球墨铸铁轮毂的缩孔形成模拟和工艺改进

本文使用了收缩膨胀动态叠加（DECAM）法，对球铁轮毂的缩孔形成进行了模拟和工艺改进，DECAM方法是对凝固过程中液态收缩、凝固收缩和石墨膨胀进行动态叠加，并考虑石墨化膨胀力导致的铸型壁位移的影响，对轮毂件原工艺的模结果与实际生产中缩孔产生的情况吻合较好，改进工艺的模拟结果和实际试制结果基本吻合，改进工艺后铸件缩孔倾向明显减小。结果表明：收缩膨胀动态叠加法够较准确地模拟球铁缩孔的形成，能够进行了工艺方案的评价和改进，但应该进一步考虑球化剂加入量和残Mg量的影响。     

From defects creation to circuit reliability - A bottom-up approach (invited)

This paper presents a theoretical framework about interface states creation rate from Si-H bonds at the Si/SiO₂ interface. It includes three mains ways of bond breaking. In the first case, the bond can be broken thanks to the bond ground state rising with an electrical field. In the two others cases, incident carriers will play the main role either if there are very energetic or very numerous but less energetic. This concept allows us physically modeling the reliability of MOSFET transistors, and particularly NBTI permanent part, and Channel Hot Carrier (CHC) to Cold Carrier (CCC) damage. Finally, the translation of these physical models into reliability spice models is discussed. These models pave the way to Design-in Reliability (DiR) approach which seeks to provide a quantitative assessment of reliability - CMOS device reliability in this case - at design stage thereby enabling judicious margins to be taken beforehand.     

Manganese stearate initiated photo‐oxidative and thermo‐oxidative degradation of LDPE,LLDPE and their blends

This study is an attempt to investigate the effect of a representative pro‐oxidant (manganese stearate) on the degradation behavior of 70 ± 5 μ thickness films of LDPE, LLDPE and their blends. Films were prepared by film blowing technique in the presence of varying quantities of manganese stearate (0.5–1% w/w) and subsequently subjected to accelerated degradative tests: xenon arc exposure and air‐oven exposure (at 70°C). The physico–chemical changes induced as a result of aging were followed by monitoring the mechanical properties (Tensile strength and Elongation at break), carbonyl index (CI), morphology (SEM), melt flow index (MFI), oxygen content (Elemental analysis), and DSC crystallinity. The results indicate that the degradative effect of pro‐oxidant is more pronounced in LDPE than LLDPE and blends, due to the presence of larger number of weak branches in the former. The degradation was also found to be proportional to the concentration of the pro‐oxidant. Flynn‐Wall‐Ozawa iso‐conversion technique was used to determine the kinetic parameters of degradation, which were used to determine the effect of the pro‐oxidant on the theoretical lifetime of the polymer. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Comparison of two methods for extraction of volatiles from marine PL emulsions

The dynamic headspace (DHS) thermal desorption principle using Tenax GR tube, as well as the solid phase micro‐extraction (SPME) tool with carboxen/polydimethylsiloxane 50/30 µm CAR/PDMS SPME fiber, both coupled to GC/MS were implemented for the isolation and identification of both lipid and Strecker derived volatiles in marine phospholipids (PL) emulsions. Comparison of volatile extraction efficiency was made between the methods. For marine PL emulsions with a highly complex composition of volatiles headspace, a fiber saturation problem was encountered when using CAR/PDMS‐SPME for volatiles analysis. However, the CAR/PDMS‐SPME technique was efficient for lipid oxidation analysis in emulsions of less complex headspace. The SPME method extracted volatiles of lower molecular weights more efficient than the DHS method. On the other hand, DHS Tenax GR appeared to be more efficient in extracting volatiles of higher molecular weights and it provided a broader volatile spectrum for marine PL emulsion than the CAR/PDMS‐SPME method.     

Investigation on rapid degradation of sodium dodecyl benzene sulfonate (SDBS) under microwave irradiation in the presence of modified activated carbon powder with ferreous sulfate

The modification of activated carbon powder (ACP) with ferreous sulfate and the degradation of sodium dodecyl benzene sulfonate (SDBS) under microwave irradiation combined with the modified ACP were studied in this work. The research results showed that the catalytic activity of the modified ACP depended on the concentration and acidity of ferreous sulfate solution as well as immersing time. Also, the influences of irradiation time, initial concentration and acidity of SDBS solution and addition amount of modified ACP on the degradation were assessed. UV-vis spectra, FT-IR spectra, ionic chromatography, HPLC and TOC technologies were brought to bear in assessing the modification and the degradation processes. For modified ACP, under given conditions such as 100 mg/L SDBS solution, 1.20 g/L catalyst dose and pH = 6.0, a high degradation ratio (75.5%) was obtained for 25 mL solution within 90 s microwave irradiation, while it was only 59.59% for unmodified ACP. Furthermore, the degradation ratios could reach 100% by the appropriate increase of addition dose (e.g. 2.80 g/L) of modified ACP or the extension of irradiation time (e.g. 230 s). Whereas, for unmodified ACP, the corresponding degradation ratios were only 88.71% or 83.54%, respectively. Hence, it can be concluded that the method adopting microwave irradiation combined with the modified ACP reveals many advantages of rapid degradation rate, low cost, no residual intermediates and no secondary pollution in actual application.     

