Effects of copper content on microstructure and mechanical properties of open-cell steel foams

The effects of copper content on the microstructural and mechanical properties of steel foams are investigated. Spherical urea granules, used as a water-leachable space holder, were coated with a mixture of iron, ultrafine carbon, and different amounts of copper powders. After the mixture was compacted and the space holder was removed by leaching, a sintering process was performed under an atmosphere of thermally dissociated ammonia. Microstructural evaluations of the cell walls were carried out using optical microscopy and scanning electron microscopy in conjunction with energy-dispersive X-ray spectroscopy. In addition, compression tests were conducted to investigate the mechanical properties of the manufactured steel foams. The results showed that the total porosity decreases from 77.2% to 71.9% with increasing copper content in the steel foams. In the foams' microstructure, copper islands are mostly distributed in pearlite and intergranular carbide phases are formed in the grain boundaries. When the copper content was increased from 0 to 4 wt%, the elastic modulus, plateau stress, fracture stress, and fracture strain of manufactured steel foams improved 4.5, 6, 6.4, and 2.5 times, respectively.

Identification and Structural Characterization of Secondary Degradant of Arformoterol Impurity in LDPE Respules of Arformoterol Tartrate Inhalation Solution

Arformoterol (R, R) is an enantiomer of racemic formoterol, was the first long-acting beta agonist (LABA), approved by U.S. food and Drug Administration (FDA). The Arformoterol which is used for the treatment of Chronic obstructive pulmonary disease (COPD) are inhaled bronchodilator drugs which are delivered directly to the patient’s airways through a different mechanism. The formulated drug product is kept for stability study as per ICH guideline [1] and during its stability interval analysis by HPLC (High performance liquid chromatography), an unknown peak observed at level around 0.1% which is well below the identification threshold of 0.5% but after heating it crossed the identification threshold. The approach to identify anonymous species of Arformoterol aqueous formulation was adopted as first to generate the impurity in sample, isolate, enrich and Characterize through LC-MS/MS and NMR Spectroscopy. Based on the spectral data the anonymous species was identified as an “Imine impurity”, it is secondary degradant of Amine impurity of Arformoterol formed due to reaction with leachable observed in LDPE respules.

An Influencing Factor - Water-Filter Ratio on Heat Resistance of Condensate Polishing Filter Material in Water

In air-cooled condenser, high temperature condensing water m summer which approaching and exceed 60＊ C, which may result in filter materials degradation and release impurities. This paper discusses an influencing factor, water-filter ratio （soaking solution and filter quality ratio）, on leachable dissolution rate and filter material degradation rate m high temperature water. The UV absorption at 254nm （A254） and the exchange capacity ware measured after heat test as composite indicators. In addition, the Wends of A254 variation with heating time were measured in different water-filter ratio. The stability is probably due to the effect of water-filter ratio. This has been further borne out that, water-filter ratio increases, leachable concentration decreases exponentially and tends to a fLxed value.

Performance Appraisal of Controlled Low-strength Material Using Sewage Sludge and Refuse Incineration Bottom Ash

This research evaluated the use of sewage sludge and refuse incineration bottom ash to replace calcium sulfoaluminate cement （CSA） in making controlled low-strength material （CLSM）. Various properties of CLSM mixtures were characterized in terms of unconfined compressive strength, microstructure and leachability. It was found that the strength of tested CLSM mixtures ranged from 3.6 to 9.0 MPa, over the upper excavatable limit of 2.1 MPa. The micro-structural analysis revealed that sewage sludge and bottom ash were crystallochemically in- corporated within CLSM system_s by forming the needle-like ettringite （C3A＇3CS＇_H32） with exiguous tu.bers via the typical Pozzolanic Reaction, leading to a dense and low-porosity microst;＇ucture. Furthermore,-the toxicity characteristic leaching procedure evidenced that the cumulative leachable metals in the leachate were much below the regulatory thresholds. The potential for us!ng sewage sludge and bottom ash!n CLSM makin.g was thus confirmed.

