Adsorptive removal of phthalate ester (Di-ethyl phthalate) from aqueous phase by activated carbon: a kinetic study

Adsorptive studies were carried out on Di-ethyl phthalate (DEP) removal from aqueous phase onto activated carbon. Batch sorption studies were performed and the results revealed that activated carbon demonstrated ability to adsorb DEP. Influence of varying experimental conditions such as DEP concentration, pH of aqueous solution, and dosage of adsorbent were investigated on the adsorption process. Sorption interaction of DEP onto activated carbon obeyed the pseudo second order rate equation. Experimental data showed good fit with both the Langmuir and Freundlich adsorption isotherm models. DEP sorption was found to be dependent on the aqueous phase pH and the uptake was observed to be greater at acidic pH.     

Enhancing biohydrogen production from chemical wastewater treatment in anaerobic sequencing batch biofilm reactor (AnSBBR) by bioaugmenting with selectively enriched kanamycin resistant anaerobic mixed consortia

The basic aim of this study was to investigate the feasibility of bioaugmentation strategy in the process of enhancing biohydrogen (H₂) production from chemical wastewater treatment (organic loading rate (OLR)—6.3 kg COD/m³-day) in anaerobic sequencing batch biofilm reactor (AnSBBR) operated at room temperature (28±2$28\pm 2$ °C) under acidophilic microenvironment (pH 6) with a total cycle period of 24 h. Parent augmented inoculum (kanamycin resistant) was acquired from an operating upflow anaerobic sludge blanket (UASB) reactor treating chemical wastewater and subjected to selective enrichment by applying repetitive/cyclic pre-treatment methods [altering between heat-shock treatment (100 °C; 2 h) and acid treatment (pH 3; 24 h)] to eliminate non-spore forming bacteria and to inhibit the growth of methanogenic bacteria (MB). Experimental data revealed the positive influence of bioaugmentation strategy on the overall H₂ production. Specific H₂ production almost doubled after augmentation from 0.297 to 0.483 mol H₂/kg COD_R-day. Chemical wastewater acted as primary carbon source in the metabolic reactions involving molecular H₂ generation leading to substrate degradation. The augmented culture persisted in the system till the termination of the experiments. The survival and retention of the augmented inoculum and its positive effect on process enhancement may be attributed to the adopted reactor configuration and operating conditions. Scanning electron microscope (SEM) images documented the selective enrichment of morphologically similar group of bacteria capable of producing H₂ under acidophilic conditions in anaerobic microenvironment. This depicted work corroborated successful application of bioaugmentation strategy to improve H₂ production rate from anaerobic chemical wastewater treatment.     

Adherence of Acanthamoeba to human corneal epithelial cells recovered from normal non-lens wearers and asymptomatic contact lens wearers.

To increase our knowledge of factors leading to Acanthamoeba keratitis in contact lens wearers, we determined the ability of this organism to adhere to corneal epithelial cells (EC) recovered from non-lens wearers (NL) and from subjects using hydrogel contact lenses on a daily (DW) and extended wear (EW) schedule. ECs were incubated with trophozoites of Acanthamoeba and, after 3 h, the median per cent of cells exhibiting adherence was 24, 23 and 23 for NL, DW and EW groups respectively (P=0.552, Kruskal-Wallis Test). There were no differences between the groups for the number of adherent amoebae and a significant majority had only one adherent trophozoite per EC. No difference in adherence was seen with increasing exposure time. Factors other than amoebic adherence to superficial corneal EC are responsible for the increased incidence of Acanthamoeba keratitis in lens wearers.     

Dielectric properties of Al V2O5 Al thin film sandwich structures

Vanadium pentoxide thin films were prepared by the electron beam evaporation technique onto Corning 7059 glass substrates kept at a temperature of T_s=423 K. The dielectric properties of Al V₂O₅ Al thin film sandwich structures were studied in the frequency range 0.1–100 kHz and in the temperature range 125–450 K. Both the dielectric constant and the dielectric loss factor were found to depend on frequency and temperature. The activation energy obtained for the dielectric relaxation process was about 0.36 eV.     

Thermal Shock Resistance of Ceramic Foams

Thermal shock behavior of a variety of open-cell ceramic foams was evaluated using infrared heating and forced air cooling. The extent of damage after thermal shock was determined by a nondestructive, dynamic resonance technique. The damage in foams was found to be strongly dependent on cell size and weakly dependent on density. In zirconia-based foams, damage was found to increase with an increase in zirconia content. A thermal stress resistance parameter R '_f was derived to predict the effect of cell size and density on the damage incurred in foams. The experimental results were found to corroborate the predictions fairly well but a better approach was to compare the maximum applied thermal strains with the degree of damage.     

