bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on Centrifugal Clutch of Frictional Lining Materials
Authors: Li Tse Chang , Huang Yu Wen , Lin Jen Fin
Published: April 2015

Using the Taguchi method, a 5-factorial, 3-level orthogonal array (L’18 (35)) was used as the experimental layout for 18 kinds of frictional lining specimen. These specimens were prepared in order to investigate their performance in establish a relationship between Ts/Td (Ts: static torque; Td: dynamic torque) and dμ/dνx (μ: friction coefficient; νx: relative velocity of frictional lining and clutch drum) parameters. The frictional torque and the rotational speeds of the driveline, clutch, and clutch drum as functions of contact time for 100 clutch cycles are experimentally obtained dμ/dνx and Ts/Td. In the study, a sharp rise in maximum contact pressure ratio occurred when the relative sliding velocity reached the critical velocity, Vc. This increase in maximum contact pressure ratio generally led to an increase of the (initially negative) dμ/dνx value. The mean values of dμ/dνx and Ts/Td for the clutching tests with 100 cycles can be roughly divided into three groups dependent on the fluctuation intensities of these two parameters, for each of which there is a linear relationship. The maximum contact pressure ratio significantly increases even increasing the mean value of dμ/dνx.
Corrosion and Wear Resistance of Electroplating Trivalent Chromium-Carbon Coating
Authors: Liao Chia Wen , Hou Kung Hsu , Wang Hsiang Cheng , Lu Chen En , Ger Ming Der
Published: April 2015

A decorative and high hardness chromium-carbon coating, electrodeposited with a trivalent chromium sulfate electrolyte, could improve the environment pollutions and toxicity of hexavalent chromium system. The trivalent chromium-carbon coatings can be deposited onto substrates directly without any buffer layer. The lifetime of various mechanical parts can be improved due to their high hardness and excellent corrosion resistance. The effect of different concentration of main salt on the composition, hardness, corrosion resistance, coefficient of friction and wear resistance of the coatings were investigated. The SEM observation of surface morphology showed that the appropriate concentration of main salt can diminish the defects caused by internal stress under excessive content, As increasing the concentration of main salt from 0.05M to 0.2M, the Icorr of the coatings would be raised from 1.04×10-6 A/cm2 to 1.26×10-5 A/cm2. XRD results showed that the structure of the coatings prepared by at 0.1 M main salt with a heat treatment at 400 °C for 1 h had Cr7C3 and Cr23C6 phases appeared as well as the hardness of that enhanced up to 1350 Hv than 880 Hv of the as-deposited coatings. Wear test results showed that the coatings prepared by at 0.1 M main salt via a heat treatment of 400 °C had the better wear resistance.
Friction and Wear Characteristics of Hydrogenated and Hydrogen-Free DLC Coatings when Lubricated with Biodegradable Vegetable Oil
Authors: Mobarak H.M. , Niza Mohamad E. , Masjuki H.H. , Kalam M.A. , Al Mahmud K.A.H.
Published: April 2015

Large amount of unsaturated and polar component of oils enhance the lubrication of ferrous materials. DLC coatings can effectively lower the coefficient of friction (CoF) and wear rate of engine components, consequently improving the fuel efficiency and durability of these components. Therefore, the interaction between nonferrous coatings (e.g., DLC) and vegetal oil must be investigated. A ball-on-plate tribotester was used to run the experiments using stainless steel plates coated with amorphous hydrogenated (a-C:H) DLC and hydrogen-free tetrahedral (ta-C) DLC sliding against 440C stainless steel ball. Raman analysis was performed to investigate the structural change of the coatings. At high temperatures, the CoF decreases in both coatings but the wear rate increases in the a-C:H and decreases in the ta-C DLC-coated plates. CoF and wear rate (coated layer and counter surface) are mostly influenced by coating graphitization. The degree of graphitization increases with increasing temperature. Graphitization occurs in the tribological contact because of friction-induced heating under contact and high contact stress conditions.
Improving the Wear Resistance of Aluminum Fly Ash Composites by Multipass Friction Stir Processing
Authors: Juang Shueiwan Henry , Fan Liang Jing , Chang Hsu Shuo
Published: April 2015

In this study, the multi-pass friction stir processing (MP-FSP) technique was performed on ADC6 aluminum alloy + 5 wt% fly ash composite (A5FC) castings to increase their surface area. The dry sliding wear behaviors of the ADC6 alloy, A5FCs, and MP-FSPed A5FCs were evaluated. Dry sliding wear tests were performed using a ring-on-washer machine at a constant rotation speed of 100 rpm for 60 min, and the normal load was 10, 20, 30, and 40 N. The results showed that the MP-FSPed A5FCs had the lowest wear rates in the load range from 10 to 40 N, and adhesive wear was the major wear mechanism in these tests. The increased wear resistance was mainly due to grain refinement and elimination of casting defects after subjecting the ash composite to MP-FSP. The microstructure of the MP-FSPed A5FCs reveals that the sizes of the added raw fly ash particles decreased from micro-to nanoscale levels, and the nanoscale fly ash was uniformly dispersed in the aluminum matrix.
Boundary Friction for a Line Contact Model: An Empirical Approach
Authors: Chong William W.F. , de La Cruz Miguel
Published: April 2015

