Viscosity and glass transition in amorphous oxides

An overview is given of amorphous oxide materials viscosity and glass-liquid transition phenomena. The viscosity is a continuous function of temperature, whereas the glass-liquid transition is accompanied by explicit discontinuities in the derivative parameters such as the specific heat or thermal expansion coefficient. A compendium of viscosity models is given including recent data on viscous flow model based on network defects in which thermodynamic parameters of configurons—elementary excitations resulting from broken bonds—are found from viscosity-temperature relationships. Glass-liquid transition phenomena are described including the configuron model of glass transition which shows a reduction of Hausdorff dimension of bonds at glass-liquid transition

The impact of a needs-based educational programme on General Practitioners' confidence and skill in managing common musculoskeletal problems

Disorders of the musculoskeletal (MSK) system are prevalent in the UK. They are a significant cause of pain, disability and health and social care resource utilisation. Most patients with MSK disorders are seen and treated by General Practitioners (GPs). MSK disorders form up to 20% of GP consultations and the majority are formed of a small number of conditions such as back, neck, and knee pain. Despite the prevalence of these conditions, there is evidence that management of affected patients is suboptimal. This thesis investigated the possibility and feasibility of improving GP delivery of care to patients with MSK problems using an evidence-based educational intervention. The study population was a cohort of GPs from Camden and Islington Primary Care Trusts. The first phase of the project was a needs assessment case study of prior training and CME experience in MSK disorders using questionnaires and face-to-face interviews. The second phase used these results to develop, deliver and evaluate an MSK training course. The principal findings from the needs assessment were that formal postgraduate training in MSK disorders was rare. CME events were mainly in the form of lectures. GPs rated the need for knowledge of MSK disorders in primary care as high. The MSK training course was based on the needs assessment, taking place in small groups, using trained patients (Patient Partners) and clinical cases. GPs evaluated the course as highly relevant to their needs, leading to increased confidence and skills. However, GPs estimated that confidence would reduce after 6 months without further training. It is feasible to deliver a research informed training course for GPs on MSK disorders. Further work needs to be done to find effective strategies to produce prolonged changes in behaviour and practice that deliver effective patient care

The Diffusion of Bt Cotton and the Economic Impact on Producers

The objective is to present the economic impact of producers adopting Bt cotton and the rapid diffusion on the main producing countries: USA, China and India. The existing literature about this type of transgenic crop has been revised and the results of different research are presented. Bt cotton varieties have been quickly adopted by the countries in this study. Data show that this technology helps reduce production losses and significantly decrease the use of pesticides, thus saving their cost and the associated labour cost. But the total cost reduction is weak due to the high prices of the seeds incorporating this technology.Innovation diffusion, Bt cotton, Crop Production/Industries,

Magnetic field effects on spin relaxation in heterostructures

Effect of magnetic field on electron spin relaxation in quantum wells is studied theoretically. We have shown that Larmor effect and cyclotron motion of carriers can either jointly suppress D'yakonov-Perel' spin relaxation or compensate each other. The spin relaxation rates tensor is derived for any given direction of the external field and arbitrary ratio of bulk and structural contributions to spin splitting. Our results are applied to the experiments on electron spin resonance in SiGe heterostructures, and enable us to extract spin splitting value for such quantum wells.Comment: 6 pages, 4 figure

Ferrohydrodynamics: testing a new magnetization equation

A new magnetization equation recently derived from irreversible thermodynamics is employed to the calculation of an increase of ferrofluid viscosity in a magnetic field. Results of the calculations are compared with those obtained on the basis of two well-known magnetization equations. One of the two was obtained phenomenologically, another one was derived microscopically from the Fokker-Planck equation. It is shown that the new magnetization equation yields a quite satisfactory description of magnetiviscosity in the entire region of magnetic field strength and the flow vorticity. This equation turns out to be valid -- like the microscopically derived equation but unlike the former phenomenological equation -- even far from equilibrium, and so it should be recommended for further applications.Comment: 4 pages, 3 figures, Submitted to Phys. Rev.

Decomposing Productivity Growth in the U.S. Computer Industry

In this paper, we examine the sources of the productivity growth in the U.S. computer industry from 1978 to 1999. We estimate a joint production model of output quantity and quality that distinguishes two types of technological changes: process and product innovations. Based on the estimation results, we decompose total factor productivity (TFP) growth rate into the contributions of process and product innovations and scale economies. The results show that product innovation associated with better quality accounts for about 30 percent of the TFP growth in the computer industry. Furthermore, we find that the TFP acceleration in the computer industry in the late 1990s is mainly derived from a rapid increase in product innovation.COMPUTER, PRODUCTIVITY; PROCESS AND PRODUCT INNOVATIONS; HEDONIC PRICE

Diet composition and food habits of demersal and pelagic marine fishes from Terengganu waters, east coast of Peninsular Malaysia

Fish stomachs from 18 demersal and pelagic fishes from the coast of Terengganu in Malaysia were examined. The components of the fishes’ diets varied in number, weight, and their frequency of occurrence. The major food items in the stomachs of each species were determined using an Index of Relative Importance. A conceptual food web structure indicates that fish species in the study area can be classified into three predatory groups: (1) predators on largely planktivorous or pelagic species; (2) predators on largely benthophagous or demersal species; and (3) mixed feeders that consume both pelagic and demersal species

Large Deviations Principle for a Large Class of One-Dimensional Markov Processes

We study the large deviations principle for one dimensional, continuous, homogeneous, strong Markov processes that do not necessarily behave locally as a Wiener process. Any strong Markov process $X_{t}$ in $\mathbb{R}$ that is continuous with probability one, under some minimal regularity conditions, is governed by a generalized elliptic operator $D_{v}D_{u}$, where $v$ and $u$ are two strictly increasing functions, $v$ is right continuous and $u$ is continuous. In this paper, we study large deviations principle for Markov processes whose infinitesimal generator is $\epsilon D_{v}D_{u}$ where $0<\epsilon\ll 1$. This result generalizes the classical large deviations results for a large class of one dimensional "classical" stochastic processes. Moreover, we consider reaction-diffusion equations governed by a generalized operator $D_{v}D_{u}$. We apply our results to the problem of wave front propagation for these type of reaction-diffusion equations.Comment: 23 page

Information Technology Externalities: Empirical Evidence from 42 U.S. Industries

Using interindustry transaction in input-output tables, we examine Information Technology (IT) externalities in U.S. private industries over the period 1984-2000. Our empirical results show that computerization of an industry's customer and supplier industries reduces both labor and material costs of the industry. Moreover, cost savings driven by supplier industries are larger than those driven by customer industries. We also find that industries in the services sector enjoy more benefits from IT spillovers than industries in other sectors because of their high IT capital intensity and composition of interindustry transaction. Decomposition of total factor productivity (TFP) suggests that IT externalities can explain considerable parts of TFP growth, although possible mismeasurement of output in services industries leads to exacerbated technical changes of services industries.INFORMATION TECHNOLOGY; NETWORK EXTERNALITY; INPUT-OUTPUT TABLE; TOTAL FACTOR PRODUCTIVITY