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251.
Alessandro Porrino Franco Sacerdotti Michel Vermeulen Clive Butler 《International Journal of Machine Tools and Manufacture》2003,43(11):1151-1156
The texturing of steel surfaces is well known to affect their functional performance. Different processes (e.g. forming, painting) are affected by different wavelengths of surface structures which, in order to study the phenomena, are usually separated through filtering processes. New texturing processes call for new filtering techniques, and amongst the latest ones, the Gram-Schmidt (GS) decomposition technique proved to be suitable for deterministic patterns such as Electron-Beam Textured (EBT) surfaces.Optimisation lead to new textures, with more dense patterns, so extending the GS methodology seemed natural and meaningful. This paper describes how the technique was algorithmically adapted and how it will benefit process control. 相似文献
252.
Vermeulen D.J. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1998,86(12):2445-2454
The article contains biographical information about this South African physicist who while continuing his studies in Germany investigated photoelectric emission using an apparatus with a photocathode, an anode, and a grid similar to de Forest's Audion. He established the behavior of this three-element system and subsequently extended the analysis to apply to the thermionic triode at the Western Electric Laboratories in New York. He used this knowledge to design many of the first tubes used in radio and telephony; he invented the grid modulation system for radiotelephony and wrote the first textbook on the vacuum tube in 1920. Soon afterwards he returned to South Africa as Scientific Advisor to the Government and created a countrywide electricity supply network, a world class steel corporation, and numerous other important industrial enterprises 相似文献
253.
254.
Some problems in a new chip design or its embedded software show up only when a silicon prototype of the chip is placed in its intended target environment and the embedded software is executed. Traditionally, embedded-system debug is very difficult and time-consuming because of the intrinsic lack of internal system observability in the target environment. Design for debug (DFD) is the act of adding debug support to a chip's design in the realization that not every silicon chip or embedded-software application is right the first time. In the past few years, functional debug has made significant progress. This article describes the most common structured approaches available for silicon debug of embedded systems. 相似文献
255.
S van den Borne AF Snik CC Hoekstra AM Vermeulen P van den Broek JP Brokx 《Canadian Metallurgical Quarterly》1998,23(5):455-461
Recent in vitro findings suggest that bisphosphonates, potent inhibitors of osteoclastic bone resorption, may also have a direct action on osteoblasts. The purpose of this study was to search for potential effects of etidronate and alendronate on the formation of early and late osteoblastic cell precursors by measuring the number of colony-forming units for fibroblasts (CFU-F) and colony-forming units for osteoblasts (CFU-OB) in murine and human bone marrow cultures. In murine marrow cultures, etidronate (10(-5) to 10(-9) mol/L) significantly stimulated the formation of CFU-F with a maximal effect at 10(-5) mol/L (mean increase over control values+/-SD: 106+/-17%;p < 0.001), whereas alendronate had a biphasic effect, being stimulatory at concentrations below 10(-7) mol/L (78+/-5%; p < 0.001), and inhibitory at higher doses. The formation of CFU-OB was also inhibited by both bisphosphonates at the highest concentrations (10(-5) mol/L and 10(-6) mol/L), but it was significantly stimulated at lower concentrations (from 10(-7) to 10(-9) mol/L for etidronate and 10(-7) to 10(-10) mol/I, for alendronate; p < 0.001). In human bone marrow cultures, alendronate (10(-8) to 10-(12) mol/L) increased CFU-F formation with a maximal effect at 10(-10) mol/L (161+/-12 %; p < 0.01). CFU-OB formation, observed only in the presence of dexamethasone (10(-8) mol/L), was markedly stimulated by alendronate at the above concentrations with a maximal increase at 10(-10) mol/L (133+/-34%; p < 0.001). The in vivo short-term effects of bisphosphonates on the formation of early osteoblast precursors were also studied in bone marrow cultures from young female mice treated with weekly subcutaneous injections of etidronate (0.3, 3, and 30 mg/kg) or alendronate (0.3, 3, and 30 microg/kg) and from aging female mice treated with the two lowest doses of both drugs. After 1 month of treatment, etidronate (0.3 and 3 mg/kg) and alendronate (0.3 and 3 microg/kg) significantly increased the number of CFU-F colonies in the bone marrow from young and old animals, whereas the highest dose of both drugs had no effect in young mice. Our results, together with previously reported observations of bone-forming effects in osteoporosis, suggest that bisphosphonates may have, in vivo, a potentially relevant influence on cells of the osteoblastic lineage, distinct from their inhibitory action on osteoclasts. 相似文献
256.
