Behaviour of 54.4SiO2-13.7Na2O-1.7K2O-5.0CaO-12.4MgO-0.6Y2O3-11.3Al2O3-0.9B2O3 HT-SOFC glass sealant under oxidising and reducing atmospheres

The behaviour of the promising glass sealant 54.4SiO₂-13.7Na₂O-1.7K₂O-5.0CaO-12.4MgO-0.6Y₂O₃-11.3Al₂O₃-0.9B₂O₃ for solid oxide fuel cells (SOFCs) under SOFC operating conditions was studied. First, the kinetics of the crystallisation processes at the operating temperature (850 °C) was discussed (maximum exposure time of 1000 h), and the effect of crystallisation on the coefficient of thermal expansion (CTE) of the sealant was studied. Furthermore, the degradation processes at the interface of the glass sealant and functional SOFC materials (Crofer 22 APU, YSZ, and NiO(Ni)-YSZ) during exposure to 850 °C in oxidising and reducing atmospheres for 500 h were studied. The tests demonstrated good performance of the sealant studied and possibility of its application in SOFCs.     

Correlations of sensory parameters with physicochemical characteristics of Argentinean honeys by multivariate statistical techniques

Honey acceptability is mainly determined by its colour, crystallisation degree and aroma. In the present work, the sensory characteristics and physicochemical parameters of Argentinean honeys from different ecoregions were analysed. Moisture content, Pfund colour, diastase activity, hydroxymethylfurfural content, electrical conductivity, sugar profile and volatile compounds were analytically determined in honey samples, while sensory characteristics (crystal size, fluency score, sweetness, persistence, granularity, crystallisation, colour intensity and aroma) were evaluated by a trained panel. Significant correlations were found between honey crystallisation degree and hydroxymethylfurfural content and diastase activity (P ≤ 0.05). It could be confirmed that honey crystallisation interferes with the visual perception of colour. Floral, fresh fruit, ripe fruit, balsamic and wood aromas could be successfully linked to honey volatile profile (P ≤ 0.05). These results demonstrate that the parameters that could best guarantee the consumers’ preference can be successfully associated with the chemical composition of honey by multivariate statistical analysis.     

Electrodeposition of amorphous Ni–P layers,thermal treatment and corrosion behaviour

The investigation reported comprises an experimental study of the thermal and corrosion properties of electrodeposited nickel-phosphorus amorphous alloy layers. The structure of the species was determined by means of X-ray diffraction spectroscopy. Samples with hypo- and hyper-eutectic compositions were synthesised out of modified classical and customised electrolytic solutions on copper substrates. The composition of the samples was determined via energy dispersive spectroscopy. A short review of the development of the composition of existing plating baths for Ni–P electrodeposition has also been presented. Thermal treatment of the samples has been carried out to crystallise the amorphous structure and to compare the thermal and the corrosion properties of the species with both types of structure. Differential thermal measurements were used to examine the thermal effects in the Ni–P samples obtained. The corrosion parameters of initial as-plated and thermally treated binary Ni–P alloy coatings were determined from Tafel plot analysis.     

非晶态Ni-W-P镀层退火晶化和激光晶化组织结构的演变

用XRD定量分析法并结合扫描电镜形貌观察,研究化学沉积高磷(13.3%)含量的Ni-W-P镀层在不同热处理条件下的晶化程度、晶粒尺寸及晶格应变等组织结构的演变规律。结果表明:高磷非晶态镀层在退火晶化过程中,Ni3P相的体积分数始终高于Ni相的,700℃时,两相的体积分数之差显著增大,镀层仍有残存的非晶相;在400~500℃之间形成的Ni3P的晶粒尺寸大于Ni的;温度为500~700℃时,Ni相的尺寸大于Ni3P的,但均未超过纳米级。镀层晶格应变表现为随退火温度的升高而降低,镀态时晶格应变最大。激光晶化处理的非晶态Ni-W-P镀层的显微结构特征介于400~500℃之间退火的镀层晶化特征。随扫描速度增加,不仅Ni3P晶粒尺寸增大,而且两相的尺寸差变大。     

超声波辅助马铃薯冻结的实验研究

为了研究超声波辅助沉浸冻结的机理,将马铃薯样品分别浸入脱气冷冻液与未脱气冷冻液中冷却。每次实验时,从?1℃时开始,启动超声波发生装置,使马铃薯内的水分在超声场中冻结。利用扫描电镜比较分析不同实验条件下马铃薯组织的微观结构,实验结果表明不同冷冻液中的马铃薯样品遭受超声波辐射后,其组织在冻结过程中受到的损伤均小于无超声波作用的样品,而且超声波对浸于未脱气冷冻液中样品组织的改善作用更为显著。表明超声波诱发的冷冻液的分子振动与空化均对沉浸冻结有影响。     

