bluuebunny/crossref_metadata_2025 huggingface dataset:
Research of the Strategy and Planning for Low-Carbon Logistics Development
Authors: Yang Tao , Cai Wei Wei , Wang Bin
Published: December 2013

The low-carbon logistics is developed as an important access for sustainable development of economy and society in China. The formulations of CO2 emissions are investigated and new one is developed for intermodal logistics and transport systems to assess the effects of the projects. The regional logistics corridor is developed by constructing dry ports between the sea port and hinterland. It is emphasized to better utilize the underground space in transportation planning.
Study on Carbon Footprint of Container Transportation System
Authors: Guo Yu Chen , Wang Wen Yuan
Published: December 2013

As an important hub of logistic chain, seaport is a major energy consumer. Therefore, the carbon footprint of container transportation system is studied in the paper. First, the operation process of container transportation system is analyzed. Second, the carbon footprint quantitative method is introduced. Finally, a case study is given as an example. Results indicate that carbon emission of quayside cranes accounts for the largest proportion in the transportation system. So, it's necessary to reduce the carbon emission of quayside crane.
Establishment of Low-Carbon Evaluation Index System for Container Terminals
Authors: Guo Zi Jian , Yu Xu Hui , Wang Wen Yuan , Song Xiang Qun
Published: December 2013

A low-carbon evaluation index system for container terminals is proposed on the basis of their characteristics and the concept of low-carbon port. This system takes quantitative indexes as the core, supplemented by qualitative ones. The weight of each index is determined by AHP, and then a fuzzy comprehensive evaluation model is established according to the AHP-fuzzy comprehensive evaluation method. Finally, the proposed model is applied to a certain region of a container terminal, and the result indicates that the proposed evaluation index system and evaluation model can provide a reference for the low-carbon level evaluation of container terminals.
Recent Advances and Opportunities in TLD Materials: A Review
Authors: Omanwar S.K. , Koparkar K.A. , Virk Hardev Singh
Published: December 2013

Thermoluminescence (TL) is the thermally stimulated emission of light from an insulator or a semiconductor following the previous absorption of energy from ionizing radiation. TL dosimetry is used in many scientific and applied fields such as radiation protection, radiotherapy, industry, and environmental and space research, using many different materials. The basic demands of a thermoluminescent dosimeter (TLD) are good reproducibility, low hygroscopicity, and high sensitivity for very low dose measurements and good response at high doses in radiotherapy and in mixed radiation fields. In this review, we have discussed the past developments and the future opportunities in TLD materials and our efforts to make better future use of low cost materials in TLD applications. For this we have studied and discussed two efficient TLD phosphors with low cost and simple method of preparation on large scale for TLD materials. One of the phosphors is LiF:Mg,Cu,P (LiF: MCP), and another one is LiCaAlF6:Eu, which has the potential to replace conventionally used CaSO4:Dy TL dosimeter. LiF: MCP and LiCaAlF6: Eu phosphors are potential candidates for TL dosimetry and could be good replacement for commercially available phosphors. Apart from this, we have also studied thermoluminescence in Aluminate and Borate materials. We have discussed in detail all three types of TLD materials. First, our study includes complete detail of material properties, methods and dosimetric characterizations of LiF: MCP Phosphor; second, it includes a new TL Dosimeter, LiCaAlF6: Eu and its dosimetric characterizations; and lastly on some TL properties of Li5AlO4: Mn and MgB4O7: Dy,Na. In this review, we discus some recent developments in radiation dosimetry with regards to the measurement techniques and material preparations. Although many materials have been and are currently being studied for TLD, still there is a scope for the improvement in the material properties useful for the TLD, and the synthesis of new, more suitable materials. Contents of Paper
Two Types of On-State Observed in the Operation of a Redox-Based Three-Terminal Device
Authors: Wang Qi , Itoh Yaomi , Tsuruoka Tohru , Hasegawa Tsuyoshi , Watanabe Satoshi , Yamaguchi Shu , Hiramoto Toshiro , Aono Masakazu
Published: December 2013

A redox-based three-terminal device was fabricated using Ta2O5 as the ionic transfer material, and its operation was investigated. We found that application of a negative polarity gate bias, which increases oxygen anions in the channel regions, can make a conductive path between a source electrode and a drain electrode. The insulating state of the pristine device is turned on to a semiconductor state by the application of a negative polarity gate bias. Since turning off to the insulating state could not be achieved, the switching process resembles the soft breakdown of the first turning-on process of oxygen vacancy controlled resistive random access memories, although the polarity of the bias is opposite to that used in the first turning-on process. Further application of a gate bias causes a transition from the semiconductor state to a metal state. Accordingly, there are two types of on-state. It is possible to switch between the semiconductor and metal states.
Improvement of Horizontal Resolution by Doppler Image under Forced Vibration
Authors: Miwa Takashi
Published: December 2013

