From Fast Fashion to Conscious Couture : Revealing the Need for Policy in Shaping a Sustainable Fashion Industry

Senior Project submitted to The Division of Social Studies of Bard College

Lower cervical spine facet cartilage thickness mapping

SummaryObjectiveFinite element (FE) models of the cervical spine have been used with increasing geometric fidelity to predict load transfer and range of motion (ROM) for normal, injured, and treated spines. However, FE modelers frequently treat the facet cartilage as a simple slab of constant thickness, impeding the accuracy of FE analyzes of spine kinematics and kinetics. Accurate prediction of facet joint contact forces and stresses, ROM, load transfer, and the effects of facet arthrosis require accurate representation of the geometry of the articular cartilage of the posterior facets. Previous research has described the orientations of the facet surfaces, their size and aspect ratio, and mean and maximum thickness. However, the perimeter shape of the cartilaginous region and the three-dimensional distribution of cartilage thickness remain ill-defined. As such, it was the intent of this research to further quantify these parameters.MethodVertebrae from seven fresh-frozen unembalmed human cadavers were serially sectioned and the osteochondral interface and the articulating surface of each facet on each slice were identified. The cartilage thickness was recorded at nine equidistant points along the length of each facet. It was observed that facets tended to have elliptic or ovoid shapes, and best-fit ovoid perimeter shapes were calculated for each facet. The thickness distribution data were used to represent the entire three-dimensional cartilage distribution as a function of one variable, and a thickness distribution function was optimized to fit the thickness distribution. The antero-posterior and medial/lateral shifts of the thickness center relative to the geometric were calculated and reported.ResultsHigh correlation was observed between the ovoid perimeter shapes and the measured facet shapes in radial coordinates, indicating that the ovoid approximation is able to accurately represent the range of facet geometries observed. High correlation between the measured and fitted thickness distributions indicates that the fitting function used is able to accurately represent the range of cartilage thickness distributions observed.ConclusionUtilization of a more physiologic cartilage thickness distribution in FE models will result in improved representation of cervical spine kinematics and increased predictive power. The consistency observed in the thickness distribution function in this study indicates that such a representation can be generated relatively easily

Emergence of intrinsic superconductivity below 1.178 K in the topologically non-trivial semimetal state of CaSn3

Topological materials which are also superconducting are of great current interest, since they may exhibit a non-trivial topologically-mediated superconducting phase. Although there have been many reports of pressure-tuned or chemical-doping-induced superconductivity in a variety of topological materials, there have been few examples of intrinsic, ambient pressure superconductivity in a topological system having a stoichiometric composition. Here, we report that the pure intermetallic CaSn3 not only exhibits topological fermion properties but also has a superconducting phase at 1.178 K under ambient pressure. The topological fermion properties, including the nearly zero quasi-particle mass and the non-trivial Berry phase accumulated in cyclotron motions, were revealed from the de Haas-van Alphen (dHvA) quantum oscillation studies of this material. Although CaSn3 was previously reported to be superconducting at 4.2K, our studies show that the superconductivity at 4.2K is extrinsic and caused by Sn on the degraded surface, whereas its intrinsic bulk superconducting transition occurs at 1.178 K. These findings make CaSn3 a promising candidate for exploring new exotic states arising from the interplay between non-trivial band topology and superconductivity, e.g. topological superconductivityComment: 20 pages,4 figure

Sleep Loss and Risk-taking Behavior

While sleep loss has been shown to have detrimental effects on cognitive, physiological, and psychological processes, it has only recently been investigated as a possible causal factor of risk-taking behavior (i.e., a conscious choice to engage in dangerous behavior despite knowledge of possible loss or harm). Among the few studies that have been conducted in this field, the majority found that as individuals become sleepier, their propensity to engage in risk-taking behavior increased. The results of the current study indicated a positive relationship between increased sleep loss and two measures of specific risk-taking behavior (i.e., substance use, sexual compulsivity), but no significant relationship between sleep loss and measures of general risk-taking behavior. There was some evidence for temporal stability of the Iowa Gambling Task (IGT), though scores on the IGT were not related to scores on other measures of risk-taking, nor to measures of sleep loss. Negative mood was found to partially mediate the relationship between sleep loss and substance use, as well as the relationship between sleep loss and sexual compulsivity

A Study of The Local Toxicity of Agents Used for Variceal Injection Sclerotherapy

Injection sclerotherapy is widely used in the treatment of oesophageal varices. However, few studies have compared the local toxicity of sclerosant agents which may be important if serious local complications are to be avoided

Preliminary - Representative Farm Analysis of House of Representatives Draft Concept Paper for 2002 Farm Bill

Agricultural and Food Policy,

Observation of a mesoscopic magnetic modulation in chiral Mn1/3NbS2

We have investigated the structural, magnetic, thermodynamic, and charge transport properties of Mn1/3NbS2 single crystals through x-ray and neutron diffraction, magnetization, specific heat, magnetoresistance, and Hall effect measurements. Mn1/3NbS2 displays a magnetic transition at TC ~ 45 K with highly anisotropic behavior expected for a hexagonal structured material. Below TC, neutron diffraction reveals increased scattering near the structural Bragg peaks having a wider Q-dependence along the c-axis than the nuclear Bragg peaks. This indicates helimagnetism with a long pitch length of ~250 nm (or a wavevector q~0.0025 {\AA}-1) along the c-axis. This q is substantially smaller than that found for the helimagnetic state in isostructural Cr1/3NbS2 (0.015 {\AA}-1). Specific heat capacity measurements confirm a second-order magnetic phase transition with a substantial magnetic contribution that persists to low temperature. The large low-temperature specific heat capacity is consistent with a large density of low-lying magnetic excitations that are likely associated with topologically interesting magnetic modes. Changes to the magnetoresistance, the magnetization, and the magnetic neutron diffraction, which become more apparent below 20 K, imply a modification in the character of the magnetic ordering corresponding to the magnetic contribution to the specific heat capacity. These observations signify a more complex magnetic structure both at zero and finite fields for Mn1/3NbS2 than for the well-investigated Cr1/3NbS2.Comment: 22 pages, 7 figure

Large-volume metrology instrument selection and measurability analysis

A wide range of metrology processes are involved in the manufacture of large products. In addition to the traditional tool-setting and product-verification operations, increasingly flexible metrology-enabled automation is also being used. Faced with many possible measurement problems and a very large number of metrology instruments employing diverse technologies, the selection of the appropriate instrument for a given task can be highly complex. Also, as metrology has become a key manufacturing process, it should be considered in the early stages of design, and there is currently very little research to support this. This paper provides an overview of the important selection criteria for typical measurement processes and presents some novel selection strategies. Metrics that can be used to assess measurability are also discussed. A prototype instrument selection and measurability analysis application is also presented, with discussion of how this can be used as the basis for development of a more sophisticated measurement planning tool. © 2010 Authors

Representative Farm Analysis of the H.R. 2646 Farm Bill Proposal

Agricultural and Food Policy,