Determination of the Dyeing Potential of Mint and Sage Crops Wastes on Wool and Cotton Fibers

In the present study, dyeing potential of waste water from distillation process was investigated for fresh and dried herbs of Menthaspicata (MS), Menthapiperita (MP), and Salvia officinalis (SO) species. Meta-mordanting method was used in the dyeing of wool and cotton fabrics in the presence of FeSO₄·7H₂O (iron) and AlK(SO₄)₂·12H₂O (alum) mordants. The color of each dyed material was investigated in terms of the CIELab (L*, a*, b*, C, and h°) and K/S values. The surfaces of the samples were observed using a scanning electron microscope. It was observed that the color strength of fresh and dried plant is depended on the plant species, mordant, and fabric type. Best color intensity (K/S = 16.68) was obtained with iron mordant using fresh SO on cotton fabric. For wool fabric, the highest color strength (K/S = 9.62) was obtained with fresh SO in the presence of alum mordant. Presence of metal mordant for natural dyeing process of cotton with MS, MP, and SO extract has shown remarkable improvement in terms of dye adherence and fastness properties thus metal mordanting could be suitable alternative dyeing method for ecofriendly industrial application.     

Counterion-coupled gemini (Cocogem) surfactants based on dodecylisopropylol amine and dicarboxylic acids: synthesis,characterization and evaluation as biocide against SRB

New cocogem surfactants were synthesized by interaction of dodecylisopropylol amine with dicarboxylic (oxalic, succinic, adipic, sebacic, tartaric, maleic, fumaric, isophthalic) acids. By tensiometric method, the surface activity of aqueous solutions of the synthesized cocogem surfactants at the border with air was studied and, by conductometric method, the specific electrical conductivity of these solutions was determined. The degree of counterion binding (β), critical micelle concentration (CMC), effectiveness of surface tension reduction (π_CMC), surface excess concentration (Γ_max), area per molecule at the interface (A_min), changes of Gibbs free energies of adsorption (ΔG_ad) and micellization (ΔG_mic) have been calculated. The character of change of the colloidal-chemical indices depending on spacer-group nature and length has been clarified. So, with an elongation of the spacer group and when passing from cis-form to trans-form, the value of CMC decreases. The obtained cocogem surfactants exhibit a considerable bactericidal effectiveness against sulfate-reducing bacteria. The bactericide properties of the cocogem surfactants containing in the spacer chain a saturated hydrocarbon fragment and benzene ring are stronger than for the others.     

Synthesis and characterization of novel polyfuran/poly(2‐iodoaniline) conducting composite

The electrically conducting polyfuran/poly(2‐iodoaniline) (PFu/P2IAn) and P2IAn/PFu composites were prepared by chemical oxidative polymerization using polyfuran and poly(2‐iodoaniline) in HCl and CHCl₃ media. The conductivities of composites were determined as a function of the amount of guest polymer. It was found out that the conductivities of P2IAn/PFu composites increased 100‐fold, whereas the conductivities of PFu/P2IAn composites did not show a specific increase. The composite compositions were altered by varying guest polymer feed ratios during preparation. Generally, the electrical conductivities of P2IAn/PFu composites increased with increasing the amount of PFu. Homopolymers and composites were further characterized thermally, employing thermogravimetry (TGA) and morphologically employing scanning electron microscopy (SEM). Further evidences concerning the polymer structures were obtained by FTIR and UV‐vis spectroscopies and magnetic susceptibility measurements. TGA results revealed that PFu/P2IAn among the homopolymers (PFu and P2IAn) and P2IAn/PFu composite have the highest thermal stability. The composites synthesized varying the host and the guest polymer order have different conductivities, morphological structures, and thermal properties. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2823–2830, 2003     

A novel method for production of activated carbon from waste tea by chemical activation with microwave energy

