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排序方式: 共有220条查询结果,搜索用时 0 毫秒
81.
We are presenting a new approach of identifying sources of variability within a manufacturing process by NIR measurements of samples of intermediate material after each consecutive unit operation (interprocess NIR sampling technique). In addition, we summarize the development of a multivariate statistical process control (MSPC) model for the production of enteric-coated pellet product of the proton-pump inhibitor class. By developing provisional NIR calibration models, the identification of critical process points yields comparable results to the established MSPC modeling procedure. Both approaches are shown to lead to the same conclusion, identifying parameters of extrusion/spheronization and characteristics of lactose that have the greatest influence on the end-product’s enteric coating performance. The proposed approach enables quicker and easier identification of variability sources during manufacturing process, especially in cases when historical process data is not straightforwardly available. In the presented case the changes of lactose characteristics are influencing the performance of the extrusion/spheronization process step. The pellet cores produced by using one (considered as less suitable) lactose source were on average larger and more fragile, leading to consequent breakage of the cores during subsequent fluid bed operations. These results were confirmed by additional experimental analyses illuminating the underlying mechanism of fracture of oblong pellets during the pellet coating process leading to compromised film coating. 相似文献
82.
空调系统控制的一种动态优化技术 总被引:1,自引:0,他引:1
为建筑空调系统控制提出一项动态的优化技术。在一个指定期间内,运用该算法,能得到使目标函数(例如运行成本或者峰值能耗)最小的房间温度曲线。该算法也能给出HVAC设备的最佳开、关时间。本文包括建筑热特性的模拟,优化技术和实例研究。 相似文献
83.
J Simó Mi?ana 《Canadian Metallurgical Quarterly》1996,18(7):404-405
OBJECTIVE: To study sister chromatid exchange (SCE) frequency in lymphocytes of pregnant women with intrauterine growth retardation (IUGR) infants. METHODS: The frequency of SCE in peripheral blood lymphocytes of 14 pregnant women with IUGR babies and 90 normal pregnant women as well as the umbilical blood of their infants were investigated. RESULTS: The mean frequency of SCE in maternal and umbilical blood with normal pregnancy were 7.58 +/- 0.32 and 5.05 +/- 0.29 respectively, while they were 10.53 +/- 2.69 and 7.25 +/- 1.34 in IUGR group respectively. The difference of SCE levels between the 2 groups of mother was statistically significant (P < 0.01), so was that of the umbilical blood group. CONCLUSION: One of the causes of IUGR may be related to heredity injury. Thus, SCE will be a new diagnostic index to predict IUGR. 相似文献
84.
Enrique Benavent Angel Corbern Estefanía Piana Isaac Plana Jos M. Sanchis 《Computers & Operations Research》2005,32(12):50-3128
In this paper we deal with the windy rural postman problem. This problem generalizes several important arc routing problems and has interesting real-life applications. Here, we present several heuristics whose study has lead to the design of a scatter search algorithm for the windy rural postman problem. Extensive computational experiments over different sets of instances, with sizes up to 988 nodes and 3952 edges, are also presented. 相似文献
85.
86.
El-Deen M García-Fiñana M Jin ZM 《Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine》2006,220(7):733-742
One of the important design parameters in current knee joint replacements is the thickness of the ultra-high molecular weight polyethylene (UHMWPE) tibial insert, yet there is no clear definition of the upper limit of the 'thick' polyethylene insert. Using one design knee implant and subjecting it to the physiological loads encountered throughout the gait cycle, measurements of the lengths of contact imprints generated were compared with the corresponding theoretical predictions for different insert thicknesses under the same applied load. Multiple regression analysis was applied to test whether the dimensions of contact imprints are influenced by UHMWPE thickness. Good agreement was obtained between the theoretical predictions and the experimental measurements of the dimensions of contact imprints when the knee was at 60 degrees flexion. Therefore, it was possible to estimate the contact pressure at the articulating surface using the theoretical model. Contact imprint dimensions increased with increasing applied load. Statistical analysis of the experimental data revealed that, at 0 degree flexion, the overall imprint dimensions increased as the UHMWPE thickness increased from 8 to 20 mm. However, the increment was not significant when the thickness subinterval 10-15 mm was considered. Furthermore, at 60 degrees flexion, thickness was not a significant factor for the overall imprint dimensions. No evidence was found from the data to suggest that an increment in polyethylene thickness over 10 mm would significantly reduce the contact imprint dimensions. These findings suggest that thicker inserts can be avoided, as they require unnecessary bone resection. 相似文献
87.
