Nano-scale composition of commercial white powders for development of latent fingerprints on adhesives

This is the post-print version of the article - Copyright @ 2010 Elsevier.Titanium dioxide based powders are regularly used in the development of latent fingerprints on dark surfaces. For analysis of prints on adhesive tapes, the titanium dioxide can be suspended in a surfactant and used in the form of a powder suspension. Commercially available products, whilst having nominally similar composition, show varying levels of effectiveness of print development, with some powders adhering to the background as well as the print. X-ray fluorescence (XRF), analytical transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and laser particle sizing of the fingerprint powders show TiO2 particles with a surrounding coating, tens of nanometres thick, consisting of Al and Si rich material, with traces of sodium and sulphur. Such aluminosilicates are commonly used as anti-caking agents and to aid adhesion or functionality of some fingerprint powders; however, the morphology, thickness, coverage and composition of the aluminosilicates are the primary differences between the white powder formulations and could be related to variation in the efficacy of print development.This work is part funded by the Home Office Scientific Development Branch, UK

Trends in Non-Assigned Reading by High School Seniors

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66634/2/10.1177_019263659608058417.pd

Explaining variation in nascent entrepreneurship

This paper aims at explaining cross-country variation in nascent entrepreneurship. Regression analysis is applied using various explanatory variables derived from three different approaches. We make use of the Global Entrepreneurship Monitor database, including nascent entrepreneurship rates for 36 countries in 2002 as well as variables from standardized national statistics. The first approach relates the level of entrepreneurship of a country to its level of economic development. We find evidence for a U-shaped relationship. The second approach deals with a regime switch where the innovative advantage moves from large, established enterprises to small and new firms, because new technologies have reduced the importance of scale economies in many sectors. The third approach assumes that nascent entrepreneurship partly depends upon various non-economic conditions in the domains technology, demography, culture and institutions, influencing opportunities, resources, skills and preferences. Several indicators of these aggregate conditions are found to influence nascent entrepreneurship. A full, eclectic model combining the three approaches includes a U-shaped relationship with per capita income as well as with Porter's innovative capacity index in addition to effects of the total business ownership rate (+), social security expenditure (-), the aggregate tax rate (+) and population growth (+). In the model a '(former) centralized command economies' dummy also plays a role (-). Finally, the paper investigates whether determinants of nascent entrepreneurship differ for opportunity-based and necessity- based forms of entrepreneurial activity. A U-shaped relationship with per capita income as well as with the innovative capacity index is only found for opportunity-based entrepreneurial activity. For economically advanced nations striving to promote entrepreneurship, the results suggest that improving incentive structures for entrepreneurship and promoting the entrepreneurial exploitation of scientific findings offer a promising approach for public policy

Explaining nascent entrepreneurship across countries

This paper aims at explaining cross-country variation in nascent entrepreneurship. Regression analysis is applied using various explanatory variables derived from three different approaches. We make use of the Global Entrepreneurship Monitor database, including nascent entrepreneurship rates for 36 countries in 2002 as well as variables from standardized national statistics. The first approach relates the level of entrepreneurship of a country to its level of economic development. We find evidence for a U-shaped relationship. The second approach deals with a regime switch where the innovative advantage moves from large, established enterprises to small and new firms, because new technologies have reduced the importance of scale economies in many sectors. The third approach assumes that nascent entrepreneurship depends upon aggregate conditions such as technology, demography, culture and institutions, influencing opportunities, resources, skills and preferences. Several indicators of these aggregate conditions are found to correlate with nascent entrepreneurship. A full model combining the three approaches includes a U-shaped relationship with per capita income as well as with Porter’s innovative capacity index in addition to effects of social security expenditure (-) and the total business ownership rate (+). Finally, a (former) communist-country dummy plays an important role

