Visitors Only? New Orleans’ Tourism Industry and the Construction of Space in the City

This paper addresses a major focus of urban studies: the politics of local economic development in the US city. It does so through a case study of New Orleans and its tourism industry. Specifically, it examines development based on tourism by analyzing it within the context of the industry's drive to create an "authentic New Orleans experience." This then creates a situation in which the industry becomes involved in the neighborhoods and wage relations in the city.No embargoAcademic Major: Geograph

Are cover crops worth it? It depends

Society is becoming increasingly more aware of the environmental consequences of agricultural production. Farmers today are under increasing pressure to adopt more sustainable farm management practices. One method to improve the sustainability of crop production is the use of cover crops. Cover crops are planted off-season to provide agronomic and environmental benefits. The objective of this research is to quantify the impacts of cover crops and determine where and under which management practices cover crops provide the greatest benefit. Management practices include different crop rotations, tillage practices and residue removal rates. This paper will focus on soil erosion, nitrate leaching and soil organic carbon. ^ To quantify the impact of cover crops, a dummy variable model was used to estimate the amount of soil erosion, nitrate leaching and soil organic carbon change for a combination of different management practices on soils with different land capability class ratings. Once the environmental outcomes have been determined, the benefits of cover crops can be quantified. Data for the environmental outcomes are simulated by the Landscape Environmental Assessment Framework (LEAF). To determine if cover crops are worth the cost, estimates for the price of soil erosion, nitrate leaching and soil organic carbon are combined with the environmental outcomes. ^ From this analysis we find that: (1) cover crops improve environmental outcomes (2) reduced till benefits more from cover crops than no till (3) continuous corn rotations benefits more from cover crops than corn soybean rotations (4) soils with higher land capability class ratings benefit the most from cover crops (5) cover crops are needed to maintain positive soil organic carbon for medium residue harvest and high residue harvest (6) considering only the nutrient benefits of reduced soil erosion, reduced nitrate leaching and increased soil organic carbon rarely justifies the cost of cover crops (7) for high residue harvest, the social benefits of cover crops always exceed the cost

Influence of Cold Expansion and Aggressive Environment on Crack Growth in AA2024-T3

This research aims to establish the effect of hole cold expansion on fatigue life of pre-cracked material under aggressive environment. A relationship between crack propagation and secondary crack initiation was established for AA2024-T3 cold worked holes subjected to cyclic loads to determine the impact on fatigue life of joints in presence of saline solution. Galvanic corrosion of a steel fastener/aluminum plate assembly was investigated assuming the presence of cracks in the aluminum plates, whose growth will be monitored in-situ with a digital microscope throughout the fatigue process. The cold expansion treatment improved the fatigue life fourfold under a corrosive environment, and 11.3 times in a clean environment when compared to a plain hole. Corrosion revealed the possibility of a location shift in critical stress intensity factor, causing growth of the critical crack happening outside of the region where benefits of cold expansion can be achieved. The benefits of cold work expansion could be applied for pre-cracked materials for an improved inspection interval, but also calls for reevaluation of inspection area to prevent secondary crack initiation that could lead to ultimate failure of the structural component

Phase Transition Induced Fission in Lipid Vesicles

In this work we demonstrate how the first order phase transition in giant unilamellar vesicles (GUVs) can function as a trigger for membrane fission. When driven through their gel-fluid phase transition GUVs exhibit budding or pearl formation. These buds remain connected to the mother vesicle presumably by a small neck. Cooling these vesicles from the fluid phase (T>Tm) through the phase transition into the gel state (T<Tm), leads to complete rupture and fission of the neck, while the mother vesicle remains intact. Pearling tubes which formed upon heating break-up and decay into multiple individual vesicles which then diffuse freely. Finally we demonstrate that mimicking the intracellular bulk viscosity by increasing the bulk viscosity to 40cP does not affect the overall fission process, but leads to a significant decrease in size of the released vesicles

Thermo-mechanic-electrical coupling in phospholipid monolayers near the critical point

Lipid monolayers have been shown to represent a powerful tool in studying mechanical and thermodynamic properties of lipid membranes as well as their interaction with proteins. Using Einstein's theory of fluctuations we here demonstrate, that an experimentally derived linear relationship both between transition entropy S and area A as well as between transition entropy and charge q implies a linear relationships between compressibility \kappa_T, heat capacity c_\pi, thermal expansion coefficient \alpha_T and electric capacity CT. We demonstrate that these couplings have strong predictive power as they allow calculating electrical and thermal properties from mechanical measurements. The precision of the prediction increases as the critical point TC is approached

Comparative Study of the Dynamics of Lipid Membrane Phase Decomposition in Experiment and Simulation

Phase decomposition in lipid membranes has been the subject of numerous investigations both experimentally and by theoretical simulation. Yet quantitative comparisons of the simulated data to the experimental results are rare. In this work we present a novel way of comparing the temporal development of liquid ordered domains obtained from numerically solving the Cahn–Hilliard equation and by inducing phase transition in giant unilamellar vesicles (GUVs). Quantitative comparison is done by calculating the structure factor of the domain pattern. It turns out that the decomposition takes place in three distinct regimes both in experiment and simulation. These regimes are characterized by different rates of growth of the mean domain diameter and there is a quantitative agreement between experiment and simulation as to the duration of each regime and the absolute rate of growth in each regime