Iron release from corroded iron pipes in drinking water distribution systems: effect of dissolved oxygen

Iron release from corroded iron pipes is the principal cause of "colored water" problems in drinking water distribution systems. The corrosion scales present in corroded iron pipes restrict the flow of water, and can also deteriorate the water quality. This research was focused on understanding the effect of dissolved oxygen (DO), a key water quality parameter, on iron release from the old corroded iron pipes. Corrosion scales from 70-year-old galvanized iron pipe were characterized as porous deposits of Fe(III) phases (goethite (alpha-FeOOH), magnetite (Fe(3)O(4)), and maghemite (alpha-Fe(2)O(3))) with a shell-like, dense layer near the top of the scales. High concentrations of readily soluble Fe(II) content was present inside the scales. Iron release from these corroded pipes was investigated for both flow and stagnant water conditions. Our studies confirmed that iron was released to bulk water primarily in the ferrous form. When DO was present in water, higher amounts of iron release was observed during stagnation in comparison to flowing water conditions. Additionally, it was found that increasing the DO concentration in water during stagnation reduced the amount of iron release. Our studies substantiate that increasing the concentration of oxidants in water and maintaining flowing conditions can reduce the amount of iron release from corroded iron pipes. Based on our studies, it is proposed that iron is released from corroded iron pipes by dissolution of corrosion scales, and that the microstructure and composition of corrosion scales are important parameters that can influence the amount of iron released from such systems.     

IT infrastructure in emerging markets: arguing for an end-to-end perspective

To help sustain large-scale pervasive computing in emerging markets, researchers must address unique challenges in the delivery fabric and enterprise backbone. Such challenges present opportunities for high impact innovation. Although most research organizations have focused on developing consumer-facing solutions, we posit that future research must take an end-to-end perspective. That is, researchers must not only consider the front end (such as consumer devices) but also the medium to reach the consumer (for example, the delivery fabric) and the back end (for example, the enterprise backbone) to create an economically sustainable, scalable solution. Although our end-to-end perspective generalizes to all emerging markets, in this article, we mainly discuss the Indian market from which we based our observations.     

Unusual cloacal exstrophy in a male neonate with a normal penis and urethra

El mouse is a mutant which has epileptic convulsions after tossing-up stimulations and has a hippocampal dysfunction. Platelet-derived growth factor B-chain homodimer has been reported to be a trophic factor of hippocampal neurons. We found that a recombinant PDGF-BB suppressed the convulsions of El mice in a dose-dependent manner. Furthermore, thrombin-treated mice manifested no convulsions, but thrombin receptor activating peptide-treated ones had convulsions. These findings suggest that an abnormality in PDGF-BB release may make El mice susceptible to tonic-clonic convulsions.     

Synthesis and performance evaluation of O, O-dialkylphosphorodithioic disulphides as potential antiwear, extreme-pressure and antioxidant additives

The ashless antiwear/EP additives based on phosphorodithioic acids are preferred to their heavy metal complexes, due to operational problems and enviromental restrictions being enforced in many countries. Four O, O-dialkylphosphorodithioic disulphides with varying alkyl chain length from C5 to C10 have been synthesized and their antiwear, EP and antioxidant performance examined vis-à-vis a commercial ZDDP in a mineral base oil. The synthesized products have been found to exhibit appreciable antiwear and antioxidant properties and mild EP performance, which are comparable to that of commercial ZDDP.     

Hybrid Type-2 Fuzzy Based Channel Estimation for MIMO-OFDM System with Doppler Offset Influences

Wireless Personal Communications - The channel estimation methods track and predict the variation in channel characteristics, so that the original signal can be obtained after nullifying the...     

从大木尺度现象看柳林香严寺毗卢殿建造年代之复杂性*

毗卢殿是山西柳林香严寺中的重要建筑,构架简明,却又在细节设计上存在独特和矛盾之处。本文基于三维激光扫描和手工补测,对毗卢殿的建筑平面、架道、材分°设计等大木尺度设计进行了解读和还原,发现毗卢殿的设计中采用了 310 毫米和 318~319 毫米两种不同长度的营造尺。两把营造尺反映出其建造年代的复杂性,毗卢殿始建于元代,明清时期经历修缮,但其斗栱仍然保留了元构的尺度和造型特征。     

An unusual congenital nasopharyngeal teratoma

A supine technique for reducing posterior dislocations of the hip is presented. We believe this technique provides more controlled traction than do other maneuvers and have found it to be a safe and effective method to reduce the posteriorly dislocated hip.     

A case of hepatocellular carcinoma associated with troublesome hypoglycemia: management by cytoreduction using percutaneous ethanol injection

Hypoglycemia is a well-known paraneoplastic manifestation of hepatocellular carcinoma. However, hypoglycemia as the first presentation is extremely uncommon. We herein report a case of HCC presenting with severe, uncontrollable hypoglycemia that was managed with percutaneous ethanol injection therapy.