Enrichment of ice cream with dietary fibre: Effects on rheological properties,ice crystallisation and glass transition phenomena

In the present study, the effects of four dietary fibre sources (oat, wheat, apple and inulin) on the rheological and thermal properties of model sucrose–polysaccharides solutions and ice cream mixes were investigated. The content of fibre in insoluble compounds increased significantly the viscosity and the shear thinning behaviour of the model solutions and ice creams, due to the increase of total solids and the formation of networks comprised of hydrated cellulose and hemicellulose. The increase of soluble material did not alter significantly the rheology of the samples but limited the freezing point depression and elevated the glass transition temperatures, indicating a potential cryoprotective action. The use of oat and wheat fibre favoured viscosity development due to water-binding, whereas inulin caused a remarkable increase of glass transition temperature (T_g) in model solutions and ice cream mixes, indicating the reduction of water molecule mobility from the bulk aqueous phase to the ice crystals’ surface. Apple fibre addition greatly increased viscosity and elevated the T_g values, particularly in the presence of proteins. Thus, our results suggest the potential use of dietary fibres as crystallisation and recrystallisation phenomena controllers in frozen dairy products.     

Development of Mould Flux for High Speed Thin Slab Casting

Mould powders impact the stability of the continuous casting process for steel at all casting speeds. The main functions of mould powder are to provide sufficient lubrication and to control the mould heat transfer between the solidifying steel shell and the copper mould. At higher casting speeds associated with thin slab casting, the role of the mould powder is even more important. Actual casting speeds for the thin slab caster at Corus IJmuiden are between 5.4 and 6 m/min; the production level is around 1.3 Mt/year (coils). It has been decided to increase the production of this caster to a level of 1.8 Mt/year (coils). In order to meet this demand, the steel in mould time has to be increased to approximately 85% and the maximum casting speed will be increased to 8 m/min. A collaborative project between Sumitomo Metal Industries (SMI) and Corus IJmuiden was initiated to develop mould powders which facilitate casting speeds up to 8 m/min at the thin slab caster. Main subjects of this project are: mould powder design, characterisation of mould powder and mould slag, trials at the pilot caster of Sumitomo and finally plant trials at the thin slab caster of Corus. A special point of attention is the condition to use mould powder as a granulated material at the thin slab caster. As a consequence, the characterisation work focussed on the choice of raw materials and on the corresponding phase relations at elevated temperatures. Typical of the developed mould powders are so‐called mild cooling properties which will result in a controlled mould heat transfer during casting. In this paper, several aspects of this joint project between Sumitomo and Corus will be described.     

Effect of Ce,Sb and Sn on mechanism and activation energy for crystallisation of X‐ray irradiated photosensitive glass

Abstract

Abstract

This work aims to determine the effect of Ce, Sb, Sn and Ag on the mechanism and activation energy of crystallisation for an X‐ray irradiated photosensitive lithium silicate glass composition and to compare it with the one that contained only Ag. According to the obtained results, while the addition of Ce, Sb and Sn changed the crystallisation mechanism of lithium silicate crystal from two‐ to three‐dimensional growths, these additions did not affect the activation energy of crystallisation for lithium metasilicate. Differential thermal analysis was used for studying the mechanism and activation energy for crystallisation of these glasses through the Matusita and the modified Kissinger methods; SEM and XRD were used to investigate the lithium silicate and silver crystallisation in the glasses.     

Using an additive to control the electrospinning of fibres of poly(ε‐caprolactone)

Electrospinning is a route to polymer fibres with diameters considerably smaller than available from most fibre‐producing techniques. We explore the use of a low molecular weight compound as an effective control additive during the electrospinning of poly(ε‐caprolactone). This approach extends the control variables for the electrospinning of nanoscale fibres from the more usual ones such as the polymer molecular weight, solvent and concentration. We show that through the use of dual solvent systems, we can alter the impact of the additive on the electrospinning process so that finer as well as thicker fibres can be prepared under otherwise identical conditions. As well as the size of the fibres and the number of beads, the use of the additive allows us to alter the level of crystallinity as well as the level of preferred orientation of the poly(ε‐caprolactone) crystals. This approach, involving the use of a dual solvent and a low molar mass compound, offers considerable potential for application to other polymer systems. Copyright © 2010 Society of Chemical Industry     

In2O3:H transparent conductive oxide films with high mobility and near infrared transparency for optoelectronic applications

Abstract

Hydrogen doped In₂O₃ (In₂O₃:H) films show high conductivity, small dispersion of refractive index and very low extinction coefficient in the visible to near infrared wavelengths. The improved properties make this transparent conducting oxide an ideal candidate for a window electrode of optoelectronic devices. This article describes the control of microstructure of In₂O₃:H, the relationship between the structure and transport properties and the Si based solar cells incorporating the In₂O₃:H window electrode.