Structure and mechanical properties of a talc‐filled polypropylene/ethylene‐propylene‐diene composite after reprocessing in the melt state

A commercial talc‐filled polypropylene/ethylene‐propylene‐diene terpolymer composite was repeatedly injection molded up to five cycles to study the effects of reprocessing on the structure, morphology, and mechanical properties. Reprocessing did not change either the chemical structure or the thermal behavior of the composite, but led to a slight molecular weight reduction, due to shear–stress‐induced chain scission. Talc and ethylene‐propylene‐diene terpolymer content remained unchanged with reprocessing, whereas size distribution slightly decreased. Young's modulus, yield stress, and Charpy impact strength of the composite did not significantly change even after five cycles, but deformation at break continuously decreased, and it was attributed to the slight molecular weight, talc, and rubber particle size reduction. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Anode Performance of Electron Irradiated Mesocarbon Microbeads for Secondary Lithium Batteries

Mesocarbon microbeads (MCMBs) heat-treated at 1,273 and 3,073 K were irradiated with an electron beam current density ~1.34μA/cm² of 0.5–1.5 MeV for 0–600 s, and the irradiated MCMBs were examined as anode materials for secondary lithium-ion batteries. Charge capacity of both materials irradiated for short time within 100 s became larger than that before irradiation. Improvement of discharge capacity of MCMB annealed at 3,073 K was achieved by irradiation with 0.5 and 1.5 MeV electrons for 600 s. Good performance of cyclical discharge of MCMB annealed at 3,073 K was also attained by the irradiation with 0.5–1.5 MeV electrons for 600 s.     

The effect of recycled plastic aggregate on chemico-physical and functional properties of composite mortars

In this paper the interaction mechanism between recycled plastic aggregates and lime matrix in composite mortars was investigated by means of thermal, morphological and Fourier Transform Infrared Spectroscopy (FTIR) analyses. In order to assess the fire behavior of the composite mortars, a cone calorimeter method was adopted. The plastic aggregate, mainly made of polyolefin and polyethylene terephthalate, is obtained from an industrial waste, through a process that provides a plasticization and densification by extrusion of plastic waste. Several composite mortars were prepared by replacing silica powder with 10%, 15% and 20% of recycled aggregate. Experimental results attest that, even if the filler was not chemically modified, there is a good chemical interaction between the plastic aggregate and mortar, involving a reduction of the negative effects on physical and functional properties of the mortar composites, such as thermal degradation and fire resistance. In fact all the specimens showed a scarce sensitivity to flashover, and can be classified as low risk materials.     

Surface and bulk analysis of bleaching soybean fabric in the presence of protein hydrolysate

The effect of oxidative and oxidative‐reductive bleaching on the colorimetric, topographical, and mechanical properties of soybean fabric has been investigated by yellowness index, abrasion resistance, tensile strength, Kawabata evaluation system for fabrics, scanning electron microscopy, X‐ray photoelectron spectroscopy, and time of flight secondary ion mass spectrometry in order to examine both the bulk and surface properties. Surface changes to the soybean fiber due to bleaching treatments have been evaluated and the protective effect of protein hydrolysates assessed. Improved tensile strength, flat abrasion performance, and handle maintenance of the soybean fabric was demonstrated with the incorporation of Byco C in both bleaching treatments. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Effect of various coal gas contaminants on the performance of solid oxide fuel cells: Part III. Synergistic effects

The coal-derived gas from a coal gasifier contains multiple contaminants, and their synergistic effects may not be simply the additive influences of individual contaminants. The present work presents the results of a study of the synergistic effects of four contaminants of major concern—S, As, P, and Cl, at the ppm level and in combinations of two, three, or four kinds—on the performance of Ni-YSZ/YSZ/LSM solid oxide fuel cells. The results indicate that both cell performance and morphology differ significantly in cells exposed to a single contaminant, and that cell performance is not simply the additive influence of each contaminant. Synergistic effects can be very destructive (accelerated degradation or even cell failure) when S is in the presence with As/P, but can also be beneficial (stabilization in power density variations over time or a slowed degradation rate) when Cl is present with other contaminants. Cl can even partially restore performance loss when it is introduced after P is already present. Therefore, with the addition of Cl the tolerance limit of SOFCs for the other three contaminants can be greatly increased. We speculate that the affinity of the contaminants to Ni catalyst increases in the following order: As < P < Cl. The interactions between and among these contaminants and possible mechanisms for their destructive and beneficial synergistic effects are discussed.