bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects and Comparison of Curcumin on Morphology Changes of Chronic Cerebral Hypoperfusion in Young and Aged Rats
Authors: Li Dan , Xiang Yue , Zhang Xiong , Li Yu
Published: August 2015

To observe the effect of curcumin on the morphology of the hippocampus in young and aged rats with vascular dementia (VD) induced by chronic cerebral hypoperfusion, then further investigate whether the effect of curcumin have any differences in age. Both young and aged Male Sprague-Dawley rats were randomly divided into normal control group, sham-operated group, 2VO group, 2VO+curcumin 50mg/Kg group and 2VO+curcumin 100mg/Kg goup. Permanent occlusion of bilateral common carotid arteries ligation (2VO) method was used to establish chronic cerebral ischemia model. The rats were injected intraperitoneally with curcumin or DMSO once daily for 30d. The pathological changes of CA1 region of the hippocampus were measured by HE staining and Nissl staining. Chronic cerebral ischemia led to pathological changes of young and aged rats, but no significant differences were found between the two ages of rats (t=0.658，P=0.523). Furthermore, curcumin could reduce the pathological injury of CA1 region of the hippocampus in young and aged VD rats, no significant differences were found between the two ages of rats (P=0.384，P=0.380). Curcumin can reduce the brain damage in young and aged VD rats in dose-dependent manner but without age difference. Our study suggests that the pathological injury of the hippocampus might be one of the mechanisms of curcumin’s protection effect of VD rats.
Preparation and Characterization of Radiopaque Calcium Alginate Microspheres Embedded Silver Nanoparticles
Authors: Li Zhao Qing , Li Li
Published: August 2015

Calcium alginate microspheres embedded with silver nanoparticles were prepared by dripping mixed solution of sodium alginate and silver nanoparticles, which were synthesized by reduction of silver nitrate (AgNO3) with sodium alginate as stabilizing agent and sodium borohydride as chemical reducing agent, into a crosslinking bath of calcium chloride solution. The concentration of sodium alginate and sodium borohydride used in synthesis step were found to have effect on the formation and growth of the silver nanoparticles as revealed by UV-visible spectroscopy. The TEM image indicated that uniform silver nanoparticles with particle size range from 20 to 60 nm are fabricated. The XRD spectrums showed that the silver nanoparticles embedded in calcium alginate microspheres exhibit crystalline state. The EDS showed that the higher the ration of AgNO3, the more silver nanoparticles embedded in calcium alginate microspheres. Moreover, X-ray images showed the calcium alginate microspheres embedded with silver nanoparticles exhibited better radiopaque properties than the pure calcium alginate microspheres and the microspheres with higher concentration of AgNO3 solution show sharper X-ray image. All the above facts indicated that these calcium alginate microspheres embedded with silver nanoparticles could therefore be used in embolization.
Study on Preparation Technology Optimization of Sultamicillin Tosilate-β-Cyclodextrin
Authors: Xu Xiang Qun , Hong Nian , Yang Jie , Zhong You Quan , Cheng Lin
Published: August 2015

To study the process conditions for preparing sultamicillin tosilate β-cyclodextrin inclusion.Method: Choose the usage ration of sultamicillin tosilate with β-cyclodextrin, the inclusion temperature and the time of reaction as the main factors, and use the inclusion yield as evaluated indicators and the process condition to conduct the L9 (34) orthogonal experiment Optimization Pack sultamicillin tosilate.Outcome: The optimum inclusion process condition: molar ratio of the sultamicillin tosilate with β-cyclodextrin is 1:8, inclusion temperature is 47°C, inclusion time is 40 minutes.Conclusion: The process condition of using β-cyclodextrin inclusion to inconcluse sultamicillin tosilate is feasible, effective, and of applicative value.
Microbial Transformation of Glycyrrhetinic Acid by Colletotrichum lini AS3.4486
Authors: He Chao Jun , Yang Yu Min , Wu Kong Yang
Published: August 2015

The biotransformation of 18β-glycyrrhetinic acid by Colletotrichum lini AS3.4486 was investigated. The conversion reaction was carried out for 72h, and the sole product was isolated by column chromatography and elucidated as 7β,15α-dihydroxy-18β-glycyrrhetinic acid by HR-ESI-MS, 1H-NMR , 13C-NMR and single–crystal X-ray diffraction. The crystal of the conversion product belongs to orthorhombic, space group P212121 with 11.828(1), 13.213(2), 19.606(2) Å , V = 3064.0 Å3, Z = 4. This study povides a new method for the synthesis of 7β,15α-dihydroxy-18β-glycyrrhetinic acid.
Production of Cellulase by Aspergillus niger FC-1 and its Application in Hydrolysis of Corncob Residues
Authors: Shi Hui Qin , Zhao Zhe Wei , Yang Wei , Wu Di , Zhao Yi , Zhao Jin , Fang Xiao Min , Xie Lu Lu , Tian Xiang Yu , Wu Jian , Dai Gui Fu
Published: August 2015

