3,556 research outputs found

    Thermodynamic behaviour of two-dimensional vesicles revisited

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    We study pressurised self-avoiding ring polymers in two dimensions using Monte Carlo simulations, scaling arguments and Flory-type theories, through models which generalise the model of Leibler, Singh and Fisher [Phys. Rev. Lett. Vol. 59, 1989 (1987)]. We demonstrate the existence of a thermodynamic phase transition at a non-zero scaled pressure p~\tilde{p}, where p~=Np/4π\tilde{p} = Np/4\pi, with the number of monomers N→∞N \rightarrow \infty and the pressure p→0p \rightarrow 0, keeping p~\tilde{p} constant, in a class of such models. This transition is driven by bond energetics and can be either continuous or discontinuous. It can be interpreted as a shape transition in which the ring polymer takes the shape, above the critical pressure, of a regular N-gon whose sides scale smoothly with pressure, while staying unfaceted below this critical pressure. In the general case, we argue that the transition is replaced by a sharp crossover. The area, however, scales with N2N^2 for all positive pp in all such models, consistent with earlier scaling theories.Comment: 6 pages, 4 figures, EPL forma

    Sickle cell disease status among school adolescents and their tribal community in South Gujarat

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    Objectives: to create awareness, to screen samples of school adolescents and then to reach their community through them by doing surveillance for sickle cell disease. Design: Field based cross-sectional study. Settings: St Xavier`s high school and Vanraj high school of Umarpada taluka of Surat district. Subjects: School adolescents, their parents and friends. Method: After taking permission from school authority, blood samples of 948 school adolescents were taken for DTT test and then for electrophoresis. Blood samples of motivated parents and friends of those adolescents found positive for DTT was taken in subsequent visit and results were communicated to them. Results: Blood samples of 948 school adolescents, out of 1081 were tested for DTT test. It was positive in 242 samples, giving a prevalence of 25.5% for sickle cell disease. On subjecting the positive blood samples to electrophoresis, the proportion of sickle cell trait and sickle cell disease was found to be 92% and 8% respectively. Then electrophoresis was done in 64 parents and friends, 24 (37.5%) of them were found positive of which, 14 (58%) were having sickle cell trait and 10 (42%) having sickle cell disease. Conclusion: approaching community can be possible through school adolescents for conduction of surveillance of sickle cell anemi

    A Modified Architecture of Multiplier and Accumulator Using Spurious Power Suppression Technique

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    High speed and low power Multiplier and Accumulator (MAC) unit is at most requirement of today’s VLSI systems and digital signal processing (DSP) applications like FFT, Finite Impulse response filters, convolution etc. In this modified architecture, Radix-4 Modified Booth Encoding (MBE) is used to produce the partial products. In this multiplication and accumulation has been combined using a hybrid type of Carry Save Adder (CSA). So the performance will be improved. A Carry Look ahead Adder is inserted in the CSA tree to reduce the number of bits in the final adder. In booth multiplication, when two numbers are multiplied some portion of the data may be zero. By neglecting those data, power has been reduced. For this purpose Spurious Power Suppression Technique (SPST) is used to remove useless portion of the data in addition process. In this modified architecture, the overall process is three stages to produce the result. The modified MAC operation is coded with Verilog and simulated using Xilinx 12.1
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