Effect of Humus on Activity of Mineral-Bound Hg: III.Effect on Leachability and Transfer of Mineral-Bound Hg Under Acid Leaching Condition

Effects of humus fractions (fulvic acid, brown humic acid and grey humic acid) on the leachability and transferring activity of five types of mineral-bound Hg were investigated. Under the acid leaching condition: fulvic acid could promote leachability and vertical transference of all the mineral-bound Hg. Brown humic acid could retard the leaching and transferring processes of CaCO3-Hg, Fe2O3-Hg, MnO2-Hg and kaolinite Hg but not bentonite-Hg. Grey humic acid could greatly enhance residing ability of the mineral-bound Hg in the soil column and restrain them from vertical transferring. The effect of humus on leachability and transferring activity on the mineral-bound Hg was closely related to its ability to convert the mineral-bound Hg into organic-bound form and the transferability of the latter in the soil column. The characteristics of the mineral-bound Hg in speciation were the internal factors that determined the extent and rate of the influence of the humus.

Impact of fixation/drying conditions on fixation rate, leachability and bioefficacy in CCA-C treated red pine and southern pine

Red pine (Pinus resinosia Ait) and southern pine (Pinus spp.) sapwood blocks were pressure treated with CCA-C at retention of 6.4, 2.0, 1.5 kg(m-3 followed by fixation using 11 post-treatment schedules ranging from 50-70 (C and 5 different relative humidity conditions. The effect of these post-treatment schedules on fixation rate, chemical leachability and decay resistant once were evaluated to better understand the effects of fixation/drying conditions on leachability and biodeterioration. Southern pine blocks fixes slightly slower than red pine. Fixation of CCA at high temperature high humidity, essential initially fixation at high humidity for fixation/drying schedules, resulted in lower leaching of chromium and arsenic elements than high temperature low humidity or initially fixation at the high temperature low humidity conditions. Copper leaching was indicated no significant difference under 11 fixation/drying conditions for both species. Weight losses for southern pine by Chaetomium globosum was lower than red pine by Gloeophyllom trabeum. There were some different capacities of decay resistance for both species under those post treatment conditions.

Red Cement-based Decorative Mortar Prepared with Dry Electroplating Sludge Containing Pb as Red Pigment

Red cement-based decorative mortars were prepared with different content electroplating sludge containing Pb （EPSP）, and their colors, water absorption, strengths, hydration characteristics and heavy metal leachabilities were investigated. The experimental results show that EPSP can adjust the mortar color well as the red pigments exclusively used in the decorative mortarS. EPSP will result in the increase of water absorption, but the mortar produced with 5% EPSP still has the very satisfactory water absorption. The mortars with EPSP are provided with nearly the same compressive, flexural and tensile bond strengths as those of the control. EPSP has no notable influence on the paste hydration. But it can densify the mortar microstructures. It is also evident that heavy metal concentrations in leachates of the mortars with EPSP are far lower than the recommended in the GB5085.3-2007.

Leachability of Oil Shale Ash from Isfir Al-Mahata Oil Shale, Southern Jordan

This paper presents the first study on the oil shale (OS) ashing and OS ash leachability of Jordanian OS located further in the south. The studied OS is from Isfir Al-Mahata subsurface OS located 10 km south of Ma’an. Chemical and physical characterization of the OS ash was performed and compared with original OS. Ashing OS was conducted at different temperatures. Important parameters affecting OS ash leachability were also investigated. The leachability of certain heavy metals was investigated based on clear leaching protocol. The Fisher Assay analysis result indicates that this OS type has quite higher moisture content, lower oil content, and higher spent shale compared with other Jordanian oil shales. Ashing of OS at higher temperatures (950°C) resulted in the disappearance of silica, due to its complete reaction with lime and Al, and formation of Anhydrite and cement materials like, Portland cement. The leachability analysis indicates that for most elements the leachability is high at low pH. The released heavy metals concentrations are below EPA limits. Chromium and lead are leached out more than other elements with the exception at low pH. In general, the higher the ashing temperature is, the lower the release of elements is. The chemical composition of the ash and the leachability results suggests that it has high fixing capacity toward the heavy metals present in the ash.

