(2, 3)-Generated Groups with Small Element Orders

Chemical kinetics of catalytic reactions are often obscured by intraphase diffusion and interphase mass transfer effects. Such complexities are especially true of catalytic combustion reactions effected within multichannel monoliths whose channel walls are coated with a catalyst layer. Assessment of the extent of intraphase and interphase resistances to the catalytic conversion of low concentrations of carbon monoxide in air were achieved by conducting experiments in a tube wall reactor, the walls of which were coated with a platinum-alumina deposit. Results indicated that, for a 1.34% CO in air mixture, kinetics below 610 K were less than first order with an activation energy of 30.4 kJ mol -1 . Above 610 K there was strong evidence of both intraphase and interphase resistances to catalytic conversion, the overall kinetics displaying an apparent activation energy of 11.7 kJ mol -1 . Near to the reactor tube entrance where the temperature was about 650 K, the mass transfer resistance from fluid to tube wall was only one-sixth that of the diffusive resistance within the thin catalyst washcoat, increasing to one half of the diffusive resistance at the tube exit where the temperature was about 820 K. Computer estimations of the performance of the tube wall reactor, using measured kinetic data for a small element of reactor containing catalyst deposited on the wall and interphase heat and mass transfer data estimated from first principles assuming laminar flow, are in satisfactory agreement with the measured performance of the whole tube wall reactor.

Download Full-text

Design of a Compact Hexa-Band Coupling Antenna for 4g Mobile Handset Using a Small Element With Two Slots

Microwave and Optical Technology Letters ◽

10.1002/mop.27698 ◽

2013 ◽

Vol 55 (8) ◽

pp. 1708-1711 ◽

Cited By ~ 1

Author(s):

Sunho Choi ◽

Gye-Taek Jeong ◽

Woosu Kim

Keyword(s):

Small Element ◽

Mobile Handset

Download Full-text

The Emergence of Bone Technologies at the End of the Pleistocene in Southeast Asia: Regional and Evolutionary Implications

Cambridge Archaeological Journal ◽

10.1017/s0959774312000030 ◽

2012 ◽

Vol 22 (1) ◽

pp. 37-56 ◽

Cited By ~ 35

Author(s):

Ryan J. Rabett ◽

Philip J. Piper

Keyword(s):

Early Modern ◽

Large Scale ◽

Minor Component ◽

Modern Human ◽

Small Element ◽

Adaptive Process ◽

Long Time ◽

One Step ◽

A Minor

For many decades Palaeolithic research viewed the development of early modern human behaviour as largely one of progress down a path towards the ‘modernity’ of the present. The European Palaeolithic sequence — the most extensively studied — was for a long time the yard-stick against which records from other regions were judged. Recent work undertaken in Africa and increasingly Asia, however, now suggests that the European evidence may tell a story that is more parochial and less universal than previously thought. While tracking developments at the large scale (the grand narrative) remains important, there is growing appreciation that to achieve a comprehensive understanding of human behavioural evolution requires an archaeologically regional perspective to balance this.One of the apparent markers of human modernity that has been sought in the global Palaeolithic record, prompted by finds in the European sequence, is innovation in bonebased technologies. As one step in the process of re-evaluating and contextualizing such innovations, in this article we explore the role of prehistoric bone technologies within the Southeast Asian sequence, where they have at least comparable antiquity to Europe and other parts of Asia. We observe a shift in the technological usage of bone — from a minor component to a medium of choice — during the second half of the Last Termination and into the Holocene. We suggest that this is consistent with it becoming a focus of the kinds of inventive behaviour demanded of foraging communities as they adapted to the far-reaching environmental and demographic changes that were reshaping this region at that time. This record represents one small element of a much wider, much longerterm adaptive process, which we would argue is not confined to the earliest instances of a particular technology or behaviour, but which forms part of an on-going story of our behavioural evolution.

Download Full-text

Recognition by Spectrum of L16(2m)

Algebra Colloquium ◽

10.1142/s1005386707000533 ◽

2007 ◽

Vol 14 (04) ◽

pp. 585-591 ◽

Cited By ~ 4

Author(s):

Maria A. Grechkoseeva ◽

Wujie Shi ◽

Andrey V. Vasilev

Keyword(s):

Linear Groups ◽

Recognition By Spectrum ◽

Element Orders ◽

Characteristic 2

In this paper we prove that the simple linear groups L16(2m)(m ≥ 1) over fields of characteristic 2 are recognizable by the sets of their element orders.

Download Full-text