Ozonation of synthetic versus natural textile tannins: recalcitrance and toxicity towards Phaeodactylum tricornutum.

A sound in-plant pollution control strategy can only be defined by paying due attention to bio-recalcitrance and toxicity. In this context the levels of toxicity and inert COD introduced to textile dyebath discharges by two alternative auxiliary chemicals, namely natural tannin (NT) and synthetic tannin (ST), were investigated. The effect of 40 minutes ozonation at 1,000 mg h(-1) at pH 3.5 on the segregated effluent streams containing the above-mentioned tannin formulations was evaluated in terms of changes in toxicity and recalcitrance. The effect of ozonation on the COD distribution of raw and ozonated NT and ST samples according to their molecular weight cut-offs was also assessed. Both untreated tannin formulations exerted high acute toxicity towards marine microalgae Phaeodactylum tricornutum. Moderate decrease in the toxicity levels of both tannins was observed upon ozonation. The raw NT formulation with a COD content more than twice that of its alternative raw ST had an initially inert soluble COD content of only 25 mg/L, while the initially inert COD was 135 mg/L for ST. As the initially inert soluble COD content of NT was considerably lower, this textile auxiliary did not need chemical pretreatment to improve its biodegradability. On the other hand, the initially inert soluble COD content of ST was reduced by 70% by ozone pretreatment. In terms of residual COD contents achievable after passing through a biological treatment system, raw NT and pretreated ST formulations yielded 100 and 95 mg/L COD, respectively. The highest proportion of COD (46% for NT and 88% for ST) was found in the <1 kDa range. The same fraction increased to 93% for NT after ozonation, while for ST no significant change was observed in the COD distribution of the molecular weight cut-offs after ozonation.     

Studies of linear polymer dimensions of poly(4-chlorostyrene) in various solvents around the θ temperatures by intrinsic viscosity

Intrinsic viscosities of poly(4-chlorostyrene) solutions in isopropyl-benzene and n-propylbenzene at temperatures above and below the theta (θ) temperatures of these solvents were measured using a capillary viscometer. The viscosity measurements were performed on three poly(4-chlorostyrene) samples having molecular weights (M?;_v) 1.75 × 10⁶, 6.5 × 10⁵ and 2.7 × 10⁵. A smooth and continuous contraction below the θ temperatures was observed for both solvents. The temperature dependence of [/eta] can be represented by a master curve in a plot of α³/eta|/tau|M^1/2 (g^1/2 mol^?1/2) versus |/tau|M^1/2 (g^1/2 mol^?1/2), where α/eta = [/eta(T)]/[/eta(θ)]^1/3 is the expansion factor and /tau = (T - θ)/T is the reduced temperature. A universal plot of reduced viscosity size (α/eta) versus reduced blob parameter (N/N_c) shows the achievement of collapsed state for T<θ. The prediction of thermal blob theory is also verified for T > θ. The temperature dependence of intrinsic viscosity, both below and above the θ temperature, exhibits similar behaviour to the temperature dependence of dipole moments for both of these solvents.     

Rehabilitation studies and recovery of a once lifeless estuary: the Golden Horn.

Within this study fluctuations in biodiversity of the Golden Horn from past to present are evaluated. Limited studies and observations dating back to 60 years ago pointed out the importance of the Golden Horn as a fishery. Unfortunately, in accordance with increase in unplanned settlements and industry around the Golden Horn in the 1960s, pollution stress became a demanding factor for this unique environment, affecting biodiversity adversely. Preliminary studies in the 1990s indicated survival of only a couple of pollution-resistant species, at the relatively cleaner outer estuary. Following intensification of "still ongoing" rehabilitation studies in 1998, a remarkable day-by-day recovery in marine life has began, in regard to improvements in water quality. Surveys conducted in 2002 using SCUBA, documented the level of diversification of life at the Golden Horn. Extended till Hali? Bridge, all appropriate substratums were intensely covered by macrobenthic forms and particularly filter feeders dominated the plankton-rich ecosystem. Detection of seahorses at the inner-middle parts of the estuary, in addition to numerous fish, invertebrate and macroalgae species, clearly depicted the level of recovery and change in the ecosystem. All results support the existence of a dynamic biological life at the Golden Horn, improving considerably with rehabilitation studies. Achieving the diversity of the 1940s is not possible, since the Black and Marmara seas, highly influencing water quality in the Golden Horn are also suffering from anthropogenic impacts and are far beyond their rich diversity in the 1940s. However, it is obvious that ecosystems should recover when mankind gave a chance to them. Recovery of the recently lifeless Golden Horn in such a short period of time is a very good example.     

