Estimating Column Density in Molecular Clouds with FIR and Sub-mm Emission Maps

We have used a numerical simulation of a turbulent cloud to synthesize maps of the thermal emission from dust at a variety of far-IR and sub-mm wavelengths. The average column density and external radiation field in the simulation is well matched to clouds such as Perseus and Ophiuchus. We use pairs of single-wavelength emission maps to derive the dust color temperature and column density, and we compare the derived column densities with the true column density. We demonstrate that longer wavelength emission maps yield less biased estimates of column density than maps made towards the peak of the dust emission spectrum. We compare the scatter in the derived column density with the observed scatter in Perseus and Ophiuchus. We find that while in Perseus all of the observed scatter in the emission-derived versus the extinction-derived column density can be attributed to the flawed assumption of isothermal dust along each line of sight, in Ophiuchus there is additional scatter above what can be explained by the isothermal assumption. Our results imply that variations in dust emission properties within a molecular cloud are not necessarily a major source of uncertainty in column density measurements.Comment: Accepted to ApJ Letter

Environmental Regulation: Effective or Defective? Assessing whether criminal sanctions provide adequate protection of the environment

Issues, such as climate change and global warming, have seen environmental protection grow in the global consciousness into something worthy and in need of regulation. In response, a number of laws have been enacted which make certain environmental actions criminal offences, enforced through the criminal justice system. These environmental crimes are enforced using the same mechanisms and must satisfy the same procedural safeguards as 'traditional' criminal offences in order to secure conviction. This discussion looks at elements of the current system and whether it provides an effective system for protecting the environment. An examination of the alternatives is also made to establish if different enforcement mechanisms would facilitate better environmental regulation

Evaluating Conflicts in the Use and Development of Geographic Information Systems

Use of geographic information systems is increasing in governments, commercial companies, and by individual users. With such pervasive use of GIs there has been surprisingly little investigation of the values that various parties would support in the development of geographic technologies. There are many parties involved in the use of GIs each with opinions of what are good goals for developing and using such systems. This research seeks to determine differences and similarities among parties in the importance placed on supporting specific societal goals germane to the use of geographic technologies and databases. Previous research determined six areas where the potential for disagreement between different parties involved in GIs might be high. The first phase of the research involved creating a survey. The survey was designed to determine to what extent conflicts are perceived to exist by those using and creating GIs and those who are subjects of such systems. Those sampled in the survey were asked how much value they would place on various societal goals. Each goal is believed to be a laudable goal by some parties using GIs. Response options ranged from unimportant societal goal to highly important societal goal. Statistical analysis of the results was performed. This allowed researchers to see if differences exist among the groups sampled for the value they place on supporting the goals. Various professional organizations with members involved in the use and development of geographic information systems are discussing the development of codes of conduct and recommendations for ethical education. The work done for this project hopes to serve as an initial step for creating ethical learning materials. The research also identifies areas where there is disagreement about what is beneficial for society so further research may be performed

Unexpected nucleophilic participation and rearrangement of DBU in reactions with saccharin derivatives

DBU attacks saccharin derivatives with subsequent rearrangement to give rise to 3-[3'-(1"-azepin-2"-onyl)propylamino]-1,2-benzisothiazole-1,1-dioxide 2 after work-up

Remote measurement of temperature using laser-induced luminescence

A technique is required to measure the temperature of rotating compressor wheels at speeds of up to 80000 rpm and within the range 100°C to 250°C. Present available methods such as emissivity cannot be used due to the substantial interference from surrounding objects, nor can thermocouples due to their effect on the airflow within the compressor. Laser induced fluorescence (LIF) has been used successfully on rotating objects, but at speeds much less than the speeds which are required for implementation on a running compressor. Previous work with LIF has related the decay time of the fluorescence with temperature, this cannot be accurately implemented at high speeds due to the short amount of time that fluorescence is available to the detector, and as such as short amount of the decay curve is collected. The fluorescent peak positions and intensities are to be used for temperature measurement in this project. [Continues.