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J. HADGRAFT 《International journal of cosmetic science》1985,7(3):103-115
The skin comes into contact with a large range of materials either deliberately or inadvertently. It should be possible to predict the exact transport rates of these materials through the skin as a function of the physicochemical properties of the different compounds. With this sort of knowledge it is possible to predict the exact disposition of compounds and use this in the formulation of new products both in the pharmaceutical and cosmetic field. The information will also be useful from the standpoint of skin toxicology and environmental health. In order to be able to predict this complex process it is necessary to split the overall transport into different component parts. This article will identify these components and provide illustrations. The major areas discussed will be barrier function of the skin, the release properties of different topical formulations and how these may be monitored. Novel means of enhancing the penetration of drugs will be discussed and how some additives that are incorporated into formulations will perhaps alter the barrier function of skin. A mathematical model describing skin penetration has been developed and its use in predicting blood levels will be described. This model has been tested both in animal experiments and in limited human studies and its relevance to these situations will be highlighted.
Absorption cutanée et transcutanée in vivo 相似文献
Absorption cutanée et transcutanée in vivo 相似文献
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本文以耦合模理论和Floquet理论为基础,把本征模展开与空间谐波展开巧妙地结合起来,严格分析了斜入射情况下介质周期结构的色散特性-三维边值问题。这种新方法既避免了通常耦合模方法分析此类问题所引入的微扰近似,又比Floquet方法简单方便。通过对斜入射情况下一些介质结构滤波特性的数值分析,证实了本文方法的有效性,精确性和实用性。 相似文献
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QP19-L型PDC钻头在TK320井的应用 总被引:1,自引:0,他引:1
针对塔河地区的地层特点和PDC钻头的破岩机理,优选了适合于该地层钻进的QP19-L型PDC钻头,总结了PDC钻头的使用技术措施。在TK320井二开井段的应用表明,该钻头能明显提高机械钻速,缩短钻井周期,值得推广应用。 相似文献
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Jonathan D. Bray Rodolfo B. Sancio Turan Durgunoglu Akin Onalp T. Leslie Youd Jonathan P. Stewart Raymond B. Seed Onder K. Cetin Ertan Bol M. B. Baturay C. Christensen T. Karadayilar 《Canadian Metallurgical Quarterly》2004,130(7):673-685
Ground failure in Adapazari, Turkey during the 1999 Kocaeli earthquake was severe. Hundreds of structures settled, slid, tilted, and collapsed due in part to liquefaction and ground softening. Ground failure was more severe adjacent to and under buildings. The soils that led to severe building damage were generally low plasticity silts. In this paper, the results of a comprehensive investigation of the soils of Adapazari, which included cone penetration test (CPT) profiles followed by borings with standard penetration tests (SPTs) and soil index tests, are presented. The effects of subsurface conditions on the occurrence of ground failure and its resulting effect on building performance are explored through representative case histories. CPT- and SPT-based liquefaction triggering procedures adequately identified soils that liquefied if the clay-size criterion of the Chinese criteria was disregarded. The CPT was able to identify thin seams of loose liquefiable silt, and the SPT (with retrieved samples) allowed for reliable evaluation of the liquefaction susceptibility of fine-grained soils. A well-documented database of in situ and index testing is now available for incorporating in future CPT- and SPT-based liquefaction triggering correlations. 相似文献
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Pipe piles can be classified as either closed- or open-ended piles. In the present paper, the load capacity of both closed- and open-ended piles is related to cone penetration resistance qc through an experimental program using calibration chamber model pile load tests and field pile load tests. A total of 36 calibration chamber pile load tests and two full-scale field pile load tests were analyzed. All the test piles were instrumented for separate measurement of each component of pile load capacity. Based on the test results, the normalized base resistance qb/qc was obtained as a function of the relative density DR for closed-ended piles, and of both the relative density DR and the incremental filling ratio (IFR) for open-ended piles. A relationship between the IFR and the relative density DR is proposed as a function of the pile diameter and driving depth. The relationship between IFR and DR allows the estimation of IFR and thus of the pile load capacity of open-ended piles at the design stage, before pile driving operations. 相似文献