bluuebunny/crossref_metadata_2025 huggingface dataset:
Patient-Centered Clinical Trials Decision Support using Linked Open Data
Authors: MacKellar Bonnie , Schweikert Christina , Chun Soon Ae
Published: April 2015

Patients often want to participate in relevant clinical trials for new or more effective alternative treatments. The clinical search system made available by the NIH is a step forward to support the patient's decision making, but, it is difficult to use and requires the patient to sift through lengthy text descriptions for relevant information. In addition, patients deciding whether to pursue a given trial often want more information, such as drug information. The authors' overall aim is to develop an intelligent patient-centered clinical trial decision support system. Their approach is to integrate Open Data sources related to clinical trials using the Semantic Web's Linked Data framework. The linked data representation, in terms of RDF triples, allows the development of a clinical trial knowledge base that includes entities from different open data sources and relationships among entities. The authors consider Open Data sources such as clinical trials provided by NIH as well as the drug side effects dataset SIDER. The authors use UMLS (Unified Medical Language System) to provide consistent semantics and ontological knowledge for clinical trial related entities and terms. The authors' semantic approach is a step toward a cognitive system that provides not only patient-centered integrated data search but also allows automated reasoning in search, analysis and decision making using the semantic relationships embedded in the Linked data. The authors present their integrated clinical trial knowledge base development and a prototype, patient-centered Clinical Trial Decision Support System that include capabilities of semantic search and query with reasoning ability, and semantic-link browsing where an exploration of one concept leads to other concepts easily via links which can provide visual search for the end users.
A Cognitive Engineering Design of a Smart Phone Information Appliance with Improved Usability
Authors: Okada Masato , Takiguchi Keishi , Ohwada Hayato
Published: April 2015

This paper focuses on a cognitive engineering design for a smart phone application with improved usability at a software-level update of an information appliance (digital video remote controller). The design process is based on the Norman's cognitive engineering framework that can be used to detect human-interface problems with the existing controller through a usability assessment. The process includes considering a menu structure and error location in a more detailed-level analysis, and proposes an improved design for the smart phone application that emulates a video controller. The resultant system is tested to show how much the usability has been enhanced. The proposed method indicates that smart-phone applications can be regarded as useful alternatives to improve the information appliances, yielding a typical case study toward the next generation cognitive computing systems.
Information and Password Attacks on Social Networks
Authors: Franchi Enrico , Poggi Agostino , Tomaiuolo Michele
Published: April 2015

Online social networks have changed the way people interact, allowing them to stay in touch with their acquaintances, reconnect with old friends, and establish new relationships with other people based on hobbies, interests, and friendship circles. Unfortunately, the regrettable concurrence of the users' carefree attitude in sharing information, the often sub-par security measures from the part of the system operators and, eventually, the high value of the published information make online social networks an interesting target for crackers and scammers alike. The information contained can be used to trigger attacks to even more sensible targets and the ultimate goal of sociability shared by the users allows sophisticated forms of social engineering inside the system. This work reviews some typical social attacks that are conducted on social networking systems, carrying real-world examples of such violations and analysing in particular the weakness of password mechanisms. It then presents some solutions that could improve the overall security of the systems.
Cloud Computing for Secure Services in E-Government Architecture
Authors: Hashemi Sajjad , Monfaredi Khalil , Hashemi Seyyed Yasser
Published: April 2015

E-government tries to take advantage of new technology to provide better service to citizens. Some of the main challenges in the face of E-government are query processing high volume applications, data center management, data security and E-government services. Cloud computing can be a good option for responding to these issues and fixing them, and guarantee the realization of E-government, with maximum efficiency and maximum safety. In this paper, the authors propose a novel architecture for E-government by using Cloud computing architecture which can largely increase the integrity and security service in E-government, and also increase users' confidence in the system and may lead to increased participation.
Calculation of the Heat Content of the Electrode Metal Droplet When Applying Power Supplies for Manual Arc Welding with Different Volt-Ampere Characteristic
Authors: Il’yashchenko D.P. , Chinakhov Dmitry A. , Gotovshchik Yu.M.
Published: April 2015

In the paper the authors provide the method for calculating the heat content of the molten electrode metal droplets according to the energy parameters of the power supplies for manual metal arc welding. It was established that the type of the welding power supply has a significant impact upon the temperature, mass and active surface area of the electrode droplets.
Modal Analysis as a Means of Researching the Vibrations in Grinding
Authors: Ardashev Dmitrii V.
Published: April 2015

During the grinding process the main role is played by the vibrating phenomena caused by primary imbalance of a wheel, features of its structure, and also the existence of a component arising in the general scale of vibrations and caused by the change of the structure of a working surface of a grinding wheel, wear of its working abrasive grains during the process. Intensity and amount of wear of the grinding wheel depends on conditions of grinding operation – kind of grinding, processed material, etc. In turn, the existence of close correlation connection between parameters of vibrations and modes of grinding allows to assume, that vibrating processes possess sufficient information and can form the basis for an assessment and forecast the perfection factor of a grinding wheel directly in operating conditions.
Influence of Crystal Defects on the Reflectivity of the Aluminum
Authors: Umnov S.P. , Asainov O.Kh. , Lemachko A.N.
Published: April 2015

