The influence of additives on the thermal degradation and oxidation of polyethylene

Imperial Users onl

An examination of ongoing trends in airline ancillary revenues

The airline industry seems permanently embedded in producing thin margins and continuously combatting downward pressure on yields. To perpetuate the problem, the industry remains eclipsed with high cost structures and low barriers to entry. However, a new sizzling concept continues to counterbalance these effects in the form of ancillary revenues. Globally, these revenues have increased by 121% from 2010 to 2014 – and the trend is set to continue as carriers are quickly implementing structural changes to accommodate these revenues streams. This paper examines the performance of the two core classifications of ancillary revenues, which are unbundled products and commission based income. It also investigates the willingness of passengers to pay for these services together with what type of ancillary items are acceptable at a particular price point. The study found that passengers value a narrow range of perceived ‘necessity’ products and services such as food and drink, checked baggage and seat assignment as opposed to perceived ‘optional’ unbundled or commission based products/services. It also found significant differences in WTP for specific ancillary services based on carrier type (FSC/LCC/Charter), length of flight (long and short haul) and journey purpose (business, leisure, VFR)

Responding to a world of change

The BGS is proud of the central role our surveying has played in the development of geology as a science. We are equally proud of our contribution to the understanding of key issues such as the age and evolution of the Earth and life, the origin and classification of rocks, and the impact of humans on the earth system. With 175 years of dedicated surveying behind us, the UK is already better served with geological information than most other countries. However, in today’s rapidly evolving, knowledge-based economy, we must continually adapt our surveying to meet the changing needs of society

An Initial Evaluation of a Proposed Statewide Education Sales Tax

This report provides a preliminary analysis of a proposal to replace education property taxes with a statewide sales tax

Towards a Theory of Flavor from Orbifold GUTs

We show that the recently constructed 5-dimensional supersymmetric $S^1/(Z_2\times Z_2')$ orbifold GUT models allow an appealing explanation of the observed hierarchical structure of the quark and lepton masses and mixing angles. Flavor hierarchies arise from the geometrical suppression of some couplings when fields propagate in different numbers of dimensions, or on different fixed branes. Restrictions arising from locality in the extra dimension allow interesting texture zeroes to be easily generated. In addition the detailed nature of the SU(5)-breaking orbifold projections lead to simple theories where $b-\tau$ unification is maintained but similar disfavored SU(5) relations for the lighter generations are naturally avoided. We find that simple 5d models based on $S^1/(Z_2\times Z_2')$ are strikingly successful in explaining many features of the masses and mixing angles of the 2nd and 3rd generation. Successful three generation models of flavor including neutrinos are constructed by generalizing the $S^1/(Z_2\times Z'_2)$ model to six dimensions. Large angle neutrino mixing is elegantly accommodated. Novel features of these models include a simple $m_u=0$ configuration leading to a solution of the strong CP problem.Comment: 18 pages, 6 figure

Full-wave simulations of electromagnetic cloaking structures

Based on a coordinate transformation approach, Pendry {\it et al.} have reported electromagnetically anisotropic and inhomogeneous shells that, in theory, completely shield an interior structure of arbitrary size from electromagnetic fields without perturbing the external fields. We report full-wave simulations of the cylindrical version of this cloaking structure using ideal and nonideal (but physically realizable) electromagnetic parameters in an effort to understand the challenges of realizing such a structure in practice. The simulations indicate that the performance of the electromagnetic cloaking structure is not especially sensitive to modest permittivity and permeability variations. This is in contrast to other applications of engineered electromagnetic materials, such as subwavelength focusing using negative refractive index materials. The cloaking performance degrades smoothly with increasing loss, and effective low-reflection shielding can be achieved with a cylindrical shell composed of an eight (homogeneous) layer approximation of the ideal continuous medium

The Families\u27 Civil War: Black Soldiers and the Fight for Racial Justice

In this well researched, cogently written, and original longitudinal social history of a sampling of freeborn African American families in Philadelphia from 1850 until the 1920s Holy A. Pinheiro Jr. examines the wartime experiences of Black soldiers in the Union Army and their families\u27 struggles on the homefront, and extends his analysis into the Reconstruction era

The River Was Dyed With Blood

The Culpability of Nathan Bedford Forrest at Fort Pillow In A Battle from the Start: The Life of Nathan Bedford Forrest (1992), a work that many consider the best biography of the slave trader turned “wizard of the saddle turned Klansman, Brian Steel Wills summarized his interpret...