Ozonation of the reactive dye intermediate 2‐naphthylamine 3,6,8‐trisulphonic acid (K‐Acid): kinetic assessment,ozonation products and ecotoxicity

Ozonation of the commercially important, recalcitrant reactive dye intermediate 2‐naphthylamine 3,6,8‐trisulphonic acid (K‐Acid) was investigated. Ozonation performance was examined by following ozone absorption rates and K‐Acid, chemical oxygen demand and total organic carbon removals. Mean oxidation states and unidentified organic products were also determined. At pH 3, where direct ozone reactions are dominant, the second‐order rate constant between K‐Acid and molecular ozone was determined as 20 m ^?1 s^?1 for steady‐state aqueous ozone concentration. The competition kinetics approach was also adopted where a reference compound, phenol, and K‐Acid were subjected to ozonation. By applying this method, the second‐order reaction rate constant was found to be 76 m ^?1 s^?1. Common oxidation products formed during ozonation at pH 3, pH 7 and pH 7 with 1 mm hydrogen peroxide were identified as methoxy‐phenyl‐oxime, phenol, benzene, benzaldehyde and oxalic acid via high‐performance liquid chromatography and gas chromatography/mass spectrometry analyses. Continuous nitrate and sulphate evolution were observed during K‐Acid ozonation as a consequence of the abrupt release and subsequent oxidation of its amino and sulphonate groups. The number and amount of reaction products were most intensive for K‐Acid ozonation at pH 7 with 1 mm hydrogen peroxide. According to the acute toxicity tests conducted with Vibrio fischeri, ozonation products were not less toxic than the original K‐Acid solution that caused only 15% inhibition.     

Reuse and recycle potentials of the temporary houses after occupancy: Example of Duzce,Turkey

Temporary housing reconstruction after the earthquake is a crucial issue regarding its social, physical, psychological and environmental effects. The needs of disaster victims for the temporary shelters and houses should be met rapidly. In that way the victims have chance for returning back to their daily life activities as soon as possible. Thus, national and international aids–resources used in post-disaster construction activities were mainly focused on sheltering and housing after the emergency phase. Consequently, temporary housing sites were frequently constructed as a solution on the aftermath of the disaster. The purpose of this study is to research temporary housing sites reuse and recycle potentials after occupancy in the case study of Duzce, Turkey. Solution proposals for obtaining the sustainability of the temporary housing sites were determined with respect to the observations made in production, occupancy, dismantling and evacuation processes of the temporary housing sites in a case study by taking the existing dwellers’ expectations into consideration. The results showed the need for pre-disaster design and organization to accelerate reuse and recycle potentials of the houses and sites. The reuse and recycle recommendations of the case study can be used to boost the reconstruction of the disaster affected regions by the assistance of local and central government as well.     

SWOT analysis for safer carriage of bulk liquid chemicals in tankers

The application of strengths, weaknesses, opportunities and threats (SWOT) analysis to formulation of strategy concerned with the safe carriage of bulk liquid chemicals in maritime tankers was examined in this study. A qualitative investigation using SWOT analysis has been implemented successfully for ships that are designed to carry liquid chemicals in bulk. The originality of this study lies in the use of SWOT analysis as a management tool to formulate strategic action plans for ship management companies, ship masters and officers for the carriage of dangerous goods in bulk. With this transportation-based SWOT analysis, efforts were made to explore the ways and means of converting possible threats into opportunities, and changing weaknesses into strengths; and strategic plans of action were developed for safer tanker operation.     

Evaluation of a physical length scale for granular materials

Classical continuum mechanics considers the interaction of microstructural units of the material through stresses and displacements of material points. Therefore, conventional continuum mechanics approaches can not incorporate any intrinsic material length scale. However in reality interaction of grains may include rotations and the corresponding couple stresses as well, and real materials have a number of important length scales (e.g., grains, particles, fibers, etc.). An equation for determining the length scale is proposed. The proposed length scale equations include the effect of plastic deformation (microrotation), the effect of normal stress and contact area. The proposed length scale is implemented into elastic–elastoplastic Cosserat formulation. The effect of length scale on the finite element simulation and yield surface was evaluated by using the proposed length scale equation. The importance of length scale on the constitutive modeling of granular materials is analyzed in numerical simulations.     