The effect of ion-assisted deposition of the Al films on their UV reflectance is investigated in this paper. The films' reflectance is measured by a spectrophotometer. The obtained films are examined by using transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), and atomic force microscopy (AFM). The TEM and AFM measurements allow the determination of the size of crystallites in a film and its microstructure. The XRD analysis reveals that the films deposited with argon ion-beam assist are characterized by much higher microstress levels compared to the films deposited without ion assist. The comparison of the Al films’ reflectance measurements indicate that the films with a higher microstress level (hence, higher defect concentration) are characterized by the enhanced reflectance in the UV region. The conducted investigation shows that the defects of the Al films’ crystalline structure affect its optical properties.
Modeling of Mechanical Behavior of Ceramic Nanocomposites
Authors: Vaganova Irina K. , Skripnyak Evgeniya G. , Skripnyak Vladimir V. , Skripnyak Vladimir A.
Published: April 2015

Deformation and damage occurring at the meso-scale level in structured representative volumes (RVE) of modern nanocomposites in wide loading conditions were simulated. The computational models of a structured RVE of ceramic nanocomposites were developed using the data of structure researches on meso-, micro -, and nanoscale levels. The critical fracture stress on meso-scale level depends not only on relative volumes of voids and inclusions, but also on the parameters of inclusion clusters. The critical fracture stress at the meso-scale level depends not only on relative volumes of voids and strengthened phases, but also on sizes of corresponding structure elements. In the studied ceramic composites the critical failure stress is changed non-monotonically with growth of the volume concentration of strengthening phase particles. At identical porosity, concentration of nanovoids in the vicinity of grain boundaries causes the decrease in the shear strength of nanostructured and ultrafine-grained ceramics. It is revealed that the occurrence of bimodal distributions of the local particle velocity at the meso-scale level precedes the nucleation of microcracks. At mesoscale level of ceramic nanocomposites the pressure and particle velocity distribution don’t display a resonance behavior under submicrosecond single shock pulse loading or repeated pulse loadings.
Research on Fracture Mechanics and Dispersed Structure of the Polymeric Composite Materials under Abrasive Processing
Authors: Dyakonov Aleksandr A. , Shmidt Irina V.
Published: April 2015

This article presents results of research on microcutting mechanics and dispersed structure of metallopolymers. Main differences of the metallopolymers cutting from conventional steels and alloys were determined - under enhancing dispersion of the metallopolymers plastic cutting is almost absent; in case of grain included into solid metallopolymer inclusion, inclusion particles can stick to this grain resulting in cutting, performed by this inclusion.This document includes results of the inclusions metric parameters calculation, based on the metallopolymers dispersed structure microscopic study.
Comparison of Activation Technologies Powder ECP-1 for the Synthesis of Products Using SLS
Authors: Babakova E.V. , Gradoboev A.V. , Saprykin A.A. , Ibragimov E.A. , Yakovlev V.I. , Sobachkin A.V.
Published: April 2015

At present the development of methods of layer-by-layer and line-by-line synthesis of finished prototypes and functional products made of powder materials furthers introduction of these technologies into different areas of human activities from light to heavy industry and medicine. The research has been carried out to describe how gamma radiation of the Co60radioactive isotope and the mechanical activation makes an impact on the copper powder, as well as the nature of sintering by the layer-by-layer laser synthesis. The changes of the structure and properties of the powder, which generally affects the layer-by-layer laser process of products sintering, have been detected.
Phase Formation in the Ti-Y-O System Formed Using High-Energy Methods
Authors: Ivanov Yuriy F. , Petrikova Elizaveta A. , Teresov Anton D. , Klopotov Anatolyi A. , Gromov Victor E. , Budovskikh Evgeniy A. , Kalashnikov Mark P. , Klopotov Vladimir D.
Published: April 2015

A surface alloy of the yttrium/titanium system, enriched with oxygen atoms, has been developed using high-energy methods. Formation of a multilayer multiphase submicron-and nanoscale structure has been revealed. A substantial increase in the microhardness (by ≈3 times), a decrease in the friction coefficient (more than by 2 times) and the wear rate (by ≈3 times) of the doped layer have been revealed.
Influence of Phase Composition on Properties of Corundum-Zirconium Ceramic
Authors: Ivashutenko Aleksander S. , Martyushev N.V. , Bezborodov Valeriy P.
Published: April 2015

The results of the analysis of influence of the phase composition of corundum-zirconium ceramic on its properties are presented in this paper. It was established that the most perspective ceramic has composition 0,6 (ZrО2 + 3M% Y2O3) – 0,4 Аl2О3. High strength properties of this composition are determined by the presence of compressive stresses and the opportunity of retaining of tetragonal grains ZrО2 in a metastable condition at low temperatures.
On the Need to Increase Pressure and Flow Rate SCTE in the Grinding Zone
Authors: Yashkov V.A.
Published: April 2015

This work describes the hydrodynamic phenomena in internal grinding teams abrasive wheels with radially movable segments.
Research Methods of Milling Technology Elements
Authors: Gavrilin A.N. , Moyzes B.B. , Cherkasov A.I.
Published: April 2015