Generally, cross range resolution of a B-mode ultrasonic image is restricted by a point spread function of the measurement system. Although various super-resolution techniques are proposed, it is difficult to significantly improve the resolution with low calculation burden. In this paper, we propose a novel super-resolution technique in which the Doppler B-mode image is measured under forced vibration in the region of interest. The numerical simulation is carried out to demonstrate the validity of the proposed algorithm. It is shown that the cross range resolution is 3 times narrower than the original one.
Self-Calibration Techniques of Pipeline ADCs Using Cyclic Configuration
Authors: Tan Yohei , Oki Daiki , Liu Yu , Arai Yukiko , Nosker Zachary , Kobayashi Haruo , Kobayashi Osamu , Matsuura Tatsuji , Yang Zhi Xiang , Katayama Atsuhiro , Quan Li , Li En Si , Niitsu Kiichi , Takai Nobukazu
Published: December 2013

This paper proposes a digital self-calibration technique for pipelined ADC. In this technique, the pipelined ADC is composed of a series of cyclic ADCs and each stage has independent digital self-calibration. Because of this, our technique achieves higher accuracy calibration than the conventional method that calibrates by using later stages. Applying the proposed method, we simulated the pipelined ADC with MATLAB and showed that higher accuracy calibration can be achieved with a smaller number of pipeline stages.
Design of Analog Filter Using Genetic Algorithm
Authors: Arai Naoki , Takai Nobukazu , Kumar Biswas Sumit , Kobayashi Haruo
Published: December 2013

In this paper, we propose a method that automatically designs an analog lter tosatisfy target specication. Using a genetic algorithm, circuits that satisfy target specicationcan automatically be identied. Moreover using this method output of any phase can be achievedfor the analog lter working in any frequency band. For example, this method has been usedto automatically design the analog lter that generates constant phase of -/2[rad] at terminalVout1 and /2[rad] at terminal Vout2 for a frequency band of 100MHz to 300MHz, and also phaseof -/6[rad] and /6[rad] for a frequency band of 100MHz to 300MHz. In both cases relativeerrors of target phase was less than 5%.
Improvement of Photovoltage in Dye-Sensitized Solar Cells with Azobenzene and Azulene Sensitizing Dyes by Applying Br3-/Br- Redox Mediator
Authors: Kakiage Kenji , Fujimura Emi , Nakada Yoshinori , Ogino Takashi , Kyomen Toru , Hanaya Minoru
Published: December 2013

In dye-sensitized solar cells (DSSCs) fabricated with azobenzene and azulene derivatives as the photosensitizing dyes, the replacement of the conventional I3-/I-redox mediator with Br3-/Br-redox mediator possessing more positive redox potential has been examined to improve open-circuit photovoltages (Voc) of the cells. The cells with the Br3-/Br-redox mediator exhibited highVocof ~0.8 V, resulting in higher light-to-electric energy conversion efficiencies (η) than the cells with the I3-/I-redox mediator by a factor of 1.7 under the simulated sunlight irradiation (AM-1.5G, 100 mW cm-2). The results indicate a high potential of the Br3-/Br-redox mediator in DSSCs.
Functional-Group-Retaining Polymerization of Hydroxyethyl Methacrylate by Atmospheric Pressure Non-Equilibrium Plasma
Authors: Fei Xiao Meng , Kondo Yuki , Qian Xiao Yi , Kuroda Shin-ichi , Mori Tamio , Hosoi Katsuhiko
Published: December 2013

In this study, functional-group-retaining polymerization of hydroxyethyl methacrylate (HEMA) was carried out by using an atmospheric pressure non-equilibrium Ar plasma jet. The polymeric films deposited under different conditions were characterized by Fourier transform infrared spectroscopy (FT-IR). The FT-IR spectra show that HEMA was polymerized (carbon-carbon double bond disappeared) and the main functional groups were successfully retained in the plasma-polymerization films. The plasma-polymerization mechanism and the polymerization reaction kinetics will be discussed.
Fabrication of 6-nm-Sized Nanodot Arrays with 12 nm-Pitch along Guide Lines Using both Self-Assembling and Electron Beam-Drawing for 5 Tbit/in2 Magnetic Recording
Authors: Hosaka Sumio , Akahane Takashi , Huda Miftakhul Huda , Komori Takuya , Zhang Hui , Yin You
Published: December 2013

A possibility to fabricate nanodot arrays with a dot size of <10 nm="" and="" a="" dot="" pitch="" of="" 12="" along="" guide="" lines="" has="" been="" studied="" for="" ultrahigh-density="" patterned="" media="" in="" magnetic="" recording="" this="" was="" by="" using="" self-assembling="" block="" copolymers="" polystyrene-poly="" dimethyl="" siloxane="" ps-pdms="" electron="" beam="" eb="" drawing="" with="" hydrogen="" silsesquioxane="" hsq="" negative="" resist="" their="" fusion="" method="" it="" demonstrated="" that="" the="" could="" possibly="" achieve="" 6-nm-sized="" nanodot="" arrays="" 10="" 4="" x="" sup="">2 using self-assembling with PS-PDMS of molecular weight 7000-1500 and EB-drawing for narrow guide lines. These results prove that the fusion method is required for achieving extremely small dot arrays as 5 Tbit/in2magnetic storage devices.Keywords: Nanodot, self-assembly, electron-beam drawing, graphoepitaxy, patterned media, magnetic recording.
Study of Perpendicular Magnetic Anisotropy in Co/Au Multilayer Probed by Magnetic Compton Profile
Authors: Suzuki Kosuke , Hayata Masaki , Minegishi Katsuhiko , Kondoh Ryosuke , Kato Tadashi , Hoshi Kazushi , Itou Masayoshi , Sakurai Yoshiharu , Sakurai Hiroshi
Published: December 2013

