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In this paper, we simulated and designed an all-optical Fredkin gate. The proposed structure is very simple and compact. We used air holes with radii of 177 nm in a silicon slab waveguide in a square lattice with a lattice constant of a = 466 nm. First, we created input and output waveguides in the structure. After that, by imposing a non-linear ring resonator, we controlled the coupling of light. This ring is composed of doped glass with linear and non-linear refractive indices of 1.4 and 10–14 m2/w respectively. The results of the time analysis showed that the worst rising time of the proposed gate is 0.61 ps and hence is very fast. We set the parameters of the lattice in a way that the proposed device works on λ = 1550 nm. All of the mentioned features make this gate suitable for all-optical integrated circuits. [ABSTRACT FROM AUTHOR]

Aim: Malaria is one of the most serious public health issues worldwide and is still responsible for the deaths of nearly half a million individuals every year worldwide. The aim of this study is to investigate the epidemiology of the incidence of and mortality from malaria and its association with the human development index (HDI). Subjects and methods: The present research is an ecological study conducted in 2017 that explored the association between the HDI and incidence of and mortality from malaria in WHO regions based on data extracted from the World Bank. In this study, the two-variable correlation method was adopted to analyze the data extracted to investigate the correlation between malaria incidence and HDI. A significance level of P < 0.05 was considered. The analyses were performed using Stata14 software. Results: The highest incidence of malaria in the world was reported in 2001 (80.73 per 1000 people) and the lowest in 2017 (59.12 per 1000). The results revealed a significant reverse correlation between malaria incidence (r = −0.640, P < 0.0001) and the HDI index in 2017. The analysis of HDI decomposites with malaria incidence in 2017 demonstrated a reverse and significant correlation between malaria incidence and gross national income per 1000 capita (r = −0.365, P < 0.0001), mean years of schooling (r = −0.477, P < 0.0001), life expectancy at birth (r = −0.694, P < 0.0001) and expected years of schooling (r = −0.458, P < 0.0001). Conclusion: Given the reverse correlation between malaria incidence and HDI, a greater emphasis on factors associated with the disease in these countries, effective prevention and awareness raising about the means of transmission can be effective in curbing the incidence of this disease. [ABSTRACT FROM AUTHOR]

In this paper, by using the non-linear effects and also destructive and constructive interferences between waveguides, we have designed and simulated an all-optical full-Subtractor based on two-dimensional photonic crystals. The proposed Subtractor has a very simple structure which is composed of 33 × 31 silicon rods immersed in air in a square lattice and involves three input ports (bits) and an additional waveguide to exhaust the unwanted light. We imposed some defect rods to control the behavior of the light. The used non-linear material, is a doped glass with 1.4 × 10–14 m2/w non-linear refractive index which is very greater than the non-linearity refractive index of silicon, 3.46 × 10–20 m2/w. Since the proposed structure is very simple and compact, it can be applicable in optical integrated circuits and optical calculations. [ABSTRACT FROM AUTHOR]