In this study,the cellulase-producing ability of Aspergillusniger FC-1 through solid-state fermentation (SSF) and characteristics of the cellulase were investigated. The maximum activities of total cellulase (FPase) and endoglucanase (CMCase) were 8.2 and 31.5 IU per gram of dried substrate respectively after 96-h incubation period. The activities of both FPase and CMCase produced by Aspergillus niger FC-1 exhibited the optimal values at pH 5.5 and 50°C(as shown in Fig.2). Thermostability and pH stability of the enzymes were respectively appreciable at temperature ranging from 45°C to 55°C, pH ranging from 5.0 to 5.5. In addition, with an optimal 1:10 (w/v) substrate to moisture ratio (a cellulase loading of 8.5 FPU per cellulose), the glucose concentration was as high as 36.6 g glucose l-1 for a 48 h hydrolysis of corncob residues.
Lycopene Nanoparticles Coated with Microemulsions to Improve Stability
Authors: Lu Zhu Fen , Chen Yan Zhong , Ban Jun Feng , Deng Guang Han , Xin Huang , Fang Ruo Huai
Published: August 2015

Delivery systems play important roles in improving drug efficacy. In particular, insoluble functional pigments must be handled carefully when increasing their solubility, in order to ensure that they remain active. In this study, the nanoparticles were coated by the oil phase in the microemulsion system (NPs-SEs), and this system was found to both increase the stability of the drug and improve drug loading. NPs-SEs containing lycopene, soybean oil, Span-40, Tween-20, stabilizer and glycerol were prepared by high pressure homogenization technology. It was characterized and its droplet size, and Zeta potential were 181±15 nm ( PDI 0.092±0.01), -70.83±1.64mV, respectively. The drug loading capacity of NPs-SEs was 1.02±0.16mg/ml and was nearly 4 times more than the highest concentration of lycopene O/W emulsion.
Synthesize of Carboxymethyl Chitosan-Graft-Polycaprolactone (CMCS-g-PCL) and the Preparation of Micelles
Authors: Zhang Meng Ru , Xu Heng , Lang Mei Dong
Published: August 2015

In this study, we synthesized carboxymethyl chitosan-graft-poly(ε-caprolactone) (CMCS-g-PCL) by grafting ε-CL onto the hydroxyl groups of CMCS via ring-opening polymerization. The graft copolymers were characterized by 1H NMR spectroscopy and thermogravimetric analysis (TGA). Then use the graft copolymer to produce the micelle by solvent-evaporation method. The DLS and TEM were utilized to evaluate the particle size and morphology and showed that the micelles were in a well-defined spherical shape with a uniform size distribution. The results indicated that the size of range is below 200 nm and could be used as drug carrier and have better active cellular uptake.
Analysis and Research on Different Thermal Conditions of Copper Bar
Authors: Xue Yan Lin , Qiang Wang
Published: August 2015

With copper bar as the research object, using ANSYS Workbench to analyze the temperature distribution and characteristics of copper bar under different thermal conditions and the same current load, provide a basis for the choice of the design of the copper.
Hot Deformation Behavior of Nano-Precipitation Strengthening Steel
Authors: Zhu Yan , Li Hong Tao , Zhang Mei , Zhong Yong , Li Lin
Published: August 2015

The hot deformation behavior of nanoprecipitation strengthening steel was studied using a Gleeble-3500 thermo-mechanical simulator. The results show that the peak stress reduces as the temperature increases, and increases as the strain rate increases. The dynamic recrystallization will more likely occur at higher deformation temperature and lower strain rate. The deformation activation energy of the tested steel at 950-1150οC is calculated to be 333.844kJ/mol by regression analysis. Flow stress equation of the tested steel is also established.
Investigation of Preparation and Thermoelectric Properties of Ca2.5La0.5Co4O9 Porous Ceramics
Authors: Ji Peng Xia , Zhang Hui Min , Chang Ai Min
Published: August 2015

CO(NH2)2 as pore-former used to prepare porous Ca2.5La0.5Co4O9 thermoelectric materialsby solid-state reaction technique.Microstructure,density and thermoelectric properties (temperature dependence of electrical resistivity,Seebeck coefficient) of the samples were studied in details.The results have shown that the porosity increases and the pore structure is improved with the pore-former content increasing,and electrical resistivity and density decrease while Seebeck coefficient raise.The improvement in electrical resistivity and Seebeck coefficient leads to higher power factor values at 913 K (around 1.32 mW/cm·K2) than undoped samples.
The Transformation of Martensite and Analysis of its Microstructure and Properties in Carbon Steel
Authors: Shen Yan An , Liang Xiang Feng , Sun Xia Fei , Wang Xiao Lu
Published: August 2015

The quenching process of 20 steel and 45steel is investigated in the paper and the changing law of martensite in carbon steel is discussed. The carbon content in 20steel and 45steel is both less than 0.77%,which means they are hypoeutectoid steel. The microstructure of 20 steel after quench shows lath shape while martensite in that of 45steel exhibits both lath shape and flake which occupies approximately 80%. The plasticity and toughness of martensite depend on the substructure, that is, the toughness of dislocation martensite is better than that of twin martensite under the same condition.
Interface Characterization of Bimetallic Casting with a 304 Stainless Steel Surface Layer and a Gray Cast Iron Base
Authors: Ramadan Mohamed
Published: August 2015