Magnetic Compton profiles (MCPs) of Co/Au multilayers have been measured and analyzed by DV-Xαcluster model calculations from a viewpoint of perpendicular magnetic anisotropy (PMA). The PMA and the MCPs are discussed for the presently obtained results for Co/Au, along with the previously obtained results for Co/Pd and Co/Pt. A Co/Au multilayer shows a weak PMA which is caused by |m|=1 states of Co 3d electrons at a smooth Co/Au interface. The increase of the interface-to-volume ratio plays the main role in determining the perpendicular anisotropy in Co/Au multilayers. The strain of a Co layer can have a secondary role in determining the magnetic anisotropy in Co/Au multilayers, although the strain dominates PMA in the case of Co/Pd and Co/Pt multilayers.
Fabrication of CoPt Nanodot Array with a Pitch of 33 nm Using Pattern-Transfer Technique of PS-PDMS Self-Assembly
Authors: Huda Miftakhul , bin Mohamad Zulfakri , Komori Takuya , Yin You , Hosaka Sumio
Published: December 2013

The progress of information technology has increased the demand of the capacity of storage media. Bit patterned media (BPM) has been known as a promising method to achieve the magnetic-data-storage capability of more than 1 Tb/in.2. In this work, we demonstrated fabrication of magnetic nanodot array of CoPt with a pitch of 33 nm using a pattern-transfer method of block copolymer (BCP) self-assembly. Carbon hard mask (CHM) was adopted as a mask to pattern-transfer self-assembled nanodot array formed from poly (styrene)-b-poly (dimethyl siloxane) (PS-PDMS) with a molecular weight of 30,000-7,500 mol/g. According to our experiment results, CHM showed its high selectivity against CoPt in Ar ion milling. Therefore, this result boosted the potential of BCP self-assembly technique to fabricate magnetic nanodot array for the next generation of hard disk drive (HDD) due to the ease of large-area fabrication, and low cost.
High Speed Milling Vibration Surveillance with Optimal Spindle Speed Based on Optimal Speeds Map
Authors: Kalinski Krzysztof J. , Galewski Marek A. , Mazur Michał R.
Published: December 2013

The paper presents the method of the surveillance of the self-excited chatter vibration. At first, the workpiece modal parameters are estimated based on experimental data which leads to verification of computational model. Then, for selected surface points optimal spindle speeds are calculated. By considering sufficient amount of points it is possible to build a map of optimal spindle speeds. Experimental results show that this map may be used effectively for eliminating chatter in case of the process of ball end milling of a curved flexible detail.
On Software Unit Testing for Improving Security and Performance of Distributed Applications
Authors: Krawczyk Henryk , Barylski Marcin , Barylski Adam
Published: December 2013

Performance and security are software (SW) application attributes situated on the opposite corners of system design. In the most drastic example the most secure component is the one totally isolated from the outside world, with communication performance reduced to zero level (e.g. disconnected physically from the network, placed inside a Faraday cage to eliminate possible wireless accessibility). On the other hand the most performance-optimized system is the one with all security rules taken off. Obviously such extreme implementations cannot be accepted, thus a reasonable trade-off between security and performance is desired, starting from the appropriate design, resulting in the adequate implementation, confirmed by security and performance testing in production environment. Unit testing (UT) is a well-know method of examining the smallest portion of SW application source code – units: methods, classes, interfaces in order to verify whether they behave as designed. Ideally, each UT test case is separated from others, taking advantage of stubs and mocks to provide full isolation from external test factors. This paper is an extension to research about joint security testing and performance testing for improving quality of distributed applications working in public-private network environments,addressing SW quality assessment at different, unit test level.
Frequency Response Spectra Applied to Assess Efficiency of the Training Techniques
Authors: Kucharski Tomasz
Published: December 2013

The purpose of the research is to assess the increase of the muscle strength and power. Movement of the human body when the moving one impacts a stationary or moving body is taken under consideration. The waveform produced by an impact is transformed into frequency domain. The acceleration record is transformed as a complex spectrum, by the use of a Discrete Fourier Transformation. In this paper the applications of the discrete Fourier transform is discussed and it was pointed out that it can be fruitfully applied to analyze movement techniques during competition or training exercises. The acceleration response spectrum contains knowledge about efficiency of certain techniques. It has distinct features which can show that the energy is concentrated around several discrete frequencies. Data from the shape of a frequency response spectra curve can provide the coach and the performer with valuable information on technique and also give information on recommendations with respect to corrections and adjustments that can lead to performance enhancement. In this paper, the technique of a database creation is proposed what allows us to establish a particular set of circumstances under a specified protocol to observe and evaluate the implications of the resulting observations.
Diffusible Hydrogen Control in Flux Cored Arc Welding Process
Authors: Fydrych Dariusz , Świerczyńska Aleksandra , Tomków Jacek
Published: December 2013

