Bose-Einstein Correlations and Sonoluminescence

Sonoluminescence may be studied in detail by intensity correlations among the emitted photons. As an example, we discuss an experiment to measure the size of the light-emitting region by the Hanbury Brown-Twiss effect. We show that single bubble sonoluminescence is almost ideally suited for study by this method and that plausible values for the physical parameters are within easy experimental reach. A sequence of two and higher order photon correlation experiments is outlined.Comment: Latex File, 8 pages, Postscript file with 2 figs. attache

Block copolymer self-assembly for nanophotonics

The ability to control and modulate the interaction of light with matter is crucial to achieve desired optical properties including reflection, transmission, and selective polarization. Photonic materials rely upon precise control over the composition and morphology to establish periodic interactions with light on the wavelength and sub-wavelength length scales. Supramolecular assembly provides a natural solution allowing the encoding of a desired 3D architecture into the chemical building blocks and assembly conditions. The compatibility with solution processing and low-overhead manufacturing is a significant advantage over more complex approaches such as lithography or colloidal assembly. Here we review recent advances on photonic architectures derived from block copolymers and highlight the influence and complexity of processing pathways. Notable examples that have emerged from this unique synthesis platform include Bragg reflectors, antireflective coatings, and chiral metamaterials. We further predict expanded photonic capabilities and limits of these approaches in light of future developments of the field

Haematological Response of Clarias Gariepinus to Rubber Processing Effluent

Industrialization has led to huge waste generation over the last decades, the absence of adequate facilities for treating such wastes in most developing nations has led to the discharge of effluents into the environment without proper treatment. Toxicological effects of effluents from rubber processing plant (collected during the period of low rivertide i.e. between October 2012 and February 2013) were carried out in this study. Lethal concentration (96-h LC50) was evaluated using 0.25mg/L, 0.30mg/L, 0.35mg/L and 0.40mg/L while sub-lethal effects (42 days) was carried out on haematological parameters like Red Blood Cell (RBC), White Blood Cell (WBC), Haemoglobin (Hb), Packed Cell Volume (PCV), Mean Corpuscular Volume (MCV), Mean Corpuscular Haemoglobin (MCH) and Mean Corpuscular Haemoglobin Concentration (MCHC) using 0.064mg/L, 0.048mg/L, 0.032mg/L and 0.016mg/L which are the 20%, 15%, 10% and 5% of the 96-h LC50 value. Mortality increased as the concentrations of the effluent increases and 0.32mg/L was obtained as LC50. In comparison with the control, the mean value obtained for PCV, HB and RBC showed significant differences (P<0.05) most especially at highest concentration while there was no significant difference in all values obtained for WBC, MCV, MCH and MCHC. It was concluded that the rubber processing effluent had some negative effect on the haematology of Clarias gariepinus. Therefore, it is recommended that the effluent should be properly treated before discharge into the environme

Mollusk species at a Pliocene shelf whale fall (Orciano Pisano, Tuscany)

The recovery of an intact, 10 m long fossil baleen whale from the Pliocene of Tuscany (Italy) offers the first opportunity to study the paleoecology of a fully developed, natural whale-fall community at outer shelf depth. Quantitative data on mollusk species from the whale fall have been compared with data from the sediments below and around the bones, representing the fauna living in the muddy bottom before and during the sinking of the carcass, but at a distance from it. Although the bulk of the fauna associated with the fossil bones is dominated by the same heterotrophs as found in the surrounding community, whale-fall samples are distinguishable primarily by the presence of chemosymbiotic bivalves and a greater species richness of carnivores and parasites. Large lucinid clams (Megaxinus incrassatus) and very rare small mussels (Idas sp.) testify to the occurrence of a sulphophilic stage, but specialized, chemosymbiotic vesicomyid clams common at deep-sea whale falls are absent. The whale-fall community is at the threshold between the nutrient-poor deep sea and the shallow-water shelf, where communities are shaped around photosynthetic trophic pathways and chemosymbiotic specialists are excluded by competition. © SEPM (Society for Sedimentary Geology)