Radio Source Heating in the ICM: The Example of Cygnus A

One of the most promising solutions for the cooling flow problem involves energy injection from the central AGN. However it is still not clear how collimated jets can heat the ICM at large scale, and very little is known concerning the effect of radio lobe expansion as they enter into pressure equilibrium with the surrounding cluster gas. Cygnus A is one of the best examples of a nearby powerful radio galaxy for which the synchrotron emitting plasma and thermal emitting intra-cluster medium can be mapped in fine detail, and previous observations have inferred possible shock structure at the location of the cocoon. We use new XMM-Newton observations of Cygnus A, in combination with deep Chandra observations, to measure the temperature of the intra-cluster medium around the expanding radio cavities. We investigate how inflation of the cavities may relate to shock heating of the intra-cluster gas, and whether such a mechanism is sufficient to provide enough energy to offset cooling to the extent observed.Comment: To appear in the Proceedings of "Heating vs. Cooling in Galaxies and Clusters of Galaxies", August 2006, Garching (Germany), Eds. H. Boehringer, G.W. Pratt, A. Finoguenov, P. Schuecker, Springer-Verlag series "ESO Astrophysics Symposia", p.101, in press. 8 pages, 3 multiple figure

Effects of climate change on reproduction,larval development, and adult health of coral trout (Plectropomus spp.)

Climate change is emerging as the single greatest threat to coral-reef ecosystems.The most immediate impacts will be a loss of diversity and changes to fish community composition and may lead to eventual declines in abundance and productivity of key fisheries species. A key component of this research is to assess effects of projected changes in environmental conditions (temperature and ocean acidity) due to climate change on reproduction, growth and development of coral trout (Plectropomus leopardis).Ultimately, this research will fill key knowledge gaps about climate change impacts on larger fishes, which are fundamental to optimizing resilience-based management, and in turn improve the adaptive capacity of industries and communities along the Great Barrier Reef

Nanostructure and paramagnetic centres in diamond-like carbon: Effect of Ar dilution in PECVD process

Diamond-like carbon (DLC) films were deposited utilising plasma enhanced chemical vapour deposition (PECVD) with acetylene precursor, diluted with 0 – 45% argon. Electron paramagnetic resonance (EPR) measurements show the presence of one paramagnetic centre with no change in spin population over the range of film deposition conditions. However, the EPR linewidth decreases with increasing argon content of the precursor mix, suggesting an enhancement of motional narrowing due to an increase in electron delocalization, related to an increase in the sp2 cluster size. Atomic force microscopy (AFM) measurements indicate the surface of the DLC is formed of nanoscale asperities of material. With radii of tens of nanometres for films deposited with zero argon, the size of the features increases with the argon dilution of the acetylene. Energy dispersive x-ray analysis and electrical measurements further elucidate the changes in film structure

Thinking about growth : a cognitive mapping approach to understanding small business development

School of Managemen

Exceptionally Slow Rise in Differential Reflectivity Spectra of Excitons in GaN: Effect of Excitation-induced Dephasing

Femtosecond pump-probe (PP) differential reflectivity spectroscopy (DRS) and four-wave mixing (FWM) experiments were performed simultaneously to study the initial temporal dynamics of the exciton line-shapes in GaN epilayers. Beats between the A-B excitons were found \textit{only for positive time delay} in both PP and FWM experiments. The rise time at negative time delay for the differential reflection spectra was much slower than the FWM signal or PP differential transmission spectroscopy (DTS) at the exciton resonance. A numerical solution of a six band semiconductor Bloch equation model including nonlinearities at the Hartree-Fock level shows that this slow rise in the DRS results from excitation induced dephasing (EID), that is, the strong density dependence of the dephasing time which changes with the laser excitation energy.Comment: 8 figure

Nonextensivity of the cyclic Lattice Lotka Volterra model

We numerically show that the Lattice Lotka-Volterra model, when realized on a square lattice support, gives rise to a {\it finite} production, per unit time, of the nonextensive entropy $S_q= \frac{1- \sum_ip_i^q}{q-1}$ $(S_1=-\sum_i p_i \ln p_i)$. This finiteness only occurs for $q=0.5$ for the $d=2$ growth mode (growing droplet), and for $q=0$ for the $d=1$ one (growing stripe). This strong evidence of nonextensivity is consistent with the spontaneous emergence of local domains of identical particles with fractal boundaries and competing interactions. Such direct evidence is for the first time exhibited for a many-body system which, at the mean field level, is conservative.Comment: Latex, 6 pages, 5 figure