This study presents the production of activated carbon from waste tea. Activated carbons were prepared by phosphoric acid activation with and without microwave treatment and carbonisation of the waste tea under nitrogen atmosphere at various temperatures and different phosphoric acid/precursor impregnation ratios. The surface properties of the activated carbons were investigated by elemental analysis, BET surface area, SEM, FTIR. Prior to heat treatment conducted in a furnace, the mixture of the waste tea and H₃PO₄ was treated with microwave heating. The maximum BET surface area was 1157 m²/g for the sample treated with microwave energy and then carbonised at 350 °C. In case of application of conventional method, the BET surface area of the resultant material was 928.8 m²/g using the same precursor and conditions. According to the Dubinin–Radushkevich (DR) method the micropore surface area for the sample treated with microwave energy was higher than the sample obtained from the conventional method. Results show that microwave heating reasonably influenced the micropore surface area of the samples as well as the BET surface area.The samples activated were also characterised in terms of the cumulative pore and micropore volumes according to the BJH, DR and t-methods, respectively.     

Recovery of Ruthenium Via Zinc in the Presence of Accelerator

In this study, the recovery of ruthenium from spent bath solutions via cementation reaction with zinc powder was investigated. Studied parameters included the quantity of zinc, reaction temperature, reaction time and sodium chloride additions to understand their effects on the reaction. Tests were performed in a temperature controlled water-bath with temperatures between 20 and 70 °C at atmospheric pressure. Furthermore, in order to determine activation energy of cementation reaction, several mathematical kinetic models were used and the activation energy, which was calculated from best fit, was found to be 12.48 kJ/mol. Addition of sodium chloride to the solution greatly accelerated the cementation reaction, in that, more the addition of sodium chloride, the better was the precipitation efficiency. In the absence of sodium chloride at 25 °C a percentage of ruthenium recovery was below 75% whereas 1000 mg sodium chloride addition at 65 °C ensured a percentage of ruthenium recovery more than 95%. This corresponded to more than about 28% increase.     

Cost and safety optimization of structural design specifications

The design of buildings, bridges, offshore platforms and other civil infrastructure systems is controlled by specifications whose purpose is to provide the engineering principles and procedures required for evaluating the safety of structural systems. The calibration of these codes and specifications is a continuous process necessary to maintain a safe national and global infrastructure system while keeping abreast of new developments in engineering principles, and data on new materials, and applied loads. The common approach to specification calibration is to use probabilistic tools to deal with the random behavior of materials and to account for the uncertainties associated with determining environmental and other load effects. This paper presents a procedure to calibrate load factors for a structural design specification based on cost and safety optimization. The procedure is illustrated by determining load factors that may be applicable for incorporation in a bridge design specification. Traditional code calibration procedures require a set of pre-determined safety levels that should be used as target values that each load combination case should satisfy. The procedure in this paper deduces the failure cost implied in present designs, and provides consistent safety levels for all load combination cases. For greater accuracy, load effects showing variance in time have been modeled by separating them into two random variables; time dependent r.v. (wind speed, vehicular loads, etc.) and time independent r.v. (modeling uncertainties). The total expected lifetime cost is used in the optimization to account for both initial construction cost and future equivalent failure costs.     

Metal chelating properties of Cibacron Blue F3GA‐derived poly(EGDMA‐HEMA) microbeads

Metal chelating properties of Cibacron Blue F3GA‐derived poly(EGDMA‐HEMA) microbeads have been studied. Poly(EGDMA‐HEMA) microbeads were prepared by suspension copolymerization of ethylene glycol dimethacrylate (EGDMA) and hydroxy‐ethyl methacrylate (HEMA) by using poly(vinyl alcohol), benzoyl peroxide, and toluene as the stabilizer, the initiator, and the pore‐former, respectively. Cibacron Blue F3GA was covalently attached to the microbeads via the nucleophilic substitution reaction between the chloride of its triazine ring and the hydroxyl groups of the HEMA, under alkaline conditions. Microbeads (150–200 μm in diameter) with a swelling ratio of 55%, and carrying 16.5 μmol Cibacron Blue F3GA/g polymer were used in the adsorption/desorption studies. Adsorption capacity of the microbeads for the selected metal ions, i.e., Cu(II), Zn(II), Cd(II), Fe(III), and Pb(II) were investigated in aqueous media containing different amounts of these ions (5–200 ppm) and at different pH values (2.0–7.0). The maximum adsorptions of metal ions onto the Cibacron Blue F3GA‐derived microbeads were 0.19 mmol/g for Cu(II), 0.34 mmol/g for Zn(II), 0.40 mmol/g for Cd(II), 0.91 mmol/g for Fe(III), and 1.05 mmol/g for Pb(II). Desorption of metal ions were studied by using 0.1 M HNO₃. High desorption ratios (up to 97%) were observed in all cases. Repeated adsorption/desorption operations showed the feasibility of repeated use of this novel sorbent system. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1397–1403, 1999     