The paper introduces an alternative approach to predict boundary friction for rough surfaces at micros-scale through the empirical integration of asperity-like nanoscale friction measurements. The nanoscale friction is measured using an atomic force microscope (AFM) tip sliding on a steel plate, confining the test lubricant, i.e. base oil for the fully formulated SAE grade 10w40. The approach, based on the Greenwood and Tripp’s friction model, is combined with the modified Elrod’s cavitation algorithm in order to predict the friction generated by a slider-bearing test rig. The numerical simulation results, using an improved boundary friction model, showed good agreement with the measured friction data.
Influences of Various Zr Target Current on Tribological Behavior of a-C:H:Zr-x Coatings
Authors: Kao Wen Hsien
Published: April 2015

A series of a-C:H:Zr-x coatings (the x in the term a-C:H:Zr-x is the Zr target current varied in the deposition process) have been deposited on AISI M2 steel used unbalanced magnetron sputtering system (UBMS). During deposition process, different a-C:H:Zr-x topcoats were deposited by varying the Zr target current from 0.0 A to 0.5A while maintaining the remaining process conditions at the constant settings. The microstructure, adhesion and tribological properties of the a-C:H:Zr-x coatings were found to vary with the Zr content. The tribological properties of the coatings had been tested against AISI 52100 or Si3N4 counterbody under ball-on-disk point contact wear mode using an oscillating friction and wear tester. Of the various coatings, the a-C:H:Zr-0.4 coating provided the best tribological properties, including the lowest wear depth, the friction coefficient and the longest lifetime. Compare to the coatings sliding against both counterbodies, all of coatings possessed the high wear depth as sliding against Si3N4, but it displayed longer wear lifetime than sliding against AISI 52100.
Surface Modification of Ultra-High Molecular Weight Polyethylene with Crosslinked Hyaluronic Acid and its Antiwear Performance
Authors: Chou Chau Chang , Hao Yu Hsiang , Hsu Fu Yin
Published: April 2015

The surface of high-pressure crystallized ultra-high molecular weight polyethylene (UHMWPE) was modified for application as an artificial cartilage material. A UHMWPE surface pretreated by a series of processes, including treatment with O2-plasma and ethylenediamine solution, was coated with hyaluronic acid (HA). After that, adipic acid dihydrazide (AAD) was added to partially crosslink the HA coating in order to enhance its durability. The modified samples were verified by water contact angle measurement and Fourier transform infrared spectrometry. Both HA layers, original and crosslinked, were also quantitatively evaluated by carbohydrate chemistry assay according to the absorbance of the incident light. The tribological performance of the samples was evaluated by a pin-on-disk test rig lubricated by normal saline under an average pressure of 18 MPa and at a sliding speed of 0.03 m/s for 45 h. The wear resistance of the HA-coated UHMWPE specimens promoted by the crosslink process was superior to that of the original HA-coated sample, and that resistance was maintained after immersion in saline solution for one month.
Effect of Pulse Current on the Microstructure of Tungsten Electrode in Tensile Process
Authors: Cao Jie , Yang Jian Can , Zhu Wen Guang
Published: April 2015

The forming of rare earth tungsten electrode is difficult. The mechanical properties and microstructure evolution of several φ2.4mm rare earth tungsten electrodes were studied by SEM, EBSD and TEM technology. The static tensile test was carried out in different pulse current density, and the temperature of the samples in processing was measured with K thermocouple. The results showed that the sample had the best elongation of 8.87% when the pulse current density was 800 A/mm2. SEM analysis showed that the second phase was broken and some of them were spheroidized in electric sample. It is indicated that the electric pulse accelerated the formation of [110] texture and the low angle boundaries decreased by EBSD, and TEM analysis revealed that the dislocation cell wall was thinner and the adjacent cell got merged in electric sample.
Effect of Cu Content on the Formability and Portevin-Le Chatelier Effect of Al-Mg Alloys
Authors: Ma Peng Cheng , Zhang Di , Zhuang Lin Zhong , Zhang Ji Shan
Published: April 2015

Al-Mg alloys developed for auto body sheets with different Cu contents were fabricated in the laboratory scale. The effects of Cu content on the microstructures, formability and Portevin–Le Chatelier(PLC) effect of the alloys were investigated by polarizied optical microscopy and room temperature tensile testing. It has been found that with increasing Cu content, there was little change of the strain hardening exponent, but the plastic strain ratio and limiting drawing ratio increased firstly and then decreased. A quantitative statistical analysis of the characteristics of the PLC effect was made, including the stress drop and the reloading time, which follow a common linear relationship with plastic strain, and the increase rate of stress drop and reloading time was bigger with more Cu content. A detailed discussion of the corresponding mechanism of Cu and Cu-containing precipitates on the dynamic strain aging(DSA) was made.
Investigation of Tungsten/Steel Brazing Using Nb Interlayer
Authors: Wang Zi Xuan , Ma Yun Zhu , Liu Wen Sheng , Liu Shu Hua , Cai Qing Shan
Published: April 2015