The increasing of vibration stability for the technological system is always the vital task for different material processing. Vibration stability increasing methods are divided into constructive and technological. It’s necessary to take into consideration different factors such as vibration whence, vibration parameters, immediate changing of processing mode possibility while choosing the method of vibration decreasing for the technological systems. The present article is reviewing the research methods of milling technology elements as one of the basis of technological methods for increasing of vibration stability.
Calculation of Heat Exchange Characteristics Transpiration Cooling Systems
Authors: Yakimov A.S.
Published: April 2015

The effect of high-enthalpy gas flow on transpiration cooling systems is considered. The influence of thermo-physical properties and porosity of some metals on heat transfer of the models is studied.
Influence of the Shaper Design of Pneumohydraulic Impact Device on the Form and Duration of the Impact Impulse
Authors: Angatkina Oyuna O. , Krauinsch Petr Y. , Deryusheva Valentina N.
Published: April 2015

Impact devices are used in various areas of mechanical engineering and deal with a variety of materials. At the moment, it is determined that an increase in the duration of the impact impulse ensures the constant contact of a headgear (tool) with the work environment. This increases the efficiency of impact devices. We have proposed a shaper that allows to control the shape and duration of the impact impulse. In this paper, results of mathematical modeling of the pneumohydraulic impact device with elastic and viscoelastic shaper is considered. Several designs of impact devices are presented. Parameters which affect the impact impulse are determined. These results can be used in constructing pneumohydraulic impact devices for a specific area of implication.
Study of the Effect of the Rolling Mill Inter-Stand Tension on the Strip Gauge Deviation
Authors: Radionov Andrew Alexandrovich , Andryushin Igor Yuryevich , Karandaev Alexander Sergeevich , Khramshin Vadim Rifhatovich , Khramshin Rifhat Ramazanovich
Published: April 2015

The paper studies issues of the cross impact of tension and strip gauge at the rolling in the continuous roughing sub-train of the wide strip hot-rolling mill. Functional dependencies and chart of the mathematical model defining interrelation between the specific tension and strip gauge increment are provided. Based on the example of the 2,000 mm hot rolling mill of OJSC Magnitogorsk Iron and Steel Works (OAO MMK), it has been proved that rolling is carried out with tension values which exceed several times allowable values. The paper also considers new technical solutions enhancing the speed mode control algorithms and systems of the electric drives of the wide strip hot-rolling mill continuous subgroup.
The Evolution Equations of Shock Deformation Problems with Plane Surfaces of Discontinuities in Elastic Inhomogeneous Mediums
Authors: Ragozina Victoria , Ivanova Yulia
Published: April 2015

For the model of the nonlinear elastic medium with inhomogeneous properties represented by a continuous change of the elastic moduli and density, the motion problems of a plane longitudinal or transverse shock waves are considered. The matched asymptotic expansions method allows to determine the evolution equations reflecting the nonlinearity of the wave processes and the inhomogeneity of the medium. The transition to the limiting inner problem of the small parameter method is dictated by the chain of inner problems, the solutions of which require a changes in all of the independent variables and their scales.
Asymptotic Model of Free Convection Flow on a Vertical Surface in Porous Media with Newtonian Heating
Authors: Bocharova Anna A. , Plaksina Irina V. , Obushnyy Andrey A.
Published: April 2015

The mathematical model based on system of momentum and energy equations for free convection flow along a vertical surface in porous media under boundary conditions of the third sort is solved analytically using the method of matched asymptotic expansions. The region of validity for boundary layer model and expansions for stream function and temperature with parameter of perturbations were defined. The dependence of characteristic flow from governing dimensionless parameters and was analyzed numerically. The influence of viscous and convective terms of momentum equation in the proposed mathematical model significantly increases the rate of heat transfer on plate in porous media in comparison with Darsy flow model.
Two-Wave Processes in the Magnetic Vibrations of a String
Authors: Tomilin A.K.
Published: April 2015

It is shown that principal amplitude waveforms in the magnetic vibrations of a string can be expressed by complex (two-wave) functions. The research results can be used in the design of mechatronic systems with vibrating elements.
Numerical Simulation of Neural Network Components of Controlling and Measuring Systems
Authors: Danilin S.N. , Makarov M.V. , Shchanikov S.A.
Published: April 2015

The article deals with the problem of calculating the fault tolerance of neural network components of industrial controlling and measuring systems used in mechanical engineering. We have formulated a general approach to developing methods for quantitative determination of the level of the fault tolerance of artificial neural networks with any structure and function. We have studied the fault tolerance of four artificial feedforward neural networks as well as the correlation between the result of determining the fault tolerance level and a selected performance parameter of artificial neural networks.
Numerical Simulation of High-Speed Orthogonal Cutting of Metals
Authors: Zelepugin Aleksey S. , Zelepugin Sergey A.
Published: April 2015

Processes of high-speed orthogonal cutting of metal workpieces are numerically investigated with modified finite element method in the framework of the elastic-plastic model in the range of cutting speeds 1-200 m/s. To simulate the failure of the material under high-velocity impact, we applied an active-type kinetic model determining the growth of microdamages, which continuously changes the properties of the material and induce the relaxation of stresses. The threshold value of specific energy of shear deformations is used as a criterion of chip separation. Necessity of using an additional criterion of chip formation is revealed, the threshold value of specific volume of microdamages is offered as the additional criterion.
Boundary Element Approach in Impedance Cloaking Problem
Authors: Baydin Andrei , Larkina Olga
Published: April 2015

