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.
Controllable assembly of zeolite beta monolayers and bilayers on various substrates using the Langmuir-Blodgett technique
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.
Preparation of mesoporous Al-MCM-41 from natural palygorskite and its adsorption performance for hazardous aniline dye-basic fuchsin
Contributors: Yuan Guan, Shaomang Wang, Xin Wang, Cheng Sun, Yongbo Wang, Lingjie Hu
... 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: T. Dorn, A. Janssen, J.C. de Keijzer, G.L. van Rijk-Zwikker, U.J.L. Reijnders, J.S.K. Luitse, E. Vandewalle, M.P. Gorzeman, R.C. van Nieuwenhuizen, M. Ceelen
... This study describes how many detainees have been referred to emergency departments for further evaluation or emergency care while in police custody in Amsterdam (years 2012/2013). It provides insights into the diagnoses assigned by forensic doctors and hospital specialists and the appropriateness of the referrals. We made use of the electronic registration system of the Forensic Medicine Department of the Public Health Service Amsterdam. This department is in charge of the medical care for detainees in the Amsterdam region. Hospital diagnoses were obtained through collaboration with several Amsterdam-based hospitals. According to our results, in 1.5% of all consultations performed, the detainee was referred to hospital. The most frequent reasons for referral were injuries (66%), intoxication/withdrawal (11%) and cardiac problems (7%). In 18% of all referrals, hospital admission (defined as at least one night in the hospital) was the consequence. After review of hospital files, the indication for referral as stated by the forensic physician was confirmed in 77% of all cases. A minority of referrals was considered unnecessary (7%). The identified cases allow for a discussion of cases of over-referral. Future research should focus on the problem of under-referral and associated health risks.
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.
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.
Police custody in the north of England: Findings from a health needs assessment in Durham and Darlington
Contributors: Charlie Brooker, Karen Tocque, Damian Mitchell, Malcolm Pearce
... To report on a health needs assessment undertaken in the Durham Constabulary (England) in 2013.
Contributors: V. Shabunko, C.M. Lim, S. Mathew
... 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.
Contributors: Sergey Bereg, Binay Bhattacharya, Sandip Das, Tsunehiko Kameda, Priya Ranjan Sinha Mahapatra, Zhao Song
... 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.
Electrical Engineering - Universal shift register implementation using quantum dot cellular automata
Contributors: Tamoghna Purkayastha, Debashis De, Tanay Chattopadhyay
... Quantum-dot Cellular Automata (QCA) demands to be a promising alternative of CMOS in ultra large scale circuit integration. Arithmetic and logic unit designs using QCA are of high research interest. A layout of four and eight bit universal shift register (USR) has been proposed. Initially QCA layouts of D flip-flop with clear and 4 to 1 multiplexer are designed, which are extended to design 4 and 8-bit parallel in parallel out (PIPO) shift register. Finally the PIPO is utilized to design 4-bit and 8-bit USR. By the comparative analysis it is observed that the proposed D Flip-flop achieved 40% clock delay improvement, whereas the modified layout of 4 to 1 multiplexer achieved 30% cell count reduction and 17% clock delay reduction from the previous works. This results in 31% reduction in cell count, 45% reduction in area and 55% reduction in clock cycle delay in 8 bit USR layout.