Due to its excellent thermal physical properties, tungsten is used as structural material in divertor components of fusion reactors. With the rapid development of the technology, the joining of W to reduced activation ferritic/martensitic steel is required for use as a component according to the design of helium cooled high performance divertors. However, W and steel have remarkable differences in their coefficients of thermal expansion, which results in a large residual stress in the joints during the manufacturing and service and consequently leads to failure of the joint. In order to obtain a sound W/steel joint, an appropriate interlayer material inserted between tungsten and steel is necessary to solve the above-mentioned problem. A brazing process, using a Ni–based foil–type filler and a Nb slice as intermediate materials, was carried out in vacuum at 1150 °C for 30 min to investigate the joining of tungsten and steel. The microstructures, chemical composition, hardness and strength of the joint were investigated by scanning electron microscopy (SEM), electron probe microanalysis (EPMA), nanoindentation and tensile strength measurement, respectively. The results show that brazing of W and steel was successfully carried out using a Nb interlayer. The bonding interfaces were bonded well. The average tensile strength of 284 MPa was obtained and all specimens fractured in W near the joining seam, in a brittle fracture mode. The nanoindentation test results indicated that the high hardness of 23 GPa were produced at the W/Ni–based filler brazed seams due to the formation of the Boron–riched phase.
Effect of Annealing Temperature on Microstructures and Mechanical Properties of 1000MPa Grade Cold Rolling High-Strength Steel on Ultra-Fast Cooling Condition
Authors: Hua Jing Fan , Song Ren Bo , Yu San Chuan , Gao Zhe , Wanglin Wei Jie
Published: April 2015

The effect of annealing temperature on microstructures and mechanical properties of 1000MPa grade cold rolling steel was studied under the condition of ultra-fast cooling in the present investigation. The component of the experimental steel has been designed and the carbon content is 0.13%[wt]. A small amount of V and Nb were added to the steel. Simulated annealing steel experiment has been carried out in the laboratory condition. The experimental steel was heated to 780°C, 800°C, 820°C, 840°C, 860°C for 80s, then slowly cooled to 680°C, and finally water quenched to room temperature. The aging temperature was 240°C(for 240s) and then the steel was air cooled to room temperature. Using optical microscope, scanning electron microscopy (SEM) and tensile testing machine to analyze and test the microstructures and properties of the steel after annealing process. The result showed that the microstructures of the annealed steel was martensite and ferrite, and when the annealing temperature was 820°C, the tensile strength could reach 999MPa, elongation could reach 13.3%. It was easy to see that the tensile strength increased and the elongation decreased with the increase of annealing temperature.
Effect of Ausforming Temperature on Bainite Transformation of High Carbon Low Alloy Steel
Authors: He Jian Guo , Zhao Ai Min , Yao Huang , Zhi Chao , Zhao Fu Qing
Published: April 2015

The effect of ausforming temperature on bainite transformation of high carbon low alloy steel was studied by in situ experiments using a Gleeble 3500 thermal and mechanical testing system. Morphology and crystallography of ausforming bainite were examined by scanning electron microscopy (SEM) and electron backscattered diffraction (EBSD). It has been found that deformation at all temperatures range from 230°C to 600°C can accelerate low temperature bainite transformation, and transformation rate increased with deformation temperature reduced. Quantitative X-ray analysis shows that the volume fraction of retained austenite was about 35.84% after deformation and isothermal transformation for 20 hours, it was approximately the same amount with austempering bainite transformation process (no strain) which austenite volume fraction was about 32.01%. Low temperature bainite formation can be accelerated with a smaller increase amount of retained austenite by deformation at a low temperature range of 230~600 oC.
Splitting Property Analysis of Automotive Con-Rod Steel C70S6
Authors: Wen Xin Li , Jiang Bo , Zhou Le Yu , Chen Lie , Wang Hai Long , Liu Ya Zheng
Published: April 2015

In order to analysis the splitting property of automotive con-rod steel C70S6, a type of con-rods using this material were manufactured on a domestic production line. Both the fracture and the cracks of the con-rods were observed by SEM, the relationship between the cracks and the grain orientation were analyzed by EBSD. The results show that the fracture of the steel is cleavage fracture and most cleavage planes are {001} , the crack initiation is mainly ferrite or inclusions, and the crack propagation race is along the {001} planes, most microcracks in the vicinity of the main crack induced by the notch can coalesce with it and change its propagation direction, this is the probable formation mechanism of the step-like fracture.
Manufacture of Aluminum Foam without Thickening Agent via Melt Foaming Method and its Compressive Behavior
Authors: Hu Zhong Yun , Yang Dong Hui , Chen Wei Ping , Chen Jian Qing , Wang Hui , Jiang Jing Hua , Ma Ai Bin
Published: April 2015

This paper reported the fabrication of cellular Al foams without thickening agent addition via melt foaming method with the porosity rage of 62.4%-83.3% and the pore size of approximate 2.0mm. CaCO3 was selected as the blowing agent. 1.0wt.%-3.0wt.% Mg was added in the matrix. The gas releasing reaction mechanism was revealed by TG-DTA (Thermo Gravimetric Analysis-Differential Thermal Analysis) experiments. The influence of the adding methods of Mg and CaCO3 on the foaming process was studied and the results showed that, compared to adding powder mixture, the method of adding Mg bulk into the melt before the addition of CaCO3 produces Al foams with better pore structure. Finally, the compressive behaviors of Al foams were investigated.
Effects of Additives on the Properties of SiO2-B2O3-Al2O3-Na2O-PbO System Glass Powders
Authors: Yang Qing , Huang Jin Yang , Zou Jun Tao
Published: April 2015

