102,697 research outputs found
Influence of the headgroup molecular structure on the anionic surfactant-PVP interaction studied by Electron Paramagnetic Resonance of a cationic nitroxide
No full textIn the present work the mixtures water–sodium decylsulfate (C10OS)-poly(vinylpyrrolidone) (PVP) and water–sodium decylsulfonate (C10S)–PVP have been investigated by electron paramagnetic resonance (EPR) spectroscopy employing 4-(N,N-dimethyl-N-(2-hydroxyethyl)) ammonium-2,2,6,6-tetramethyl-piperidine-1-oxyl chloride (TEMPO-choline, TC) as spin probe. TC cations condense on the surface of the aggregates formed by anionic surfactants, acting as counterions, and fit their NO moiety in the outer shell of the hydrophobic core. In water–C10OS–PVP mixtures the nitrogen isotropic hyperfine coupling constant of TC (〈AN〉), reported as a function of the surfactant molality at constant PVP composition, shows two breakpoints: the former (critical aggregation concentration, c.a.c.) corresponds to the formation of surfactant–polymer clusters while the latter (c2) corresponds to the formation of free surfactant micelles. The trend of the correlation time (τC) of the nitroxides in the same system shows that the electrostatic repulsion among the clusters formed onto the PVP macromolecules favours a broadening of the polymer coil and a stiffening of its chain. In contrast, in water–C10S–PVP mixtures no surfactant–polymer interaction could be detected. The effect of the molecular structure of the surfactant headgroup on the surfactant–polymer interaction has been discussed in terms of charge density distribution. In order to further highlight the importance of the headgroup molecular structure on the surfactant association behaviour, the micellisation process of the sodium alkylsulfates (CnOS, n = 6,8,10) has been investigated by the same experimental approach, and the results have been compared with those, previously reported (A. M. Tedeschi, G. D'Errico, E. Busi, R. Basosi and V. Barone, Phys. Chem. Chem. Phys., 2002, 4, 2180, ref. 46), relative to the sodium alkylsulfonates (CnS). CnOS micelles are more ordered and compact with respect to the CnS ones. For the former class of surfactants the electrostatic interaction with TC is stronger and the hydrophobic behaviour of the TC solubilization site is higher
Analisis Pengaruh Jenis Busi dan Celah Pada Performa Sepeda Motor Satria F 150
No full textSpark plugs are one of the most critical components during the combustion process in gasoline engines. A mismatch between the spark plug gap and the fuel can cause a backfire and knock. This study aims to analyze the effect of standard and iridium spark plug gaps on the performance of the Satria F 150 motorcycle engine. The parameters studied in this study include spark plug type (standard and iridium) and spark plug gap distance (0.55 mm, 0.70 mm and 0.85 mm). This research uses an experimental method, where the test uses a dyno test. Based on the research results, the best type of spark plug is an iridium spark plug with a spark plug gap of 0.55 mm. The best torque obtained is 11.8 Nm, engine power is 7.758 kW, and specific fuel consumption is 0.072 kg/kWh.Busi merupakan salah satu komponen yang paling penting selama proses pembakaran pada mesin bensin. Ketidaksesuaian antara jarak celah busi dengan bahan bakar dapat menyebabkan backfire dan knock. Penelitian ini bertujuan untuk menganalisa pengaruh celah busi standar dan iridium terhadap perfoma mesin sepeda motor Satria F 150. Parameter yang diteliti pada penelitian ini meliputi jenis busi (standar dan iridium) dan jarak celah busi (0,55 mm, 0,70 mm dan 0,85 mm). Penelitian ini menggunakan metode eksperimen, dimana pengujiannya menggunakan dyno test. Berdasarkan hasil penelitian dilakukan jenis busi terbaik yaitu busi iridium dengan celah busi sebesar 0,55 mm. Dimana torsi terbaik yang didapatkan sebesar 11,8 Nm, daya mesin sebesar 7,758 kW, dan konsumsi bahan bakar spesifik sebesar 0,072 kg/kWh.
La Convenzione di Bruxelles sul reciproco riconoscimento delle società e delle persone giuridiche nella CEE del 1968
No full textThe seismic history of Italy in the Hebrew sources
No full textOver more than two thousands years the Italian Jews have produced an impressive quantity of documentary
materials. To spot the data of the seismical events. therefore, has not been easy, and the results can still be supplemented,
though the research has been carried out on a quite large and rich material both manuscript and
printed in the Hebrew language. The crop was large and interesting, since documents about eleven different
earthquakes in Italy have been found. They are texts of various kinds. sornetilnes just short notes, but very often
long liturgical poems or whole writings. through which the Jewish minority traces its own historical memory
and its own understanding of these exceptional tragic events. From the Middle Ages till the first half of the
XIX century. Italian literature in the Hebrew language records the earthquakes of Ancona (1279), Norcia
(1328). Ravenna (1468). Ferrara 11570). Lugo (1688), Ancona (1690), Mantua (1693), Leghorn (1742), Lugo
(1781). Siena (1798) and Alessandria (1829). Naturally. in the towns that had a major Jewish community the
data are richer and give more detailed inforn~ation:th is is the case, for instance, of the earthquake of Ferrara,
in the second half of the fifteenth century. Here Azaryah de' Rossi gives us not only a vivid account of the reactions
of his fellow Jews, but also the fullest and most organic essay on the causes and the meaning of the
earthquakes. We also possess a remarkable abundance of Hebrew sources on the earthquake that struck
Leghon~ in January 1742: among other very interesting documents. there is also a true daily diary, in which
the strength and the nature of the shakes are recorded, during the quite long period the earthquake lasted, that
is till the end of March of the same year.JCR Journalope
A Process Algebraic View of Coordination
No full textAbstractCoordination languages have been introduced since the early 80s as programming notations to manage the interaction among concurrent collaborating software entities. Process algebras have been successfully exploited for the formal definition of the semantics of these languages and as a framework for the comparison of different coordination models
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