ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

Treffer pro Seite

Treffer 1 - 4 | 4 Treffer

Sortierung

Digitale Medien

Fragment rotational distributions from the dissociation of NeBr2: Experimental and classical trajectory studies (1997)

Nejad-Sattari, Mehdi ; Stephenson, Thomas A.

College Park, Md. : American Institute of Physics (AIP)

The Journal of Chemical Physics 106 (1997), S. 5454-5467

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1089-7690

Quelle: AIP Digital Archive

Thema: Physik , Chemie und Pharmazie

Notizen: The Br2 fragment rotational distributions that result from the vibrational predissociation of NeBr2 in the B electronic state have been measured for several initial vibrational levels. In each case, the rotational distributions extend to the effective energetic limit determined by the amount of energy available (Eavl) for disposal into the fragment rotational and translational degrees of freedom. Analysis of the data allows refinement of the NeBr2 dissociation energy; we find that D0=70.0±1.1 cm−1 for the X electronic state, v=0. Both Δv=−1 and −2 dissociation events have been examined. For dissociation pathways with approximately the same value of Eavl the Δv=−2 pathways are observed to have a higher fraction of the fragment energy in rotational excitation. The overall shape of the Δv=−1 distributions are insensitive to the value of Eavl, suggesting that a Franck–Condon model for the dissociation may have some validity, though quantitative quantum mechanical calculations demonstrate that this model does not reproduce the large degree of fragment rotational excitation. Two classical models for the dissociation also fail to reproduce the extent of fragment rotational distribution. This result is discussed in light of previous experimental and theoretical investigations, focusing on the apparent agreement of classical models with the IBr fragment rotational distributions that result from the dissociation of NeIBr. © 1997 American Institute of Physics.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1063/1.473570

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

Digitale Medien

Morphology of porous media studied by nuclear magnetic resonance (1997)

Allen, S. G. ; Stephenson, P. C. L. ; Strange, J. H.

College Park, Md. : American Institute of Physics (AIP)

The Journal of Chemical Physics 106 (1997), S. 7802-7809

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1089-7690

Quelle: AIP Digital Archive

Thema: Physik , Chemie und Pharmazie

Notizen: The filling processes of water and cyclohexane in porous silica (40 Å, 60 Å and 112 Å pore size samples) were studied using T2 nuclear magnetic resonance (n.m.r.) experiments. The silica pores contained water or cyclohexane and the experiments were performed at room temperature and at filling fractions ranging from 0.02 to 1.0 (that is, completely full). Two distinct processes were observed which depended on the hydrophilicity of the silica surface (or the surface adhesion of the liquid). Water was found to collect in small puddles in the silica interstices, and to form a surface layer over the silica before the remaining pore volume was filled. Water in a surface-treated porous silica and cyclohexane in regular porous silica appeared to completely fill the smaller before the larger pores, and not form a separate surface-coating layer. This work also presents the techniques used to calculate quantitative information about the filling process; specifically, determination of the volume to surface-area ratio of the liquid puddles as well as the number of these puddles, is demonstrated. © 1997 American Institute of Physics.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1063/1.473780

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

Digitale Medien

SURGE process - a time-to-market approach to reliability improvement (1997)

Donovan, John ; Murphy, Eamonn ; Stephenson, M.I.

Bingley : Emerald

International journal of quality & reliability management 14 (1997), S. 834-848

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 0265-671X

Quelle: Emerald Fulltext Archive Database 1994-2005

Thema: Wirtschaftswissenschaften

Notizen: States that the time taken to deliver a product to the market determines a company's success, and that research has shown that a delay of six months leads to 33 per cent of its potential profit being lost. Explores the existing method of assessing new product reliability, namely reliability demonstrating testing, and presents its numerous shortcomings and deficiencies. Analyses the results of performing reliability demonstration testing on eight products which support the viewpoint that it is no longer appropriate. Proposes a SURGE (stress unveiled reliability growth enhancement) process, leading to significant saving in development time and thereby time-to-market while providing a more reliable product and process. Places emphasis on the control of all of the development processes, design, manufacturing, and materials procurement and producing prototype units via the intended volume process. Performs monitoring by appropriate stress testing designed to precipitate all potential defects and involves testing beyond design specification. By correcting defects on the product, and ultimately on the processes which produced them, develops more reliable products. Concludes that the results of the SURGE process have led to a reduction in development times of 14 per cent while also reducing the time taken to ramp up to full volume production by 50 per cent.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1108/02656719710181376

Permalink