The cloaking problem is considered for a 2-D wave scattering model in an unbounded homogenous medium containing an impenetrable covered (cloaked) boundary. The control is a surface impedance which enters the boundary condition as a coefficient. The problem is reduced to the inverse extremal problem of choosing the surface impedance. The solvability of the original scattering problem for 2-D Helmholtz equation and of the extremal problem is proved. Optimality system describing the necessary extremum conditions is derived. The algorithm for numerical solving of the control problem based on the optimality system and boundary element method is designed.
Measurement of the Current Transfer Function for Power Transducers of Current to Voltage
Authors: Baranov Pavel F. , Borikov Valeriy N. , Tsimbalist Edvard I.
Published: April 2015

Transducers of current to voltage, such as current shunts are widely used in control systems for the mechanical engineering. The shunt is required to determine the value of its resistance on DC and AC currents to determine the transfer ratio error in the wide frequency band in process of verification or calibration. Well-known methods for resistance measuring (by Thompson' double bridge; magnetic comparator, compensation technique, etc.) require a commerce resistance and difficult to implement for shunts with resistance less than 0.1 Ohms. The paper describes a procedure for measuring the complex impedance of transfer ratio of current shunts in the frequency band using the lock-in amplifier with the differential input. The experimental results of the proposed procedure for coaxial shunt with nominal resistance at DC 750 uOhm and 160 uOhm are described.
Utilization Prospects of Coalbed Methane in Kuzbass
Authors: Tailakov O.V. , Zastrelov D.N. , Tailakov V.O. , Efremenkov A.B.
Published: April 2015

It views evaluation approaches of coalbed methane resources developed in the area, taking into account the peculiarities of its supply from coal seams during and after mining. Was given an estimation of economic efficiency of methane utilization in generating stations, boilers and gas stations, fueled by compressed and liquefied coal mine methane.
Multidimensional Fuzzy Control System Development of Oil Transportation and Treatment Technological Processes Based on the Input/Output Parameters Model in the Precise Terms Set Form
Authors: Sagdatullin Artur
Published: April 2015

As pumps and pumping stations of oil collecting, maintaining reservoir pressure, transportation and treatment processes account for over 50 % of oil and gas enterprises estimated total cost of electricity, relevant issue is the development and application of intelligent control systems for energy efficiency of these processes. For the booster pump station as a multivariable nonlinear control object are proposed: a structure in which the function of regulating valves transferred to the pumps with frequency speed control; conceptual model with seven inputs and five outputs (adjustable) variables, which is the basis for constructing three-dimensional fuzzy controller with not-fuzzy terms to stabilize and improve the energy efficiency of oil transportation and treatment processes and minimize energy losses. In this paper we propose a control system of pumping station on the basis of multidimensional fuzzy logic controller with compensation of the mutual influence of control loops in the form of an additional system of production rules that helped to stabilize the liquid level at 2.5 m given level with an absolute error of ± 0.2 m and thus improve quality oil emulsion on the installation of oil and gas refining central collection point.
Intellectual Control of Oil and Gas Transportation System by Multidimensional Fuzzy Controllers with Precise Terms
Authors: Sagdatullin Artur , Emekeev Alexander , Muravyova Elena Alexandrovna
Published: April 2015

In order to improve the pump station control quality a special case of fuzzy controllers has been suggested to use, in which both the input and output variables are represented by a set of mutually non-overlapping terms of the rectangular shape of the membership function (precise terms). As it has been found out there is only one term in this set at any moment of time that is equal to a logical unit, whereas in the production rules system operating such terms, at any arbitrary moment of time, only one production rule antecedent is equal to a logical unit. This allows without losing of the control adequacy in each controller production system scanning cycle not to execute it completely, but solely as far as the rule, whose antecedent at a given moment is equal the logical unit, which also offers immense opportunities to increase the controller speed. In fuzzy controllers with precise terms, unlike the conventional fuzzy controllers the control precision has been shown to be invariant with respect to the complexity of the production rules conditional part structure. It is now clear that precision of fuzzy controllers with precise terms in the control systems as represented by verbal models is compatible with PID-controllers precision while using them to control the linear process facilities.
Adaptive Structural Reconfigurable Algorithms of Control
Authors: Shidlovskiy S.V. , Syryamkin V.I.
Published: April 2015

The paper is to study the use of reconfigurable machines and the computational environments for the synthesis of high quality reconfigurable automatic control systems, constructed on their basis. A key feature of the constructed system is that during establishment of the command variable the exact value of the error signal and its derivatives is not used. However the data regarding their signs are used. Besides the signal of the command variable can only take values from a binary set {0, 1}.
Expert Evaluation of the Quality of the Development of New Technics' Samples: Experience in the Development of a New Kind of Multipurpose Shield-Type Heading Machine
Authors: Nesteruk Dmitriy , Momot Mikhail , Beglyakov Vyacheslav , Politsinskaya Ekaterina
Published: April 2015