The SiO2-B2O3-Al2O3-Na2O-PbO system glass powders were prepared by the high temperature water quenching and ball milling. The effects of CaO, Li2O and ZnO with content of 1~5 wt.% on the glass-forming ability, softening temperature and crystallization behavior of the SiO2-B2O3-Al2O3-Na2O-PbO system glass powders were investigated by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The results showed that the glass crystallization tendency became obvious with the increase of CaO and Li2O content, the melting temperature of the glass decreased with the addition of 1% Li2O, while the effect of CaO with content lower than 2% on the formation of glass was not obvious. The addition of ZnO favored the formation of glass, however, the softening temperature of the glass increased with the increase of ZnO content. The softening temperature of the SiO2-B2O3-Al2O3-Na2O-PbO system glass powder decreased by 42.5°C with the addition of 2%CaO-1%Li2O-1%ZnO.
Hydrogen Isotopic Effects of Uranium Hydrides: First-Principles Calculations
Authors: Lu Hai Yan
Published: April 2015

In this paper, we study the ground-state and lattice dynamical properties of β-UH--3by means of the first-principles density functional theory within the local spin-density approximation (LSDA)+Uformulism. The lattice constants and electronic structure are correctly described by taking into account the strong on-site Coulomb repulsion among the 5felectrons localized on uranium atoms. Good agreement with experiments is achieved by tuning the effective Hubbard parameter at around 4 eV. The phonon band structure confirms the dynamical stability of β-UH--3, and the Raman-active modes are consistent with Raman spectrum measurements. The substitution of the deuterium (tritium) atom for hydrogen atom makes significant variations in the typical frequency of Raman-active modes. It is found that the Raman-active mode frequency is approximately inversely proportional to the square root of the hydrogen isotope mass. We conclude that Raman spectrum provides a powerful method for detecting hydrogen isotopic effects.
Modeling of Flow Stress and Grain Size Based on Z Parameter and Material Constants of Al-5.2Mg-0.6Mn Alloy during Hot Deformation
Authors: Yuan Ge Cheng , Yang An Chen , Zhu Zhen Hua , Cheng Yong Qi
Published: April 2015

The flow stress curves of Al-5.2Mg-0.6Mn alloy were tested by isothermal compression method with Gleeble-1500 thermal simulator at the temperatures of 300, 350, 400, 450 and 500°C with strain rate of 0.001, 0.01, 0.1 and 1s-1, respectively. The morphologies of grains deformed were analyzed by TEM. Four material constants including structural factor (A), stress exponential (n), stress multiplier (α) and average activation energy (Q) of the alloy were calculated by linear regression processing. The models of flow stress (σ) and grain size (d) based on Zener-Hollomon parameter (Z) and the constants were established. The results show that the values of A, n, α, Q of the alloy were equal to 3.058×109s-1, 3.314, 0.0184 mm2N-1, 160.94 kJmol-1 respectively, and the models of flow stress and average sub-grains size can be described as σ=54.31ln {(0.327×10-9Z)0.302 +[(0.327×10-9Z)0.604+1]0.5} and d=(0.045lnZ-0.675)-1, respectively. The flow stress appreciably reduced but average grain size increased with decreasing Z value. The conditions of dynamic recrystallization occurring for the alloy were the temperature above or equal to 350°C and lnZ below or equal to 24.47.
Characteristics of the Dead Zones in RH Desgasser with Simulation Methods
Authors: Niu De Liang , Liu Qing Cai , Ma Dong Ran , Yang Jian , Xu Min Ren , Wang Zhu
Published: April 2015

A mathematical model has been constructed for simulating the RH degasser of an iron and steel Co. Ltd. The flow field of molten steel in the ladle has been investigated; in addition, it is also investigated through physical modeling study. The main objective of the investigation was to assess the influence of gas flow rate and immersion depth on dead zones in the ladle. The results show that the flow pattern of molten steel in RH degasser can be well represented by the mathematical model and the physical model. Except the areas close to the free surface and the zones between the two snorkels and the sidewall in the ladle, these dead zones can be reduced by increasing of gas flow rate and immersion depth. These dead zones were marked with 1, 2, 3, results calculated by mathematical modeling are in good agreement with which obtained by means of physical modeling (water modelling) study increasing of immersion depth could markedly reduce the area of dead zone 3, yet the area of dead zone 1 and 2 could be markedly reduced by increasing the gas flow rate, hence indicate that mixing of dead zones could be intensified through improving gas flow rate and immersion depth.
Superhydrophobic Surface Prepared by Organic-Inorganic Hybrid Material on Plasma Spraying Al2O3+13wt. %TiO2 Ceramic Coating
Authors: Mi Yu Xiao , Zhou Ze Hua , Wang Ze Hua , Wang Guo Wei , Yao Juan
Published: April 2015

The plasma spraying Al2O3+13wt. %TiO2 ceramic coating was coated with organic-inorganic hybrid emulsion. The hybrid emulsion prepared through co-hydrolysis and copolycondensation reactions of tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES), and methylsilicone resin was added in the emulsion to improve the film-forming properties. The morphologies, chemical compositions and hydrophobicity of the resulting surfaces were analyzed by scanning electron microscopy (SEM), 3-dimensional stereoscopic microscope, energy dispersive X-ray detector (EDX), Fourier transfer infrared spectrometer (FT-IR) and water contact angle measurement. When the mole ratio of TEOS/MTES and the weight ratio of methylsilicone resin were 1:1 and 3.5wt. %, respectively, this surface displayed good film-forming properties. The contact angle was 130.24°, and the contact angle hysteresis was less than 10°.
First-Principle Investigation on the Secondary Bond in Stable mGeTe·nSb2Te3 Pseudo-Binary Chalcogenides
Authors: Sa Bai Sheng , Zhou Jian , Sun Zhi Mei
Published: April 2015