Comparison of adsorption capacity of young brown coals and humic acids prepared from different coal mines in Anatolia

Binding of Zn2+ and Cd2+ cations to relatively young brown coals YBC (lignite), humic acids (HAs) and commercial humic acid (CHA) were studied in aqueous media at pH 2.7-6 by polarographic method. This study was conducted to evaluate the removal of heavy metals in an aquatic system without prior treatment. The general principles of cation binding to YBC and humic materials are discussed. Sorption of heavy metal ions (Zn2+ and Cd2+) on samples of YBCs from three areas (Ilgin, Beysehir, and Ermenek) in the vicinity of the city of Konya in Anatolia (Turkey) were compared with sorption of these metal ions on HAs, prepared from these YBCs. The ability of both types of sorbent to remove metals from aqueous solutions was studied as a function of pH and concentration of initial metal solutions. Sorption depends strongly on pH, the origin of the YBC and on the nature of the metal ion. Whereas, for YBCs the main ligand groups seem to be carboxylate ions, this is not the case for the HA polymers, prepared from three YBCs, which differ substantially from properties of commercial samples of "HA". The process is very efficient especially in the case of low concentrations of pollutants in water, where common methods are either economically unfavorable or technically complicated. Of the two metal ions examined, Cd2+ was found to form the most stable HA complexes, followed by Zn. Effective removal of metals was demonstrated at pH-values of 5-5.7. The adsorption isotherm was measured at 25 degrees C, using adsorptive solutions at the optimum pH-value to determine the adsorption capacity. An important aspect of the proposed method was that the removal was performed on several metals at a pH-range in which a given metal undergoes an adsorption process making the method useful for wastewater treatment.     

Complete CO oxidation over Cu2O nanoparticles supported on silica gel

We find that nearly monodisperse copper oxide nanoparticles prepared via the thermal decomposition of a Cu(I) precursor exhibit exceptional activity toward CO oxidation in CO/O2/N2 mixtures. Greater than 99.5% conversion of CO to CO2 could be achieved at temperatures less than 250 degrees C for over 12 h. In addition, the phase diagram and pathway for CO oxidation on Cu2O (100) is computed by ab initio methods and found to be in qualitative agreement with the experimental findings.     

Elastic limits of a radially heated thick-walled cylindrically curved panel

In analogy to the theory of wide curved beams, the basic equations for a cylindrically curved panel of homogeneous thickness in a state of plane strain subject to a radial temperature gradient are derived. The ends of this thick-walled shell are presupposed to be guided in such a way that a displacement in circumferential direction may occur and that the radius of the initial middle surface remains unchanged. Then, couples act on those ends, giving rise to pure bending conditions. Based thereon, the stresses occurring for a heated inner and/or outer surface are analyzed, and—taking thermal softening and hence a reduced yield stress into account—the elastic limits according to the yield criteria of Tresca and von Mises are discussed comprehensively.     

Effect of stress levels applied to pre‐stressing strands on post‐tensioned beam‐to‐column connections

This article presents an experiment study on precast beam‐to‐column connections with 15.24 mm diameter pre‐stressing strands. Stress levels of 40%, 50% and 60% tensile stress were applied to the pre‐stressing strands. Following the experiments, precast specimens were compared with those of the reference specimen. The load capacity of the precast specimen stressed at the level of 60% tensile stress reached 98% of the load capacity of the reference specimen, and the amount of energy dissipated by the same specimen reached 48% of that dissipated by the reference specimen. The stiffness of the same precast specimen at 1.5% drift was observed to be 71% of the reference specimen at the same drift. In the experimental studies, it was seen that the maximum stress determined in this specimen, which pre‐stressing strands provide connection, reached approximately 75% of the tensile strength of the pre‐stressing strands. It could not be said that topping concrete in experiment specimens increased strength. Copyright © 2010 John Wiley & Sons, Ltd.     

A reinforcement learning approach for transaction scheduling in a shuttle-based storage and retrieval system

With recent Industry 4.0 developments, companies tend to automate their industries. Warehousing companies also take part in this trend. A shuttle-based storage and retrieval system (SBS/RS) is an automated storage and retrieval system technology experiencing recent drastic market growth. This technology is mostly utilized in large distribution centers processing mini-loads. With the recent increase in e-commerce practices, fast delivery requirements with low volume orders have increased. SBS/RS provides ultrahigh-speed load handling due to having an excess amount of shuttles in the system. However, not only the physical design of an automated warehousing technology but also the design of operational system policies would help with fast handling targets. In this work, in an effort to increase the performance of an SBS/RS, we apply a machine learning (ML) (i.e., Q-learning) approach on a newly proposed tier-to-tier SBS/RS design, redesigned from a traditional tier-captive SBS/RS. The novelty of this paper is twofold: First, we propose a novel SBS/RS design where shuttles can travel between tiers in the system; second, due to the complexity of operation of shuttles in that newly proposed design, we implement an ML-based algorithm for transaction selection in that system. The ML-based solution is compared with traditional scheduling approaches: first-in-first-out and shortest process time (i.e., travel) scheduling rules. The results indicate that in most cases, the Q-learning approach performs better than the two static scheduling approaches.