Bimetallic castings are widely employed as working elements in winning machines which work in conditions of intensive friction wear. The main features of wear are: dynamic percussive loads, intensive abrasive wear caused by erosion and corrosion. Three cylindrical rods cavities of the same dimensions of φ 20x200 mm were made in sand mould. Different amount of liquid iron alloy with carbon equivalent of 4.14, Mn of 0.58 and Cu of 0.17 wt% was poured into the three rod cylindrical cavities over the solid 304 stainless steels cylindrical desks inserts. Good coherent interfaces for all liquid/Solid volumes (16 to 24) are produced and multi-layers interfacial microstructure bimetal are produced. Increasing the liquid/solid volumes from 16 to 24 increases the thickness of transient layer from 52 to 89 μm and decreases the amount of ledeburite in the structure of solidified gray cast iron.
Heat-Reflecting Geocement Based Coatings Containing Perlite for Fire Protection of Timber
Authors: Guzii Sergii , Kravchenko Anastasiia , Kryvenko Pavlo V. , Tsapko Yurii , Sotiriadis Konstantinos
Published: August 2015

In this paper, the application of a heat-reflecting geocement coating, containing perlite, to reduce timber combustibility was studied. An optimized coating composition was prepared, which consisted of a geocement (Na2O·Al2O3·6SiO2·21.5H2O) and expanded perlite (9.5%). The main firing properties of this coating were invastigated. In terms of flammability, the fire protected timber reduces mass loss by 13 times and temperature of combustion gases by 5.2 times compared to unprotected timber. According to standard indicators, the reduction is by 1.3 and 10 times, respectively. The smoke generation of fire protected timber was decreased by 4.9 times (combustion mode) and 3.8 times (smoldering mode) in comparison to the unprotected timber. According to standard indicators, the decrease is by 4.5 and 2.3 times for each mode, respectively. The index of flame spread and the combustion rate reduced by 20.3 and 6.3 times, respectively, in the case of the fire protected timber compared to the unprotected one. The pine timber protected by heat-reflecting fireproofing geocement based coating, which contains perlite, refers to flame-retardant materials with moderate smoke generation and with low index of flame spread on the surface.
Shielding Silicate Composition of Increased Durability for Repair and Rehabilitation
Authors: Shaybadullina Arina Valentinovna , Politaeva Alena , Yakovlev Grigory , Pervushin Grigory Nikolaevich
Published: August 2015

The composition of silicate paint developed for rehabilitation of buildings and structures and including white Portland cement, binder based on sodium liquid glass and complex additive with nanodispersed additives does not require the use of traditional silication. Modifying the composition of coating with multi-walled carbon nanotubes has provided a coating with a shielding effect weakening high-frequency man-made electromagnetic radiation. Moreover, the use of carbon nanotubes has provided the increase of density of the coating structure, improved the physical and technical characteristics of cement and silica coating and ensured the durability of the repair coating 3,5 times compared to its analogues.
Special Repair Materials and Influence of Aggressive Environment on their Properties
Authors: Mészárosová Lenka , Tumova Eva , Dufka Ámos , Drochytka Rostislav
Published: August 2015

The rehabilitation of structures can be achieved by secondary protection. Concrete structures are during their use exposed to environmental effects which – owing to their chemical action – are corrosive and are causing degradation of these structures. One of the necessary steps to ensure adequate service life of structures is their continuous maintenance and in the case of once damaged structures, their rehabilitation.
Development of Lightweight Repair Materials Applicable to Re-Profiling to the Lightweight Concrete
Authors: Keprdová Šárka , Bydžovský Jiří , Žižková Nikol
Published: August 2015

The paper discusses the development and study of the properties of lightweight repair materials applicable to the re-profiling of lightweight concrete. The main objective in the development of the lightweight repair materials to achieve the best properties of matter at maximum lightness and ease of application on re-profiled construction. The basic formula has been derived from previously produced of repair materials applicable for re-profiling of concrete and reinforced concrete structures.
Experimental Determination of Innovative Plaster Moisture Expansion
Authors: Lukovičová Jozefa , Pavlendová Gabriela , Unčík Stanislav
Published: August 2015

The problem of the reconstruction of the historical building surface layers is in material compatibility. The basics of the convenient choice of materials for reconstruction is understanding some physical properties of used materials. The crucial properties are moisture and temperature induced deformation. The effect of moisture sorption on the elastic behavior of innovative plaster for renovation is investigated. The measurements are performed for moisture content from the dry state to the saturation water content and temperature range of 10 - 40°C.
Long-Term Durability of Modified Wood-Polymer Composite to Alternate the Solid Wood External Application
Authors: Benešová Anna , Vanerek Jan
Published: August 2015

The contribution deals with the durability of modified wood-polymer composite samples intended to alternate solid wood non-bearing structures (fences, sidings). The modification was made to the polymer matrix, which is partly consisting of commercially available regranulate. Four types of composite with varying amount of regranulate admixture are exposed to adverse ambience simulating the external conditions through moisture, freeze and high temperature action. The aim of the research is to determine the influence of regranulate share on the visual and mechanical characteristic of the material, which would be decisive in the process of specific tile creation.
Non-Destructive Defectoscopy of Building Structures by Pulsed Thermography
Authors: Peřina Zdeněk , Fabian Radek , Wolfová Marie , Valíček Pavel , Panovec Vladan
Published: August 2015