The Te-Te van der Waals-type secondary bond in stable mGeTe·nSb2Te3 (GST) pseudo-binary chalcogenides was investigated by means of ab initio calculations. The generalized gradient approximation of Perdew-Burke-Ernzerhof pseudopotential describes the Te-Te secondary bond very well. Whereas the local density approximation pseudopotential over-estimates the bond energy by underestimating the repulsive forces between the adjacent Te atoms. The electron localization function illustrates the chemical bonding nature of the Te-Te secondary bond. Our present results will shed insights on the secondary bonds in GST phase change materials.
Stability of the Structure of WE43 Cast Magnesium Alloy Welded Joints at Elevated Temperatures
Authors: Turowska Agata , Adamiec Janusz
Published: April 2015

The WE43 cast magnesium alloy is characterized by high development prospects due to its strength properties and maximum operating temperature of up to 250°C. It is used in the automotive and aircraft industries for engine, hull and gear parts. These are mainly individual or low-volume large-size casts, which in the casting process may display some defects in the form of misruns, shrinkage porosities and cracks. These defects are repaired with the application of welding technologies, which are also used to joint castings into structures and to repair castings after operation. The weld joint is an integral part of the structure. Therefore, it decides on the properties of the entire structure. It is important to get to know the microstructure and properties of magnesium alloy weld joints, and in particular those of the fusion weld. In this paper stability of the structure of WE43 cast magnesium alloy welded joint was researched.
Effect of Heat Treatment on the Microstructure and Properties of Ti-8Al-1Mo-1V Alloy with Carbon Addition
Authors: Szkliniarz Agnieszka
Published: April 2015

The paper concerns a new group of titanium alloys with improved properties caused by presence of carbon. The effect of heat treatment processes like annealing, solution treatment and precipitation hardening on the microstructure of Ti-8Al-1Mo-1V alloy with carbon content not exceeding the limit of solubility of carbon in the alpha phase (0.2 wt. %) were presented. The result of hardness test, static tensile test and creep test of research alloy in both annealing and hardening state was showed. The obtained results were referred to the same alloy without carbon. Investigated alloy is characterized by improved tensile strength with comparable plastic properties. The investigated alloy was characterized better creep resistance after duplex annealing treatment than after hardening.
Influence of Technological Options on the Material Reliability of AlSi17Cu5 Cast Alloy
Authors: Piątkowski Jaroslaw
Published: April 2015

In the dissertation the influence of overheating of around 250oC above Tliqon the material reliability of AlSi17Cu5 cast alloy has been shown. On the basis of static tensile test, the following had been determined: HB hardness, tensile strength and yield strength for four, chosen technological variants. The results were the base to verify the thesis of compliance between tested feature arrangement and normal arrangement, and on this ground also material reliability determined with Weibull’s statistic arrangement had been defined. This parameter grasp the interdependence between lasting probability and chosen material property of the alloy.
Influence of the Wall Thickness on Castability and Microstructure of the QE22 Magnesium Alloy
Authors: Poloczek Łukasz , Dybowski Bartłomiej , Jarosz Robert , Kiełbus Andrzej
Published: April 2015

Majority structural elements from magnesium alloys are produced by means of casting. The big and complicated elements are mainly sand cast. The aim of the research was to investigate the influence of wall thickness on the castability and microstructure of modern magnesium alloy with RE and Ag additions – QE22. Eight 145x98mm plates have been cast for the research. Their designed thickness was equal: 0.5mm, 1mm, 1.5mm, 2mm, 3mm, 4mm, 5mm as well as 6mm. The parameters of microstructure constituents in each cast has been estimated quantitatively. The critical wall thickness, at which liquid alloy fill the mould cavity completely, is equal 4mm. With decreasing wall thickness, percentage of filled cavity is decreasing linearly. Mean area of grain flat section increased 7 times in the thickest plate (from 501μm2 to 3773μm2). The volume fraction of eutectics as well as alloy hardness decreased in the thickest plate.
Relationship between CEO remuneration and company financial performance in the South African retail and consumer goods sector
Authors: Bussin Mark , Nel Morne
Published: April 2015

Purpose: This study was motivated by the need to better understand the effects of the global financial crisis in 2008 on the relationship between company financial performance and CEO guaranteed cost to company (CTC). The aim of this study was to understand the relationship between company financial performance using DuPont analysis and CEO guaranteed CTC in the South African retail and consumer goods sector.Design: The research was a quantitative, archival study of companies listed on the Johannesburg Stock Exchange (JSE), measured over a period of six years (2006–2011). The statistical analysis included regression and correlation analysis.Findings: The research found that CEO guaranteed CTC has shown no sensitivity towards company financial performance in terms of DuPont analysis over the six-year period, which included the global financial crises in 2008. Furthermore, a negative relationship existed between the return on equity and the guaranteed CTC of CEOs in the retail and consumer goods sector during this period.Practical implications: The findings suggest that there is misalignment between company strategy and performance and the guaranteed CTC of CEOs. A practical implication would be to have independent and competent remuneration committees ensuring alignment of the interests of a company with those of its leaders in this regard.
BioMiner: Paving the Way for Personalized Medicine
Authors: Bauer Chris , Stec Karol , Glintschert Alexander , Gruden Kristina , Schichor Christian , Or-Guil Michal , Selbig Joachim , Schuchhardt Johannes
Published: April 2015