257.
To debug a digital chip with a scan-based debug methodology, the chip is stopped at a certain point in time in the application. The states of the flip-flops and the memory elements are observed and compared with the simulation results. If the chip contains multiple clock domains then these clock domains must be stopped simultaneously, otherwise some of the elements in one or more of the clock domains will capture old data/invalid data. The phenomenon of capturing invalid data is known as data invalidation. This paper describes the data invalidation problem in depth and presents a data invalidation detector circuit. An automated data invalidation analysis tool named DIAna is also presented. By means of experimental results for an industrial SOC, we show the amount of data invalidation that can occur during silicon debug. 相似文献
258.
Plante Thomas G.; Gores Carissa; Brecht Carrie; Carrow Jessica; Imbs Anne; Willemsen Eleanor 《Canadian Metallurgical Quarterly》2007,14(1):88
Two experiments examined the psychological benefits of exercise environment. In Experiment 1, 128 female college students were assigned to 1 of 3 laboratory conditions that differed only in with whom they were exercising; in Experiment 2, 88 students were assigned to 1 of 4 walking conditions that differed in the environment (i.e., indoors vs. outdoors) and whom they were with. Before and after exercise, participants completed several mood and enjoyment measures. Participants in Experiment 1 were most calm when exercising alone than with others, and participants in Experiment 2 found the experience most enjoyable if outdoors. Our findings suggest that perceived enjoyment and outdoor exercise may account for some of the psychological benefits of exercise for women. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
259.
AIM: It is assumed that disturbances of cellular ion homeostasis, especially an increase in the cytosolic Ca2+ concentration, are of decisive importance for hypoxic cell injury. The aim of this study is the determination of alterations in the cytosolic Ca2+, Mg2+, H+, Na+ and K+ concentration in cultured hepatocytes during hypoxia. METHODS: The alterations of ion homeostasis under hypoxic conditions were studied in primary cultures of isolated rat hepatocytes by using fluorescence microscopy. RESULTS: The measurements of cytosolic Ca2+ concentration showed no alterations during the first 3-4 h of hypoxia. About 1-2 h before cell injury became evident Ca2+ increased from 147 +/- 28 to 385 +/- 31 nM. Similarly the cytosolic Mg2+ concentration increased from 0.63 +/- 0.05 to 1.42 +/- 0.11 mM in a late stage of hypoxia. In contrast, the cytosolic Na+ concentration increased continuously from 16 +/- 2 mM at start to 76 +/- 9 mM after 5 h of hypoxic conditions. The cytosolic K+ concentration remained constant for 2 h (129 +/- 7 mM) but then decreased down to 31 +/- 18 mM. The intracellular H+ concentration increased slightly under hypoxic conditions, the pH decreased from 7.35 +/- 0.02 to 7.19 +/- 0.04. CONCLUSION: The results indicate that cytosolic Ca2+ plays only a minor role in the pathomechanism of hypoxic hepatocellular injury but suggest an important role of the cytosolic Na+ concentration in this process. 相似文献
260.
G. Vermeulen 《Journal of Low Temperature Physics》1994,94(1-2):5-13
The method, pioneered by Nocher et al1 to produce polarised3He by fractional distillation in a saturated3He-4He mixture at s.v.p has been improved by using higher pressures. In principle, this method gives access to a non equilibrium steady-state polarisation in the concentrated as well as the dilute phase. The maximum polarisation achieved in the dilute phase at a pressure of 10 bar, a temperature of 100–150 mK and an external field of 6.6 T is nearly 20 %. 相似文献