Based on the experience of realization the project of design and implementation in the production of a new of a new kind of multipurpose shield-type heading machine - geokhod, suggests the using of information technology of estimation and forecasting innovative activity based on distributed data input with elements of the neural network to assessing the quality of new engineering products in the stages of its development. The results were obtained in the course of project implementation with the financial support of the Ministry of Education and Science of Russian Federation.
Investigating the Regularities of Surface Roughness Structuring while Processing with Surface Plastic Deformation for Calculation
Authors: Telkov Ivan
Published: April 2015

This paper describes the regularities of structuring of surface roughness at surface plastic deformation in order to revise calculation of operating modes at the design stage of the technological process. The formula of roughness profile that allows calculating its general parameters has been obtained.
Dependence of Silicon and Manganese Content in the Weld Metal on the Welding Current and Method of Gas Shielding
Authors: Chinakhov Dmitry A.
Published: April 2015

The influence of the welding current and method of gas shielding in MAG welding on the content of silicon and manganese is considered. Results of study of the welded specimens of steels 45 and 30HGSA when applying welding wire of different formulas and different types of gas shielding (traditional shielding and two-jet shielding) are given. It is established that in MAG welding the value of the welding current and the speed of the gas flow from the welding nozzle have a considerable impact on the chemical composition of the weld metal. The consumable electrode welding under double-jet gas shielding provides the directed gas-dynamics in the welding area and enables controlling the electrode metal transfer and the chemical composition of a weld.
Ultrasound Measurements for the Detection of Disintegration of Concrete Slabs Exposed to Fire
Authors: Nováková Iveta , Macháňová Petra
Published: April 2015

The paper presents the application of ultrasound measurements for the determination of structural alterations of concrete exposed to fire. Concrete is evaluated as an incombustible material, class A1, but the high exposure temperature, like in fire, may cause cracks and changes of internal structure. The ultrasound measurement is a nondestructive method. It is possible to measure ultrasound velocity before and after thermal loading. The ultrasound measurement could be used also at building side as to detect structural alterations after a fire or imperfection in concrete elements.
Three different concrete mixtures were prepared and tested in this study. The basalt aggregate were used in the reference mixture and in a mixture with addition of polypropylene fibers (PP-fibers). The third concrete was made with light weight aggregates (LWA). The test slabs (dimension 10 × 30 × 1150 mm) were poured and cured in laboratory ambient (22°C and 40% RH) for 3 months. Then the slabs were exposed to fire, according to standard temperature-time curve ISO 834. The ultrasound velocity was determined on crossline screen of 10 points before and after heating of the concrete slabs.
The results of ultrasound measurements indicate the changes of internal concrete structure. The cracks are formed by pressure of evaporating unbounded water and thermal extensibility of single components.
Effect of High Temperatures on Microstructure of Repair Mortars Containing Artificial Aggregate Based on Sintered Ash
Authors: Bydžovský Jiří , Melichar Tomáš , Dufka Ámos , Fiedlerová Michaela
Published: April 2015

The research presented in this article is focused on analyzing of high temperature influence on behaviour and microstructure of polymeric-cement matrix based repair materials containing lightweight aggregates on the basis of sintered ash. Also admixtures and polymeric fibres were applied to obtain the required parameters. The study of microstructure and its changes was realized using SEM, XRD and DTA analytical methods. Maximum temperature of exposure environment of the tested mortars was 1000°C, while cooling of specimens was gradual.
Chemical Analysis of Historic Lime Mortars: Role of Sample Preparation
Authors: Ševčík Radek , Šašek Petr , Pérez-Estébanez Marta , Viani Alberto
Published: April 2015

The characterization of historic lime mortars is crucial for many cultural heritage conservation issues. In this work, the characterization of a historical lime mortar is described. Samples for chemical analysis were obtained after different milling times and using the RILEM acid digestion method on several replicates. Qualitative and quantitative determination of phases in the mortar and in the residues after acid attack and the potential presence of CaCO3 polymorphs, were accomplished with X-ray powder diffraction. Results suggest that representativeness of the sample and the homogenisation, although not always achievable in conservation practice, are strongly affecting results.
Testing of Waterproofing Gels Penetration Rate while Exposure to Higher Temperature
Authors: Melichar Jindřich , Drochytka Rostislav , Dohnálek Pavel
Published: April 2015

Creating of waterproofing screens in building structure is nowadays one of the most widespread technology of redevelopment of wet and old masonry. Especially for old or damaged structures which would not withstand any other, more damaging, type of treatment is this method ideal. One of the biggest advantages of this method is its quick and relatively easy application, excellent efficiency and low impact on buildings statics. This articles main object is observing penetration rate and final functionality of hydroinsulating injection gels in sandstone building materials.
The Study of Washed Recycled Concrete Aggregates and Blast Furnace Slag Utilization in Concrete Production
Authors: Junak Jozef , Števulová Nadežda
Published: April 2015

This contribution is focused on re-use of different types of industrial raw-wastes in concrete production. From examined wastes, blast-furnace slag and washed recycled concrete were prepared our tested concrete samples with dimension 150 mm. In these samples were fraction 0-4 mm replacement by blast-furnace slag with a range of variation from 0 to 100%. Fraction 4-8 mm and 8-16 mm were replacement by aggregate prepared from washed recycled concrete parts with a range of variation from 0 to 100% in both fractions. Concrete samples contained aggregate prepared form recycled concrete and blast-furnace slag, are tested after 14 and 28 days of hardening.

