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81.
The isothermal phase diagram for poly(vinylidene fluoride)/dimethyl formamide/water system was derived. The binodal and spinodal were calculated based on the Flory–Huggins theory and the calculated binodal was approximately in agreement with the experimental data of the cloud points. The isothermal crystallization line was also obtained according to the theory of melting point depression. Mass transfer of the three components during membrane formation by the precipitation from the vapor phase has been analyzed. During this process, phase separation of the polymer solution is induced by the penetration of water vapor in the solution. The calculated result on the changes of the cast film weights indicated the good agreement with the experimental data. The time‐course of the polymer concentration profile in the film was calculated for various cases of different humidity of the vapor phase and different initial polymer concentration. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 159–170, 1999 相似文献
82.
The effects of storage at 25°C in swelling solvents having different solubility parameter (δs) values of 16.8–26.0 J0.5 cm−1.5 on the physical properties and structure of as‐cast poly(L ‐lactide) (PLLA) films was investigated by the degree of swelling (DS), differential scanning calorimetry (DSC), and tensile tests. It was found that PLLA film shows durabity to swelling solvents having δs values much lower or higher than the value range of 19–20.5 J0.5 cm−1.5 and that the polymer solubility parameter (δp) for PLLA is in the value range of 19–20.5 J0.5 cm−1.5. The decrease in the glass transition temperature (Tg) and tensile properties and the increase in melting temperature (Tm) and crystallinity (xc) were larger for PLLA films swollen in solvents having a high DS at 7 days (DS7days). The slight increase in Tm and xc for PLLA films after swelling in solvents with high DS7days values was due to the crystallization of PLLA that occurred during swelling, while the small increase in Tg and elongation at break (εB) for PLLA films after immersion in the solvents having low DS7days values was ascribed to stabilized chain packing in the amorphous region. The Tg, εB, and Young's modulus of the PLLA films after swelling in the solvents varied in the ranges of 47–57°C, 4–8%, and 55–77 kg/mm2, depending on their DS7days or δs values. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1582–1589, 2001 相似文献
83.
Effects of the mixing ratio of poly(DL-lactide) (PDLLA) and poly (ε-caprolactone) (PCL) on the thermal and mechanical properties and morphologies of the solution-cast blends were investigated by differential scanning calorimetry (DSC), polarizing microscopy, tensile tests, and dynamic mechanical analysis. The presence of amorphous PDLLA did not disturb crystallization of PCL over the PDLLA content [XPDLLA = PDLLA/(PCL + PDLLA)] from 0.1 to 0.9 and allowed PCL to form spherulites over XPDLLA ranging from 0.1 to 0.6. The spherulite radius was larger for the blends than for the nonblended PCL. Phase separation occurred for the blends with XPDLLA between 0.1 and 0.9 Tm of PCL remained unchanged in the XPDLLA range up to 0.6 but decreased at XPDLLA above 0.6, whereas the crystallinity of PCL was constant around 60%, irrespective of XPDLLA. The tensile strength (σB, the yield stress (σY), the Young's modulus(E), and the storage modulus (G′) of the blends increased monotonously with XPDLLA if σB at XPDLLA = 0 and 0.6 and σY at XPDLLA = 0.6 were excluded. Elongation-at-break (εB) of PDLLA increased dramatically, while εB of PCL decreased remarkably when a small amount of the other component was added. Equations and parameters predicting σY, E, and G′ of the PCL-PDLLA blends were proposed as a function of XPDLLA. © 1996 John Wiley & Sons, Inc. 相似文献
84.