Blue Light Source Based on a ppKTP SHG Using a Grating-Coupled Laser Diode

In this letter, we present the first experimental results of a single-pass second-harmonic (SH) generation from a grating-coupled surface-emitting laser (GCSEL) with integrated dual-grating reflector. In pulse operation, the maximum SH peak power was obtained at 0.66 W, yielding a normalized conversion efficiency of 0.6times10^-3 W^-1. A high-level monolithical integration of the GCSEL device led to a compact blue light source, which was based on a frequency-doubled near-IR laser diode.     

Flocculation of fine particles in ceramic wastewater using new types of polymeric flocculants

It appears to be quite a few national and international studies were reported regarding flocculation and settling properties of ceramic industry wastewater containing various mineral matters. Cleaning of ceramic industry wastewaters with ever increasing environmental standards needs effective and economical solid–liquid separation processes. In this study, quantity and type of optimum flocculant concentration were investigated for solid–liquid separation of Umpac ceramic plant (located at Usak, Turkey) wastewaters. A new generation of flocculants namely unique molecular architecture (UMA) are used to obtain high settling velocity along with high solid content waste and circulation water with low turbidity values. Zeta potential of the tailings including quartz, feldspar, clorite, and mica was also measured at different pH values. The flocculation tests were performed in the presence of different types of polymers at different polymer dosages. It seems that Magnafloc 5250 shows higher performance than the anionic flocculant SPK 508 and other anionic UMA flocculants Magnafloc 6260 and Magnafloc 3230. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

A new testing method for indirect determination of the unconfined compressive strength of rocks

A new testing method for the indirect determination of unconfined compressive strength (UCS) of rock core samples is presented. As known, there exist several methods for indirect estimation of UCS, such as point load index (I_s), Schmidt hammer, sonic velocity, block punch strength test, etc. Although the point load index testing method is widely used to estimate UCS, there are many problems and limitations related to this method as reported in the recent literature. The “core strangle test” (CST) proposed in this paper overcomes some of these deficiencies and limitations. The principle of this test depends on the “strangle” type of loading a core along a circle perpendicular to the core axis. In the first stage of this study, blocks of different types of rocks having the strength in a range from weak to strong were collected and cored for UCS, point load index and CST tests. These tests were then conducted and relationships between UCS with I_s(50) and CST were empirically explained and discussed.     

Simplex lattice mixture design approach on the rheological behavior of glucomannan based salep-honey drink mixtures: An optimization study based on the sensory properties

The rheological properties of salep drink sweetened with different honeys were measured using a controlled-stress rheometer. Mixture design experiments were used to study the effect of interactions among pine, flower and highland honeys on the rheological properties of salep-honey drink mixture (SHDM) samples. In addition, product optimization was carried out using the ridge analysis to determine the optimum mixture proportions based on sensory properties of SHDM samples. Flower honey was the component showing the highest effect on the consistency coefficient values of SHDM samples. The preference of panelists was more prominent for the SHDM samples including the higher concentrations of highland honey with respect to odour and overall preference parameters. Optimum values of pine, flower and highland honeys in the mixture were found to be 0–85%, 0–40% and 15–100%, respectively, with respect to sensory properties. In addition, ridge analysis results revealed that the SHDM should include 65% highland honey, 35% pine honey and no flower honey to obtain the maximum overall preference score (7.24). The consistency coefficient and flow behavior index values of the sample to get maximum overall preference score (7.24) were predicted to be 3.650 Pa sⁿ and 0.435, respectively.     

Violence in partnership of immigrant women from Turkey

Forty-one female immigrants from Turkey, who were victims of violence in their relationships and diagnosed with "reaction to severe stress and adjustment disorders" (F43, ICD-10) were compared with a controle-group of the same origin, sex, age and diagnosis who had not suffered from such violence. The frequency of emergency treatment and suicide attempts (in the last month before the first consultation) of the victims of violence were higher than in the controle-group. The victims of violence less frequently live in large families and were more often employed than the controle-group. The duration of time until the immigration of the partner was significantly higher in the group of victims than in the controle-group. The results are discussed with regard to studies concerning other ethnic groups and specific aspects of psychodynamics and migration.