ABSTRACT
Geological situation and/or anthropogenic contamination contain an increased concentration of ions such as hexavalent chromium as well as some other dissolved components such as sulfate in the upper of the established MCLs [50microg/L]. In this paper, simultaneous removal of Cr [VI] and sulfate from water was investigated using nanofiltration as a promising method for reaching drinking water standards. For varying pressure, pH, anion and cation solution effect, Sulfate and Cr [VI] concentration which have chosen were levels found in drinking water sources [Cr=0.1- 0.5mg/L] and [SO[4][-2]= 100-800mg/L].Experiments were performed using NaCl, Na[2]SO[4],K[2] Cr[2]O[7]and anhydrous CrCl[3]. 6H[2]O which prepared with de mineralized water on procedure detailed in standard methods. All salts were purchased from Merck Corporation with purity over 99%. The results for hexavalent chromium experiments showed that when the concentration decreases, the chromate anions were given a better retention to 4 bars [96%]. But when the concentration increases, concentration polarization led to increased removal of Cr [VI] [98%]. For Cr [III] the influences of the ionic strength as well as the concentrations were strongly dependant on rejection but operating pressure were found weak. In addition, with increasing total dissolved solids, perfect rejection of chromium was seen. The effect of pH showed that better retention was obtained at natural and basic pH. This study indicates that the nature of anions and cations, driven pressure and pH have significant effect on nano filtration operation. Research findings show that it seems nano filtration is a very good promising method of simultaneous removal of Cr [VI] and sulfate from water
Subject(s)
Nanoparticles , Sulfates/isolation & purification , Water Pollutants, Chemical , Water PurificationABSTRACT
Background: focal hyperhidrosis is not rare, affecting nearly 3% of the population. This condition is often socially and professionally debilitating, leading to significant quality of life impairment. Hence, its treatment is an issue of importance. To determine the comparative efficacy of tap water iontophoresis to iontophoresis with atropine
Materials and Methods: we undertook a single-blinded right-left clinical trial in 16 patients with palmoplantar hyperhidrosis attending to dermatology clinic of Loqman Hospital during 2006. We compared the efficacy and the duration of symptom relief following iontophoresis with atropine to iontophoresis with tap water according to both objective [Iodine Test] and subjective [patients' judgment] criteria
Results: therapeutic efficacy was 81.25% after 5 weeks and 100% after 10 weeks of iontophoresis. Following treatment with tap water iontophoresis and atropine iontophoresis, patients reported similar improvement in two hands. Atropine iontophoresis was superior to tap water only after five sessions; however it was not statistically significant [P> 0.05]
Conclusion: we postulate that the similar efficacy of atropine iontophoresis when compared with tap water iontophoresis relates to mechanism of action of iontophoresis which is not affected by atropine, additionally
ABSTRACT
Various factors are involved in causing inflammation following root canal treatment. Controlling these factors may relieve the related pain. One of these factors is extrusion of debris beyond the apex. Although debris extrusion happens in all instrumentation techniques, researchers have declared that in coronal flaring technique, there is minimum debris extrusion. The purpose of this study was to evaluate and compare the inflammation of periapical area following root canal therapy, using conventional and profile rotary instrumentation in cats' teeth, from a histopathological point of view. This experimental study conducted on thirty Persian one year old cats. Three groups of samples were chosen and treated with different methods. First group were prepared by step-back instrumentation technique using stainless steel K-type files. Second group were prepared by crown down technique using Ni-Ti files. Third group were prepared using profile GT rotary system at 150-rpm speed. Animals were subjected to vital perfusion at 8, 24 and 48 hour intervals after instrumentation. The canine teeth were separated from the jaw along with some of the supporting structures. Then decalcification and laboratory processing were carried out and samples were evaluated histologically. Collected data were analyzed using Kruskal-Wallis test. The results showed that in vital teeth with no evidence of periapical pathosis, the inflammation following various instrumentation methods was not statistically different. In vital teeth, the periapical inflammation following various methods of instrumentation is not statistically different