Deryagina I.L.
Published: August 2015

The evolution of structure and morphology of superconducting Nb3Sn layers forming under various regimes of the diffusion annealing in multifilamentary Nb/Cu–Sn superconductors of different design is briefly reviewed based on the authors’ (with their coauthors) original studies and the available publications. Different modes of the solid-state diffusion formation of the superconducting phase are compared. Possible mechanisms of the Nb3Sn nucleation upon the diffusion reaction of the Nb filaments and bronze matrixes are discussed. The effects of different doping elements, especially Ti, on the formation of the superconducting phase, its structure and morphology, and, consequently, on the current-carrying capacities of multifilamentary Nb3Sn-based wires are considered. Special attention is paid to the effect of the mode of Ti doping, the content of this alloying element and the regimes of the diffusion annealing on the structure, morphology and resulting performance of the bronze-processed wires with coupled Nb filaments worked out at Bochvar Institute of Inorganic Materials for the creation of International Thermonuclear Experimental Reactor.
Analysis of Local and Global Segregation Occurring in Grain Boundary Diffusion
Authors: Belova Irina V. , Murch Graeme E.
Published: August 2015

It is generally well recognized that in the course of a grain boundary (GB) diffusion experiment the diffusion of solute atoms in grain boundaries must exhibit a strong time-dependent segregation. But there has been no clear understanding of exactly how this time dependence develops. In this chapter, we review and analyse transient solute GB diffusion by means of the computer simulation technique of Lattice Monte Carlo (LMC). This technique has been successfully used on numerous occasions for the purposes of systematically studying the GB transition regimes that occur between the principal well-defined Harrison GB kinetics regimes (A, B and C-Types). Recently, the analysis using LMC has been extended to the case of solute GB diffusion when the segregation factor is independent of time. In the present paper, we analyse two cases of solute segregation in GB diffusion: first, where the solute atoms are homogeneously distributed along the tracer source plane but their mobility is not high at this plane; and the second, where the mobility of the solute atoms along the tracer source plane is comparable to their mobility along the GB. It is shown that the time dependence of the segregation can contribute significantly into the resulting values of the triple-product that is usually obtained experimentally in the Harrison Type-B kinetics regime.
Grain Boundary Design of Bulk Nanomaterials for Advanced Properties
Authors: Valiev Ruslan Z.
Published: August 2015

Nanostructuring of metals and alloys by severe plastic deformation techniques is an effective way of enhancing their mechanical and functional properties. The features of the nanostructured materials produced by severe plastic deformation (SPD) are stipulated by forming of ultrafine-sized grains as well as by the state of grain boundaries. The concept of grain boundary (GB) design of ultrafine-grained metals and alloys is developed for enhancement of their properties by tailoring grain boundaries of different types (low-angle and high-angle ones, special and random, equilibrium and nonequilibrium) and formation of grain boundary segregations and precipitations by SPD processing. The paper presents experimental data demonstrating the super-strength and “positive” slope of the Hall-Petch relation when passing from micro-to nanostructured state in a number of metallic materials subjected to severe plastic deformation. The nature of the superior strength is associated with new strengthening mechanisms and the difficulty of generation of dislocations from grain boundaries with segregations. This new approach is used for achieving the enhanced strength in several commercial Al and Ti alloys as well as steels subjected to SPD processing.
Dynamic Characteristic Analysis and Validation of Spindle Assembly of High Speed Machine Tool
Authors: Zhang Yao Man , Lin Xiu Li , Liu Chun Shi , Cai Guang Qi
Published: August 2015

To design a machine tool successfully, its essential parts should be analyzed and evaluated after design but before prototype being made. The spindle assembly is one of the most essential parts of high speed machine tool, so how the dynamic characteristics of the spindle assembly affect the performance of high speed NC machine tool are of great significance and should be studied. This paper’s research is based on a high speed machine tool manufactured by some plant. The finite element analysis model of the spindle assembly of the high speed machine tool was developed by taking the advantage of the spring-damper element to simulate the bearing supports. The modal analysis was made to confirm the dynamic characteristics of the spindle assembly, and the results were compared with the testing ones.
Novel Precision PZT-Driven Micropositioning Stage with Large Travel Range
Authors: Chen Hua Wei , Hagiwara Ichiro
Published: August 2015

One novel long-travel piezoelectric-driven linear micropositioning stage capable of moving in a stepping mode is developed. The stick-slip friction effect between flexure hinge actuation tips with a sliding stage is used to drive the stage step-by-step through an enlarged displacement of piezoelectric actuator. In order to enlarge the travel range, magnifying mechanism is optimally designed by use of flexure hinge and lever beam. Moreover, dynamic model of such stage is proposed by consideration of reset integrator stick-slip model. The simulation results show that the stage has considerable good dynamic properties.
Intelligent MES Based on RFID
Authors: Li Zhe Kun , Li Min , Li Fu Yu
Published: August 2015

By taking the advantages of RFID (Radio frequency identification) technology, this paper consequently raises an idea of applying RFID into MES (Manufacturing Execution System), establishing the modules concerning MES onsite-material management and monitoring of manufacturing, and studying how to construct Intelligent MES.
E-Enterprise Framework and Operation Mode for Manufacturing Enterprises
Authors: Lei Qi , Wang Qi Feng , Song Yu Chuan
Published: August 2015

To effectively realize the business integration and collaboration in manufacturing enterprises, this paper provides an e-Enterprise framework for manufacturing enterprises and has a deep study on the application system integration mode and implementation technologies based on flexible information integration approach for e-Enterprise. With the flexible information technology, the integration between information systems transformed into the integration between adapters which dependent on the data itself and unrelated to the concrete information system, which helps the information systems to integrate with each other agilely on demand. Furthermore, the integrated operation mode of e-Enterprise in manufacturing enterprises is deeply studied. Finally, the e-Enterprise framework and operation mode is applied in an electric appliance set manufacturing enterprise in Chongqing, and achieves well application effects.
A Tool-Path Interpolation Algorithm Based on Unfolding-Bending Parametric Curves
Authors: Fan Li Cheng , Sun Li Ning , Du Zhi Jiang
Published: August 2015

To grind sculptured surface by swing motion, it’s needed to interpolate the discrete data nodes on the arc-driving surface. To ensure that all the sample points locate on the arc surface, a novel unfolding parameter curve is proposed. Firstly, all the discrete data are stretched onto a plane, inside which the cubic B-spline curves are interpolated. After that, some points are sampled from the spline curves and bended to the arc-driving surface according to the swing radius. To eliminate cutting vibration and chord error exceeds limitation; radial speed is tuned by controlling the chord error. The simulation results are given to prove the proposed algorithm.
A Collaborative Design and Analysis Environment for Flexible Fixture
Authors: Chen Wei Fang , Xue Jian Bin , Lou Pei Huang
Published: August 2015

Designing a flexible fixture is much more complicated. In this paper a collaborative environment was introduced for flexible fixture design. The tasks involved in fixture design are analyzed and decomposed into five subtasks, which are assigned to workgroups by a project manager. The workgroups can be distributed in different departments or in different locations geographically. The framework of collaborate design environment is constructed. Each workgroup is responsible to a certain job. However, the information needed for flexible fixture design is shared among these workgroups. The information exchanging and management in the environment are expressed with a block diagram. Finally, an example of flexible fixture for manufacturing a thin-walled workpiece is employed to illustrate the efficiency of the collaborative environment.