At present there are many diagnostic methods for the detection of different defects in building structures. Destructive methods, which do not enable purposeful redevelopment action or a potential cause prediction of the defect without damage to the structure, are mostly used. Pulsed thermography consists in rapid (pulse) external or internal heating of the element and the subsequent evaluation of the temperature field on the surface of the element with the thermal imaging camera. A pulse method is divided into the reflective and passes according to the arrangement of the heating source, object and thermal imaging camera. The surface temperature is changing rapidly, driven by pulse stimulation due to scattering of thermal wave, radiation and convection. The paper focuses on the possibility of using pulsed thermography in the detection of various defects in building constructions.
Reconstruction of Historical Timber Roofs at Žehušice Castle
Authors: Zídek Rostislav , Utíkal Aleš , Utíkalová Ivana , Brdečko Luděk , Brdečková Helena
Published: August 2015

The paper presents some aspects of the reconstruction of timber roofs at Žehušice Castle. The roofs were built at different times and using various types of structural systems. Many timber elements of the roofs have been heavily damaged by previous unprofessional alterations to them, or, more often, by neglected maintenance and subsequent fungal attack caused by massive leaking. Because of the requirements of the National Heritage Institute it was necessary to be sensitive to the existing structures and minimize changes to them during the reconstruction of the roofs. In order to successfully achieve this, it was necessary to understand the distribution of stresses in the structure and its static behavior as well as possible. Therefore, 3D computational models were developed. On the basis of the obtained results, it was decided whether roof elements would be replaced or only parts of them. However, the informative value of relatively complicated mathematical models appeared to be limited.
Storage Properties of Water-Solube Salts in Bastion Historical Brick
Authors: Pernicová Radka
Published: August 2015

Storage properties of water-soluble salts in bastion historical brick are presented in this paper. Probably the most important factor affecting the material degradation represents water from rain, snowfalls or ice, which penetrates into the unprotected parts of building. Therefore, the deterioration of building materials is in many cases caused by water-soluble salts. The most common salts are on chloride, sulfate and nitrate origin. The aim of this article is influence of salts ions on masonry from bastions fortifications. The main practical impact will be in providing more precise information about material so it should lead to improvement the quality of reconstruction process of historical buildings.
The Thermographic Measuring of the Surface Temperature of the Peripheral Wall after Removing a Technical Device for Elimination of Reflected Radiation
Authors: Solař Jaroslav , Čmiel Filip
Published: August 2015

It is possible to measure the surface temperature of a peripheral wall in a certain point with an advantage when using a technical device for elimination of reflected radiation. Other advantages of the diagnostics of the peripheral wall using the infrared termographic system after removing the mentioned technical device from the wall is, that if we determine (using the technical device) the surface temperature in a determined point, then we are, after inserting it into the termographic systém, able to determine retroactively the real value of the apparent reflected temperature, and this is even done with higher accuracy. Then we use the value for a termographic measuring of all the surface of the peripheral wall, keeping the same angle of scanning.
Use of Glassy Slag from Biomass Combustion in the Building Industry – Coarse Aggregate
Authors: Khestl Filip , Šulková Veronika , Mec Pavel
Published: August 2015

The work deals with possibilities using of glassy slag produced during the combustion of biomass in construction. This is a waste product with glass characteristic, which may also contain ash and other pollutants. This waste is significantly different according to the used types of biomass, soil, temperature and time of combustion. Its structure is mostly porous and glassy. Building materials in which may be applied are cementitious or alkali-activated composites in which can appear in due to its nature as a filler or binder. In the paper the basic characteristics with the focus on use of this slag as a coarse aggregate were examined.
Verification of Applicability of Alternate Sources of Heat for Determination of the Surface Temperature and Emissivity of Glossy Materials
Authors: Čmiel Filip , Solař Jaroslav
Published: August 2015

The value of the surface temperature and emissivity of glossy materials can be determined by the method of four points. However, in practical measurements on the peripheral walls of buildings there may occur situations where four points are not available. In such case it is possible to use alternate sources of heat.
Verification of Applicability of Thermographical Measuring of the Surface Temperature and the Influence of Emissivity of Glossy Materials while Eliminating the Reflected Radiation Using a Metal Shield
Authors: Solař Jaroslav , Čmiel Filip
Published: August 2015

The exact determination of emissivity and the following determination of the surface temperature of glossy materials can be carried out e. g. after applying a material with a known value of emissivity on the surface (e. g. self-adhesive foil or spray tint). The contribution deals with other possibility of determination of surface temperature and the influence of emissivity of glossy materials using a metal shield that reduces the negative influence of the reflected radiation during the termographical measurement.
Statistical Simulation of Accidental Loads in the Problems of Constructional Mechanics
Authors: Yeremenko Bohdan , Pashko Anatolii , Terenchuk Svitlana
Published: August 2015

In this paper, we consider a method of simulation of random fields with known spectral density. The simulation results used to solve problems of structural mechanics, which describes the boundary value problems
Longitudinal Shear Analysis of Composite Slabs with Prepressed Embossments
Authors: Holomek Josef , Bajer Miroslav , Vild Martin
Published: August 2015