Christos Soukoulis Solmaz Behboudi-Jobbehdar Lina Yonekura Christopher Parmenter Ian Fisk 《Food and Bioprocess Technology》2014,7(5):1255-1268
Three different milk proteins — skim milk powder (SMP), sodium caseinate (SC) and whey protein concentrate (WPC) — were tested for their ability to stabilize microencapsulated L. acidophilus produced using spray drying. Maltodextrin (MD) was used as the primary wall material in all samples, milk protein as the secondary wall material (7:3 MD/milk protein ratio) and the simple sugars, d-glucose and trehalose were used as tertiary wall materials (8:2:2 MD/protein/sugar ratio) combinations of all wall materials were tested for their ability to enhance the microbial and techno-functional stability of microencapsulated powders. Of the optional secondary wall materials, WPC improved L. acidophilus viability, up to 70 % during drying; SMP enhanced stability by up to 59 % and SC up to 6 %. Lactose and whey protein content enhanced thermoprotection; this is possibly due to their ability to depress the glass transition and melting temperatures and to release antioxidants. The resultant L. acidophilus powders were stored for 90 days at 4 °C, 25 °C and 35 °C and the loss of viability calculated. The highest survival rates were obtained at 4 °C, inactivation rates for storage were dependent on the carrier wall material and the SMP/d-glucose powders had the lowest inactivation rates (0.013 day?1) whilst the highest was observed for the control containing only MD (0.041 day?1) and the SC-based system (0.030 day?1). Further increase in storage temperature (25 °C and 35 °C) was accompanied by increase of the inactivation rates of L. acidophilus that followed Arrhenius kinetics. In general, SMP-based formulations exhibited the highest temperature dependency whilst WPC the lowest. d-Glucose addition improved the storage stability of the probiotic powders although it was accompanied by an increase of the residual moisture, water activity and hygroscopicity, and a reduction of the glass transition temperature in the tested systems. 相似文献
85.
Zhuo Li Jinlian Lu Lei Jin Ján Rusz Vancho Kocevski Hideto Yanagihara Eiji Kita Joachim Mayer Rafal E. Dunin-Borkowski Hongjun Xiang Xiaoyan Zhong 《Advanced functional materials》2021,31(21):2008306
Spinel ferrites are an important class of materials, whose magnetic properties are of interest for industrial applications. The antiphase boundaries (APBs) that are commonly observed in spinel ferrite films can hinder their applications in spintronic devices and sensors, as a result of their influence on magnetic degradation and magnetoresistance of the materials. However, it is challenging to correlate magnetic properties with atomic structure in individual APBs due to the limited spatial resolution of most magnetic imaging techniques. Here, aberration-corrected scanning transmission electron microscopy and electron energy-loss magnetic chiral dichroism are used to measure the atomic structure and electron magnetic circular dichroism (EMCD) of a single APB in NiFe2O4 that takes the form of a rock salt structure interlayer and is associated with a crystal translation of (1/4)a[011]. First principles density functional theory calculations are used to confirm that this specific APB introduces antiferromagnetic coupling and a significant decrease in the magnitude of the magnetic moments, which is consistent with an observed decrease in EMCD signal at the APB. The results provide new insight into the physical origins of magnetic coupling at an individual defect on the atomic scale. 相似文献
86.
Musleh Uddin Emiko Okazaki Hideto Fukushima Sandor Turza Yamashita Yumiko Yutaka Fukuda 《Food chemistry》2006
Nondestructive near-infrared spectroscopy (NIRS) between 400 and 1100 nm regions was employed directly on surimi using a surface interactance fibre optic accessory, to investigate the potential of NIRS as a fast method to determine water and protein contents. The reason why NIRS is well suited when assessing the presence of water or protein is due to the specificity of O–H and N–H bindings. At 980 nm only one broad peak in the original spectra can be seen due to the absorption of water since it contained nearly 80% of surimi. Predictive equations were developed using partial least squares (PLS) regression where excellent predictions for protein and water are noticed. Regression coefficients are higher than 0.98, errors are small and RPD value for protein is well over 8 and that for water is very close to it which can be used for any analytical purpose. 相似文献
87.
Hideto Yoshida Kunihiro Fukui Tetsuya Yamamoto Ayumi Hashida Norihiro Michitani 《Advanced Powder Technology》2009,20(4):398-405
In order to classify fine particles in slurry continuously, a horizontal type water elutriator with electrical potential is newly developed. The experimental classification performance was compared with the numerical calculation. Test particles used were pure silica particles with the mass median diameters of 3.5 and 2.5 μm.The effects of inlet flow rate, slurry concentration, applied electro-potential and the shape of inlet on the classification performance were also studied. The classification accuracy increased by applying the electro-potential and the cut size decreased with an increase in the electro-potential. The classification performance with a three-layer inlet was higher than that with a two-layer inlet.The experimental data agreed well with the numerical calculation. It is further shown that the 50% cut size was about 1 μm for a relatively short time, and the newly developed water elutriator is, therefore, effective for the classification of fine particles in slurries. 相似文献
88.