One of the types of hydrogen degradation of steel welded joints is cold cracking. The direct cause of the formation of cold cracks is simultaneous presence of hydrogen, residual stresses and brittle structure. The way of preventing the occurring of degradation is to eliminate at least one of these factors. Practice has shown that the best solution is to control the amount of hydrogen in deposited metal. In this paper an experimental evaluation of the effect of the welding parameters on the content of diffusible hydrogen in deposited metal obtained from rutile flux cored wire grade H10 was carried out. The state of the art of considered issues was described and results of preliminary investigations were presented. Five factors were considered: the flow rate of shielding gas, the welding current, the arc voltage, the welding speed and the electrode extension. All factors were optimized using a Plackett-Burman design to get the most relevant variables. The level of diffusible hydrogen was determined by a glycerin test. The results of the experiment indicate that appropriate choice of welding parameters may significantly reduce diffusible hydrogen content in deposited metal.
The Initial Selection of Parameters for Dynamic Brake for Car Engine Test Dynamometer
Authors: Kneba Zbigniew , Kropiwnicki Jacek
Published: December 2013

The article presents an analysis of the car engine loads. The aim of the analysis was to determine the parameters of the brake / electric motor on an engine test bad. Analysis of loads on the driving tests concerned on chassis dynamo to simulate them on an engine dynamometer. To check the range of dynamometer shaft angular acceleration inertial mass of a car was reduced on the crankshaft axis. The calculations of maximum shaft acceleration were performed. Also the whole car acceleration when pulling away from the place was calculated. Calculations were verified by experiment on road. They both gave a good agreement.
Road Texture Influence on Tire Rolling Resistance
Authors: Taryma Stanislaw , Ejsmont Jerzy A. , Ronowski Grzegorz , Swieczko-Zurek Beata , Mioduszewski Piotr , Drywa Marzena , Woźniak Ryszard
Published: December 2013

Tire rolling resistance is one of the most important resistive forces acting on road vehicles. It depends on tire and surface characteristics as well as vehicle operating parameters. This paper deals with the influence of road surface texture on rolling resistance of passenger car tires. Results of road measurements performed on variety of road surfaces are presented.
Effect of Surface Roughness on Thermal-Hydraulic Characteristics of Plate Heat Exchanger
Authors: Wajs Jan , Mikielewicz Dariusz
Published: December 2013

In the paper the experimental analysis of passive heat transfer intensification in the case of modeled plate heat exchanger is conducted. The plate heat exchanger is chosen for the analysis because this kind of heat exchangers could be prospectively applied in the ORC systems, however other areas or application are equally possible. The experimental set-up was assembled at the Department of Energy and Industrial Apparatus of Gdansk University of Technology. The passive intensification was obtained by a modification of the heat transfer surface. The roughness of surface was increased by use of glass shot.During the experiment single-phase convective heat transfer in the single phase system was studied. The experiment was done in two stages. In the first stage the model of commercial plate heat exchanger was investigated, while in the second stage the identical one but with modified heat transfer surface. Model of heat exchanger consisted of three plates. The direct comparison of thermal and flow characteristics between both devices was possible due to assurance of equivalent conditions at the inlet to the system.The thermal and hydraulic characteristics are presented. The thermal analysis shows that in some range of heat flux density the overall heat transfer coefficient was higher for the commercial heat exchanger, while for the other was higher for the heat exchanger with modified surface. The influence of larger roughness on heat transfer cannot unequivocally be evaluated. Therefore as the next step the systematic investigations of model heat exchangers (only with one hot and one cold passage) will be conducted.
Methods of Determination of the Fuel Consumption of the Locomotive Diesel-Electric Propulsion System for Regular Operating Conditions
Authors: Kortas Paweł
Published: December 2013

In order to determine the fuel consumption during operation of locomotive it is necessary to work out the characteristics of fuel consumption vs. power produced by propulsion system. These characteristics can be obtained during tests in a diagnostic stand equipped with water rheostat, which allows to simulate any load on the main generator. Another method depends on utilization data from monitoring system of the propulsion system, obtained during regular operation of the locomotive. The main disadvantage of this method is lack of long-term constant loads, which is caused by frequently changing operating conditions. This has a major impact on the measuring error, which can be minimized by suitable utilization of a large number of measurements. Practical remarks of those methods usage have been presented in this paper.
Investigation of the Initial Stage of Hot Dip Zinc Coatings on Iron Alloys with Various Silicon Contents
Authors: Liberski Piotr , Tatarek Adam , Mendala Jacek
Published: December 2013

In this work tests on the course of zinc coating formation on model iron alloys with diversified silicon additions in molten zinc, with short times of contact at the solid-liquid border have been presented. The experiments were carried out at the temperature of 440°C. The assumed time of contact between solid and liquid phases was: 1, 4, 9, 14, 29, 59 seconds. The test stand was designed. The structure and thickness of coatings obtained on steel without silicon, on Sandelin steel and on high-silicon steel was defined. Based on the results we may ascertain that in the first stadium of the galvanizing process the impact of silicon upon the intensity of coating growth is small. Increased reactivity of silicon is already observed after about 29-59 seconds of the process.
The Structure and Growth Kinetics of Zinc Coatings on Link Chains Produced of the 23MnNiCrMo5-2 Steel
Authors: Kania Henryk , Liberski Piotr
Published: December 2013

