[ effect of shoe-heel height on the static and dynamic postural stability in healthy young women]

Wearing high-heeled shoes increases the height of the center of gravity and takes the line of gravity away from the center of the base of support. This may result in the loss of body balance. In this study the effect of 3 heel heights on the static and dynamic postural stability in healthy young women was investigated. In this cross-over quasi-experimental study with repeated measures, three dynamic indices of anteroposterior, mediolateral, and overall stability were determined using Biodex stabilometer and static stability using a modified CTSIB test. The measurements were made at 4 conditions of the feet, i. e., barefoot, and wearing shoes with a heel height of 3, 5, or 7 centimeters. The mean static stability index in the barefoot condition was significantly different from that in any the 3 conditions of wearing heels. With the eyes closed, the most unstable condition was in the case of the 7-cm heel, which caused also the most unstable dynamic condition; the differences were all statistically significant. The findings indicate that postural instability increases with increases in the height of shoe heels. On the whole, considering both the static and dynamic stability, the 3-cm heel can be recommended as the optimum-height hee

Degradation of trace aqueous 4-chloro-2-nitrophenol occurring in pharmaceutical industrial wastewater by ozone

Degradation of 4-chloro-2-nitro phenol by ozonation in aqueous solution was studied in a semi batch reactor under constant ozone dosage and variable pH conditions. The effectiveness of the process was estimated based on the degree of conversion of 4-chloro-2-nitro phenol. It was observed that ozonation is more effective at alkaline reaction of medium than other conditions. The degree of conversion achieved [at the first 5 minutes of the process] at pH 9 was 99.64% compared to 99.03% and 77.35% at pH 7 and 3, respectively. Another parameter used to quantify the 4-chloro-2-nitrophenol during ozonation was the pseudo first order rate constant k [min[-1]]. Results showed that the rate constant of the process was approximately much higher at the alkaline pH compared to acidic ones. A considerable improvement in chemical oxygen demand removal was observed at pH above 7. At pH 9, the reduction in chemical oxygen demand at the end of the process reached 56.9%. The degree of organically bounded nitrogen conversion to nitrate was higher at pH 3. Of the total organic carbon reduction, 15.89% was observed at pH 9. The 4-chloro-2-nitro phenol degradation intermediate products were analyzed by mass- spectrometry. The main intermediate product was chlorophenol

Removal of Congo red from textile wastewater by ozonation

Congo red, which has a complex molecular structure with various diazo aromatic groups, is widely used in textile industry as an anionic dye. The purpose of this study was to investigate the degradation of Congo red in laboratory solution which had the chemical properties of the rinse waters of textile manufacturing dye-houses and the samples with Congo red alone wastewater by ozonation and to optimize the reaction parameters such as pH and time which influence the efficiencies of total organic carbon, total kjeldahl nitrogen and chemical oxygen demand removal. Ozonation of Congo red dye were carried out in a semi-batch reactor with constant ozone flow rate and concentration of 23 mL/sec and 13.6 mg/L, respectively. Decolorization was complete within a few minutes of ozonation possibly due to the cleavage of chromophore groups. It was observed that its structural destruction occurs predominantly at higher pHs. The reduction of chemical oxygen demand and destruction of the dye was more than 60% and 42%, respectively. Total kjeldahl nitrogen removal was accompanied by slight changes in nitrogen oxides. It can be deduced from the experimental results that: [a] the mineralization is very weak; [b] the reaction follows the indirect mechanism; i.e., the interaction of hydroxyl radicals with the dye and [c] the nitrification is rather predominant. Biological oxygen demand is declined in simulated alkalic and neutral samples respectively. At 13.6 mg O3/L, the biological oxygen demand levels were significantly enhanced. This might be attributable to the enhancement of its biodegradation at alkaline pHs