Composite slabs with prepressed embossments present an effective solution for horizontal load bearing structures. Sheeting serves as a formwork in construction stage and as a tension bearing member after hardening of concrete. There is no need for additional tensile reinforcement in case of sufficient longitudinal shear bearing capacity of the embossments. Longitudinal shear bearing capacity is not precisely determined when designing according to nowadays standards. Full scale bending tests of the slabs are used to determine characteristics for m – k method or partial connection method. Bending tests are expensive and space demanding. Alternatively small-scale shear tests can be used to determine shear characteristics of the sheeting. However, shear tests cannot include all the effects affecting the bearing capacity of bended slab, such as effect of curvature or distribution of load. Therefore, related design method has to be used to determine load bearing capacity of the slab in bending. This paper extends achievements presented by the authors in contribution in CRRB 2013. The results of small-scale tests are compared with results of numerical models of the slab in shear. Numerical models are created in two different finite element codes. Setting of steel-concrete interface properties in the models is validated using data from literature.
In Situ Applicability of Selected Nanotextiles on Surfaces of Historic Plasters
Authors: Šmidtová Markéta , Kroftová Klára
Published: August 2015

The paper deals with the stabilization, conservation and strengthening of historic plaster fabrics based on nanofibres. As a result of degradation processes, especially of a chemical nature accompanied by increased humidity historic masonry, there is a loss of cohesion and disturbance od the surface finish and plaster. Traditional remediation techniques and methods normally lead to a reduction of diffuse permeability in multiphase structure and create different expansion properties under the plaster. The undesirable features of these methods are their irreversible character. Currently, there are primarily preferred procedures which stabilize the structure of the external finishes and at the same time preserve the original features of the historical plasters. The paper will be listed in the partial results of the ongoing in-situ and laboratory research applications of fabric based on nanofibres, which are formed by the supporting layer and spinning polymer.
Drying Technologies in Masonry Structures
Authors: Novotný Miloslav , Šuhajda Karel , Sobotka Jindřich , Jiroušek Zdeněk
Published: August 2015

Drying of masonry building structures using a high-frequency electromagnetic (EMW) radiation, the so-called microwave technology, is increasingly used in building practice. This is a progressive method, with the use of which removal of excess moisture can be significantly accelerated. This article describes physical phenomena that occur in the course of drying, and compares the standard, the most widely used, technological procedures in the drying of buildings.
The Application of Carbon Composites in the Rehabilitation of Historic Vaults
Authors: Witzany Jiří , Brozovsky Jiri , Čejka Tomáš , Kroftová Klára , Maršík Václav , Zigler Radek
Published: August 2015

The on-going renovation and reconstruction of the Premonstrate Monastery in Teplá was the site for the application of the results of research carried out within the NAKI research project [1]. Barrel vaults with lunettes over the arcaded walk of the convent had been damaged at the crown by a continuous tensile crack one to several millimetres in width. The vault was reinforced and stabilised with strips of a carbon composite and epoxy resin. The article describes the design and the stabilisation and reinforcement procedure of the vaults over the arcaded walk on the 1st overground storey of the convent damaged by a continuous, at places prominent tensile crack at the vault crown using the method of non-prestressed strips of a carbon composite.
Determining the Presence of the Corrosion Inhibitors Based on Amines in Hardened Mortars
Authors: Fiedlerová Michaela , Taranza Luboš , Drochytka Rostislav , Tupý Michael
Published: August 2015

The presence of corrosion inhibitors in the composition of building materials is an innovative feature that significantly contributes to the prolongation of the life cycle of reinforced concrete and the rehabilitation procedure itself. Limited control and the high cost of modifying additives result in failure of prescribed dosage and thus limited function. The article describes the methodology for determining the presence of corrosion inhibitors based on amines through a colored reaction of amines with ninhydrin agent.
Grain Boundary Diffusion in Severely Deformed Metals: State of the Art and Unresolved Issues
Authors: Divinski Sergiy V.
Published: August 2015

An overview of current understanding of diﬀusion properties of grain boundariesin severely deformed materials is presented. The results are evaluated with respect to thetypes of severe plastic deformation, defects introduced by such processing, and processing pa-rameters. An extended hierarchy of diﬀusion paths is shown to exist in ultra- ne grainedmaterials, with relative diﬀusion rates being diﬀerent by orders of magnitude. Properties ofdeformation-modi ed grain boundaries, such as width, diﬀusivity, diﬀusion mechanism and freevolume excess, are examined. A model of deformation-modi ed state of general high-angle grainboundaries is discussed with respect to the underlying concept of free volume accumulation.The relaxation stages of the deformation-modi ed state of grain boundaries are analyzed.
The Role of Grain Boundaries and other Defects on Phase Transformations Induced by Severe Plastic Deformation
Authors: Sauvage Xavier , Nasedkina Yana
Published: August 2015