In the paper the results of tests on obtaining zinc coatings on chains produced of the 23MnNiCrMo5-2 steel of grades C and PW9 have been presented. The growth kinetics of coatings obtained in the traditional galvanizing process at the temperature of 450°C has been established. The structure of coatings obtained on chains of various grades has been developed. The chemical composition of structural components of the coating has be established. It has been determined that the obtained coatings are continuous and they are quite thick. No significant impact of the chain grade upon the structure of coating has been established, however, it has been observed that the thickness of coating slightly decreases as the grade increases.
Gas Corrosion of Chromium-Manganese Steel in Atmospheres with Low Oxygen Partial Pressure
Authors: Przeliorz Roman , Piątkowski Jaroslaw
Published: December 2013

Studies were conducted on the kinetics and mechanism of oxidation of chromium-manganese steel under partial oxygen pressure pO2from 10-11to 10-2Pa at a temperature of 1173 K. The low oxygen partial pressure was produced in a gas mixture of CO-CO2and helium containing 0.2 ppm of oxygen. The kinetics of oxidation was examined by thermogravimetry using a thermobalance made by Setaram Company. Scale growth mechanism was determined with the use of markers. The oxidation products were analyzed by scanning electron microscopy (SEM, EDS). It was found that at low partial pressure of oxygen, MnO oxide was forming on the steel surface. From an analysis of the curves of the steel weight growth per unit surface in function of time it followed that the oxidation assumed a parabolic course. A relationship has been determined between the coefficient of self-diffusion of manganese in MnO and the oxygen partial pressure.
Evaluation of Refractory Lining of the Blast Furnace Hearth and Bottom in Five Years of its Operation on the Basis of the Isotherms Shapes
Authors: Kopeć Grzegorz , Machulec Bolesław
Published: December 2013

Based on archival temperature measurement data regarding a blast furnace (capacity of 3200 m3) hearth and bottom refractory lining, empirical isotherms T = 300°C, for various periods of the first five years of the furnace campaign were determined. This resulted in an attempt to assess the hearth and bottom refractory lining in the third month and subsequently, in the next years of the blast furnace operation. The empirical isotherms, determined after the first three months, were compared to the isotherms determined using the method of mathematical modelling. These empirical isotherms were compared to each other, respectively in one-year intervals. The most distinctive changes of the hearth and bottom refractory lining were observed during the first three months of the furnace campaign. In the further period of five years, the changes were insignificant. During the early stage of furnace operation, observed deterioration of the refractory lining was associated with partial damage of the bottom ceramic layer and elephants foot-shaped defects of the refractory lining in the lower, thickened parts of the hearth walls. Early, elephants foot-shaped wear of the refractory lining is related to the mechanism of its wash-out by liquid products of the process during tapping, which results from certain maladjustment of the hearth and bottom inner geometry in modern furnaces to the hydrodynamic conditions of metal and slag flow.
Effects of Raw Material Contaminants on the Ferrosilicon Melting Process in the Submerged Arc Furnace
Authors: Machulec Bolesław , Bialik Wojciech
Published: December 2013

Based on the Minimum Gibbs Free Enthalpy algorithm (FEM) and a model of reaction zones located around electrode tips in the submerged arc furnace, an analysis of the raw material chemical composition influence on the ferrosilicon smelting process was carried out. A model of the ferrosilicon process in the submerged arc furnace is a system of two closed isothermal reactors: an upper one with a lower temperature T1, and a lower one with a higher temperature T2. Between the reactors and the environment as well as between the reactors inside the system, a periodical exchange of mass occurs at the moments when the equilibrium state is reached. Based on the model, sets of calculations were performed: for a Fe-Si-O-C system and, subsequently, for a more complex Fe-Si-O-C-Al-Ca-Mg-Ti system. For both systems, the energy and mass balance values were calculated and the effects of raw material contaminants on the efficiency of the ferrosilicon melting process were determined.
Influence of the Steel Scrap Classes on the Liquid Steel Output Melt in Electric Arc Furnace
Authors: Janiszewski Krystian , Socha Ladislav , Gryc Karel
Published: December 2013

The paper analyses methods, the influence of use of charges of steel scrap of different qualities in the EAF on the index of liquid steel output from a melt using statistical analysing methods. The used research methodology consists of analytical simulation of variations in mass of liquid steel obtained from melts differing in steel scrap content in the metallic charge and of statistical analyses of industrial results acquired from the corresponding process documentation (so called melt cards). The obtained research results can be utilized in each steelmaking facility, which employs the Electric Steelmaking process, in order to “design” the metallic charge compositions, having in view the quality and economic aspects. The results presented in this paper are directed to the steelmakers employing the Electric Steelmaking process and constitute the authors original study.
Effect of Solution Treatment on the Microstructure of Ti-C Alloys
Authors: Szkliniarz Agnieszka , Szkliniarz Wojciech
Published: December 2013

