The laser-induced damage threshold properties of material structures play a key role in identifying and selecting optimum materials with the respective geometric configurations for laser shielding applications. The laser-induced damage mechanism is predominantly influenced by the absorption, thermal conductivity, and transition temperature characteristics of the materials. Ultrahigh-molecular weight polyethylene (UHMW-PE) ballistic composite sheet structures, traditionally employed for conventional ballistic purposes, merit examination for their laser shielding capabilities, leveraging their established use in conventional shielding applications.
View Article and Find Full Text PDFHeterojunction formation is the key to adjusting the electronic and optoelectronic properties of various semiconductor devices. There have been various reports on the formation and importance of semiconducting heterojunction devices based on metal oxides. Titanium dioxide (TiO) is one of the metal oxides that has many unique properties.
View Article and Find Full Text PDFA rapid and in situ method has been developed to detect and quantify adulterated milk powder through adding whey powder by using laser induced breakdown spectroscopy (LIBS). The methodology is based on elemental composition differences between milk and whey products. Milk powder, sweet and acid whey powders were produced as standard samples, and milk powder was adulterated with whey powders.
View Article and Find Full Text PDFFor understanding the mechanisms of low-level laser/light therapy (LLLT), accurate knowledge of light interaction with tissue is necessary. We present a three-dimensional, multilayer reduced-variance Monte Carlo simulation tool for studying light penetration and absorption in human skin. Local profiles of light penetration and volumetric absorption were calculated for uniform as well as Gaussian profile beams with different spreads over the spectral range from 1000 to 1900 nm.
View Article and Find Full Text PDFThis article reports a combined experimental and numerical study on the efficient operation of Porous Substrate Bioreactors. A comprehensive model integrating light transport, mass transport, and algal growth kinetics was used to understand the productivity of photosynthetic biofilms in response to delivery rates of photons and nutrients. The reactor under consideration was an evaporation driven Porous Substrate Bioreactor (PSBR) cultivating the cyanobacteria Anabaena variabilis as a biofilm on a porous substrate which delivers water and nutrients to the cells.
View Article and Find Full Text PDFBiotechnol Prog
September 2014
This article presents a multispectral image analysis approach for probing the spectral backscattered irradiance from algal cultures. It was demonstrated how this spectral information can be used to measure algal biomass concentration, detect invasive species, and monitor culture health in real time. To accomplish this, a conventional RGB camera was used as a three band photodetector for imaging cultures of the green alga Chlorella sp.
View Article and Find Full Text PDFColloids Surf B Biointerfaces
December 2013
This paper reports the cell to substratum and cell to cell interactions of a diverse group of microalgae based on the Extended Derjaguin, Landau, Verwey, Overbeek (XDLVO) approach using the previously reported physico-chemical surface properties. The microalgae included 10 different species of green algae and diatoms from both freshwater and saltwater environments while the substrata included glass, indium-tin oxide (ITO), stainless steel, polycarbonate, polyethylene, and polystryrene. The results indicated that acid-base interactions were the dominating mechanism of interaction for microalgae.
View Article and Find Full Text PDFThis study reports a comprehensive set of experimentally measured physico-chemical surface properties of 12 different microalgae including fresh and seawater species of green algae, diatoms and cyanobacteria. The surface free energy and its components including the acid-base (AB), van der Waals (LW), electron donor/acceptor parameters were quantified based on contact angle measurements along with the Lifshitz-van der Waals acid-base approach using the probe liquid surface tension parameters proposed by van Oss et al. as well as by Della Volpe and Siboni.
View Article and Find Full Text PDFThis paper reports the cell-substratum interactions of planktonic (Chlorella vulgaris) and benthic (Botryococcus sudeticus) freshwater green algae with hydrophilic (glass) and hydrophobic (indium tin oxide) substrata to determine the critical parameters controlling the adhesion of algal cells to surfaces. The surface properties of the algae and substrata were quantified by measuring contact angle, electrophoretic mobility, and streaming potential. Using these data, the cell-substratum interactions were modeled using thermodynamic, DLVO, and XDLVO approaches.
View Article and Find Full Text PDFThis article reports a novel multispectral image processing technique for rapid, noninvasive quantification of biomass concentration in attached and suspended algae cultures. Monitoring the biomass concentration is critical for efficient production of biofuel feedstocks, food supplements, and bioactive chemicals. Particularly, noninvasive and rapid detection techniques can significantly aid in providing delay-free process control feedback in large-scale cultivation platforms.
View Article and Find Full Text PDFThis study presents a second-order energy return on investment analysis to evaluate the mutual benefits of combining an advanced wastewater treatment plant (WWTP) (with biological nutrient removal) with algal biofuel production. With conventional, independently operated systems, algae production requires significant material inputs, which require energy directly and indirectly, and the WWTP requires significant energy inputs for treatment of the waste streams. The second-order energy return on investment values for independent operation of the WWTP and the algal biofuels production facility were determined to be 0.
View Article and Find Full Text PDFThis paper reports the construction and performance of an algae biofilm photobioreactor that offers a significant reduction of the energy and water requirements of cultivation. The green alga Botryococcus braunii was cultivated as a biofilm. The system achieved a direct biomass harvest concentration of 96.
View Article and Find Full Text PDFRheological properties of microalgae slurries were measured as a function of biomass concentration from 0.5 to 80 kg/m(3) for Nannochloris sp., Chlorella vulgaris, and Phaeodactylum tricornutum.
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