During the past two decades, processing of ultrafine grained materials using severe plastic deformation techniques has attracted great interest in the scientific community. Although the up-scaling of processes and the lack of ductility of ultrafine grained alloys are still some important challenges, these techniques look promising because they produce bulk materials free of porosities. More recently, some strategies to combine precipitation hardening and ultrafine grained structures have been proposed. It has also been shown that nanoscaled composite materials could be successfully processed. This experimental work rose however some very fundamental scientific questions about the influence of severe plastic deformation on the precipitation mechanisms or on the formation of supersaturated solid solution through mechanical mixing. The driving force and the thermodynamics of these phase transformations are of course affected by the high amount of energy stored in severely deformed alloys, especially as interfacial energy. But grain boundaries, with the help of dislocations and point defects, also play an important role in the kinetics. In this paper, it is proposed to shortly review these phenomena and the underlying mechanisms with a special emphasis on the contribution of grain boundaries.
Kinematics Simulation of a Tripod Parallel Universal Wrist
Authors: Zou Ping , Wu Guang Lei , Yang Xu Lei
Published: August 2015

The prototype of a new 3-DOF tripod parallel universal wrist was developed. Its structure, characteristics and applications were introduced. The inverse kinematics model was established by the vector and kinematics influence coefficient method. The schematic diagram of simulation was established through the software — MATLAB/Simulink. Based on the above model and diagram, the inverse kinematics simulation was made. The simulation curves under different initial conditions about angle, acceleration, velocity, displacement varying as time processed can intuitively reflect the kinematic relation between the parallel bars and the moving platform of this mechanism and this is valuable and significative for the further research.
The Study of Constant Grinding Removal Rate Model of Turning-Grinding Composite Machine Tool
Authors: Wang Hongjun , Luan Zhong Quan , Han Qiu Shi
Published: August 2015

As the key parts of cars, camshafts influences a lot on the quality and durability of cars. Their processing is complicated, time and place consuming and the quality is difficult to guarantee. The turning-grinding composite machine tool (TGCM) for camshafts is studied on basis of ‘process integration with one setup’ theory in this paper. It presents the structure of the turning-grinding composite machine tool by the analysis of the function of TGCM. The revolving working table is used to transfer the turning and grinding function. It also discusses the constant grinding removal rate mathematic model of the cam contour machining. The opened-CNC system for this machine tool is developed by using the VC++6.0 based on PC and UMAC controller. The constant grinding rate model of the cam contour is verified by the experiment results.
Agile Manufacturing Data Management
Authors: Qiao Li Hong , Liu Wei
Published: August 2015

An agile data service framework was proposed in the paper to meet the requirement of agile manufacturing data management in product lifecycle management. The framework was comprised of four layers: core object and ontology layer, meta-data and meta-mode layer, service component layer and implementation layer. The realization of agile manufacturing data management was investigated through the analysis of the unified manufacturing data modeling and the implementation based on services. The descriptive structure and the main content of the manufacturing data model was given. The architecture of the manufacturing data management system based on services was addressed to conduct service implementation of the framework. The proposed approach of agile data services brought forward a new feasible solution to agile data management throughout product lifecycle.
Stress in Diamond Coatings on Cutting Tools Deposited by Hollow Substrate Holder
Authors: Lu Wen Zhuang , Zuo Dun Wen , Xu Feng , Yang Chun , Wang Min
Published: August 2015

Chemical vapor deposition (CVD) diamond coatings were deposited on milling cutter substrate using a hollow substrate holder. The substrate is WC–Co cemented carbide contained 6% of cobalt concentration. Structures and stress state of diamond films were analyzed by scanning electron microscopy (SEM) and Raman spectroscopy. It was found that the diamond coating is of the same quality at the same cutting tool deposited on a hollow substrate holder. Diamond (sp3) bonds are better developed with substrate temperature of ~760°C. A higher or lower substrate temperature could lead to a higher non-diamond carbon content in the films. A higher substrate temperature could lead to a higher thermal stress. The compressive stress increases when the substrate temperature is higher or lower than 760°C. The concentration of amorphous phase in the coatings is low with CH4 concentration of 1.0% and 1.5%. A higher non-diamond carbon content and defects in the diamond coatings increase with the increase of CH4 concentration, which leads to the compressive stress value does not increase significantly under a high CH4 concentration.
Toolpath Optimization on Automatic Removal Uncut and Application
Authors: Zhao Zhen Yu , Zhang Meng , Liu Bai , Zhou Hou Ming , Yu Song Sen
Published: August 2015

In milling pocket corner, there maybe residual material left at sharp corners when stepover is extremely large in contour-parallel toolpath. This paper describes an improved pocket toolpath by inserting biarc transitions segments in contour-parallel toolpath. When reaching the sharp corner, the cutter moves along the biarc transitions toolpath so that the corner material is removed. The efficient toolpath is continuous for clearing residual material at sharp corner. Milling test has been conducted to demonstrate and verify the significance of the proposed method.
Integrated Process Planning Based on 3D Product Models
Authors: Qiao Li Hong , Zhang Jin
Published: August 2015