Personalized medicine is promising a revolution for medicine and human biology in the 21st century. The scientific foundation for this revolution is accomplished by analyzing biological high-throughput data sets from genomics, transcriptomics, proteomics, and metabolomics. Currently, access to these data has been limited to either rather simple Web-based tools, which do not grant much insight or analysis by trained specialists, without firsthand involvement of the physician. Here, we present the novel Web-based tool “BioMiner,” which was developed within the scope of an international and interdisciplinary project (SYSTHER†) and gives access to a variety of high-throughput data sets. It provides the user with convenient tools to analyze complex cross-omics data sets and grants enhanced visualization abilities. BioMiner incorporates transcriptomic and cross-omics high-throughput data sets, with a focus on cancer. A public instance of BioMiner along with the database is available at http://systherDB.microdiscovery.de/ , login and password: “systher”; a tutorial detailing the usage of BioMiner can be found in the Supplementary File.
Optimising methodology for determining the effect of ocean acidification on bacterial extracellular enzymes
Authors: Burrell T. J. , Maas E. W. , Teesdale-Spittle P. , Law C. S.
Published: April 2015

Abstract. To fully understand the impact of ocean acidification on biogeochemical cycles, the response of bacterial extracellular enzymes needs to be considered as they play a central role in the degradation and distribution of labile organic matter. This study investigates the methodology, and potential artefacts involved in determining the response of bacterial extracellular glucosidase and protease to ocean acidification. The effect of pH on artificial fluorophores and substrates was examined, as well as the impact of three different acidification methods. The results indicate that pH has a significant effect on the fluorescence of the artificial fluorophore 4-methylumbeliferone for glucosidase activity, and 7-amino-4-methylcoumarin for protease activity, while artificial aminopeptidase substrate alters the pH of seawater, confirming previous observations. Before use in ocean acidification research these enzyme assay components must be buffered in order to stabilise sample pH. Reduction of coastal seawater pH to 7.8 was shown to increase β-glucosidase activity rapidly (0.5 h), while no significant response was detected for leucine aminopeptidase, highlighting the need for short-term direct effects of pH on enzyme activities. Bubbling with CO2 gas resulted in higher β-glucosidase activity when compared to acidification using gas-permeable silicon tubing and acidification with HCl. Although bubbling showed variable effects between two experiments conducted at different times of the year. In addition, bacterial cell numbers were 15–40% higher with bubbling relative to seawater acidified with gas-permeable silicon tubing and HCl. Artefacts associated with bubbling may lead to the overestimation of extracellular enzyme activities, and interpretation of the impacts of ocean acidification on organic matter cycling.
Coupled Climate–Economy–Biosphere (CoCEB) model – Part 2: Deforestation control and investment in carbon capture and storage technologies
Authors: Ogutu K. B. Z. , D'Andrea F. , Ghil M. , Nyandwi C. , Manene M. M. , Muthama J. N.
Published: April 2015

Abstract. This study uses the global climate–economy–biosphere (CoCEB) model developed in Part 1 to investigate economic aspects of deforestation control and carbon sequestration in forests, as well as the efficiency of carbon capture and storage (CCS) technologies as policy measures for climate change mitigation. We assume – as in Part 1 – that replacement of one technology with another occurs in terms of a logistic law, so that the same law also governs the dynamics of reduction in carbon dioxide emission using CCS technologies. In order to take into account the effect of deforestation control, a slightly more complex description of the carbon cycle than in Part 1 is needed. Consequently, we add a biomass equation into the CoCEB model and analyze the ensuing feedbacks and their effects on per capita gross domestic product (GDP) growth. Integrating biomass into the CoCEB and applying deforestation control as well as CCS technologies has the following results: (i) low investment in CCS contributes to reducing industrial carbon emissions and to increasing GDP, but further investment leads to a smaller reduction in emissions, as well as in the incremental GDP growth; and (ii) enhanced deforestation control contributes to a reduction in both deforestation emissions and in atmospheric carbon dioxide concentration, thus reducing the impacts of climate change and contributing to a slight appreciation of GDP growth. This effect is however very small compared to that of low-carbon technologies or CCS. We also find that the result in (i) is very sensitive to the formulation of CCS costs, while to the contrary, the results for deforestation control are less sensitive.
Loss of Proapoptotic Gene Apaf-1 Expression in Pancreatic Cancer
Authors: Daukša Albertas , Jakštaitė Aldona , Gasianec Augustina , Dambrauskas Žilvinas
Published: April 2015

