Applications of confocal microscopy in industrial solid materials: some examples and a first evaluation

We report here the first results of the application of confocal scanning laser microscopy (CSLM) for the study of the microstructure of solid industrial materials. Glass-fibre-reinforced composites, heterogeneous and conductive polymers, homogeneous as well as heterogeneous catalyst (precursor) specimens and soils were examined. We conclude that both the fluorescence and reflection modes of CSLM can yield valuable information. In particular, the optical sectioning capability of CSLM appears to be of great value as it enables one to access the 3-D organization of the specimen without the need for a difficult and time-consuming specimen preparation procedure. However, local obscuration may be an important factor in confocal image formation, limiting the penetration capabilities of the technique for industrial materials.     

Techniques for localisation of konjac glucomannan in model milk protein–polysaccharide mixed systems: Physicochemical and microscopic investigations

The effect of conjugating konjac glucomannan with fluorescein isothyocyanate (FITC) via covalent labelling on selected physicochemical properties of FITC and konjac was investigated using spectrophotometry, rheometry, and size exclusion chromatography (SEC). The binding of the lectin concanavalin A (ConA) to sugar residues of konjac was investigated using SEC. Covalent conjugation of konjac with FITC led to a shift in the absorbance spectrum peak of FITC to a lower wavelength and a decrease in the average molecular weight distribution of konjac. Furthermore, covalently labelled konjac showed reduced apparent viscosity compared to unlabelled konjac. ConA bound to the sugar residues in konjac. The potential of konjac–FITC covalent labelled conjugate or konjac–lectin labelled ConA complexes as fluorescent markers for localisation of konjac in a phase separated micellar casein–konjac mixture was investigated using confocal laser scanning microscopy. Results indicated that covalently labelled konjac has microscopic phase behaviour similar to that of un-labelled konjac and are therefore suitable for localising konjac glucomannan in a phase-separated micellar casein–konjac system.     

Microstructure of Buckwheat and Barley During Malting Observed by Confocal Scanning Laser Microscopy and Scanning Electron Microscopy

The structures of buckwheat and barley were observed by Scanning Electron Microscopy (SEM) and Confocal Scanning Laser Microscopy (CSLM) throughout the malting process. SEM and CSLM have different merits when studying grains and seeds. SEM can be used to study the detailed structure (high magnifications can be achieved) and CSLM to study the overall change in structure during processing. SEM proved that buckwheat starch is degraded by both pitting and surface erosion. A concentric sphere structure was visible when buckwheat starch granules were partly broken down. With CSLM, the organization of protein and starch of buckwheat and barley could be examined independently in projections and images visualizing the 3D structure. CSLM proved that buckwheat starch is surrounded by a protein matrix. Buckwheat protein was structured and surrounded starch granules, while barley protein was present in an amorphous mass through the endosperm. The differences in overall structure between unmalted and malted seeds were evident, as the starch and protein in both the barley and buckwheat were degraded. CSLM may be used in the future to couple processing characteristics to the structure of grains and seeds.     

高温共聚焦显微镜原位观察非金属夹杂物溶解行为研究进展

摘要：总结了高温共聚焦显微镜观察夹杂物在渣中溶解工作原理和非金属夹杂物溶解行为的研究现状和研究方法,探讨了未反应核模型和扩散方程2种常用于研究非金属夹杂物溶解的动力学模型,各类非金属夹杂物的溶解机制,温度、渣成分、夹杂物性质等影响非金属夹杂物溶解行为的因素,在前人研究的基础上得到不同夹杂物的溶解速率公式。指出该领域对于由钙铝酸盐、钙硅酸盐、镁铝尖晶石等由复合化合物构成的夹杂物颗粒研究较少,对铝脱氧钢和硅锰脱氧钢等生产中常用的精炼渣系的研究不够全面的问题,为今后其他学者在该领域的研究提供参考。     

Study of a new energy efficient process for French fries production

A new, energy efficient production process for French fries was developed and evaluated. Superheated steam (SHS) was used for evaporation of water instead of pre-drying with air and par-frying with oil. The product was frozen by vacuum cooling. Unfortunately, with this process it was not possible to reach the quality of conventional French fries. Sensory analysis indicated that the main quality defect was a tough crust with a fatty appearance. Confocal Scanning Laser Microscopy showed that this was caused by skin formation on the surface during both SHS drying and vacuum cooling. A frying step was necessary to obtain a porous crust. A satisfactory product quality was feasible after drying with SHS instead of air. Due to the concessions made for the product quality, the final energy reduction was limited. Nevertheless, this study has gained more insight into how processing affects potato tissue on micro-scale and it has shown that a porous structure is essential for good quality French fries.     

Re-evaluation of differential phase contrast (DPC) in a scanning laser microscope using a split detector as an alternative to differential interference contrast (DIC) optics

In this paper, differential phase imaging (DPC) with transmitted light is implemented by adding a suitable detection system to a standard commercially available scanning confocal microscope. DPC, a long‐established method in scanning optical microscopy, depends on detecting the intensity difference between opposite halves or quadrants of a split photodiode detector placed in an aperture plane. Here, DPC is compared with scanned differential interference contrast (DIC) using a variety of biological specimens and objective lenses of high numerical aperture. While DPC and DIC images are generally similar, DPC seems to have a greater depth of field. DPC has several advantages over DIC. These include low cost (no polarizing or strain‐free optics are required), absence of a double scanning spot, electronically variable direction of shading and the ability to image specimens in plastic dishes where birefringence prevents the use of DIC. DPC is also here found to need 20 times less laser power at the specimen than DIC.     

双辊薄带连铸含硅低碳钢的高温力学性能

采用先进的共焦扫描激光显微镜(CSLM)的拉伸装置对双辊薄带连铸含硅低碳钢进行了高温力学性能研究.结果表明:在0.0005s-1的应变速率下,含硅低碳钢薄带在750～600℃塑性显著下降,在600℃附近呈现显著的脆性断裂.其原因是奥氏体向铁素体相变的过程中,由于奥氏体晶界处的低强度铁素体影响了高温塑性,导致材料塑性大大降低.含硅低碳钢薄带在后续的卷取过程中应选择偏离600℃的脆性区域,以防止卷取过程中裂纹的产生.     

Application of a Model for Liquid Inclusion Separation at a Steel‐Slag Interface for Laboratory and Industrial Situations

A mathematical model based on the equations of particle motion was used to predict inclusion behavior observed at steel‐slag interface in an in‐situ Confocal Scanning Laser Microscope. The results show that the model can be used to explain some phenomena observed in the experiments. In addition, a parameter study was done in order to illustrate how the model can be used to study the effect of physical properties on the inclusion behavior at the slag‐steel interface for some typical industrial ladle metallurgy conditions. Furthermore, to study the effect of steel temperature, sulfur and oxygen content in the steel, slag and inclusion density as well as initial inclusion velocity on the inclusions behavior at the slag‐steel interface. The results show that the temperature and initial velocity was of less importance and that the oxygen content in the steel had a larger influence on the inclusion behavior than the sulfur content in the steel.     

Ti脱氧钢含Ti复合夹杂物诱导晶内针状铁素体的原位观察

采用高温共聚焦激光显微镜(CSLM)对含Ti复合夹杂物诱导晶内针状铁素体(IAF)进行动态原位观察,并用OM,FE-SEM,EDS和EPMA研究奥氏体晶粒尺寸和冷却速率对含Ti复合夹杂物诱导生成IAF的影响.结果表明,IAF的开始生成温度随奥氏体晶粒尺寸的增加,先升高后降低；生成IAF体积分数随冷却速率的提高显著增加,...