The highest value of compressive strength after 14 days (25.2 MPa) and 28 days of hardening (32.3 MPa) reached sample, which contained 20% of blast furnace slag as a substitute for natural aggregate in fraction 0/4 mm. Compressive strength of this sample is the same kind of reached a comparative sample. Lowest value of compressive strength after 14 and 28 days of hardening reached a sample, which contained 30% blast-furnace slag fraction 0-4 mm, and 100% aggregate prepared from recycled concrete fraction 4-8 and 8-16 mm. Before wider using of these selected wastes, another properties as a durability and corrosion are necessary to investigate.
The Influences of Ru Seed Layer Microstructure on Structural Properties of CoCrPt-SiO2 Perpendicular Media
Authors: Zhang Jun Min , Sheng Yue , Wang Chuan Ju , Tan Zhi Long , Bi Jun , Guan Wei Ming , Wen Ming
Published: April 2015

CoCrPt-SiO2 granular film is well known as a perpendicular magnetic recording (PMR) media. To control the segregated structure of the recording layer, the role of the Ru underlayer is important. CoCrPt-SiO2 perpendicular recording films were prepared by magnetron sputtering, with a series of Ru films as seed layer. The microstructure of Ru seed layers and their influences on the grain size, roughness and surface morphology of CoCrPt-SiO2 granular films were investigated. It was found that the microstructure of seed layer obviously effected the structure and grain isolation of recording layers. The grain size and roughness of CoCrPt-SiO2 recording layer were both increased with increasing the thickness of Ru seed layer. It is concluded that the thin and rough Ru seed layer is suitable for high-density magnetic recording media, and Ru seed layer with suitable thickness is very helpful for the achievement of perfect isolation and excellent magnetic properties. The result revealed that it was relatively easy for the CoCrPt grains to get perfect isolation with Ru thickness of 70 nm.
Phase Transitions and Elementary Processes in Shape Memory Alloys
Authors: Adiguzel Osman
Published: April 2015

Shape memory effect is a peculiar property exhibited by certain alloy systems, and shape memory alloys are recognized to be smart materials. These alloys have important ability to recover the original shape of material after deformation, and they are used as shape memory elements in devices due to this property. The shape memory effect is facilitated by a displacive transformation known as martensitic transformation. Shape memory effect refers to the shape recovery of materials resulting from martensite to austenite transformation when heated above reverse transformation temperature after deforming in the martensitic phase. These alloys also cycle between two certain shapes with changing temperature.Martensitic transformations occur with cooperative movement of atoms by means of lattice invariant shears on a {110} - type plane of austenite matrix which is basal plane of martensite.Copper based alloys exhibit this property in metastable β-phase field. High temperature β-phase bcc-structures martensiticaly undergo the non-conventional structures following two ordered reactions on cooling, and structural changes in nanoscale level govern this transition cooling. Atomic movements are also confined to interatomic lengths due to the diffusionless character of martensitic transformation.
Electrochemical Oxidation of Dissolved Carbon Monoxide on Rotating Disk Electrodes and Micro-Electrodes
Authors: Lin Andrew S. , Chen Jerry , Huang Trav
Published: April 2015

This work was to study the dissolved CO in solution phase by using rotating disk electrodes and the solution phase CO demonstrate the limiting currents dependence of rotating speeds. Gold and gold-platinum metals clusters are used in glassy carbon supported rotating disk electrode for electrochemical oxidation of the solution phase CO. Small metal clusters and Au-Pt alloy effects are observed in the measurements. The comparison of microelectrode and RDE study of solution phase CO electrochemical oxidation is confirmed the limiting currents dependence of the boundary layers concentrations.
Characterizations of Indium-Doped Cu2SnSe3 Bulks Made by Reactive Sintering at 550 °C
Authors: Wubet Walelign , Kuo Dong Hau
Published: April 2015

Indium-doped Cu2SnSe3 bulk materials with the Cu2(Sn1-xInx)Se3 (In-x-CTSe) formula at x = 0, 0.05, 0.1, 0.15, and 0.2 were prepared at 550 °C for 2 h with soluble sintering aids of Sb2S3 and Te. Defect chemistry was studied by measuring structural and electrical properties of In-x-Cu2SnSe3 as a function of dopant concentration. In-x-CTSe pellets show p-type at x = 0, 0.05 and 0.1 and n-type at x = 0.15 and 0.2. The low hole concentration of 4.56×1017 cm-3 and high mobility of 410 cm2 V-1 s-1 were obtained for Cu2(Sn1-xInx)Se3 bulks at x= 0.1 (10% In). The explanation based upon the In-to-Cu antisite defect for the changes in electrical property was declared.
Die Soldering Phenomenon on the H13 Tool Steel with Shot Peening and Nitriding Surface Treatment
Authors: Mochtar Myrna Ariati , Nurjaya Dwi Marta , Aldila Rizki
Published: April 2015