Pancreatic cancer has one of the worst prognoses of allgastrointestinal malignancies. One of the key proteins in themechanism of apoptosis is apoptosis protease-activating factorAPAF-1. The aim of this study was to determine expression ofAPAF-1 mRNA in pancreatic cancer. Real time PCR for APAF-1 mRNA was performed on 29 pancreatic cancer cases. Theassociation of APAF-1 mRNA expression with clinico-pathological features was analysed. APAF-1 mRNA expression was lower in 82.8 % in pancreatic cancer than in healthy tissues. The difference was found statistically significant (p=0.02). No association was found between APAF-1 mRNA expression in cancerous tissues and clinico-pathological features. To conclude, in this study we have demonstrated mRNA decrease of APAF-1, indicating that gene involved in cellular apoptosis might be involved in pancreaticcancer pathogenesis.
Burbujas especulativas y crisis fi nancieras. Una aproximación neofuncionalista
Authors: García Blanco José María
Published: April 2015

Si la economía suele enfatizar el papel de las conductas irracionales en la formación de la burbuja especulativa que ha originado la crisis fi nanciera, la sociología realza el de las instituciones y estructuras sociales que sustentan el funcionamiento del sistema fi nanciero, muy particularmente, las densas redes sociales establecidas por las élites fi nancieras, que formarían un círculo socio-culturalmente cerrado y proclive al gregarismo. El presente artículo propone otra interpretación de este supuesto gregarismo, apoyándose en la diferenciación funcional y el impulso que da a la observación interna, de segundo orden. Los mercados modernos son un ejemplo particularmente notable de ello, y muy en especial los fi nancieros, en los que el cierre autorreferencial es particularmente intenso porque lo que allí se negocia es dinero, el medio que soporta la autorreferencia del sistema económico.
Free Riding, Upsizing, and Energy Efficiency Incentives in Maryland Homes
Authors: Alberini Anna , Gans Will , Towe Charles
Published: April 2015

We use a unique dataset that combines an original survey of households, information about the structural characteristics of their homes, utility-provided electricity usage records and program participation status, to study the uptake of energy efficiency incentives and their effect on residential electricity consumption. Attention is restricted to homes where heating and cooling is provided exclusively by air-source heat pumps. We deploy a difference-in-difference study design and find that replacing a heat pump with a new one does reduce electricity usage by 8% on average. The effect differs dramatically across households based upon whether they receive an incentive towards the purchase of a new heat pump.

Among incentive recipients, the effect is small, and the larger the incentive, the smaller the reduction in electricity usage. These findings suggest that capital costs are incorporated into the (long-term) cost of energy, generating an apparent rebound effect that is much more pronounced for incentive recipients.
The impact of cardiovascular drug innovation on the longevity of elderly residents of Switzerland, 2003-2012
Authors: Lichtenberg Frank R
Published: April 2015

Previous investigators have argued that one of the two most important contributors to improved human survival is the treatment of cardiovascular disease. Among Swiss inhabitants age 65 and over, 90% of the 1994-2010 decline in the overall death rate was due to the decline in the rate of deaths from diseases of the circulatory system. Little if any of the decline in cardiovascular mortality is likely to have been due to changes in behavioral risk factors, especially tobacco use and obesity. This study examines the impact of cardiovascular drug innovation on the longevity of elderly residents of Switzerland using cross-sectional patient-level data on about 22 thousand patients insured by a major health insurer (CSS) during the period 2003-2011. We investigate the effect of the vintage (world launch year) of the cardiovascular drugs used by an individual in 2003 on his or her longevity (time till death), controlling for several demographic characteristics and indicators of health status. We are able to track a patient’s vital status until 12/31/2011: 8 years after the end of the period in which cardiovascular drug use (and other variables) are measured. Our estimates indicate that people who used newer cardiovascular drugs in 2003 had longer time till death than people who used older cardiovascular drugs, controlling for the number of 2003 prescriptions and their distribution by main anatomical group, the number of 2003 doctor visits and their distribution by specialty, whether the person was hospitalized in 2003, sex, and age. Our most conservative estimates imply that cardiovascular drug innovation accounted for almost a quarter of the increase in longevity among elderly residents of Switzerland during 2003-2012, and that it increased their longevity by almost 3 months. Other estimates are about twice as large. All of the estimates are consistent with the hypothesis that newer classes of drugs tend to be therapeutically superior to older classes of drugs, and that newer drugs tend to be superior to older drugs within the same class.Even our more conservative estimates indicate that the use of new cardiovascular drugs by elderly residents of Switzerland has been highly cost effective. Our conservative estimate of the cost per life-year gained from cardiovascular drug innovation is below $10,000, and some economists have argued that the value of a statistical life-year is as high as $300,000.
Can the municipalities prevent medication of lifestyle related diseases?
Authors: Bech Mickael , Hansen Maja Bæksgaard , Lauridsen Jørgen , Kronborg Christian
Published: April 2015

In extension of a large municipality reform in 2007, which reduced the number of Danish municipalities from 275 to 98, it was the intention that the municipalities should assume responsibility for a part of the expenditure connected to secondary sector health care treatment. Furthermore, the municipalities were assigned the responsibility for – and equipped with a number of opportunities for – exerting primary preventive initiatives. The purpose of the present study is to investigate, whether the municipalities by applying these opportunities have been able to prevent medication of selected lifestyle related diseases (type 2 diabetes, cardiovascular diseases, and asthma and chronically obstructive lung disease). Though our results initially seem to support this, a closer investigation indicates that the relationship between municipal preventive initiatives and medication is a structural, intra-municipal relationship rather than a cause-response effect.
Use of Primary Care Emergency Services in Norway: Impact of Birth Country and Duration of Residence
Authors: Goth Ursula Småland , Godager Geir
Published: April 2015