The work concerns a new group of titanium alloys with properties improved due to the presence of carbon. Investigated alloys were melted in a vacuum induction furnaces with copper water cooled crucibles. It was showed the influence of the solution temperature in range of 875 to 975oC on the number, size and distribution of carbides in pure titanium with content of 0.2 wt.% carbon and on the hardness test of researched alloys. The observed changes in the microstructure and properties are the result of phase transformations taking place during heating: α + TiC α α + β β + TiC.
Effect of Cooling Rate and Modification on the Structure of Cast AlSi17 Alloy
Authors: Piątkowski Jaroslaw , Matuła Tomasz
Published: December 2013

In the paper an effect of alloy modification, the mold material and the heat dissipation on the structure of hypereutectic silumin AlSi17 are presented. The investigated alloy was cast into: a ceramic (ATD), graphite and copper molds. In order to verify the conditions of heat dissipation through the mold, were used an additional cooling agents, such as water and liquid nitrogen. From the obtained ingots were prepared samples, which were stereological analyzed in the Metilo program.
X-Ray Analysis of the Precipitation Process in an Fe-Ni Superalloy
Authors: Pająk Lucjan , Ducki Kazimierz J. , Wojtynek Lilianna
Published: December 2013

The influence of prolonged ageing on the kinetics of the precipitation process of the secondary phases in an A-286 type Fe-Ni superalloy has been studied. The samples were subjected to a solution heat treatment at 980°C for 2 h and water quenched, and then aged at temperatures of 715, 750 and 780°C at holding times from 0.5 to 500 h. Structural investigations were conducted using X-ray diffraction methods. The values of the austenite lattice constant were estimated with the use of the cos2θ extrapolation function, and by the Toraya (WPPF) and Rietveld methods. It was found that the largest decrease in the austenite lattice constant took place during the initial period of ageing at all investigated temperatures, which corresponds to the spinodal decomposition of supersaturated austenite and formation of the γ'-Ni3(Al,Ti) intermetallic phase. Good agreement between the values of the austenite lattice constant determined using the extrapolation function and the Rietveld method was found.
The Effect of Heat Treatment on Creep Resistance of Castings from the Modified Superalloy MAR-247
Authors: Cieśla Marek , Binczyk Franciszek , Mańka Marcin
Published: December 2013

mpact of heat treatment on durability has been evaluated in this study in conditions of high-temperature creep of castings made from nickel superalloy MAR-247 post production rejects. Castings made in the processes of modification and filtration when pouring into moulds were subject to solubilization (1185°C/2 h) with subsequent ageing (870°C/20 h). It has been found on the basis of performed tests that in conditions of high-temperature creep at temperature 980°C with stress σ = 150 MPa the resistance of specimens of coarse-grain structure was significantly higher when compared to fine-grain material. The conditions of initiation and propagation of cracks in these specimens were analysed with consideration of morphological properties of material macro-, micro-and substructure. Moreover, it has been proven that creep resistance of heat treated MAR-247 superalloy significantly improves when compared to its condition after the process of modification only. Macrostructural changes in the MAR-247 superalloy that determine the increase of superalloy creep resistance after solubilization and ageing, as observed in the tests, were also examined.
Scanning Transmission Electron Microscopy Studies of the Microstructure of High Chromium Steel after Long Time Exposure
Authors: Rodak Kinga B. , Hernas Adam
Published: December 2013

The detailed microstructural analysis of HCM12 steel after long time (100 000 hours) exposure at service temperatures around 600°C was investigated by means of scanning transmission electron microscopy. The results show, that the recovery processes of the martensite lath structure and δ ferrite are significantly different. Moreover are differences in particles precipitating at the martensite and δ ferrite. The intensive process intragranular M23C6 and Laves particles precipitating is observed at the martensite/ δ ferrite interfaces.
Porosity in Turbine Blades Cast into New Shell Moulds Made of SiC Based Ceramics
Authors: Roskosz Stanisław
Published: December 2013

The subject matter of the paper is the quantitative evaluation of gaseous and shrinkage porosity in the turbine blades using quantitative metallography methods. The research material consisted of blades with a polycrystalline structure made of IN 713C superalloys. Three different shell mould systems were used during the investment casting: shell A - typical industrial shell mould system and used in this work as the reference; shell B – similar to version A, but SiC grit was applied as back-up stucco; shell C – entirely SiC shell mould system. The blades of superalloy IN-713C cast into the wholly SiC shell mould system have revealed much lower porosity as compared to the blades cast into the typical industrial shell mould system.
Research on Mechanical Properties of Thin Sheets Blanks Made of Creep-Resisting Nickel Superalloys
Authors: Hyrcza-Michalska Monika
Published: December 2013