Mobilities and leachabilities of heavy metals in sludge with humus soil

Chemical forms of Zn, Ni, Cu, and Pb in municipal sewage sludge were investigated by adding humus soil to sludge and by performing sequential extraction procedures. In the final sludge mixtures, Zn and Ni were mainly found in Fe/Mn oxide-bound （F3） and organic matter/sulfide-bound （F4） forms. For Zn, exchangeable （F1）, carbonate-bound （F2）, and F3 forms were transformed to F4 and residual forms （F5）. For Ni, F1 and F2 forms were transformed to F1, F2, and F3 forms. Both Cu and Pb were strongly associated with the stable forms F4 and F5. For Cu, F2 and F3 forms were major contributors, while for Pb, F3 and F4 forms were major contributors to F5. Humus soil dosage and pH conditions in the sludge were strongly correlated with the forms of heavy metals. Five forms were used to evaluate metal mobilities in the initial and final sludge mixtures. The mobilities of the four heavy metals studied decreased after 28 days. The metal mobilities in the final sludge mixtures were ranked in the following order： Ni 〉 Zn 〉 Cu = Pb. Leaching tests showed that the mobilities of Zn and Ni in lower pH conditions （pH 4） were higher than those in higher pH conditions （pH 8）.

Self-propagating high-temperature synthesis of ZrO_2 incorporated Gd_2Ti_2O_7 pyrochlore

In this research, Zr-doped Gd_2Ti_2O_7 pyrochlores, with the composition of Gd_2(Ti_(1-x)Zr_x)_2O_7, were firstly synthesized by self-propagating high-temperature synthesis plus quick pressing(SHS/QP) using CuO as the oxidant and Ti as the reductant. To improve the radiation resistance of titanate–pyrochlore, up to 35 at% Zr was incorporated to substitute the Ti site of Gd_2Ti_2O_7 pyrochlore(Gd_2(Ti_(0.75)Zr_(0.35))_2O_7). XRD and SEM microstructural characterizations showed the formation of a composite ceramic with the major pyrochlore phase and the minor Cu phase. The generated temperature of samples decreased from 1702to 1011 ℃ with increasing Zr content. The effects of sintering temperature and pressure time on phase composition and microstructure were systematically studied. Besides, the influence of thermal transmission on the whole combustion process was also explored. The pyrochlore-based waste form possessed high bulk density of 6.25 g/cm^3 and Vickers hardness of 10.81 GPa. The MCC-1 leaching test showed the normalized elemental leaching rates(42d) of Cu, Gd, and Zr are 1.27×10^(-2), 1.33×10^(-3), and 8.44×10^(-7)g·m^(-2)·d^(-1), respectively.

Leachability and fractionation of heavy metals in stainless steelmaking plant dusts

The leachability and fractionation of the selected heavy metals （Cr, Cd, Pb and Zn） in the stainless steelmaking plant dusts were studied by the modified HJ/T299-2007 method, the modified TCLP test and a seven-step sequential extraction procedure. The results show that the stainless steelmaking plant dusts are considered as hazardous materials since at least one of the leachable heavy metals exceeds the corresponding limit levels of State Environmental Protection Administration of China. Pb is the most extractable heavy metals by the sequential extraction procedure, while Cr, Cd and Zn mainly presents in the residual fraction bound to spinel phase and silicates. The mobile heavy metals in the dusts, which present as the species of water soluble, exchangeable species and the species bounded to carbonates and hydroxides, can be estimated as 0.08 1.2% of Cr, 7.6% 31.8% of Cd, 34.1% of Pb, 0.052-0.4% of Zn, respectively.