One of the major barriers to the integration of CAD, CAPP and CAM is insufficiency and incompatibility of product model data among various application systems. This paper presented an effective approach to achieve integrated process planning with CAD and CAM under a product data management environment based on 3D product models. The system architecture and the processes of an integrated process planning system (3D-IPP) were constructed using feature information and specific CAD/CAPP/CAM integration technologies based on feature. A feature-based product information model is designed as the information source for the 3D-IPP. A feature-based integrated process planning method was developed based on group technology, intelligent decision-making algorithms and parametric operation templates in numerically controlled (NC) programming. The procedures of intelligent process route planning and parametric NC operation planning were addressed. The 3D-IPP system and its implementation provide an effective solution to strive for complete information sharing among application systems of CAD, CAPP and CAM.
Study on Metabolic System for Water-Soluble Coolant — Machining Performance and Long-Term Stability of Recycled Coolant
Authors: Yamaguchi Kenji , Kondo Yasuo , Sakamoto Satoshi , Kohira Shu
Published: August 2015

To reduce the management cost and environmental load of water-soluble coolant, authors have been studying on a metabolic system for water-soluble coolant. More than 90% of waste water-soluble coolant is composed of water phase. If the oily additives and contaminants can be isolated from the waste coolant, the amount of waste coolant decreases remarkably because the recycled water can be reutilized as a diluent of renewal coolant. Authors has been developed some types of water recovery methods for the metabolic system. To complete the metabolic system for water-soluble coolant, the coolant diluted with recovered water should have the same machining performance and long-term stability as those of coolant diluted with tap water. In this report, we examined the machining performance and ability change of water-soluble coolant diluted with recycled water under operations encountered in machine tool.
Experimental Research on Cutting Heat Dissipation under Various Cooling Conditions
Authors: Quan Yan Ming , Xu Hao , Dou Yong
Published: August 2015

Cutting heat dissipation in high speed milling of medium carbon steel was experimentally investigated based on calorimetric method under the cooling conditions of hard cutting, applying compressed air or water. Special containers holding water medium were designed to collect cutting heat in chips, workpiece and tool respectively, and the heat distribution ratio in these components was calculated in terms of the temperature varieties of each component. The results were compared with the cutting power which came from the cutting forces measured.
Micro Machining of Three-Dimensional Microstructure with the Tiny-Grinding Wheel Based on the Electro-Magneto-Rheological Effect
Authors: Liu Yi , Yan Qiu Sheng , Lu Jia Bin , Gao Wei Qiang , Yang Yong
Published: August 2015

Using the tiny-grinding wheel based on the synergistic effect of the electro-magneto- rheological (EMR) fluid, a novel method is presented to machine the three-dimensional (3D) microstructure of hard-brittle materials. Machining experiments of micro-groove were conducted to reveal the machining performances of the tiny-grinding wheel. Experimental results confirm the effectiveness and feasibility of the micro machining technique with the EMR effect-based tiny-grinding wheel. The shape of machined micro groove is found to be an inverted trapezoid, and the material removal mode of normal glass with the micro machining method is the plastic-removal mode. With the increase of the rotation speed of the tool, the material removal rate, width and depth of micro grooves increased first and decreased afterwards. The maximum removal rate, width and depth of micro groove occur at different speeds of the tool.
Improvement of Thickness Uniformity of Bulk Silicon Wafer by Numerically Controlled Local Wet Etching
Authors: Yamamura Kazuya , Mitani Takuro , Ueda Kazuaki , Nagano Mikinori , Zettsu Nobuyuki
Published: August 2015

We have developed numerically controlled local wet etching (NC-LWE) as a novel deterministic subaperture figuring and finishing technique, which is suitable for fabricating various optical components and finishing functional materials. In this technique, a chemical reaction between the etchant and the surface of the workpiece removes the surface without causing the degradation of the physical properties of the workpiece material. Furthermore, the processing properties of NC-LWE are insensitive to external disturbances, such as the vibration or thermal deformation of the machine or the workpiece, because of its noncontact removal mechanism. By applying the NC-LWE process using HF/HNO3 mixtures to etch the silicon, we corrected the thickness distribution of the bulk silicon wafer with a diameter of 200 mm and achieved the total thickness variation of less than 0.23 µm within the diameter of 190 mm.
Figuring of Elliptical Neutron Focusing Mirror Using Numerically Controlled Local Wet Etching
Authors: Nagano Mikinori , Takai Hiroyuki , Yamamura Kazuya , Yamazaki Dai , Maruyama Ryuji , Soyama Kazuhiko
Published: August 2015

Numerically controlled local wet etching is a novel figuring method for fabricating the ultraprecision optical components and/or finishing the functional materials. In this method, localized wet etching area is formed by applying the combination nozzle which consists of a supply part and a suction part of an etchant, and the removal volume at any point on the workpiece surface is determined by the dwelling time of the nozzle. In this paper, we proposed the two-step figuring process, which consists of a rough figuring process by applying a one-dimensional numerically controlled scanning using a large rectangular nozzle and a finishing process by applying two-dimensional numerically controlled scanning using a small circular nozzle, for figuring the plano-aspherical mirror. By applying the two-step figuring process, we fabricated the plano-elliptical neutron focusing mirror with the figure accuracy of less than 0.5 µm and succeeded in achieving the focusing gain of 6.
Mirror Finishing of Austenitic Stainless Steel with a Cermet Insert
Authors: Sekiya Katsuhiko , Tezuka Ryo , Yamane Yasuo , Yamada Keiji
Published: August 2015