Objective: In Norway, the General Practitioner Scheme was established in 2001. Satisfaction with the system is generally high. However, people often choose to visit community-based emergency wards (EW) for routine care instead. The aim of this paper is to describe which factors influence the choice of seeking care at the EW.Design, setting, and patients: Prior national research on utilization patterns has been based mostly on surveys showing a low response rate. By using merged register data, we analyzed the choice of the EW as a care provider in Oslo (Norway) for 2006 and 2007. Applying 1,934,248 observations of 279,531 different individuals, we estimated the probability of choosing the emergency ward for the Norwegian-born population as well as for the14-largest immigrant groups. Substantial variation between groups was identified.Main outcome: The proportion of EW visits was highest among patients from Somalia (11.7 percent) while the lowest proportion of EW users was among immigrants from Germany and Vietnam (5.3 percent). The results vary substantially within individual migrant groups; gender, age, and the duration of residence each influence the probability of visiting an EW.Conclusions: We found large differences in the probability of using an EW between individuals from immigrant populations, presumably because of barriers in access to primary care. Continuity in the physician–patient relationship is an important policy goal. A suggestion for policy is thus to improve communication about the organization of the Norwegian health-care sector to newly arrived immigrants, as well as to patients at the EW.  For Appendix klick on "Supplementary Files" in the right hand menu
A New Paradigm for Health Economics?
Authors: Pedersen Kjeld Møller
Published: April 2015

Culyer and Newhouse in their introduction to the Handbook of Health Economics1 noted that as a research program health economics seemed to be in good shape. “Moreover, its ‘hard core’ of neoclassical economics (especially welfare economics) is itself a part of the ongoing developmental agenda of the subject”. They further observed that there is something in health economics for almost all kinds of health economists: “Powerful defenders of conventional methods and aggressive challengers; pure theorists and applied economists, those who undertake academic research for its own sake and those who see it as an instrument for the improvement of societies …”. ...
The Need for a New Paradigm in Scandinavian Health Economics
Authors: Mooney Gavin , Tinghög Gustav , Kalkan Almina
Published: April 2015

This paper argues that the discipline of health economics has lost its way due to its persistent focus on individualistic and consequential values. The paper suggests how this might be remedied in both theory and practice. It proposes a new paradigm for health economics, which focuses on communitarian values. This new paradigm is discussed in the context of the Scandinavian welfare model.
The association between age and mortality related hospital expenditures: Evidence from a complete national registry
Authors: Gregersen Fredrik Alexander , Godager Geir
Published: April 2015

The aim of this paper is to contribute to the debate on population aging and growth in health expenditures, by providing precise estimates on how mortality related expenditures are influenced by age. Using a complete register of inpatient hospital admissions to create gender-cohort specific panels for each of the 430 Norwegian municipalities, we are able to identify mortality related hospital expenditures by separating the impact of mortality on current hospital expenditures from the impact of patients’ age and gender. We apply model estimates to quantify the mortality-related hospital expenditures for twenty age groups. The results suggest that mortality-related hospital expenditures are a decreasing function of age. Furthermore, the results clearly suggest that, both age and mortalities should be included when predicting future health care expenditures. The estimation results suggest that 9.2 % of all hospital expenditures is associated with treating individuals in their last year of life. Our results also suggest that the reduction in mortality rates in the period from 1998 to 2009 have, cet. par. contributed to an estimated reduction in total hospital expenditures of 0.6 billion NOK, a difference corresponding to 2 % of the expenditures in 2009. (The appendix can be found under "Supplementary Files" in the menu to the right)
Contributions to the knowledge of Formicidae (Hymenoptera, Aculeata): a new diagnosis of the family, the first global male-based key to subfamilies, and a treatment of early branching lineages
Authors: Boudinot Brendon E.
Published: April 2015

The diagnosis of the Formicidae is revised, including five new, unreversed apomorphies, of which one is a unique synapomorphy. The first global male-based key to all subfamilies is provided and illustrated, and all ant subfamilies are diagnosed for males on a global scale for the first time. Three lineages of “basal ants” are assessed in detail: the Amblyoponinae, Leptanillinae, and Martialinae. The males of Martialis heureka (Martialinae) and Apomyrma (Amblyoponinae) are described. The Martialinae and Leptanillinae are diagnosed based on males, and additional diagnostic traits for the male of Amblyoponinae and worker of Martialis are provided. The placement of Scyphodon and Noonilla in the Formicidae and Leptanillinae is confirmed. Morphological characters of the Amblyoponinae, the Leptanillinae, and the Martialinae are contrasted, and potentially homologous apomorphies are signaled.
Sobre tres ejercicios literario-filosóficos de moral desde el prisma de Juan David García Bacca
Authors: Gimeno Monfort Xavier
Published: April 2015

En el presente artículo se pretende exponer una pequeña aproximación crítica en torno a la noción de moral, según lo expuesto en una obra de uno de los más desconocidos y desatendidos filósofos del exilio Español, Juan David García Bacca. A través del análisis de tres ejercicios de literatura, G. Bacca pretende exponer qué es eso de Bien y de Mal y su relación con la moral cristiana, siempre siguiendo una posición esencialmente crítica.