Surfactant-mediated variation of band-edge emission in CdS nanocomposites

The optical-structural characteristics of the direct optical band-gap semiconducting series of surfactant template-mediated laminar (CdS)x(CdCl2)y(CnH2n+4N)z nanocomposites are reported. X-ray diffraction measurements of the nanocomposites exhibited interlaminar distances in the range 2.9-3.6 nm with observations of eighth order {0 0 l} diffraction planes indicative of a high degree of laminarity and crystallographic order. Diffuse reflectance measurements have determined that the profile of their emission spectrum is that of a direct band-gap with absorption edges in the range 2.11-2.40 eV, depending on the CdS mole fraction in the nanocomposite. Photoluminescence (PL) excitation and time-resolved PL spectroscopies give an estimate of the maximum relative absorbance of the nanocomposites at ∼420 nm while the minimum was observed at ∼560 nm. The main emission was observed at ∼700 nm with emission from doubly ionized sulphur vacancies observed at ∼615 nm at room temperature. The CdS-containing nanocomposite is thus a surfactant-mediated modular system with variable band-gap energy emission.

The effect of alcohol consumption on household income in Ireland

This paper presents a study of the effects of alcohol consumption on household income in Ireland using the Slán National Health and Lifestyle Survey 2007 dataset, accounting for endogeneity and selection bias. Drinkers are categorised into one of four categories based on the recommended weekly drinking levels by the Irish Health Promotion Unit; those who never drank, non-drinkers, moderate and heavy drinkers. A multinomial logit OLS Two Step Estimate is used to explain individual's choice of drinking status and to correct for selection bias which would result in the selection into a particular category of drinking being endogenous. Endogeneity which may arise through the simultaneity of drinking status and income either due to the reverse causation between the two variables, income affecting alcohol consumption or alcohol consumption affecting income, or due to unobserved heterogeneity, is addressed. This paper finds that the household income of drinkers is higher than that of non-drinkers and of those who never drank. There is very little difference between the household income of moderate and heavy drinkers, with heavy drinkers earning slightly more. Weekly household income for those who never drank is €454.20, non-drinkers is €506.26, compared with €683.36 per week for moderate drinkers and €694.18 for heavy drinkers.

Average-case analysis of power consumption in embedded systems

Power efficiency is one of the most important constraints in the design of embedded systems since such systems are generally driven by batteries with limited energy budget or restricted power supply. In every embedded system, there are one or more processor cores to run the software and interact with the other hardware components of the system. The power consumption of the processor core(s) has an important impact on the total power dissipated in the system. Hence, the processor power optimization is crucial in satisfying the power consumption constraints, and developing low-power embedded systems. A key aspect of research in processor power optimization and management is “power estimation”. Having a fast and accurate method for processor power estimation at design time helps the designer to explore a large space of design possibilities, to make the optimal choices for developing a power efficient processor. Likewise, understanding the processor power dissipation behaviour of a specific software/application is the key for choosing appropriate algorithms in order to write power efficient software. Simulation-based methods for measuring the processor power achieve very high accuracy, but are available only late in the design process, and are often quite slow. Therefore, the need has arisen for faster, higher-level power prediction methods that allow the system designer to explore many alternatives for developing powerefficient hardware and software. The aim of this thesis is to present fast and high-level power models for the prediction of processor power consumption. Power predictability in this work is achieved in two ways: first, using a design method to develop power predictable circuits; second, analysing the power of the functions in the code which repeat during execution, then building the power model based on average number of repetitions. In the first case, a design method called Asynchronous Charge Sharing Logic (ACSL) is used to implement the Arithmetic Logic Unit (ALU) for the 8051 microcontroller. The ACSL circuits are power predictable due to the independency of their power consumption to the input data. Based on this property, a fast prediction method is presented to estimate the power of ALU by analysing the software program, and extracting the number of ALU-related instructions. This method achieves less than 1% error in power estimation and more than 100 times speedup in comparison to conventional simulation-based methods. In the second case, an average-case processor energy model is developed for the Insertion sort algorithm based on the number of comparisons that take place in the execution of the algorithm. The average number of comparisons is calculated using a high level methodology called MOdular Quantitative Analysis (MOQA). The parameters of the energy model are measured for the LEON3 processor core, but the model is general and can be used for any processor. The model has been validated through the power measurement experiments, and offers high accuracy and orders of magnitude speedup over the simulation-based method.

The effect of moderate gestational alcohol consumption during pregnancy on speech and language outcomes in children: a systematic review

Consensus has not been reached on safe alcohol consumption recommendations during pregnancy. The National Institutes for Care and Health Excellence (NICE) in the UK suggest that one to two drinks not more than twice per week is safe. However, the speech and language effects of even low levels of alcohol use among offspring are unknown. The aim of this study was to review systematically the evidence on studies of the effect of low to moderate levels of alcohol consumption during pregnancy (up to 70 grams of alcohol per week) compared to abstinence on speech and language outcomes in children.

Alcohol consumption among university students: a typology of consumption to aid the tailoring of effective public health policy

Objective: Elevated levels of alcohol consumption among university students are well documented. Policymakers have attempted to combat this issue at a university, national and international level. Tailoring public health policy to effectively tackle alcohol use is crucial. Using Q-methodology, the current study aims to develop a typology of alcohol consumption in the Irish university student population. Setting: A large Irish university. Participants Hundreds of possible statements on types of consumption were generated from a systematic review and a set of one-on-one interviews. These were reduced to 36 statements, 6 statements which define each of the 6 previously defined consumption types. Participants were advised to scan through the 36 statements and fill the statements into a ‘forced choice, standardised distribution’. Following this, a 45–90 min interview was conducted with students to illuminate subjectivity surrounding alcohol consumption. Analysis was conducted using PQ Method and NVivo software. Principal component analysis, followed by varimax rotation, was conducted to uncover the final factor information. Results: In total, 43 students completed the Q-study: 19 men and 24 women. A typology describing 4 distinct groupings of alcohol consumer was uncovered: the guarded drinker, the calculated hedonist, the peer-influenced drinker and the inevitable binger. Factor loadings of each of the consumer groupings were noted for type description. Conclusions: This is the first study to propose ideal types of alcohol consumption among a university student population. Further research is required to investigate the degree to which each of these ideal types is subscribed. However, this typology, in addition to informing public policy and strategies, will be a valuable analytic tool in future research.