TREATED VERSUS UNTREATED AGGREGATE BASES FOR FLEXIBLE PAVEMENTS: A NATIONWIDE COMPARITIVE STUDY

Aggregates are a major part of highway construction and its quality as well as strength affects the overall performance of the pavement structure. The base material near the construction site does not always meet the strength requirement needed for the pavement construction and the hauling of quality aggregate increases the construction costs. For better use of local available materials, stabilizing agents such as lime and asphalt cement have been utilized to increase the strength of crushed aggregate bases. Performance of pavement structures is heavily influenced by the thickness of the structure as well as material properties of each layer. The stiffness of the base layer influences the tensile strain experienced by the asphalt layer and the compressive strain in the subgrade layer. The tensile strain at the bottom of the asphalt layer and the compressive strain in the top zone of the subgrade layer are the main components affecting fatigue cracking and rutting resistance of any pavement structure, respectively. In this study, field performance (rutting, cracking, and surface roughness) of pavement sections with treated and untreated bases were compared to determine the effects of the stabilizing agents of aggregate bases. In terms of fatigue cracking, surface rutting, and pavement surface roughness, the treated sections performed significantly better as compared to the untreated sections. The combined average values of all the three distresses showed a better performance for the treated sections with the fatigue cracking averaging 2.5 times lower than the untreated sections. The combined rutting and roughness (IRI) of the treated sections averaged about 0.08-inch lower and 1.4 times lower than that of the untreated sections, respectively

High-resolution spectroscopy of the R Coronae Borealis and Other Hydrogen Deficient Stars

High-resolution spectroscopy is a very important tool for studying stellar physics, perhaps, particularly so for such enigmatic objects like the R Coronae Borealis and related Hydrogen deficient stars that produce carbon dust in addition to their peculiar abundances. Examples of how high-resolution spectroscopy is used in the study of these stars to address the two major puzzles are presented: (i) How are such rare H-deficient stars created? and (ii) How and where are the obscuring soot clouds produced around the R Coronae Borealis stars?Comment: 16 pages, 9 figures, Astrophysics and Space Science Proceedings, Springer-Verlag, Berlin, 201

Liability of Foreignness in Global Stock Markets: Liquidity Dynamics of Foreign IPOs in the US

Using a unique dataset of foreign and domestic IPOs listings in the US from 1990 to 2012, we study how foreignness affects IPO liquidity. We find that foreign IPOs enjoy higher liquidity than IPOs in their home countries, but do not fully gain the same liquidity benefits as for IPOs of domestic US issuers. In contrast to prior evidence for mature cross-listed firms, we show that liquidity differentials between foreign and domestic IPOs in the US are determined by information asymmetry related to foreignness rather than to home-country institutional environment characteristics. Thus, our results extend prior findings to reveal salient differences in liquidity and liquidity determinants between IPOs offerings by foreign and domestic firms in the US.postprin

Intersecting black branes in strong gravitational waves

We consider intersecting black branes with strong gravitational waves propagating along their worldvolume in the context of supergravity theories. Both near-horizon and space-filling gravitational wave modes are included in our ansatz. The equations of motion (originally, partial differential equations) are shown to reduce to ordinary differential equations, which include a Toda-like system. For special arrangements of intersecting black branes, the Toda-like system becomes integrable, permitting a more thorough analysis of the gravitational equations of motion.Comment: 17 pages; v2: cosmetic improvements, published versio

Geometrical CP violation in multi-Higgs models

We introduce several methods to obtain calculable phases with geometrical values that are independent of arbitrary parameters in the scalar potential. These phases depend on the number of scalars and on the order of the discrete non-Abelian group considered. Using these methods we present new geometrical CP violation candidates with vacuum expectation values that must violate CP (the transformation that would make them CP conserving is not a symmetry of the potential). We also extend to non-renormalisable potentials the proof that more than two scalars are needed to obtain these geometrical CP violation candidates.Comment: 8 pages, 2 figures. v2: table added, accepted by JHE

Exact One Loop Running Couplings in the Standard Model

Taking the dominant couplings in the standard model to be the quartic scalar coupling, the Yukawa coupling of the top quark, and the SU(3) gauge coupling, we consider their associated running couplings to one loop order. Despite the non-linear nature of the differential equations governing these functions, we show that they can be solved exactly. The nature of these solutions is discussed and their singularity structure is examined. It is shown that for a sufficiently small Higgs mass, the quartic scalar coupling decreases with increasing energy scale and becomes negative, indicative of vacuum instability. This behavior changes for a Higgs mass greater than 168 GeV, beyond which this couplant increases with increasing energy scales and becomes singular prior to the ultraviolet (UV) pole of the Yukawa coupling. Upper and lower bounds on the Higgs mass corresponding to new physics at the TeV scale are obtained and compare favourably with the numerical results of the one-loop and two-loop analyses with inclusion of electroweak couplings.Comment: 5 pages, LaTeX, additional references and further discussion in this version. Accepted for publication in Canadian Journal of Physic

On Some Geometric Properties of Slice Regular Functions of a Quaternion Variable

The goal of this paper is to introduce and study some geometric properties of slice regular functions of quaternion variable like univalence, subordination, starlikeness, convexity and spirallikeness in the unit ball. We prove a number of results, among which an Area-type Theorem, Rogosinski inequality, and a Bieberbach-de Branges Theorem for a subclass of slice regular functions. We also discuss some geometric and algebraic interpretations of our results in terms of maps from $\mathbb R^4$ to itself. As a tool for subordination we define a suitable notion of composition of slice regular functions which is of independent interest