The effects of drought on the growth and water balance of Lolium Perenne and Dactylis Glonerata

Imperial Users onl

Engaging retailers: giving them voice or controlling their voice, a supplier's perspective

This full paper from the Marketing and Retail track of BAM 2013 investigates the relationships between suppliers and retailers in the UK convenience store sector in terms of Hirschman's model whereby members of a group can influence it by either expressing their opinions (voice) or leaving it in protest (exit). Suppliers may create loyalty among retailers by raising exit costs and/or allowing them to express their voices. The investigation was carried out using the recorded turnover of the top thirty wholesalers and the major store chains/franchises in 2005-12, publications by the main trade organisation, in the trade press and online, and interviews. The results of the research suggest that the wholesalers do not use cost of exit or enabling retailer voice exclusively; instead they now tend to combine both within their retailer relationship strategies

Pressured Into Deception: Using General Strain Theory as a Framework for Testing the Validity of Self-Reported Drug Use

Determining the accuracy of self-reported drug use is important for criminal justice professionals so that they are better able to provide proper treatment referrals to those in the criminal justice system who may need substance abuse help (Rosay et al., 2007). However, self-reports, especially those of drug users, are not always accurate (Harrison, 1997). Drug use is a highly sensitive topic and disclosure of such behavior could lead to negative repercussions for the individual within the criminal justice system as well as lead to further stigmatization of the individual outside the system (Golub et al., 2002; Harrell, 1997). The current study uses data from the 2003 Arrestee Drug Abuse Monitoring (ADAM) survey to examine the accuracy of self-reported drug use across seven different types of drugs to determine if the anticipated strain of admitting to the use of drugs, compounded by respondents’ current levels of strain, are strong enough to inhibit individuals from accurately reporting drug use. Binomial conditional logistic regression models with fixed effects and robust standard errors were used to conclude that experiencing strain reduces the likelihood of accurately reporting drug use. The current study expands the current literature on Agnew’s general strain theory to include purposeful deception as a deviant coping mechanism used in response to strain. The results of the current study may help criminal justice professionals more accurately identify active substance abusers who may be less than truthful about their drug use. Implications from this study suggest that it may be useful to incorporate strain-related variables into the risk and needs assessment measures that criminal justice professionals use to better guide treatment referrals

Sizing up nanoelectronics: gauging the potential for new productivity wave

The Federal Reserve Bank of Dallas, in cooperation with the Semiconductor Industry Association (SIA), hosted a conference on nanoelectronics and the economy in Austin on Dec. 3, 2010. Economists and scientists explored how information technology has affected U.S. productivity and output growth and prospects for the future.Technological innovations ; Productivity

The relationship between monetary policy and investment in South Africa

This thesis examines the relationship of monetary policy and investment in a theoretical framework in which monetary and real economic forces are intrinsically interlinked. The full shift from a money, real dichotomy in historical economic thought to the notion of money being an essential determinant of economic outcomes is traced to the work of Keynes, partly in the Treatise (1930), but more completely in the General Theory (1936). The treatment of monetary forces in economic growth models is examined. It is found that the money, investment relationship, with close money, real interaction, is appropriately pursued in the approach to monetary theory adopted by those who could broadly be characterised as Post Keynesian. The operation of monetary forces through the banking system is examined using this theoretical backdrop. A symbolic model is developed of the influence channels implied by the theoretical analysis, using the South African monetary system as the specific focus. The symbolic model is expressed in a form which enables empirical examination. South African data are compiled and used to determine the nature and statistical significance of hypothesised relationships. The implications of the theoretical analysis and empirical examination are drawn out both for monetary theory within the Post Keynesian mould, and for the conduct of monetary policy, in South Africa in particular.EconomicsD. Litt. et Phil. (Economics

Effect of excess iron on oxidative dehydrogenation of 1-butene over a series of zinc ferrite catalysts

The influence of excess Fe3+ in ZnFe2O4 for the catalytic oxidative dehydrogenation of 1-butene to 1, 3-butadiene was investigated to try to clarify inconsistencies in the existing literature. A series of nanoscale zinc ferrite powders were produced with increasing Fe: Zn ratios. The materials were characterized by a range of techniques, which showed the presence of α-Fe2O3 as a distinct phase with an increasing excess of Fe3+ and SEM highlighted the increased presence of surface structures on the ferrites at higher Fe: Zn ratios. Reaction testing showed α-Fe2O3to be virtually inactive for the oxidative dehydrogenation of 1-butene. Results for the ferrite catalysts showed a significant decrease in both conversion and yield with an increasing excess of Fe3+. Therefore an excess of Fe3+ has a negative effect on catalytic activity and selectivity of zinc ferrite for the oxidative dehydrogenation of 1-butene, but acts as a promoter for competing hydrogenation and combustion side reactions

Optical Investigation of Structural Phase Transitions in the Oxide Perovskites {KT}a(1−x)_{(1-x)}{N}bx_x{O}3_3 and ({N}a0.5_{0.5}{B}i0.5_{0.5}){T}i{O}3_3}

This thesis studies static and dynamic optical effects through the phase transitions of two perovskite materials, potassium tantalate niobate (KTN) and sodium bismuth titanate (NBT). In the first part, the temperature dependence of the birefringence of three different potassium tantalate niobate, or KTN, crystals is examined upon approaching the phase transition from cubic to tetragonal. This birefringence, which is in violation of crystalline symmetry conditions, is caused by the strain originating from the difference in unit cell size of the end materials, KNbO$_3$ and KTaO$_3$. This strain is either a gradient or a modulation due to the growth striations in the material, and diffraction is observed from the volume phase gratings via the difference in refractive indices. Upon approaching the phase transition, the birefringence displays rapid temperature dependence due to the formation of polar nano-domains which are preferentially oriented perpendicular to the striations. The variation of the birefringence with temperature is reported and discussed in the context of the existing literature. A sample of K$_{0.977}$Li$_{0.003}$Ta$_{0.845}$Nb$_{0.155}$O$_3$ or KLTN15.5 with well defined striations, KTa$_{0.73}$Nb$_{0.27}$O$_3$or KTN27) with no well defined striations and a sample of KLTN36 doped with copper and vanadium and diffuse striations are examined with respect to their optical behaviors in the cubic paraelectric phase.In the second part, Raman spectroscopic measurements of sodium bismuth titanate (Na$_{0.5}$Bi$_{0.5}$TiO$_{3}$ or NBT) were carried out upon cooling from 1000 K to 80 K to study its two phase transitions. Full spectral deconvolution was performed, comparing the results from several fitting models, with a particular emphasis on the evolution of the central peak and low frequency phonon modes. The central intensity profile is found to be composed of two well-defined Lorentzian peaks, the temperature dependence of which suggests the presence of fluctuations in M-point and R-point rotations of the oxygen octahedra as well as fluctuations in cation displacements related to polar nano-domains. The temperature behavior of both central peaks is discussed in relation to the (tilting or shifting) transition behavior in similar perovskite systems. The four observed low frequency phonon modes indicate a different symmetry assignment than the commonly assigned R3c for the low temperature phase