Die soldering occurs when molten aluminum sticks to the surface of a die material and remains there after the ejection of the part. This resulted in low productivity and economic value in the foundry industry. Nitriding surface treatment is considered as an effective way in enhancing the service life of AISI H13 steel dies and to prevent soldering effect. The focus of this paper is to investigate the influence of three different surface conditions in terms of roughness, gas nitriding and pretreatment prior to gas nitriding on the soldering effect. Three kind of samples made of AISI H13 steel were pretreated (quenched and tempered) and followed by : shot peened, gas nitrided and shot peening followed by gas nitriding, were immersed in liquid melted ADC 12 Aluminium alloy at 30 seconds, 30 minutes, 2 hours and 5 hours, at a constant temperature of 680oC in a holding furnace. Characterizations on the surface of the steel were focused on the optical microstructure, microhardness profile, FE SEM observation and enegy dispersive spectrometry mapping. It was found that shot peening prior to nitriding gives a higher surface hardness and depth of nitride layer of H13 tool steel, 1140 HV (>70 HRC) and 120.5 μm, than the nitriding only process, 1033 HV (68 HRC) and 105 μm. The higher the hardness and depth of nitride layer expected would reduce the die soldering effect at the surface of the H13 tool steel dies. It was also found that the only shot peening treatment resulted in a tendency of soldering accompanied by the formation of intermetallic layers ; while soldering is not found on the nitrided and shot peened-nitrided samples.
Effect of Aging on Phase Transition Behavior of Ti50Ni15Pd25Cu10 High Temperature Shape Memory Alloys
Authors: Rehman Saif ur , Khan Mushtaq , Ali Liaqat , Jaffery Syed Imran Husain
Published: April 2015

Formation of Ni4Ti3 precipitates during aging of Ni-rich binary NiTi shape memory alloys and its effect on transition behavior during transformation from austenite to martensite phase has been studied extensively. However for equi-atomic NiTi-based quaternary high temperature shape memory alloy, two-stage martensitic transformation was detected for the first time. The Ti50Ni15Pd25Cu10 high temperature shape memory alloys were investigated for the hardness and transformation temperatures at aging temperature of 550°C. Aging at 550°C for 6 h resulted in remarkable increase in the hardness, whereas the phase transformation temperatures decreased significantly. During forward transformation from austenite to martensite, two-stage martensitic transformation; B2 (cubic) → R-phase and R-phase → B19 (orthorhombic) was observed.
Synthesis of Metal Doped BiFeO3 Nanoparticles and their Dielectric and Magnetic Properties
Authors: Ahmmad Bashir , Basith M.A. , Koike Kunihiro , Kubota Shigeru , Hirose Fumihiko
Published: April 2015

Dielectric and magnetic properties of BiFeO3 samples, co-doped with Gd or Ba and Ti in place of Bi and Fe, respectively, were investigated. The bulk powder samples of nominal compositions of Bi0.9Gd0.1Fe1–xTixO3 and Bi0.7Ba0.3Fe1-xTixO3 (x=0.00-0.25) ceramics were synthesized by conventional solid state reaction technique. The as prepared ceramics showed improved dielectric and magnetic properties. Also, ultrafine nanoparticles of the samples were prepared by milling assisted ultrasonic fragmentation of the bulk powder. The particles size was studied as a function of sonication time with TEM imaging and electron diffraction. These confirmed the formation of a large fraction of single-crystalline Bi0.9Gd0.1Fe1–xTixO3 nanoparticles with a mean size of 11-13 nm. The synthesized nanoparticles exhibit an improved magnetic behavior compared to their bulk counterparts at room temperature. The preparation and characterization of bulk ceramics as well as their nanoparticles were reported.
Recovery of Nanoparticles of Metal Values from Spent Metallized Graphite Brushes and Slip Rings
Authors: Rabah Mahmoud A.
Published: April 2015

This work provides a method to recover monolayer metal values having nanoparticle in size from spent metalized graphite brushes. The recovered metals are supported on porous glassy carbon substrate by chemical or electro deposition process. The chemical method involves crushing and grinding of the spent brushes to pass 200 mesh. Magnetic separation removed magnetic susceptible metals such as iron. Nonferrous metals were leached using 3N nitric acid in hot conditions. Hydroxide gel of the dissolved metals generated with 1N ammonium hydroxide. The carbon substrate was multi-impregnated with metals hydroxide 3-4 times. In each time, the loaded carbon was dried. Free metals on the carbon substrate are obtained by reducing the hydroxide with hydrazine hydrate or by thermal reduction using hydrogen gas at 900°C. In the electro deposition process, ground spent brushes were packed in a polyethylene cloth used as anode. The electrolyte is 3M of sulfate salt of the metal of concern. Pulse current cyclic voltmetric technique was applied to control the particle diameter and thickness of the deposited metal. Results revealed that monolayer silver and copper of nanoparticles has been successfully prepared from spent metalized graphite brushes. Electro deposition is more friendly environment procedure and more convenient, less cost and more precise.
Surface Treatments of Titanium Alloy for Preparing Laminated Composite Material
Authors: Sibileva Svetlana Vladimirovna , Botanogov Andrey Leonidovich , Trofimov Nikolay Vadimovich , Zaharova Ludmila Viktorovna
Published: April 2015

