One-electron redox reactions of troxerutin in aqueous solutions

The oxidation of flavonoids is of great interest because of their action as antioxidants with the ability to scavenge radicals by means of electron-transfer processes. The redox reactions of the flavonoid derivative troxerutin, (2-[3,4-bis-(2-hydroxyethoxy) phenyl]-3[[6-deoxy-α-L-manno-pyranosyl)-β-(D-glucopyranosyl]-oxy]-5-hydroxy-7-(2-hydroxyethoxy)-4H-1-benzo-pyran-4-one), were investigated over a wide range of conditions, using pulse radiolysis and cyclic voltammetry. The oxidation mechanism proceeds in sequential steps. One-electron redox potentials for troxerutin were found to be +1.196, +0.846 and −0.634 V vs. NHE.     

A Simple Alkylative 1,2-Carbonyl Transposition of Cyclohexenones

Acid catalysed dehydration of the diols 5 , derived from the cyclohexenone 3 affords mixtures of 8 and 11 . The product ratio 8/11 , although strongly dependent on both the reaction conditions and the substituent R, is independent of the diol configuration; this indicates a cationic intermediate 6 . Conditions were found, which allow the sequence A → B → C → D (Scheme 2) to be applied to the syntheses of the enones 8, 21 and 25 in fair to good yields from the corresponding cyclohexenones 3, 18 and 22 .     

Synthesis and characterization of SPE membrane based on sulfonated FEP‐g‐acrylic acid by radiation induced graft copolymerization for PEM fuel cell

A Novel solid polymer electrolyte (SPE) membrane containing both ? COOH and ? SO₃H group has been prepared by simultaneous method of radiation grafting of acrylic acid onto FEP followed by sulfonation. The presence of weakly acidic acrylic acid controls the swelling in water while ? SO₃H group provides conductivity due to its strongly ionic characteristic. FEP‐g‐acrylic acid and its sulfonated derivatives were characterized by their properties. While the mechanical properties decreased, other properties such as ion exchange capacity (IEC), water uptake and ionic conductivity increased with increase in graft content. These properties further changed on sulfonation. Acrylic acid being weakly acidic in nature, conductivity values of the grafted membrane were quite low. However, introduction of strong ? SO₃H group resulted in conductivity closer to Nafion 117. Few sulfonated membranes have been tested with respect to H₂/O₂ fuel cell performance. Short‐term fuel cell test for 100 hr gave a stable performance. These membranes are less expensive compared to Nafion. Copyright © 2004 John Wiley & Sons, Ltd.     

Magnetic moments and the proton structure function

The EMC collaboration have reported a measurement of the proton structure function which has been interpreted to mean that the spin of the proton is not predominantly that of the quarks (=u+d+s=0.13±0.19). We show that the magnetic moments of the baryons are independent of this measurement and are given (within 10–20%) for a range of including the valence model value =1. The magnetic moments of the quarks can only be fixed if the quantity is determined very accurately.     

Studies on the feasibility of production of57Co by alpha bombardment of Mn and Ni targets

We have studied the feasibility of producing⁵⁷Co (271.3 d) via the⁵⁵Mn(, 2n)⁵⁷Co reaction (⁵⁵Mn–100%). The thick target yield of⁵⁷Co in the 28 to 18 MeV energy region was measured as 3.87 Ci/Ah. However, the proximity and overlap of the excitation functions for (, n), (, 2n) and (, 3n) reactions on⁵⁵Mn are such that the production of pure⁵⁷Co in high yields free of⁵⁸Co (70.8 d) and⁵⁶Co (78.8 d) has not been feasible. We have also studied a new method for ancillary production of⁵⁷Co via the reactions⁵⁸Ni(, p)⁵⁷Co and during the course of producing⁶²Zn by⁶⁰Ni(, 2n)⁶²Zn reaction. In this case the yield of⁵⁷Co of reasonable purity has been up to 1 Ci/Ah.     

Thermal noise in Hg0.795Cd0.205Te detectors for large biasing fields

Thermal noise in Hg_0.795Cd_0.205Te detectors is estimated for large biasing fields at a lattice temperature of 77 K, by computing the correlation functions of the velocity fluctuations with the Monte Carlo technique. The noise temperature for current components transverse to the field is almost independent of the field, but that corresponding to the parallel component increases by a factor of about 1.3 at 50 V/cm and by a factor of 3.0 at 300V/cm. The thermal noise voltage for a detector of 85 resistance increases from 0.6nV/Hz^1/2 at low biasing fields to about 3nV/Hz^1/2 at a field of 300 V/cm. The noise power is also found to remain constant up to about 75 GHz, and it decreases thereafter by a factor of 0.25 for doubling of the frequency.     

Correlation of Phosphorus Adsorption with Chemical Properties of Aluminum-Based Drinking Water Treatment Residuals Collected from Various Parts of the United States

Over the past several decades, the value of drinking water treatment residuals (WTRs), a byproduct of the coagulation process during water purification, has been recognized in various environmental applications, including sustainable remediation of phosphorus (P)-enriched soils. Aluminum-based WTRs (Al-WTRs) are suitable adsorbent materials for P, which can be obtained and processed inexpensively. However, given their heterogeneous nature, it is essential to identify an easily analyzable chemical property that can predict the capability of Al-WTRs to bind P before soil amendment. To address this issue, thirteen Al-WTRs were collected from various geographical locations around the United States. The non-hazardous nature of the Al-WTRs was ascertained first. Then, their P adsorption capacities were determined, and the chemical properties likely to influence their adsorption capacities were examined. Statistical models were built to identify a single property to best predict the P adsorption capacity of the Al-WTRs. Results show that all investigated Al-WTRs are safe for environmental applications, and oxalate-extractable aluminum is a significant indicator of the P adsorption capacity of Al-WTRs (p-value = 0.0002, R² = 0.7). This study is the first to report a simple chemical test that can be easily applied to predict the efficacy of Al-WTRs in binding P before their broadscale land application.     

Phosphorus and Heavy Metals Removal from Stormwater Runoff Using Granulated Industrial Waste for Retrofitting Catch Basins

Phosphorus and heavy metals are washed off and transported with stormwater runoff to nearby surface water bodies resulting in environmental and human health risks. Catch basins remain one of the primary gateways through which stormwater runoff and pollutants from urban areas are transported. Retrofitting catch basins to enhance their phosphorus and heavy metal removal can be an effective approach. In this study, aluminum-based water treatment residual (WTR, a non-hazardous byproduct of the water treatment process) was granulated via a green method to serve as a sustainable filter material, called WTR granules, for enhancing the capabilities of catch basins to remove phosphorus and heavy metals. The WTR granules were field tested in a parking lot in Hoboken, New Jersey. Twelve storm events were monitored. The results showed that the WTR granules significantly (p < 0.05) reduced dissolved P, Cu, and Zn, as well as total P, Cu, Pb, and Zn concentrations in stormwater runoff without signs of disintegration. No flooding or water ponding was observed during the implementation. Results suggest the WTR granules are an inexpensive, green filter material that can be used for retrofitting catch basins to remove phosphorus and heavy metals effectively.