Measuring electron energy distribution by current fluctuations

A recent concept of local noise sensor is extended to measure the energy resolved electronic energy distribution $f(\varepsilon)$ at a given location inside a non-equilibrium normal metal interconnect. A quantitative analysis of $f(\varepsilon)$ is complicated because of a nonlinear differential resistance of the noise sensor, represented by a diffusive InAs nanowire. Nevertheless, by comparing the non-equilibrium results with reference equilibrium measurements, we conclude that $f(\varepsilon)$ is indistinguishable from the Fermi distribution

Phase behavior and material properties of hollow nanoparticles

Effective pair potentials for hollow nanoparticles like the ones made from carbon (fullerenes) or metal dichalcogenides (inorganic fullerenes) consist of a hard core repulsion and a deep, but short-ranged, van der Waals attraction. We investigate them for single- and multi-walled nanoparticles and show that in both cases, in the limit of large radii the interaction range scales inversely with the radius, $R$, while the well depth scales linearly with $R$. We predict the values of the radius $R$ and the wall thickness $h$ at which the gas-liquid coexistence disappears from the phase diagram. We also discuss unusual material properties of the solid, which include a large heat of sublimation and a small surface energy.Comment: Revtex, 13 pages with 8 Postscript files included, submitted to Phys. Rev.

Deformation and tribology of multi-walled hollow nanoparticles

Multi-walled hollow nanoparticles made from tungsten disulphide (WS$_2$) show exceptional tribological performance as additives to liquid lubricants due to effective transfer of low shear strength material onto the sliding surfaces. Using a scaling approach based on continuum elasticity theory for shells and pairwise summation of van der Waals interactions, we show that van der Waals interactions cause strong adhesion to the substrate which favors release of delaminated layers onto the surfaces. For large and thin nanoparticles, van der Waals adhesion can cause considerable deformation and subsequent delamination. For the thick WS$_2$ nanoparticles, deformation due to van der Waals interactions remains small and the main mechanism for delamination is pressure which in fact leads to collapse beyond a critical value. We also discuss the effect of shear flow on deformation and rolling on the substrate.Comment: Latex, 13 pages with 3 Postscript figures included, to appear in Europhysics Letter

Acute toxicity of synyhetic resin effluent to African Catfish, Clarias gariepinus [BURCHELL, 1822].

Aquatic pollution as a field has gained a lot of attention over the decades majorly because of the vital role the aquatic environment plays in the human lifecycle. Indusrial wastewaters are often generated and discharged into the environment without treatment. Toxicity of effluents from Synythetic Resin production plant were evaluated in this study. Acute toxicity (96-h LC50) was evaluated using 0.23, 0.31, 0.35 and 0.39 mg/L of the effluent in a renewal bioassay procedure. Physicochemical parameters of the effluent were also evaluated, the values obtained for lead, cyanide, total suspened solid, total hadness, total dissolved solids and alkalinity were higher than the Federal Environmental Protection Agency standard specification for effluent discharge into aquatic environment and as such contributed to the effluent's toxicity. Mortality increased as the concentrations of the effluent increases and 0.355mg/L was obtained as LC50. The research eventually revealed that the synthetic resin effluent has a high level of toxicity to catfish. Deleterious effects such as biomagnification and other abberations may occur in man if exposed to substantial concentration of the effluent

Co-digestion of Food Waste and Human Excreta for Biogas Production

The ever increasing cost of fossil fuels and its attendant pollution menace has provided the pedigree to consider alternative sources of energy. An investigation was launched into the design and construction of an Anaerobic Digester system from locally available raw materials using local technology and the production of biogas from food wastes and Human excreta generated within a University campus. The experiment lasted for 60 days using a 40-liters laboratory scale anaerobic digester. The volume of gas generated from the mixture was 84,750cm3 and comprised of 58% CH4, 24% CO2, and 19% H2S and other impurities. The physico-chemistry of the feedstock in the digester revealed an initial drop in pH to more acidic range and a steady increase 4.52 – 6.10. The temperature remained relatively constant at mesophilic range: 22.0ºC– 30.5ºC throughout the study. The Carbon/Nitrogen (C/N) ratio of the feedstock before digestion was within 139:1. Population distributions of the microflora show aerobic and anaerobic bacteria to include Klebsiella spp, Bacillus spp, Escherichia coli, Clostridium spp and a methanogen of the genera Methanococcus. In most developing nations of Sub-Saharan Africa where biomass is abundant, and where biogas technology is in its infant stage, the anaerobic digestion system could be the much awaited solution