Design, manufacturing, and performance analysis of mid-infrared achromatic half-wave plates with diamond subwavelength gratings

In this paper, we present a solution for creating robust monolithic achromatic half-wave plates (HWPs) for the infrared, based on the form birefringence of subwavelength gratings (SWGs) made out of diamond. We use the rigorous coupled wave analysis to design the gratings. Our analysis shows that diamond, besides its outstanding physical and mechanical properties, is a suitable substrate to manufacture mid-infrared HWPs, thanks to its high refractive index, which allows etching SWGs with lower aspect ratio. Based on our optimized design, we manufactured a diamond HWP for the 11-13.2?μm region, with an estimated mean retardance ～3.143±0.061 rad (180.08±3.51°). In addition, an antireflective grating was etched on the backside of the wave plate, allowing a total transmittance between 89% and 95% over the band.     

Nanophotonic switch: gold-in-Ga2O3 peapod nanowires

A novel metal-insulator heterostructure made of twinned Ga2O3 nanowires embedding discrete gold particles along the twin boundary was formed through a reaction between gold, gallium, and silica at 800 degrees C during simple thermal annealing. The Au-in-Ga2O3 peapods spontaneously crystallized under phase separation induced by the formation of twin boundaries. The nanostructures were analyzed by field emission scanning (FESEM) and transmission electron microscopes (FETEM), and their photoresponse was investigated using a double-frequency Nd:YAG laser with a wavelength of 532 nm on a designed single-nanowire device. The surface plasmon resonance (SPR) effects of embedded Au nanoparticles are proposed to be responsible for the remarkable photoresponse of these novel structures.     

Mixed-Weibull parameter estimation for burn-in data using the Bayesian approach

A Bayesian approach is presented for both grouped and ungrouped burn-in test data, to come up with the posterior parameters of the bimodal mixed-Weibull distribution. The concepts of belonging probabilities and fractional ranks are introduced for this approach. A numerical comparison is made by conducting the Kolmogorov-Smirnov goodness-of-fit test on the parameter estimates obtained by Jensen's graphical method, by the Bayesian approach using the conventional separation plotting method and by the Bayesian approach using the fractional rank plotting method. It turns out that the Bayesian approach with the fractional rank plotting method yields the best results.     

3Gmap L-systems: an application to the modelling of wood

In this paper an extension of L-systems is proposed, based on three-dimensional (3D) generalized maps that allow an easier control of the internal structure of 3D objects. A first and original application of this extension is also proposed: wood modelling by growth simulation. Numerous other applications of our work are possible, in the area of computer graphics, as well as in botanical science.     

Trends of enrichment of free mica grains in crushed rock aggregates

The paper reports a study of the behaviour of free mica grains in crushed rock aggregates of metamorphic origin undertaken to identify any typical trends of enrichment with grain size. The mineralogical composition of the various grain size fractions was obtained using a polarizing microscope and point counting. Two general trends of enrichment of mica are presented: Type I (isotropic source rock) and Type A (anisotropic source rock). Type I is associated with a general increase in free mica towards the finer fraction, with or without a peak for “coarser” grain fractions. Type A is associated with an increase in free mica up to a certain grain fraction, after which there is a decrease with progressively smaller grain size.      

Young adolescent cancer survivors and their parents: Adjustment, learning problems, and gender.

Investigated adjustment in 59 10–15 yr old long-term survivors of childhood cancer and their parents at 2 points 1 yr apart. Behavioral concerns, parental distress, anxiety, hopelessness, social support, and family functioning were assessed. Gender and the presence of learning problems were examined. The data indicated levels of adjustment that were near normative levels. However, gender differences were found, with male adolescents reporting low levels of anxiety and hopelessness. Those survivors with learning difficulties appeared particularly vulnerable with respect to long-term adjustment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multiplier methods: A survey

The purpose of this paper is to provide a survey of convergence and rate of convergence aspects of a class of recently proposed methods for constrained minimization—the, so-called, multiplier methods. The results discussed highlight the operational aspects of multiplier methods and demonstrate their significant advantages over ordinary penalty methods.     

Life-cycle cost analysis of reinforced concrete structures in marine environments

Chloride-induced corrosion of carbon steel reinforcement is the main cause of deterioration of reinforced concrete (RC) structures in marine environments. One of the ways to protect RC structures from corrosion is to use corrosion-resistant stainless steel reinforcing bars. However, stainless steel is between six and nine times more expensive than carbon steel. Thus, its use can only be justified on a life-cycle cost basis. In the paper a time-variant probabilistic model was presented to predict expected costs of repair and replacement which was then used to calculate life-cycle costs for RC structures in marine environments under different exposure conditions. Results of the life-cycle cost analysis can be applied to select optimal strategies improving durability of RC structures in marine environments, including the use of stainless steel reinforcement.