Mechanical working manufacturing methods of nickel alloys used conventionally strips and blanks need to solve many problems concerning high strength material forming which is characteristic limited plasticity. The production pressed elements of vehicle constructions and aircraft engine elements requires the high quality drawpieces since these are essential for safety. They are also the main structural components. Conventional methods of mechanical working such as pressing can be used in quantity production of the above mentioned elements and their production can also be cost-effective. Forming nickel alloys generates a lot of technological wastes resulting from back-springing effects determining the most appropriate pressure in the process of pressing. Failure holes in the process of bulging as well as cracking of drawpieces in the process of deep drawing. The heterogeneous mechanical properties distribution on thin sheet blanks made of Inconel alloy, which is different than material quality certificate shows, produces also a lot of manufacturing problems. These problems are usually solved by production engineers in the following way: dividing the production of ready drawpieces into a bigger number of simple blank profiling operations, shallow pressing, using a rubber punch for pressing or hydroforming. Complex drawpieces shapes are quite often made of several parts which are next welded. In the case of presented tube a tubular diffuser made of Inconel 718 alloy blank and cone made of Inconel 625. However the process of forming high strength materials like nickel alloys requires the application bigger forming forces than in the same kind of conventional formable steel processes. Tools get jammed quite often in the process and high force presses of 10 MN or more need to be used so is very expensive. The aspect of cold mechanical forming discussed materials has been a particular interest. The researches based on precise evaluation mechanical properties and technological plasticity of the selected materials in basic mechanical and technological tests as well as in FEM numerical simulation (finite elements method). The material models applied to simulation contain the pointed out experimentally the mechanical characteristics of Inconel alloys. The thin sheets blanks made of 0,9 mm thick Inconel 718 alloy and 0,45 mm thick Inconel 625 alloy blanks have been examined. The possibilities of using numerical simulations for solving the problems of selecting or modifying the pressing technology and hydroforming that type materials as well as forecasting the results of forming processes have been also presented. The evaluation of drawability of thin sheets blanks made of Inconel 718 and 625 alloys has also been discussed in the paper.
Effect of Boron Addition on the Microstructure of Ti-47Al-2W-0.5Si Alloy
Authors: Szkliniarz Wojciech , Szkliniarz Agnieszka
Published: December 2013

In this article, characteristics of the macro- and microstructure of cast Ti-47Al-2W-0.5Si intermetallic alloy were determined. The abilities to shape unfavorable parameters of this structure, i.e. large grain and high content of columnar grains, by using crystalline boron modifier were presented. The effect of modification process on selected alloy properties was shown. The content of modifier at which structural changes are highest as well as the form in which it exists after modification were determined.
Effect of Carbon Addition on the Microstructure and Properties of Unalloyed Titanium
Authors: Szkliniarz Agnieszka
Published: December 2013

The effect of carbon additions on the microstructure and properties of unalloyed titanium with 0.2 and 0.5 wt. % C has been studied. Carbon has been found to appear as TiC carbide in these alloys. Its presence translates into increase in allotropic transformation temperature as well as hardness and strength properties of alloys at the expense of reduction in its ductility. It has been demonstrated that these alloys can be subject to hot deformation, and with low carbon content also to cold deformation, and additionally strengthened by solution treatment.
Influence of Forming on the Properties of Alloy Based on the Matrix of FeAl Intermetallic Phase
Authors: Cebulski Janusz , Basa Katarzyna , Pasek Dorota
Published: December 2013

Presented article describes results of studies concerning on influence of forming processes on alloy characteristics based on the FeAl intermetallic phase matrix. Microstructure of the alloy was evaluated with optical microscope after crystallization and forming process. Measures of hardness were taken using Vickers method. Static tensile test was used to set limitation of malleability and ultimate tensile strength. Crack surface after static tensile test was observed using scanning electron microscope.
Estimation of Flow Stress of Zinc-Titanium Strip during Reverse Rolling
Authors: Spyra Marek , Tkocz Marek , Hadasik Eugeniusz
Published: December 2013

Due to some specific features (high corrosion resistance and long-life durability in particular) as well as interesting aesthetic appeal, zinc-titanium strips are widely used as roof coverings, facade panels and rain gutters. The Zn-Ti strips are manufactured either in the hot rolling lines or in the reverse rolling mills at elevated temperatures. A problem of determination the average flow stress of zinc-titanium strip in the latter mentioned technology and in the actual rolling conditions is discussed in the paper. The analysis is based on the results of plastometric compression tests, FEM simulations and industrial practice.
Structure of Aluminium Matrix Composite with Ceramic Preform Obtained by Centrifugal Infiltration Process
Authors: Dolata Anna Janina
Published: December 2013

The paper presents the microstructure analyzing of composite with aluminium matrix containing porous Al2O3 preform. The AlSi12CuMgNi eutectic alloy have been modified by 1 wt% Mg and 0.03 wt% Sr additions. The magnesium to improve the wettability between matrix and ceramic reinforcement have been added. In turn 0.03 wt% strontium addition were used to changes the size and morphology of the Al-Si eutectic grains. The components and composite material obtained by the centrifugal infiltration process was characterized by means of light and scanning microscopy methods. The conducted investigations proved the large degree of infiltration of ceramic porous by the aluminium alloy and good connection in the boundary area.
Numerical approximation of capillary surfaces in a negative gravitational field
Authors: Hardering Hanne
Published: December 2013

