Quantification of powder holdups in the presence of a cavity with lateral gas–powder injection in a packed bed

The lateral flow of gas–powder through a packed bed in a cold model is studied to understand the flow and holdup behaviour of powder in the presence of a cavity, nozzle (tuyere) protrusion, and decreasing gas condition, a system used in the ironmaking blast furnace. Experiments conducted in the current study included a two-dimensional (2D) slot-type packed bed. A previously published mass balance and elutriation velocity concept formed the basis for accurately quantifying the static and dynamic powder holdups. Experiments conducted under different conditions such as powder size and flux, gas flow rate, and packed particle density and size resulted in quantifying the powder holdups. The pressure drop in both horizontal and vertical directions is studied in all two-phase flow experiments. The formation of the static holdup with time in the packed bed is studied. The reproducibility of the experiments was confirmed. The static holdup inside the packed bed at various locations along the vertical direction (i.e., height) is also quantified. The static holdup correlation developed based on experimental data resulted in a 95% confidence interval. Static powder holdup increases with a decrease in the superficial gas velocity, an increase in the size of the powder particle, and powder flux. Dynamic holdup also showed a similar trend.     

Effect of Ozone Pretreatment on Biodegradability Enhancement and Biogas Generation Potential From Biomethanated Distillery Effluent

The study evaluates the effect of ozone pretreatment on biodegradability enhancement of biomethanated distillery effluent. Results revealed that ozone pretreatment led to biodegradability index (BI = BOD/COD) enhancement up to 0.58 along with COD, color and toxicity reduction of up to 33%, 25% and 40%, respectively. Anaerobic digestion of pretreated effluent resulted in favorable biogas generation with methane content, yield and COD reduction of up to 62%, 39 mL/g COD and 57%, respectively. Kinetics of biogas generation determined by modified Gompertz model indicated methane production potential and production rate of 48.08 mL/g COD and 8.085 mL/g COD.day respectively under optimal conditions.     

Optimisation of Detergent Ingredients for Stain Removal Using Statistical Modelling

Artificially soiled test fabrics are widely used to study the cleaning performance of detergents formulations. In this study, artificial soiled cotton test fabrics were prepared in the laboratory using carbon black as a model soil. Design of experiments was used to optimise the concentration of detergent ingredients for stain removal. A multi‐factorial analysis of variance was used to model the effect of sodium dodecylbenzene sulfonate, nonylphenol ethoxylate, sodium silicate, sodium citrate and sodium carbonate as builders on soil removal. A colourimetric evaluation using the CIELAB system was used to measure soil removal. In general, performance increases with increasing concentration of surfactant, silicate and soda ash.     

Nonwoven viscose fabric-polyvinyl alcohol based flexible composite

Development of ecofriendly packaging materials is still a challenging area. Researchers are continuously working to improve the mechanical and barrier properties of the different polymers which are used in the packaging industry. Selection of reinforcement and matrix for any composite are based upon end use applications. The novelty of the work is development of fully biodegradable, flexible, lightweight biocomposite by reinforcing needle punched flexible nonwoven viscose fabric to the PVA solution. The effect of PVA concentration and areal density of viscose fabric on the properties of prepared composite is examined. The composite thus prepared is assessed in terms of mechanical, thermal, breathability, and UV blocking properties. The nonwoven viscose-PVA composite shows excellent improvement in tensile strength of 100% to 300% with respect to PVA film of equivalent concentration for two different areal densities of viscose fabric. The composite also exhibits improved thermal stability and UV blocking property with respect to parent components. However, a reduction in flexibility (with respect to PVA film) as well as breathability (with respect to viscose fabric) of the composite is observed. Based upon the improved performance of the viscose-PVA composite in terms of mechanical properties, UV and water vapor permeability, it seems that the composite has a strong potential for application in the packaging sector as a flexible as well as biodegradable composite.     

Characterization procedure for adsorption of DOC (Dissolved Organic Carbon) from synthetic wastewater

A characterization method to evaluate the composition of background organic matters in terms of adsorbability was presented and applied to synthetic and domestic wastewater. The binomial distribution of DOC (Dissolved Organic Carbon) fraction in relation of a characterizing variable, the Freundlich coefficient, k, was proposed to describe the initial composition of wastewater by a finite number of pseudospecies. This method was tested for removal of DOC by using granular and powdered activated carbons. These experiments enable us to get information on the distribution function of species in the solution. From the results obtained in this work, kinetic experimental data were predicted on the assumption that the diffusion coefficients were unchanged during the experiments. It was confirmed to be effective in determining the initial composition and describing the equilibria of the DOC. From the experiments, it was found that this synthetic solution has a sigmoid type isotherm on activated carbons. This implies that there are two different adsorption regions in a system, favourable and unfavourable cases, depending on the solution concentration. This unfamiliar problem can be solved by using a characterization method based on IAST-Freundlich model.     