Stainless steel SUS304 is one of the typical difficult-to-cut materials due to strong tendency to adhesion and work hardening. Therefore finished surface becomes rough in machining operations. In this report, precision cutting of SUS 304 is discussed. Surface roughness depends on accuracy of the machine tool, adhesion and roughness of tool flank. We analyzed the factors of surface roughness in turning of SUS304 on an engine lathe. M20 tungsten carbide inserts, coated carbide inserts and cermet inserts were used. Peak-to-valley height of machined surface included approximately 1μm of machine error. Surface profile reflected roughness of tool flank. Polished flank decreased the roughness of finished surface. Adhesion was least in the case of cutting with cermet inserts. We also conducted face turning of SUS304 on an ultra-precision lathe with cermet inserts. Flank of the inserts were polished to 100nmRz. We obtained 50nm of minimum peak-to-valley height and 220nmRz of surface roughness.
Study on Precision Finishing of PCD by Constant-Pressure Grinding and UV-Polishing
Authors: Touge Mutsumi , Nakano Takayuki , Yamaguchi Keishi , Kubota Akihisa , Watanabe Junji
Published: August 2015

Polycrystalline diamond (PCD) has been widely used for various cutting tools and die components making use of its hardness and wear resistance properties. The polishing method of a single crystal diamond substrate and SiC using ultraviolet irradiation was newly developed to obtain mirror-finished surfaces. Due to the long polishing time in this method, a better pre-machined surface is required to shorten the total processing time. In this work, the constant-pressure grinding was performed using a cup type metal-bonded diamond wheel and a constant pressure device. After the good constant-pressure grinding, the PCD was finished by the polishing under the ultraviolet irradiation, and the microroughness was reached to be 0.71 nmRa.
The Investigation of Tool Wear in Metal Machining Using Finite Element Method
Authors: Ruan Hong Yan , Yan Hua , Lu Shu Bin , Liu Hui Xia , Wang Xiao
Published: August 2015

The existing studies based on 2-dimension cutting model are partial investigations on tool wear. In order to get close to the true cutting conditions, the Lagrangian thermo-viscoplastic cutting simulations were conducted and the tool wears were predicted under different cutting speeds using 3-dimension finite element models. The simulation results indicate that when the cutting speed increases the cutting forces will reduce accordingly while the wear depth will be deeper. As a result, different factors should be considered at the same time when the speed range is selected. This study has shown that the finite element method is a valuable approach to understand the tool wear mechanism in machining and the influences of different cutting speeds.
A New Approach for Friction Modeling at the Tool-Chip Interface in Orthogonal Cutting
Authors: Wang Jia Chun , Li Na , Kou Yun Peng , Yang Yu Lin
Published: August 2015

A better understanding of friction modeling is really important for producing more realistic finite element models of machining processes. This paper presents a methodology to determine the friction at the tool-chip interface. By matching the measured values of the cutting forces with the predicted results from finite element simulations (FEM), a revised friction model on the tool-chip interface is developed. Reasonable distribution of the stress, strain and strain-rate, as well as the temperature fields at the tool-chip interface could be achieved by using this approach. An attempt is made by FEM to obtain a full understanding of relationships between the complex physical behavior and friction at the tool-chip interface. It is found that the sticking-sliding separated area is located at the points with the greatest temperature. And the corresponding relationship between cutting parameters and sticking-sliding friction separated area is found.
Calculation of Material Flow in Orthogonal Cutting by Using Streamline Model
Authors: Bi Xue Feng , List Gautier , Liu Yong Xian
Published: August 2015

The streamline method was used to investigate the plastic strain rate in machining. The streamline function presented in this paper is a general equation with three parameters controlling the complex variation of flow line shape. Velocity and deformation field were obtained by streamline analysis. The validation of this model was conducted by comparing with other experimental results published. It shows that the streamline model presented in the paper can be applied to the evaluation of strain rate in machining.
Generation of Wear Protective Layer in High Speed Turning of Gray Cast Iron Containing Aluminium and Magnesium
Authors: Furuya Satoshi , Ozoe Nobuaki , Yamane Yasuo
Published: August 2015

This paper focuses on the influence of difference of tool materials on generation of wear protective layer when turning gray cast iron containing Al and Mg. In this experiment, the gray cast iron to which small quantities of Al and Mg was added were cut with cermet, P grade carbide (P10), silicon nitride ceramics (Si3N4), titanium nitride (TiN) coated carbide and K grade carbide (K10) at high speed. In turning gray cast iron containing Al and Mg with cermet, the tool wear was significantly reduced compared to that resulting from the cutting of conventional gray cast iron. Further, the protective layer consisting of nonmetallic inclusions in the work material was formed on the tool surface. In addition to cermet, this layer was formed on tool surface of Si3N4 and TiN coated carbide. The elements of Al and Mg added to the work materials were detected in the layers formed on these tool surfaces as well as cermet. The inhibiting effect on tool wear was also caused when turning with P10. However, P10 had much greater wear than cermet. On the other hand, in the case of turning with K10, the effect reducing wear with the addition of Al and Mg was not caused. The wear increased as cutting speed increased regardless of work materials.