Irreversible Thermodynamics

Contains reports on one research project

Industrial Engineering and the Law

BOOM BACKLASH made recent headlines in the May 26th issue of The Wall Street Journal. The sub-heading, Efficiency Falls and Pay Training Costs Increase as Labor Supply Shrinks delves into the heart of industrial engineering. This represents, also, an expansive and enigmatic economic problem which is now confronting employers in northern Ohio and western Pennsylvania. It is the job of the industrial engineer to deal with the resulting problems of decreased productivity, contract erosion, and unbalanced labor relations

Integrating theories of alcohol consumption: how do drinking motives influence self-efficacy?

Integrating theories regarding alcohol consumption can create complementary explanations and reduce unexplained variance in drinking behaviour prediction. This study investigated the utility of integrating the Motivational Model of Alcohol Use (MMAU) with the Health Action Process Approach (HAPA). A cross-sectional study was conducted to test the mediation of HAPA self-efficacy between episode-specific drinking motives and drinking frequency/quantity

Health behaviours and health literacy: Hepatitis B regarding Sub-Saharan African migrants living in Queensland

Introduction: Hepatitis B Virus (HBV) is becoming an increasing health burden worldwide. Previous research indicates that lack of HBV awareness is a key contributing factor regarding individuals not engaging in preventative health behaviours, nor seeking medical treatment. A particular target group whom have higher rates of HBV are people from Culturally and Linguistically Diverse (CALD) backgrounds; including migrants from Sub-Saharan African (SSA) countries which are known to have higher rates of HBV infection. This study identified gaps in health literacy and HBV knowledge, and investigated how these factors influence related health behaviours among SSA migrants in Queensland. Methods: Cultural workers from a community organisation recruited 187 SSA migrant participants via ‘awareness stalls’ in Queensland. Participants answered self-report surveys regarding HBV knowledge, health literacy and health-protective behaviours; utilising quantitative cross-sectional surveys. The research also replicated previous methodology and compared findings to previous studies conducted with other cultural groups. Results: Preliminary findings indicated HBV knowledge significantly mediated health literacy and HBV screening. Health literacy (regarding self-efficacy) significantly predicted health behaviours (HBV screening, vaccinations). Participants with higher education and participants aged under 40 years of age, reported higher health literacy and engaged in more health-protective behaviours. Conclusions: Preliminary findings indicate significant associations between health-protective behaviours, HBV knowledge and health literacy. Greater awareness of the relationships between these constructs may assist in creating more informed prevention and health promotion strategies for identified target communities to reduce health disparities

Experimental Results of Neutron Fluence Outside an Iron Shield in the Forward Direction

This work represents the first systematic study at a high energy accelerator of the depth dependence of neutron fluence in longitudinal shielding

Universal criterion for the breakup of invariant tori in dissipative systems

The transition from quasiperiodicity to chaos is studied in a two-dimensional dissipative map with the inverse golden mean rotation number. On the basis of a decimation scheme, it is argued that the (minimal) slope of the critical iterated circle map is proportional to the effective Jacobian determinant. Approaching the zero-Jacobian-determinant limit, the factor of proportion becomes a universal constant. Numerical investigation on the dissipative standard map suggests that this universal number could become observable in experiments. The decimation technique introduced in this paper is readily applicable also to the discrete quasiperiodic Schrodinger equation.Comment: 13 page

Bactericidal activities of the cationic steroid CSA-13 and the cathelicidin peptide LL-37 against Helicobacter pylori in simulated gastric juice

BACKGROUND: The worldwide appearance of drug-resistant strains of H. pylori motivates a search for new agents with therapeutic potential against this family of bacteria that colonizes the stomach, and is associated with adenocarcinoma development. This study was designed to assess in vitro the anti-H. pylori potential of cathelicidin LL-37 peptide, which is naturally present in gastric juice, its optimized synthetic analog WLBU2, and the non-peptide antibacterial agent ceragenin CSA-13. RESULTS: In agreement with previous studies, increased expression of hCAP-18/LL-37 was observed in gastric mucosa obtained from H. pylori infected subjects. MBC (minimum bactericidal concentration) values determined in nutrient-containing media range from 100-800 μg/ml for LL-37, 17.8-142 μg/ml for WLBU2 and 0.275-8.9 μg/ml for ceragenin CSA-13. These data indicate substantial, but widely differing antibacterial activities against clinical isolates of H. pylori. After incubation in simulated gastric juice (low pH with presence of pepsin) CSA-13, but not LL-37 or WLBU2, retained antibacterial activity. Compared to LL-37 and WLBU2 peptides, CSA-13 activity was also more resistant to inhibition by isolated host gastric mucins. CONCLUSION: These data indicate that cholic acid-based antimicrobial agents such as CSA-13 resist proteolytic degradation and inhibition by mucin and have potential for treatment of H. pylori infections, including those caused by the clarithromycin and/or metronidazole-resistant strains

A framework for experimental-data-driven assessment of Magnetized Liner Inertial Fusion stagnation image metrics

A variety of spherical crystal x-ray imager (SCXI) diagnostics have been developed and fielded on Magnetized Liner Inertial Fusion (MagLIF) experiments at the Sandia National Laboratories Z-facility. These different imaging modalities provide detailed insight into different physical phenomena such as mix of liner material into the hot fuel, cold liner emission, or reduce impact of liner opacity. However, several practical considerations ranging from the lack of a consistent spatial fiducial for registration to different point-spread-functions and tuning crystals or using filters to highlight specific spectral regions make it difficult to develop broadly applicable metrics to compare experiments across our stagnation image database without making significant unverified assumptions. We leverage experimental data for a model-free assessment of sensitivities to instrumentation-based features for any specified image metric. In particular, we utilize a database of historical and recent MagLIF data including $N_{\text{scans}} = 139$ image plate scans gathered across $N_{\text{exp}} = 67$ different experiments to assess the impact of a variety of features in the experimental observations arising from uncertainties in registration as well as discrepancies in signal-to-noise ratio and instrument resolution. We choose a wavelet-based image metric known as the Mallat Scattering Transform for the study and highlight how alternate metric choices could also be studied. In particular, we demonstrate a capability to understand and mitigate the impact of signal-to-noise, image registration, and resolution difference between images. This is achieved by utilizing multiple scans of the same image plate, sampling random translations and rotations, and applying instrument specific point-spread-functions found by ray tracing to high-resolution datasets, augmenting our data in an effectively model-free fashion.Comment: 17 pages, 14 figure