Contributors:F.M. Siam, M. Grinfeld, A. Bahar, H.A. Rahman, H. Ahmad, F. Johar
The main goal of our study is to develop a realistic mechanistic model of the effect of ionizing radiation on DNA in mammalian cells. We consider a population of cells structured by the number of DNA double strand breaks due to radiation. Using the system of linear differential equation, the model describes the evolution of the irradiated population of cells in time. The work is in three parts. First, we consider the effect of a single dose of radiation, while in the second part we work on the model parameter estimation using Nelder–Mead simplex algorithm which allows us to relate the clinically useful parameters of the LQ relation to aspects of cellular activity that can be manipulated experimentally. In the third part, we deal with cell killing effects of fractioned doses of radiation. Using MATLAB, we observed the cell survival fractions can be well approximated by the Linear–Quadratic relation and also show fewer cell will die if the dose is fractionated in two or more fractions.
Contributors:Honghong Xu, Baoquan Zhang, Jian Li, Xiufeng Liu
The Langmuir-Blodgett (L-B) technique was employed to fabricate the monolayers and bilayers of nano-sized beta (nano-beta) crystals, and the monolayers of micrometer-sized beta (micro-beta) crystals on various substrates including glass plate, α-Al2O3 disk, glass capillary tube, copper wire, stainless-steel tube and γ-Al2O3 tube. With respect to the methanol suspension of 1 wt.% Nano-beta modified with cetyltrimethylammonium bromide (CTAB), a two-region surface pressure-area isotherm was obtained, leading to the formation of both Nano-beta monolayers and bilayers with satisfactory degree of coverage (DOC) and close packing (DCP) under each transfer surface pressure. When nano-beta crystals were dealuminated, the surface pressure-area relation was reduced to the one-region isotherm, and the resulting L-B film contained aggregated areas. As for the assembly of micro-beta crystals, both methanol and sec-butanol were used as the dispersant. The resulting micro-beta monolayer was randomly oriented with the sedimentation of large truncated-square-bipyramid crystals on compression by using the methanol suspension. The use of sec-butanol as the dispersant resulted in the enhanced hydrophobicity of micro-beta crystals due to the chemical reaction of sec-butanol molecules with surface silanols, leading to the formation of c-oriented micro-beta monolayers over various substrates, and simultaneously the sedimentation of large truncated-square-bipyramid crystals did not occur. Under the structure direction of the c-oriented micro-beta monolayer in the seeded growth, the dense and preferentially c-oriented zeolite beta film could be fabricated, which could not be formed on either the Nano-beta monolayer or the micro-beta monolayer with random orientation. Therefore, it would be concluded that the growth of beta crystals over the seed layer could be followed by the epitaxial growth mechanism.
A promising mesoporous SiAl material, Al-MCM-41 was successfully prepared by alkali calcination leaching of natural palygorskite, and sequent hydrothermal synthesis coupled with calcination. The morphology, structure, surface area and pore-size distribution of the material were characterized by scanning electron microscopy, small-angle X-ray diffraction and N2 adsorption–desorption isotherms. The Al-MCM-41 possessed better crystallinity and larger specific surface area with CTAB/SiO2 mass ratio of 0.1:1, pH of 5, crystallization temperature of 110 °C, crystallization time of 12 h and calcination of 550 °C for 5 h. The Al-MCM-41 was used as an adsorbent for the removal of hazardous aniline dye-basic fuchsin from water. Adsorption kinetics and isotherms analysis indicated that adsorption of basic fuchsin onto Al-MCM-41 followed pseudo-first-order model and Langmuir adsorption isotherm. In addition, intra-particle diffusion was rate determining step of the adsorption process. The results demonstrated that the as-synthesized Al-MCM-41 had potential applications in the treatment of waste water.
Contributors:Beatriz Fernández-Muñiz, José Manuel Montes-Peón, Camilo José Vázquez-Ordás
The sensitivity of occupational accidents to the economic cycle can shed light on the effectiveness of occupational health and safety policies. This work analyses the effect of the economic cycle on occupational accidents in Spain in the period 1994–2014. We first perform a regression analysis to evaluate the relation between GDP growth and incidence rate, comparing Spain and Germany. Statistics on GDP growth (OECD) and standardised incidence rates (from Eurostat) are used. Then, from a sectorial perspective, we perform a variance decomposition analysis to measure the effect of the increase in the incidence rates on the growth in the number of accidents in Spain between 2013 and 2014. We use data disaggregated by sector from national databases on occupational accidents to this end.
Deaths in police custody often attract a huge amount of public interest and are frequently associated with controversy related to causation. While systematic investigations of deaths in police custody are currently available for countries in Europe, North America and Australia, the different inclusion and exclusion criteria and the lack of a uniform definition limits their comparability.
Contributors:S. Heide, P. Chariot, P. Green, J. Fabian, J.J. Payne-James
Death and harm is well-recognised in detainees in police custody worldwide. Based on the results of previous global surveys and the CPT (European Committee for the Prevention of Torture) recommendations a questionnaire was developed to summarise the current medical aspects of police custody in European countries. The survey was distributed to named contacts in all European countries. Data from 25 European countries was obtained.
The current financial crisis has imposed significant pressure upon the labour market and working conditions while, at the same time, Occupational Safety and Health (OSH) is challenged. Crucial organizational functions such as training, new work equipment purchasing and innovation are mainly affected. Literature suggests a positive correlation between a country’s GDP (Gross Domestic Product) and accidents’ rate with a respective phase shift (time lag) representing the required time needed for adaptation.
Energy performance of buildings is a highly important measure for Energy Efficiency and Conservation initiatives. The fundamental step toward the understanding of energy use is benchmarking. In this study, the EnergyPlus simulation tool is used to benchmark the energy performance of 400 residential buildings from which three types of buildings were classified. EnergyPlus models were developed for the three types of building designs typically found in the national housing scheme in Brunei Darussalam. The EnergyPlus models produced the energy use intensity (EUI) per year for these buildings, with values ranging from approximately 64.2 to 47.8kWh/m2. The EnergyPlus outputs were verified against the power consumption data, and data from selected door-to-door survey. This study demonstrates the capability of engineering models in producing benchmarking, and simulating conditions for the improvements of energy performance in buildings.
We investigate three kinds of optimization problems regarding n points in the 2-dimensional plane that need to be enclosed by squares. (1) Find a given number of squares that enclose all the points, minimizing the size of the largest square used. (2) Problem (1) with the additional condition that the center of each enclosing square must lie on one of the two given axis-parallel lines, which are either parallel or perpendicular. (3) Enclose the maximum number of points, using a specified number of squares of a fixed size.