A capillary surface in a negative gravitational field describes the shape of the surface of a hanging drop in a capillary tube with wetting material on the bottom. Mathematical modeling leads to the volume- and obstacle-constrained minimization of a nonconvex nonlinear energy functional of mean curvature type which is unbounded from below. In 1984 Huisken proved the existence and regularity of local minimizers of this energy under the condition on gravitation being sufficiently weak. We prove convergence of a first order finite element approximation of these minimizers. Numerical results demonstrating the theoretic convergence order are given.
Well-posedness of the linearized plasma-vacuum interface problem
Authors: Secchi Paolo , Trakhinin Yuri
Published: December 2013

We consider the free boundary problem for the plasma-vacuum interface in ideal compressible magnetohydrodynamics (MHD). In the plasma region the flow is governed by the usual compressible MHD equations, while in the vacuum region we consider the
pre-Maxwell dynamics
for the magnetic field. At the free-interface we assume that the total pressure is continuous and that the magnetic field is tangent to the boundary. The plasma density does not go to zero continuously at the interface, but has a jump, meaning that it is bounded away from zero in the plasma region and it is identically zero in the vacuum region. Under a suitable stability condition satisfied at each point of the plasma-vacuum interface, we prove the well-posedness of the linearized problem in conormal Sobolev spaces.
Indoor/outdoor relationships of quasi-ultrafine, accumulation and coarse mode particles in school environments in Barcelona: chemical composition and sources
Authors: Viana M. , Rivas I. , Querol X. , Alastuey A. , Sunyer J. , Álvarez-Pedrerol M. , Bouso L. , Sioutas C.
Published: December 2013

Abstract. The mass concentration, chemical composition and sources of quasi-ultrafine (quasi-UFP, PM0.25), accumulation (PM0.25–2.5) and coarse mode (PM2.5–10) particles were determined in indoor and outdoor air at 39 schools in Barcelona (Spain). Quasi-UFP mass concentrations measured (25.6 μg m−3 outdoors, 23.4 μg m−3 indoors) are significantly higher than those reported in other studies, and characterised by higher carbonaceous and mineral matter contents and a lower proportion of secondary inorganic ions. Results suggest that quasi-UFPs in Barcelona are affected by local sources in the schools, mainly human activity (e.g. organic material from textiles, etc.; contributing 23–46% to total quasi-UFP mass) and playgrounds (in the form of mineral matter, contributing about 9% to the quasi-UFP mass). The particle size distribution of toxicologically relevant metals and major aerosol components was characterised, displaying bimodal size distributions for most elements and components, and a unimodal distribution for inorganic salts (ammonium nitrate and sulphate) and elemental carbon (EC). Regarding metals, Ni and Cr were partitioned mainly in quasi-UFPs and could thus be of interest for epidemiological studies, given their high redox properties. Children exposure to quasi-UFP mass and chemical species was assessed by comparing the concentrations measured at urban background and traffic areas schools. Finally, three main indoor sources across all size fractions were identified by assessing indoor/outdoor ratios (I/O) of PM species used as their tracers: human activity (organic material), cleaning products, paints and plastics (Cl− source), and a metallic mixed source (comprising combinations of Cu, Zn, Co, Cd, Pb, As, V and Cr).
Modelling soil organic carbon stocks in global change scenarios: a CarboSOIL application
Authors: Muñoz-Rojas M. , Jordán A. , Zavala L. M. , González-Peñaloza F. A. , De la Rosa D. , Pino-Mejias R. , Anaya-Romero M.
Published: December 2013

Abstract. Global climate change, as a consequence of the increasing levels of atmospheric CO2 concentration, may significantly affect both soil organic C storage and soil capacity for C sequestration. CarboSOIL is an empirical model based on regression techniques and developed as a geographical information system tool to predict soil organic carbon (SOC) contents at different depths. This model is a new component of the agro-ecological decision support system for land evaluation MicroLEIS, which assists decision-makers in facing specific agro-ecological problems, particularly in Mediterranean regions. In this study, the CarboSOIL model was used to study the effects of climate change on SOC dynamics in a Mediterranean region (Andalusia, S Spain). Different downscaled climate models were applied based on BCCR-BCM2, CNRMCM3, and ECHAM5 and driven by SRES scenarios (A1B, A2 and B2). Output data were linked to spatial data sets (soil and land use) to quantify SOC stocks. The CarboSOIL model has proved its ability to predict the short-, medium- and long-term trends (2040s, 2070s and 2100s) of SOC dynamics and sequestration under projected future scenarios of climate change. Results have shown an overall trend towards decreasing of SOC stocks in the upper soil sections (0–25 cm and 25–50 cm) for most soil types and land uses, but predicted SOC stocks tend to increase in the deeper soil section (0–75 cm). Soil types as Arenosols, Planosols and Solonchaks and land uses as "permanent crops" and "open spaces with little or no vegetation" would be severely affected by climate change with large decreases of SOC stocks, in particular under the medium–high emission scenario A2 by 2100. The information developed in this study might support decision-making in land management and climate adaptation strategies in Mediterranean regions, and the methodology could be applied to other Mediterranean areas with available soil, land use and climate data.