Some Further Results on the Impact of Migrants on Trade

This paper investigates the relationship between migration and trade. Specifically it adds to the existing literature by allowing for the endogeneity of migration, as predicted by theory, while also allowing for the relationship between trade and migration to be non-linear. In contrast to previous single country studies this paper utilises a large cross section dataset for 26 countries and their trading partners.DYNREG, International Migration, International Trade, Gravity Model

Computational physics from simple to complex systems

This thesis deals with computer simulations and analytical calculations in simple and complex systems. In the last decades there has been a great interest in the area of complexity, and there are numerous definitions of complexity. In this work the attribute complex will be given based on two criteria. On the one hand we shall call a system “complex” if it is composed of a great number of simple interacting systems. Regarded from this perspective, every system we consider is complex, however on the other hand the classification is different when dealing with fluids. In this case one distingushes between simple and complex fluids using the interaction potentials as a criterion. Fluids with isotropic intermolecular potentials like Lennard-Jones systems are referred to as simple fluids, whereas e.g. liquid crystals belong to the class of complex fluids due to their anisotropic interaction potentials. After explaining some basic notions of statistical mechanics the theory of stochastic processes and molecular dynamics computer simulations, these methods are applied systematically to systems with increasing “complexity” in the next chapters. In Chapters 4 and 5 the discussed problems are of a fundamental nature: The Ehrenfest urn is a model introduced in order to explain the irreversibility of macroscopic thermodynamics as stated by Boltzmann’s H-theorem, although resulting from a time-reversible microscopic dynamics. After reviewing the defintition and derivation of Boltzmann’s state function in Chapter 4, the model of the Ehrenfest urn is studied via MD simulations of a realistic fluid in Chapter 5, and it turns out that the Markov hypothesis lying at the foundations of statistical mechanics is valid even in the liquid phase. In Chapter 6 liquid crystalline systems are studied. After introducing basic notions a discotic system confined in a cylindrical nanopore is simulated. Discotic liquid crystals are interesting from a technical point of view, since, due to their anisotropic conductivity in the columnar phase, they are promising for applications like organic light emiting diodes field effect transistors and solar cells. Finally in Chapter 7 first passage times for a stochastic process relevant for many physical chemical biological and other problems are calculated analytically and simulated numerically

Are Groups more Rational than Individuals? A Review of Interactive Decision Making in Groups

Many decisions are interactive; the outcome of one party depends not only on its decisions or on acts of nature but also on the decisions of others. In the present article, we review the literature on decision making made by groups of the past 25 years. Researchers have compared the strategic behavior of groups and individuals in many games: prisoner’s dilemma, dictator, ultimatum, trust, centipede and principal-agent games, among others. Our review suggests that results are quite consistent in revealing that groups behave closer to the game-theoretical assumption of rationality and selfishness than individuals. We conclude by discussing future research avenues in this area.group decision making, interactive decision making, rationality, discontinuity effect

An analysis of teachers' and laymen's understanding of educational terms and of the relationship of understanding of terms to certain factors

Thesis (Ed.D.)--Boston Universit

Optimization and automation of a thermal oyster shucking process

Louisiana Gulf Coast oysters (Crassostrea virginica) were subjected to thermal shucking treatments to effect adductor muscle release from both left and right valves. The oysters were instrumented with thermocouples to monitor and record process temperatures in the oysters and on the shell. Following treatment, the oysters were evaluated for relaxation and release of the adductor muscle, meat quality and texture, and for the effect of the treatments on the storage life of the oysters as measured by total microbial plate counts. The treatments of many oysters resulted in a complete release of the adductor muscle from the shell while maintaining a quality raw product. One of the most promising treatments was a 60 second steam injection followed by a 60 second hold time and 120 seconds of ice water bath. This treatment proved exceptional overall with shelf stability over 14 days, an overall Average Release Value of 1.18 and an overall Quality of 1.86, both of which are good. A second treatment consisting of a 15 second pre-heat followed by a 45 second steam injection, no hold time and 4 minutes of ice water bath resulted in an overall Average Release Value of 0.33, which is excellent, and an overall Quality of 2.10 which is very close to acceptable. Sixty-seven percent of the oysters subjected to this treatment were considered successfully shucked based on degree of release and quality. Processing did affect the texture of the oysters but seemed to have little overall effect on storage life. This low-pressure steam process shows promise as an effective, low-cost alternative to current, high pressure commercial oyster shucking processes

Assessment of global dimming and brightening in IPCC-AR4/CMIP3 models and ERA40

Observations indicate that solar radiation incident at the Earth surface underwent substantial decadal variations in the second half of the twentieth century, with a tendency towards reduction from the 1950s to the 1980s ("global dimming”) and a partial recovery thereafter ("brightening”) at widespread locations. The most reliable observational records from the Global Energy Balance Archive (GEBA) are used to evaluate the ability of the climate models participating in CMIP3/IPCC-AR4 as well as the ERA40 reanalysis to reproduce these decadal variations. The results from 23 models and reanalysis are analyzed in five different climatic regions where strong decadal variations in surface solar radiation (SSR) have been observed. Only about half of the models are capable of reproducing the observed decadal variations in a qualitative way, and all models show much smaller amplitudes in these variations than seen in the observations. Largely differing tendencies between the models are not only found under all-sky conditions, but also in cloud-free conditions and in the representation of cloud effects. The ERA40 reanalysis neither reproduces the major decadal variations in SSR, despite strong observational constraints on the temporal evolution of the state of the atmosphere, since time varying aerosol loadings are missing. Climate models and reanalyses are therefore not yet at a stage to provide regionally consistent estimates of decadal changes in SSR. Reproduction of these changes would be essential for an adequate representation of regional scale climate variations and impacts, and short-term (decadal) climate projection

Medium range structural order in amorphous tantala spatially resolved with changes to atomic structure by thermal annealing

Amorphous tantala (a-Ta2O5) is an important technological material that has wide ranging applications in electronics, optics and the biomedical industry. It is used as the high refractive index layers in the multi-layer dielectric mirror coatings in the latest generation of gravitational wave interferometers, as well as other precision interferometers. One of the current limitations in sensitivity of gravitational wave detectors is Brownian thermal noise that arises from the tantala mirror coatings. Measurements have shown differences in mechanical loss of the mirror coatings, which is directly related to Brownian thermal noise, in response to thermal annealing. We utilise scanning electron diffraction to perform Fluctuation Electron Microscopy (FEM) on Ion Beam Sputtered (IBS) amorphous tantala coatings, definitively showing an increase in the medium range order (MRO), as determined from the variance between the diffraction patterns in the scan, due to thermal annealing at increasing temperatures. Moreover, we employ Virtual Dark-Field Imaging (VDFi) to spatially resolve the FEM signal, enabling investigation of the persistence of the fragments responsible for the medium range order, as well as the extent of the ordering over nm length scales, and show ordered patches larger than 5 nm in the highest temperature annealed sample. These structural changes directly correlate with the observed changes in mechanical loss.Comment: 22 pages, 5 figure