Comparison of metal chelate affinity sorption of BSA onto Dye/Zn (II)-derived poly(ethylene glycol dimethacrylate-hydroxyethyl methacrylate) microbeads

Poly(ethylene glycol dimethacrylate-hydroxyethyl methacrylate) [poly-(EGDMA-HEMA)]microbeads in the size range of 150–200 μm were produced by a modified suspension copolymerization of EGDMA and HEMA. The dyes (Congo red, Cibacron blue F3GA, and alkali blue 6B) were covalently immobilized; then, Zn(II) ions were incorporated within the microbeads by chelation with the dye molecules. The maximum amounts of dye loadings were 14.5 μmol/g, 16.5 μmol/g, and 23.7 μmol/g for Congo red, Cibacron blue F3GA, and alkali blue 6B, respectively. Different amounts of Zn(II) ions(2.9–53.8 mg/g polymer) were incorporated on the microbeads by changing the initial concentration of Zn(II) ions and the pH of the medium. Bovine serum albumin (BSA) adsorption onto dye/Zn(II)-derived microbeads containing Congo red, Cibacron blue F3GA, and alkali blue 6B was investigated. The maximum BSA adsorptions onto the dye/Zn(II)-derived microbeads from aqueous solutions containing different amounts of BSA were 159 mg/g, 122 mg/g, and 93 mg/g for the Congo red, Cibacron blue F3GA, and alkali blue 6B dyes, respectively. The maximum BSA adsorptions were observed at pH 6.0 in all cases. Desorption of BSA molecules was achieved by using 0.025M EDTA (pH 4.9). High desorption ratios (more than 93% of the adsorbed BSA) were observed in all cases. It was possible to reuse these novel metal chelate sorbents without significant losses in their adsorption capacities. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 2085–2093, 1997     

A review on the performance of photovoltaic/thermoelectric hybrid generators

Utilization of a broad range of solar spectrum has the potential for high power output from solar cells. However, solar photovoltaics (PVs) can convert only part of the solar electromagnetic spectrum into electricity efficiently. The remaining of the solar radiation is often dissipated in the form of heat, which causes performance reduction and reduces the life expectancy of the solar PV cell. Thermoelectric generators (TEGs) are devices that operate like a heat engine by converting thermal energy into electricity through thermoelectric effect. Integrating a TEG into a PV converter will enhance its efficiency and reduce the amount of heat dissipated. Different studies have been carried out and are still taking place to increase the total efficiency of a coupled photovoltaic thermoelectric generator (PV-TEG) system. This review discusses the concept of PV converters and thermoelectric devices and presents the various models and numerical and experimental investigations on performance enhancement of integrated PV-TEGs. The influence of key parameters on the performance of PV-TEG were also discussed. The review is expected to serve as a reference to recent work on research and development of integrated PV-TEG systems.     

Mass transfer enhancement factor for chemical absorption of carbon dioxide into sodium metaborate solution

Hydrogen is getting increasing attention as a medium for energy storage, and sodium borohydride is accepted as a suitable carrier for hydrogen. The main product of the process by means of which hydrogen is produced from sodium borohydride is sodium metaborate. Our aim was to find an alternative use for sodium metaborate and specifically investigating the feasibility to use it for carbon dioxide capture from flue gases. The products of this chemical absorption are sodium carbonate, sodium bicarbonate and boric acid, all of which are industrially important chemicals. A bubble column was used in the experiments. Oxygen desorption technique was employed to determine the liquid side physical mass transfer coefficient. Chemical mass transfer coefficient was determined by absorption of carbon dioxide from its mixture with nitrogen into sodium metaborate solution. Enhancement factor was then calculated and a correlation was developed for it.