Infrared transmission spectrometry for the determination of urea in microliter sample volumes of blood plasma dialysates

Application of mid-infrared spectroscopy for the determination of urea in blood plasma dialysates of microliter sample volumes using a transmission microcell was investigated. Infrared spectra of the dialysates of plasma samples collected from 75 different patients using CMA 60 microdialysis catheters were evaluated with multivariate partial least squares regression. Using the absorbance spectral data from 1520-1420 cm(-1) and 1220-1120 cm(-1), a minimum standard error of prediction (SEP) of 0.88 mg/dL (0.14 mM) was achieved with spectral variable selection. Our findings suggest the feasibility of developing a mid-infrared sensor in combination with micro-fluidics for on-line monitoring of urea in patients undergoing dialysis treatment.     

Strain paint: noncontact strain measurement using single-walled carbon nanotube composite coatings

Composite coatings have been developed that reveal strains in underlying structural elements through noncontact optical measurement. Dilute individualized single-walled carbon nanotubes are embedded in a polymeric host and applied to form a thin coating. Strain in the substrate is transmitted through the polymer to the nanotubes, causing systematic and predictable spectral shifts of the nanotube near-infrared fluorescence peaks. This new method allows quick and precise strain measurements at any position and along any direction of the substrate.     

Canteen based composite food waste as potential anodic fuel for bioelectricity generation in single chambered microbial fuel cell (MFC): Bio-electrochemical evaluation under increasing substrate loading condition

Canteen based composite food waste, which is rich in organic constituents was evaluated as anodic fuel (substrate) in single chambered microbial fuel cell (MFC; mediator less; non-catalyzed graphite electrodes; open-air cathode) to harness electrical energy via anaerobic treatment. The performance of MFC was evaluated with anaerobic consortia as anodic biocatalyst under various increasing organic loading rates (OLR1, 1.01 kg COD/m³-day; OLR2, 1.74 kg COD/m³-day; OLR3, 2.61 kg COD/m³-day). The experimental results illustrated the feasibility of bioelectricity generation from food waste along with treatment but depend on the applied organic load. The maximum power output was observed at OLR2 (295 mV; 390 mA/m²), followed by OLR3 (250 mV; 311 mA/m²) and OLR1 (188 mV; 211 mA/m²). The variation in substrate degradation has also showed a relation with organic load applied (OLR1, 44.28% (0.47 kg COD/m³-day); OLR2, 64.83% (1.13 kg COD/m³-day); OLR3, 46.28% (1.39 kg COD/m³-day)). The increase in loading from OLR1 to OLR2, the catalytic ability of biocatalyst increased from 7.5 mA (24 h) to 11.22 mA (24 h) along with the increase in power generation from 39.38 mW/m² to 107.89 mW/m². At the higher OLR (OLR3), the bioelectrocatalytic current decreased to 5.3 mA (24 h) along with decrement in power to 78.92 mW/m². The optimum organic load (OLR2) showed maximal catalytic activity and power output. Fuel cell behavior with respect to polarization, anode potential and bio-electrochemical behavior supported the higher performance of MFC at OLR2. Specific power yield was also observed to be higher at OLR2 (0.320 W/kg COD_R) indicating the combined process efficiency. Volatile fatty acids generation and pH profiles also correlated well with the observed results.     

Flexural creep of long fiber-reinforced thermoplastic composites: Effect of processing-dependent fiber variables on creep response

Flexural creep properties were studied as a function of fiber weight fraction and processing-induced fiber alignment in extrusion/compression-molded, long fiber-reinforced thermoplastic (LFT) nylon 6/6, polypropylene, and high-density polyethylene and their 10 wt.% and 40 wt.% E-glass fiber reinforced LFT composites. The residual fiber lengths and probability distribution parameters were near-equal, regardless of the initial fiber length and processing. Creep compliances decreased with increasing fiber weight fraction, and clear influence of fiber alignment was found in model parameters. Processing-induced fiber alignment imaged using X-ray radiography, was correlated with the creep compliances of strategically sectioned specimens, and tested as per ASTM D-2990. Longitudinal fibers aided in lowering the creep compliance, and the range in compliance decreased with lower preferential fiber alignment. Creep compliances from flexural creep tests and dynamic mechanical analysis/static creep tests were combined using time–temperature–stress superposition (TTSSP) to construct long-term master curves that correlated closely with long-term tests.     

Experimental investigation on the effects of process parameters of GMAW and transient thermal analysis of AISI321 steel

Gas metal arc welding (GMAW) develops an arc by controlling the metal from the wire rod and the input process parameters. The deposited metal forms a weld bead and themechanical properties depend upon the quality of the weld bead. Proper control of the process parameters which affect the bead geometry, the microstructures of the weldments and the mechanical properties like hardness, is necessary. This experimental study aims at developing mathematical models for bead height (HB), bead width (WB) and bead penetration (PB) and investigating the effects of four process parameters
viz: welding voltage, welding speed, wire feed rate and gas flow rate on bead geometry, hardness and microstructure of AISI321 steel with 10 mm thickness. The transient thermal analysis shows temperature and residual stress distributions at different conduction and convection conditions.