Removal of tin from dilute solutions

The fluidised bed cell of inert glass beads is an electrolytic reactor which is designed to provide higher ion‐transfer conditions during electrolysis, thus enabling metals to be removed efficiently from dilute solutions. The effectiveness of the method as a means of removing metals from effluent to meet discharge consent levels is studied for the in situ removal of tin from dilute solution (concentration range 0.25–1.00 gdm⁻³). The results show that the combination of high mass transport conditions and a moderately high electrode surface area per unit electrode volume provides a system for continuous removal of metal from dilute solutions. The effects of acid concentration, tin concentration, current density, fluidised bed agitation, electrode spacing, type of electrode and lead impurities on the removal of tin are reported and expressed in terms of the percentage removal of tin (α_Sn), the efficiency of tin deposition (ϕ_Sn), and the energy consumption (W_Sn) for 1 kg of tin deposited. The results show that tin can, under optimised conditions, be removed from dilute solutions to a residual concentration of 0.001 gdm⁻³. © 2001 Society of Chemical Industry     

Epoxidized linolenic acid salts as multifunctional additives for the thermal stability of plasticized PVC

Calcium and zinc salts of epoxidized linolenic acid were synthesized and used as multifunctional additives, to minimize or prevent the reaction of epoxidized soybean oil (ESO) with liberated hydrochloric acid (HCl) during the thermal degradation of poly(vinyl chloride) (PVC) in particular. These metal epoxy salts were incorporated as thermal stabilizers for both diisodecyl phthalate and ESO–plasticized PVC blends that underwent thermal degradation studies at 170°C. The overall performance of these metal epoxy salts was examined by thermal gravimetric analysis and visual color retention of the PVC blends. The weight loss profiles of the metal salt stabilized PVC were comparable to those of blends containing metal stearates. There were, however, vast improvements in color retention of the plasticized PVC using these novel additives. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41736.     

Identification of Oxidized Phosphatidylinositols Present in OxLDL and Human Atherosclerotic Plaque

Oxidized low-density lipoprotein (OxLDL) plays an important role in initiation and progression of atherosclerosis. Proatherogenic effects of OxLDL have been attributed to bioactive phospholipids generated during LDL oxidation. It is unknown what effect oxidation has on the phosphatidylinositol (PtdIns) molecules in LDL, even though PtdIns is 6% of the total LDL phospholipid pool. We sought to identify and quantitate oxidized phosphatidylinositol (OxPtdIns) species in OxLDL and human atherosclerotic plaque. Bovine liver PtdIns was subjected to non-enzymatic and lipoxygenase-catalyzed oxidation. Reversed-phase liquid chromatography with negative ESI–MS identified and confirmed compounds by fragmentation pattern analysis from which an OxPtdIns library was generated. Twenty-three OxPtdIns molecules were identified in copper-oxidized human LDL at 0, 6, 12, 24, 30, and 48 h, and in human atherosclerotic plaque. In OxLDL, OxPtdIns species containing aldehydes and carboxylates comprised 17.3 ± 0.1 and 0.9 ± 0.2%, respectively, of total OxPtdIns in OxLDL at 48 h. Hydroperoxides and isoprostanes at 24 h (68.5 ± 0.2 and 22.8 ± 0.2%) were significantly greater than 12 h (P < 0.01) without additional changes thereafter. Hydroxides decreased with increased oxidation achieving a minimum at 24 h (5.2 ± 0.3%). Human atherosclerotic plaques contained OxPtdIns species including aldehydes, carboxylates, hydroxides, hydroperoxides and isoprostanes, comprising 18.6 ± 4.7, 1.5 ± 0.7, 16.5 ± 7.4, 33.3 ± 1.1 and 30.2 ± 3.3% of total OxPtdIns compounds. This is the first identification of OxPtdIns molecules in human OxLDL and atherosclerotic plaque. With these novel molecules identified we can now investigate their potential role in atherosclerosis.     

The use of chromium waste sludge for the adsorption of colour from dye effluent streams

Adsorption studies show that chromium hydroxide precipitates can be used for the removal of methylene blue, reactive blue, congo red and disperse orange dyes from aqueous media. Three different mechanisms are involved: attraction of positive surface charges on the precipitate at low pH for dye anions (reactive blue and congo red); attraction of negative surface charges on hydroxide at high pH for dye cations (methylene blue), and dye particle entrapment for the neutral disperse orange. The point of zero charge of the chromium hydroxide precipitate based on the dye adsorption studies is pH 10.5. The changes in the surface charge of such precipitates with pH can be used to achieve the removal of any charged dye species. © 2002 Society of Chemical Industry     

A Novel Approach to Model Threshold Voltage and Subthreshold Current of Graded-Doped Junctionless-Gate-All-Around (GD-JL-GAA) MOSFETs

Silicon - This present article interprets the analytical models of central channel potential, the threshold voltage, and subthreshold current for Graded-Doped Junctionless-Gate-All-Around...