Degraded carrageenan (known as poligeenan molecular weight: 20 kDa to 30 kDa) causes ulcerative colitis in experimental animals. In this paper, the molecular weight distributions of 29 samples of food-grade refined carrageenans were studied by high performance liquid gel permeation chromatography (GPC) directly connected to vacuum-ultraviolet inductively coupled plasma-atomic emission spectrometry (ICP) (GPC/ICP) as well as GPC/refractive index (RI) detection. All samples of food-grade carrageenan had a major broad peak of high molecular weight which eluted at around 6.5 min in both RI and ICP mode (sulphur and carbon), and each sample of them had no obvious peak of poligeenan (the detection limit was about 5%). The number average molecular weights of these carrageenans ranged from 193 kDa to 324 kDa, and the weight average molecular weights ranged from 453 kDa to 652 kDa based on RI data. Some samples had a few minor peaks which eluted around 10-12 min. These peaks came from ionic sulphate, sucrose or glucose. It was considered that if the data-sampling programme was improved, the GPC/ICP system would become a more powerful technique for evaluation of carrageenan samples containing ionic substances and sugar.

Degraded carrageenan (known as poligeenan molecular weight: 20 kDa to 30 kDa) causes ulcerative colitis in experimental animals. In this paper, the molecular weight distributions of 29 samples of food-grade refined carrageenans were studied by high performance liquid gel permeation chromatography (GPC) directly connected to vacuum-ultraviolet inductively coupled plasma-atomic emission spectrometry (ICP) (GPC/ICP) as well as GPC/refractive index (RI) detection. All samples of food-grade carrageenan had a major broad peak of high molecular weight which eluted at around 6.5 min in both RI and ICP mode (sulphur and carbon), and each sample of them had no obvious peak of poligeenan (the detection limit was about 5%). The number average molecular weights of these carrageenans ranged from 193 kDa to 324 kDa, and the weight average molecular weights ranged from 453 kDa to 652 kDa based on RI data. Some samples had a few minor peaks which eluted around 10-12 min. These peaks came from ionic sulphate, sucrose or glucose. It was considered that if the data-sampling programme was improved, the GPC/ICP system would become a more powerful technique for evaluation of carrageenan samples containing ionic substances and sugar.

No abstract

No abstract

No abstract

Background: In-line metrology for three-dimensional (3D) profiling high-aspect-ratio (HAR) features is highly important for manufacturing semiconductor devices, particularly for memory devices, such as 3D NAND and DRAM. Aim: Our purpose was to obtain the cross-sectional profiles of the HAR features from top-view critical dimension scanning electron microscopy (CD-SEM) images. Approach: Based on Monte Carlo simulation results, we proposed a method for 3D profiling of HAR features using backscattered electron (BSE) signal intensities. Several kinds of HAR holes with different taper angles and bowing geometries were fabricated. High-voltage CD-SEM was used for experiments to determine the feasibility of our approach. Results: Using the BSE line-profile, we constructed cross sections of the taper holes and estimated sidewall angles (SWAs), which were approximately the same as those observed using field-emission scanning electron microscopy (FE-SEM). The constructed cross sections of the bowing holes and the trends of the geometric variance, which were estimated by the middle CD and its depth, were consistent with the cross sections observed by FE-SEM. Conclusions: The results demonstrate that the variation in the HAR holes, such as SWA and bowing geometry, can be measured and monitored using the BSE images.

Laser Thomson scattering is a method for measuring electron properties of plasmas. Recent applications have showed that this method can be applied to much lower density plasmas than was previously possible. In this paper, a formalism is given for estimating the lower detection limit for different experimental arrangements and the lower detection limit of electron density in low density discharge plasmas is presented. It is shown that the intensity of the background plasma emission is the main factor that determines the signal-to-noise ratio and hence the lower detection limit. The dynamic range for measurements of electron energy distribution functions is also discussed.

Radiation induced point defect‐light element impurity complexes, basically CiOi, are used widely for lifetime control in power devices for hybrid cars. Recently, not only CZ, but also FZ and epitaxial wafers have been examined as candidates. It has been suggested by luminescence study that CiOi behaved differently during annealing in crystals from different origins. The behavior of CiOi (and VO) during annealing was examined by highly sensitive infrared absorption spectroscopy (IR). CiOi concentration ([CiOi]) after irradiation depended strongly on the growth techniques and as‐grown carbon ([C]) and oxygen ([O]) concentrations. In the basic C‐rich MCZ case, CiOi and VO reacted with each other and decreased steadily with annealing temperature increase. They mostly disappeared at 400 °C. In low [C] CZ case, CiOi residual ratio (RR = α400°C/αRT, α is the absorption coefficient) was higher, probably due to low reaction probability of much lower [CiOi] with VO. In FZ silicon, CiOi residual ratio was low, probably due to rapid break. Thus, IR made systematic and quantitative analysis compared to the luminescence study. In nitrogen‐doped FZ silicon, NV was observed in as‐grown crystals. N2 was modified by irradiation and complicated reaction took place with V or I by annealing. This would affect the CiOi behavior. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)