In this investigation surface treatment of titanium alloy VT20 is carried out by phosphating and anodization in order to increase the adhesive bond strength. The surfaces were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), profilometry, contact angle measurements. The joined titanium specimens were shear tested before and after exposure to high humidity to a period of three months.
Surfactivity of a Series of Nonionic Fluorocarbon Surfactant − Perfluorousnonenyl Polyethylene Glycol Ether
Authors: Shi Hong Xin , Zhou Hao Miao , Shen Hai Min , Wu Hong Ke
Published: April 2015

The surfactivity of nonionic fluorocarbon surfactants, polyethylene glycol perfluoro-nonyl monoether (C9F17-PEG-n) and diether (C9F17-PEG-n-C9F17), was systematically investigated, including the surface tensions (γ), critical micelle concentration (CMC), cloud point, foaming property and emulsifiability. The relation between their surface performance and their chemical structure of C9F17-PEG-n and C9F17-PEG-n-C9F17 were studied. The result showed that this series of fluorocarbon surfactant possessed high surface activity, the CMC < 2.8 × 10-4 mol/L and the γCMC < 25 mN/m. Compared to C9F17–PEG-n, C9F17-PEG-n-C9F17 have smaller minimum molecular area (Amin), greater saturated adsorption quantity (Γm), lower cloud point, poorer emulsifiability in toluene and greater foaming volume for their aqueous solutions. For either C9F17-PEG-n or C9F17-PEG-n-C9F17, with the increase of the PEG molecular weight (PEG-n), Γm declines, Amin increases and the emulsifiability in toluene becomes better, the CMC, γCMC and cloud point of their aqueous solutions increases, and their foaming volumes increase first and then decline, getting the maximum value at n=1000.
Environmentally Friendly Catalyst of Zirconium Pillared Saponite for Solvent Free Esterification of Menthol
Authors: Fatimah Is
Published: April 2015

In this research zirconium pillared saponite clay (Zr-PILS) was prepared for catalysis application. Pillarization was conducted by zirconium isopropoxide via using sol-gel mechanism and the characterization was performed by X-ray diffraction, gas sorption analysis and surface acidity measurement by pyridine adsorption-FTIR measurement techniques. Result showed that pillaring process to saponite produced pillared saponite with increasing specific surface area, pore volume as well as surface acidity that contributed to enhance catalytic activity in menthol esterification. Reusability test was also showed that Zr-PILS activity is relatively stable.
Synthesis and Characterization of Aluminiun 2219 Reinforced with Boron Carbide and Molybdenum Disulfide Metal Matrix Hybrid Composites
Authors: Shiva Shankar G.S. , Basavarajappa S.
Published: April 2015

An attempt has been made to develop and characterize the Al2219 reinforced with Boron carbide (B4C) and Molybdenum disulfide (MoS2) hybridcomposites. The hybrid composites were prepared by using stir casting technique. Theexperimentalresult evaluates the density,micro hardness test & tensiletest.Themicrostructure shows existence of randomly dispersed reinforcement particles andfine reinforcement particles in prepared hybrid composites.X-Ray powder diffraction (XRD) analysis were conducted this confirms the physical content of constituents present in prepared composites. SEM is used to examine fracture surface of tensile specimens for hybrid composites & this consists of ductile& brittle fracture of mixed mode.The test results revels that, themicro hardness and density is minimum for Al2219 and maximum for Al+3%B4C+5%MoS2. The tensile properties of the material vary according to the percentage of reinforcing material added.
Photocatalytic Degradation of Methylene Blue Using Visible Light Active N-Doped ZnO
Authors: Sudrajat Hanggara , Babel Sandhya
Published: April 2015

A visible light active nitrogen-doped ZnO (N-ZnO) was synthesized using a solvent-free mechanochemical method and applied to degrade methylene blue (MB) dye in aqueous suspension. Results showed that nitrogen doping improved the photocatalytic activity of pristine ZnO by extending its spectral response to visible region. Using 2 g/L of N-ZnO, 98% MB with the initial concentration of 10 mg/L could be degraded within 2 h at pH 7 under 11.3 klux of visible light irradiation. After 6th run, it still exhibited appreciable photocatalytic activity with 94% MB degradation, indicating its high reusability though a simple pretreatment was performed.
Analysis of Cooling Curves, Microstructure and Properties of Chill Cast Al-B4C Composites
Authors: Sreenivas Rao K.V. , Sanman S.
Published: April 2015

The cooling rate depends on the properties of the mold material which has significant influence on the formation of microstructure and in turn on the properties of the cast components. This work is aimed at preparing the Al-B4C composite using different chill materials by gravity die casting and recording the casting temperature during pouring and subsequent solidification to analyze the cooling rate of the casting. The effect of chilling on the microstructure and mechanical properties are determined. The cast specimens are cut and polished by standard metallographic procedure. Optical micrographs are taken at different magnification to reveal the microstructure and B4C particulate distribution. The micro hardness and tensile test results indicate that there is a significant increase in these properties with the increase in B4C content.
Performance Analysis of Fine Mineral Fillers in Gypsum Plasters
Authors: Pustovgar Andrey , Ivanova Irina , Nefedov Sergey , Adamtsevich Aleksey , Pashkevich Stanislav
Published: April 2015

This study investigates the influence of limestone powder and silica flour used as fine mineral fillers on the main characteristics of gypsum plaster. Fine mineral fillers were added in various dosages from 2.5% to 20.0%.