H Uematsu N Sadato Y Yonekura T Tsuchida S Nakamura K Sugimoto A Waki K Yamamoto N Hayashi Y Ishii 《Canadian Metallurgical Quarterly》1998,39(12):2121-2127
For better localization of head and neck structures by PET with 2-(18)F-2-deoxy-D-glucose (FDG), direct incorporation of anatomical information from MRI by the coregistration of FDG PET and MRI without external markers is proposed. METHODS: Seventeen patients with neoplasms and 16 normal subjects who had both FDG PET and MRI were studied. First, the three-dimensional normal distribution of FDG was evaluated, and then the structures of the head and neck regions with normal distribution patterns of FDG were used as internal markers for the coregistration of PET and MRI. The effectiveness of the coregistration was evaluated using focal neoplasms that were identified by both PET and MRI as fiducial internal markers. RESULTS: The normal structures selected as internal landmarks for coregistration were the tonsils, salivary glands, mucosal layers of the oral cavity and pharynx, spinal cord, inferior portion of the frontal lobe, cerebellum and nasal turbinates. These structures were more easily observed in sagittal or coronal sections than in transaxial sections. All primary neoplasms were delineated by PET, whereas 4 were missed by MRI. Thirteen primary tumors and 7 cervical lymph node metastases coregistered well, with a center-of-mass distance of <2 mm, whereas 10 lymph node metastases were slightly misregistered, with a center-of-mass distance of 7.8+/-6.5 mm (mean+/-s.d.), probably due to differences in neck positions. CONCLUSION: Normal distribution of FDG uptake in the head and neck regions delineated by multidirectional sections is important for effective coregistration of FDG PET with MRI. 相似文献
89.
I Yokoyama T Ohtake S Momomura K Yonekura J Nishikawa Y Sasaki M Omata 《Canadian Metallurgical Quarterly》1998,31(7):1568-1574
OBJECTIVES: This study sought to investigate the specific role of hypertriglyceridemia in the myocardial hyperemic stress with dipyridamole/rest flow ratio (MDR). BACKGROUND: Reduced MDR has been reported in hypercholesterolemic patients without evidence of ischemia. However, the specific role of hypertriglyceridemia in MDR has not been studied. METHODS: Fifteen nondiabetic normocholesterolemic hypertriglyceridemic patients and 13 age-matched control subjects were studied. Myocardial blood flow (MBF) during dipyridamole administration and baseline MBF in hypertriglyceridemic patients and control subjects were measured using positron emission tomography and nitrogen-13 ammonia, after which the MDR was calculated. RESULTS: Baseline MBF (ml/min per 100 g heart weight) in hypertriglyceridemic patients (mean +/- SD 73.6 +/- 24.1) did not differ significantly from that in control subjects (81.6 +/- 37.2). MBF during dipyridamole loading in hypertriglyceridemic patients (198 +/- 106) was significantly reduced compared with that in control subjects (313 +/- 176, p < 0.05), as was the MDR (2.71 +/- 1.07 vs. 3.73 +/- 1.14, respectively, p < 0.05). Spearman rank-order correlation analysis showed a significant relation between plasma triglyceride concentration and MDR (r = -0.466, asymptotic SE 0.157, p = 0.0125); however, no such significant relation was seen between total plasma cholesterol concentration and MDR (r = -0.369, asymptotic SE 0.130, p = 0.059). CONCLUSIONS: Impaired myocardial vasodilation was suggested in hypertriglyceridemic patients without symptoms and signs of ischemia. 相似文献
90.
Kazumasa Yonekura Kazunori Yoshikawa Shigenori Sakamori Takayoshi Kosaka Kenji Tateiwa 《Thin solid films》2007,515(12):5012-5018
Suppression of 193-nm photoresist deformation by H2 addition to fluorocarbon plasmas in via-hole etching is investigated for sub-65-nm-node dual-damascene patterning. Photoresist deformation causes profile distortion and results in degradation of reliability, such as the line-to-line time dependent dielectric breakdown. To prevent profile distortion, H2 addition to fluorocarbon plasma is investigated in terms of fluorocarbon polymer and photoresist modification. XPS, FT-IR, and highlight etching investigations reveal that the H2 plasma treatment extracts oxygen from the photoresist and modifies it. This modification suppresses the photoresist deformation and H2 addition to fluorocarbon plasmas can have the same effects as the H2 plasma treatment. Finally, a highly reliable damascene interconnection is successfully achieved. 相似文献