Borel singularities at small x

D.I.S. at small Bjorken $x$ is considered within the dipole cascade formalism. The running coupling in impact parameter space is introduced in order to parametrize effects that arise from emission of large size dipoles. This results in a new evolution equation for the dipole cascade. Strong coupling effects are analyzed after transforming the evolution equation in Borel ($b$) space. The Borel singularities of the solution are discussed first for the universal part of the dipole cascade and then for the specific process of D.I.S. at small $x$. In the latter case the leading infrared renormalon is at $b=1/\beta_0$ indicating the presence of $1/Q^2$ power corrections for the small-$x$ structure functions.Comment: 5 pages, Latex (Talk presented at DIS'97, Chicago, IL

Applying marketing mix constructs in higher education: the case of an MBA programme in the UAE

This exploratory study identifies significant choice factors for prospective students when selecting a Master of Business Administration (MBA) programme in the increasingly competitive higher education sector in the United Arab Emirates (UAE). Implications for Higher Education Institutions (HEIs) when they develop marketing communication strategies are addressed. Study participants included current MBA students, MBA graduates who have completed their degree at a British University’s campus in the UAE and prospective students who chose not to enrol on that MBA programme. Constructs were tested for reliability using the Cronbach Alpha test. The relative importance of specific choice factors were assessed via analysis of the means of the constructs. The difference between the most important (People) and least important (Promotion) factors were as much as 34%. Differences between three groups of study participants were analysed based on the results of Scheffé's post-hoc test. Marketing implications for HEIs include: improving the quality of the factors identified and communicating the quality of these factors; especially intangible ones, to potential MBA candidates more effectively

In-vivo magnetic resonance imaging of hyperpolarized silicon particles

Silicon-based micro and nanoparticles have gained popularity in a wide range of biomedical applications due to their biocompatibility and biodegradability in-vivo, as well as a flexible surface chemistry, which allows drug loading, functionalization and targeting. Here we report direct in-vivo imaging of hyperpolarized 29Si nuclei in silicon microparticles by MRI. Natural physical properties of silicon provide surface electronic states for dynamic nuclear polarization (DNP), extremely long depolarization times, insensitivity to the in-vivo environment or particle tumbling, and surfaces favorable for functionalization. Potential applications to gastrointestinal, intravascular, and tumor perfusion imaging at sub-picomolar concentrations are presented. These results demonstrate a new background-free imaging modality applicable to a range of inexpensive, readily available, and biocompatible Si particles.Comment: Supplemental Material include

Analysis of WFPC-2 Core Samples for MMOD Discrimination

An examination of the Hubble Space Telescope Wide Field Planetary Camera 2 (WFPC-2) radiator assembly was conducted at NASA Goddard Space Flight Center during the summer of 2009. Immediately apparent was the predominance of impact features, identified as simple or complex craters, resident only in the thermal paint layer; similar features were observed during a prior survey of the WFPC-1 radiator. Larger impact features displayed spallation zones, darkened areas, and other features not observed in impacts onto bare surfaces. Craters were extracted by coring the radiator in the NASA Johnson Space Centers Space Exposed Hardware cleanroom and were subsequently examined using scanning electron microscopy/energy dispersive X-ray spectroscopy to determine the likely origin, e.g., micrometeoritic or orbital debris, of the impacting projectile. Recently, a selection of large cores was re-examined using a new technique developed to overcome some limitations of traditional crater imaging and analysis. This technique, motivated by thin section analysis, examines a polished, lateral surface area revealed by cross-sectioning the core sample. This paper reviews the technique, the classification rubric as extended by this technique, and results to date

A study of the relationship between consumers’ characteristics and purchases of branded maize flour: the case of Kampala, Uganda

