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1.
2.
The polyesterification and isomerization reaction of 1,6-hexane diol and maleic anydride in a melt without catalyst was studied by 13C and 1H n.m.r. spectroscopy. The structure and concentration of oligoester species during the polyesterification and isomerization were determined depending on the reaction temperature and time. According to the number and configuration of repeating units determined from 1H n.m.r. spectra kinetics of both reactions were also considered. The degree of isomerization is continuously increasing in the investigated reaction range. 相似文献
3.
In this work the method of response surfaces was used for the purpose of drawing up a mathematical model for the calculation
(forecasting) of the adhesion of a flame sprayed coating of powdered aluminum on S 235 JR steel. Experimental work was conducted
according to a fractional central-composite design at three levels. The adhesion of the coatings made with combinations of
input parameters of the procedure according to the experiment plan mentioned is measured in line with the EN 582 standard.
A mathematical model was derived describing the dependence of the experimentally obtained adhesion values on the input parameters
of the procedure. The possibility of analyzing the influence of the parameters on the adhesion for a certain combination of
input parameters has been presented with the use of perturbation plots. 相似文献
4.
Alberto Gutierrez-Escolar Ana Castillo-Martinez Jose M. Gomez-Pulido Jose-Maria Gutierrez-Martinez Esteban Patricio Dominguez González-Seco Zlatko Stapic 《Energy Efficiency》2017,10(2):265-282
There are very few countries that have provisions addressing the energy efficiency of the whole street lighting system, such as Spain or the Netherlands. Nevertheless, there is not an agreement about how energy efficiency must be assessed. The Spanish Government contemplates it in the Royal Decree 1890/2008 with the goal of improving energy savings and efficiency. However, this has not obtained the expected results. Nowadays, energy efficiency of this kind of systems is assessed using a label. In the case of Spain, this label only assesses one magnitude. The contributions of this paper are two evaluation systems (kiviat diagram and pie chart) which assess five magnitudes: lamps, energy efficiency index, light pollution, renewable energy contribution, and harness of the luminous flux using dimming. After that, a survey was done to study several subjects: (1) if citizens are aware about the efficiency of street lighting systems, (2) whether the sample of colors used in the label is adequate, and (3) if our proposed systems could replace the current evaluation system. Finally, the paper finishes with the conclusions of the survey. 相似文献
5.
André C. Santos João M. P. Cardoso Pedro C. Diniz Diogo R. Ferreira Zlatko Petrov 《The Journal of supercomputing》2014,70(3):1218-1248
The traditional approach for specifying adaptive behavior in embedded applications requires developers to engage in error-prone programming tasks. This results in long design cycles and in the inherent inability to explore and evaluate a wide variety of alternative adaptation behaviors, critical for systems exposed to dynamic operational and situational environments. In this paper, we introduce a domain-specific language (DSL) for specifying and implementing run-time adaptable application behavior. We illustrate our approach using a real-life stereo navigation application as a case study, highlighting the impact and benefits of dynamically adapting algorithm parameters. The experiments reveal our approach effective, as such run-time adaptations are easily specified in a higher level by the DSL, and thus at a lower programming effort than when using a general-purpose language such as C. 相似文献
6.
This article presents a review of glyph-based techniques for engineering visualization as well as practical application for the multivariate visualization process. Two glyph techniques, Chernoff faces and star glyphs, uncommonly used in engineering practice, are described, applied to the selected data set, run through the chosen optimization methods and user evaluated. As an example of how these techniques function, a set of data for the optimization of a heat exchanger with a microchannel coil is adopted for visualization. The results acquired by the chosen visualization techniques are related to the results of optimization carried out by the response surface method and compared with the results of user evaluation. Based on the data set from engineering research and practice, the advantages and disadvantages of these techniques for engineering visualization are identified and discussed. 相似文献
7.
