A photothermal deflection experiment with a variable angle pump beam is presented. It is shown that directional absorptivity of rough or corrugated opaque samples can be measured by this technique. As an illustration the absorptivity in p an s polarization of a 2D surface-relief silicon grating is studied. Grating anomalies are detected and qualitatively discussed in the framework of an electro...

Solar light-driven hydrogen by photocatalytic water splitting over a semiconductor photoelectrode has been considered promising green energy carrier. P-type semiconducting copper oxides (Cu2O and CuO) have attracted remarkable attention as an efficient photocathode for photoelectrochemical (PEC) because of their high solar absorptivity optical band gaps. In this study, CuO thin films were prepa...

The change in absorptivity during the degradation process of materials is discussed, and its influence as one of the involved parameters in the degradation models is studied. Three materials with very different behaviors are used for the demonstration of its role: a carbon composite material, which is opaque, almost grey, a plywood slab, which is opaque and spectral-dependent and a clear PMMA s...

The role of photochemical degradation of dissolved organic carbon (DOC) on UV transparency (280-400 nm) was investigated in three Pocono Plateau lakes. Diffuse attenuation coefficients (I&) in the epilimnia of these lakes varied seasonally (39-8 1% decline from maximum Z&,&, with minimum Kduv values occurring near summer solstice. Declines in K,,, corresponded to reductions in UV absorbance by ...

We have developed a new spectrophotometric assay for urinary N-acetyl-beta-D-glucosaminidase (NAGase) with use of sodio m-cresolsulfonphthaleinyl N-acetyl-beta-D-glucosaminide (MCP-NAG). MCP-NAG was synthesized from acetochloro-glucosamine and m-cresolsulfonphthalein (MCP) in four steps. MCP-NAG reacts well with NAGase (Km = 0.41 mmol/L) and is highly water soluble. The absorption maximum and m...

This paper presents an optimization algorithm for designing linear concentrating solar collectors using stochastic programming. A Monte Carlo technique is used to quantify the performance of the collector design in terms of an objective function, which is then minimized using a modified Kiefer-Wolfowitz algorithm that uses sample size and step size controls. This process is more efficient than ...

The incorporation of squaraines into DNA via the phosphoramidite approach is described. High molar absorptivity, environment-sensitive fluorescence properties and intense CD effects render squaraines valuable building blocks for DNA-based optical probes and nanostructures.