Antoni Montañana Carmen Llinares Elena Navarro 《Journal of Housing and the Built Environment》2013,28(2):273-291
This study is an analysis of the perceptions of experts and non-experts in the building industry concerning a series of real estate promotions in the city of Valencia (Spain). Differential semantics were used to obtain a set of 7 dimensions or affective responses which users employ to assess real estate offerings. Two global evaluations were obtained, differentiating between purchase for residential or investment purposes. The fieldwork was done on a sample of 160 individuals (80 architects and 80 non-architects) who were asked to give their opinion on physical stimuli which included information from real estate promotion advertising brochures. Linear regression was used to estimate 4 predictive models to estimate overall customer assessment of a given offering based on an evaluation of different dimensions or affective responses. The results show different responses in both groups and for the two global assessment variables. Differential semantics appears to be a good instrument for measuring the subjective component of consumers’ emotional states. It is an emotional design technique which provides information on the emotions an object generates by capturing the affective meaning the user attaches to it. 相似文献
88.
The biomimetic deposition of hydroxyapatite (HA) on the surface of SiO2 thin film coated metal substrates was developed and investigated. 相似文献
89.
Snežana Ilić‐Stojanović Ljubiša Nikolić Vesna Nikolić Ivan Ristić Jaroslava Budinski‐Simendić Agneš Kapor Goran M Nikolić 《Polymer International》2014,63(6):973-981
The goal of this work was to investigate a possible way of crosslinking polymer chains and the potential formation of intramolecular hydrogen bonds in thermosensitive poly(N‐isopropylacrylamide‐co‐2‐hydroxypropyl methacrylate) (p(NIPAM‐HPMet)) hydrogels obtained by radical polymerization. The chemical structure of the synthesized hydrogels was investigated by Fourier transform infrared (FTIR) spectroscopy and XRD. The FTIR spectrum confirmed the presence of hydrogen bonds formed between the chains in the copolymer. XRD analysis confirmed the amorphous ? crystalline structure of the copolymer. A three‐glass transition and two melting temperatures were detected by DSC. It was found that the addition of HPMet increased the glass transition and melting temperatures of the p(NIPAM‐HPMet) copolymer. The swelling transport mechanism of p(NIPAM‐HPMet) changed from non‐Fickian at 20 °C to case III or zero‐order time‐independent kinetics characterized by a linear mass uptake with time with increasing temperature at 40 °C. © 2013 Society of Chemical Industry 相似文献
90.
Branka Uzelac Dušica Janošević Dragana Stojičić Snežana Budimir 《Microscopy research and technique》2017,80(7):779-786
The anatomy and ultrastructure of the short glandular trichomes occurring on young expanding leaves of Nicotiana tabacum were investigated using light and transmission electron microscopy. The objective of the present research was to characterize the cellular changes that occur during morphogenesis of short glandular trichomes, from initiation to senescence. Ultrastructural analysis of their secretory cells revealed characteristics common to gland cells: numerous mitochondria in highly organized cytoplasm, large nuclei, and an elaborate network of endoplasmic reticulum. Initial changes in nuclear and plastidial organization were observed at a more advanced secretory stage, marking the onset of senescence. During trichome senescence, gradual reduction of the cytoplasm density occurred along with structural changes of the plastids and the tonoplast. As a result of inward blebbing of the cytoplasm into the vacuole, membrane bound vesicular structures appeared in the vacuolar space. At the late secretory stage, marked by an increase in vacuolation and extraplasmic space, degenerative changes included further fragmentation of the cytoplasm and deterioration of the tonoplast. Multimembrane myelin bodies observed in the vacuolar space were indicative of membrane digestion although plasma membrane did not appear massively degraded. 相似文献