Klaudija Carovi-Stanko Sandi Orli Olivera Politeo Frane Striki Ivan Kolak Mladen Milos Zlatko Satovic 《Food chemistry》2010,119(1):196-201
GC/MS was used to identify compounds of essential oils from seven Ocimum taxa (O. americanum L., O. basilicum L., O. campechianum Mill., O. x citriodorum Vis., O. kilimandscharicum Baker ex Gürke and three botanical varieties and cultivars of Ocimum basilicum L.: ‘Genovese’, var. difforme and var. purpurascens). Preliminary screening of their antibacterial activity was done against a number of common pathogens (Enterococcus faecalis, Enterococus faecium, Escherichia coli 0157:H7, Listeria monocytogenes, Listeria ivanovii, Proteus vulgaris, Staphylococcus aureus, Staphylococcus epidermis) using the filter paper disc agar diffusion technique, while further analyses were done by modification of the disc diffusion method. A broad variation in the antibacterial properties of investigated essential oils was observed. E. coli 0157:H7 was inhibited by O. basilicum ‘Genovese’ essential oil, while Ocimum americanum and Ocimum x citriodorum essential oils were the most effective against Enterococcus faecalis, Enterococcus faecium, P. vulgaris, S. aureus and S. epidermis. 相似文献
8.
D. Zhuang Z. G. Herro R. Schlesser B. Raghothamachar M. Dudley Z. Sitar 《Journal of Electronic Materials》2006,35(7):1513-1517
Seeded growth of AlN single crystals was demonstrated in an induction-heated, high-temperature reactor via a physical vapor
transport (PVT) process. AlN seeds were prepared from a self-seeded boule containing large single-crystalline grains. Seeded
growth was interrupted several times in order to refill the AlN powder source, and a dedicated process scheme was used to
ensure epitaxial growth on the seed surface, after prior exposure to air. The growth temperatures were in the range of 2200–2300°C,
and the reactor pressure was in the range of 500–900 torr of UHP-grade nitrogen during each growth run. Under these growth
conditions, a seed (10 mm diameter) expanded at an angle of 45°, and a larger single crystal up to 18 mm in diameter was obtained.
The as-grown surface had three facets, of which facet (1120) was smooth and featureless while the other two, (4150) and (2570),
showed serrated morphologies. The double-crystal x-ray rocking curve and glow discharge mass spectroscopy analysis confirmed
that the grown crystal was of high crystalline quality with low impurity incorporation. 相似文献
9.
The mechanism(s) for uptake of organic cations by renal cortical tubules was (were) examined further. Renal cortical tubules were purified from rat kidneys by a Percoll gradient centrifugation technique. Bicarbonate buffer (Krebs-Henseleit, KHS) conditions were altered, and chemical modulators were used which affect the activity of the basolateral Na+/K+-ATPase. Renal tubule uptake of the achiral organic cation amantadine was determined. The cardiac glycosides digoxin and acetylstrophanthidin and ouabagenin did not alter amantadine uptake by either proximal or distal tubule fragments in KHS. However, ouabain inhibited proximal tubule amantadine uptake in a dose-dependent manner with lower potency than distal tubule amantadine uptake in KHS. Ouabain did not inhibit amantadine tubule uptake in phosphate buffer. However, inhibition of amantadine uptake by ouabain returned in a time-dependent manner upon addition of bicarbonate to the phosphate buffer. Low extracellular sodium or potassium did not alter amantadine uptake by proximal tubules. Hypokalemic and hypokalemic/ hyponatremic conditions decreased the inhibitory potency of ouabain for amantadine uptake by proximal tubules. For distal tubules, both hyponatremic and hypokalemic conditions, alone and together, decreased the inhibitory potency of ouabain, but did not affect amantadine uptake in the absence of ouabain. Hypochloremic conditions decreased affinity for amantadine uptake by distal, but not proximal tubules. No change in maximal transport capacity for amantadine uptake was observed under hypochloremic conditions for either tubule fragment. These studies challenge the widely accepted concept of Na+/ K+-adenosine triphosphatase activity and maintenance of the basolateral membrane potential as rate-limiting steps for the energy-dependent renal tubule uptake of organic cations. Furthermore, these studies suggest a mechanism for ouabain inhibition of organic cation renal tubule uptake that may not involve the Na+/K+-adenosine triphosphatase and may be possibly bicarbonate-dependent. 相似文献
10.