Maize is one of the essential food crops in Uganda. This paper aims to examine the consumer preference for branded maize flour in urban Uganda and inform branded maize flour suppliers of the findings. The study empirically examines how the purchase of branded maize flour is influenced by consumer characteristics using survey data and a binary logit model. The survey was conducted in Kampala in October 2014. The dependent variable is the purchase of branded maize flour. Independent variables are monthly individual income, family size, gender, age, education, and quantity of purchase. The study reveals that almost half of respondents purchased branded maize flour. The results suggest that education and purchased quantity are positively and significantly related to the probability of purchasing branded maize flour. Also, the study found that gender affected the probability of purchasing branded maize flour. The probability of respondents with a college education or higher purchasing branded maize flour is 16% higher than respondents with less than a college education, holding other independent variables constant. The probability of purchasing branded maize flour is 28% greater for consumers who purchase 6 kg to 21 kg of flour compared to consumers who purchase less than 6 kg. The probability of purchasing branded maize flour is 12% greater for female consumers than for male consumers, keeping other variables constant. A clear influence of individual monthly income on the probability of purchasing branded maize flour could not be deduced in this study. Based on these results, it is recommended that suppliers of branded maize flour products in Kampala City, Uganda target female consumers, highly educated, and purchase 6-21kg of maize flour at one time. It would be recommended that further research investigates how price and aggregate household income influence purchase for branded maize flour. The study provides insight into the effect of consumer socioeconomic characteristics on branded maize preferences in the East African region.Keywords: Logit Model, Maize, Branded Maize Flour, Uganda, Maganjo, Consumer Preferenc

Quasiharmonic elastic constants corrected for deviatoric thermal stresses

The quasiharmonic approximation (QHA), in its simplest form also called the statically constrained (SC) QHA, has been shown to be a straightforward method to compute thermoelastic properties of crystals. Recently we showed that for non-cubic solids SC-QHA calculations develop deviatoric thermal stresses at high temperatures. Relaxation of these stresses leads to a series of corrections to the free energy that may be taken to any desired order, up to self-consistency. Here we show how to correct the elastic constants obtained using the SC-QHA. We exemplify the procedure by correcting to first order the elastic constants of MgSiO$_3$-perovskite and MgSiO$_3$-post-perovskite, the major phases of the Earth's lower mantle. We show that this first order correction is quite satisfactory for obtaining the aggregated elastic averages of these minerals and their velocities in the lower mantle. This type of correction is also shown to be applicable to experimental measurements of elastic constants in situations where deviatoric stresses can develop, such as in diamond anvil cells.Comment: 4 figures, 1 table, submitted to Phys. Rev. B, July 200

A DYNAMIC GENERAL EQUILIBRIUM ANALYSIS OF U.S. BIOFUELS PRODUCTION

With the rising global interest in energy security and climate change mitigation, biofuels have gained the prominent attention of researchers and policy makers. The U.S. has emerged as the leading producer of biofuels and is aiming for achieving a target of 36 billion gallons of renewable fuels by 2022 under its updated renewable fuels standard (RFS2) policy. In this paper, we study the longer-term global implications of large-scale renewable fuels production in the U.S. We utilize the GTAP v7.1 data base and introduce a detailed breakdown of agricultural crops, first and second generation biofuels and by-products. We update this fully disaggregated data base to reflect the 2010 global economy, based on secondary data for the sectors and regions included. We adapt the Applied Dynamic Analysis of Global Economy (ADAGE) model developed by Ross (2009) into a recursive dynamic framework and introduce agriculture, biofuels, and land use linkages. We construct a dynamic baseline from 2010 through 2050 in five-year time steps. The dynamics in the model comes from growth in GDP, population, capital accumulation, labor productivity, growth in natural resource stocks, and technological changes in the energy intensive and agricultural sectors. We implement a representative RFS2 policy scenario in the U.S for 2025, using two alternative approaches: (i) RFS permits approach – which assumes biofuels and petroleum fuels are perfect substitutes after adjusting for energy content, and (ii) Target share of biofuels in transportation fuels approach – which treats biofuels and petroleum fuels as imperfect substitutes. Both approaches offer insights regarding potential policy impacts, particularly on the international market and indirect land use change. Because the share approach keeps the biofuels share fixed in the regions outside the U.S., it does not result in dramatic changes in the rest of the world. In the permits approach, however, the regions without a specific policy requiring a given level of biofuels tend to reduce biofuels consumption. This is a result of the reduction in relative price of petroleum products as U.S. policy increases demand for biofuels and reduces global demand for petroleum, making renewable fuels less cost-competitive in the rest of the world.ADAGE, Biofuels, Computable General Equilibrium, Recursive Dynamic, Resource /Energy Economics and Policy,