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FT-IR spectroscopy combined infrared synchrotron light micro-spectroscopy (SMIS) advanced techniques were employed to study soil stabilizing mechanisms of two ionic polyelectrolytic polymers (PP1 & PP2) on soil and pavement composite micro- and nanostructures. The main aim of this study was to probe the micro- macroscopic changes in stabilized materials using these non-traditional chemical stabilizers (PP1 & PP2) with the aim to improve their performance. Performance was assessed by measuring strength properties of composite specimens (plasticity index). Analyses of the SMIS spectra of treated samples indicated two prominent changes in vibrations in two regions: Firstly, the 3000 - 1400 cm-1 IR region was probably due to OH deformations of the hydroxyl groups of adsorbed water (1635 - 1600 cm-1), and the expansive property of clay nanostructures; Secondly, in the 1400 - 950 cm-1 IR region, possibly due to the Si-O framework, that is, silicate plates of type T-E or T-O-E, where any new bonding or rearrangement of the silicate tetrahedron molecule in the soil samples would be sensitive. Since statistical analysis showed that these changes were not significant (p<0.05) using conventional spectroscopy, the presence of a surface composite network (interface) binding the particles was observed when infrared synchrotron light spectroscopy was successfully employed to elucidate these changes at the micro scale level and confirmed with macroscopic measurements using HR-SEM. Conclusively, the demonstrated approach is a promising tool to obtain chemical information involved in microcrystalline formation in these kind of polymeric-enhanced complex composite interfaced materials. However, a further study under varied and optimized experimental conditions would provide more insight into the molecular behaviour of such modified composite reinforced materials. [ABSTRACT FROM AUTHOR]

Abstract: A cost-effective and environmentally friendly green chemical method, the so-called aqueous chemical growth (ACG) method, was used to deposit chromium/alpha-chromium(III) oxide, Cr/α-Cr2O3, monodispersed particles, for solar absorbers applications. The deposited particles were annealed at various temperatures in a hydrogen atmosphere for 2h to study the annealing temperature dependence of the structural, chemical and optical properties of the particles grown on tantalum substrates. The deposited Cr/α-Cr2O3 was characterized by X-ray diffraction (XRD), attenuated total reflection (ATR), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), and diffuse reflectance UV–vis–NIR spectroscopy. The XRD and ATR analysis indicated that by increasing annealing temperature, the particles crystallinity was improved and Ta2O5 was formed around 600°C, due to the fast oxygen diffusion from the deposited α-Cr2O3 toward the tantalum substrate. The optical measurements show that samples annealed at 400 and 500°C exhibit the targeted high absorbing optical characteristics of “Black chrome”, while those annealed below 400°C and above 500°C show a significant low absorptivity and high emissivity. [Copyright &y& Elsevier]

The objective of this study was to (1) measure the concentration of four anions (Cl-, F-, [image omitted], and [image omitted]) and nine other elements (Al, Ba, Ca, K, Mg, Mn, Fe, Ni, and Si) in two nontraditional biopolymeric chemical stabilizers (EBCS1 and EBCS2), (2) investigate consequent environmental toxicity risk implications, and (3) create awareness regarding environmental health issues associated with metal concentration levels in enzyme-based chemical stabilizers that are now gaining widespread application in road construction and other concrete materials. Potential ecotoxicity impacts were studied on aqueous extracts of EBCS1 and EBCS2 using two thermodynamic properties models: the Pitzer-Mayorga model (calculation of the electrolyte activity coefficients) and the Millero-Pitzer model (calculation of the ionic activity coefficients). Results showed not only high concentrations of a variety of metal ions and inorganic anions, but also a significant variation between two chemical stabilizing mixtures. The mixture (EBCS2) with the lower pH value was richer in all the cationic and anionic species than (EBCS1). Sulfate ([image omitted]) concentrations were found to be higher in EBCS2 than in EBCS1. There was no correlation between electrolyte activity and presence of the ionic species, which may be linked to a possible high ionic environmental activity. The concentrations of trace metals found (Mn, Fe, and Ni) were low compared to those of earth metals (Ba, Ca, K, and Mg). The metal concentrations were higher in EBCS1 than in EBCS2. Data suggest that specific studies are needed to establish “zero” permissible metal ecotoxicity values for elements and anions in any such strong polyelectrolytic enzyme-based chemical stabilizers. [ABSTRACT FROM AUTHOR]

This paper describes a study undertaken to explore how assistive technology in the form of a wrist-worn device is perceived by older people for whom it has been devised. [ABSTRACT FROM AUTHOR]

Background: Reported incidences of prostate cancer and masculinization of animals indicate a release of compounds with androgenic properties into the environment. Large numbers of environmental pollutants have been screened to identify such compounds; however, not until recently was 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH) identified as the first potent activator of the human androgen receptor (hAR). TBECH has been found in beluga whales and bird eggs and has also been found to be maternally transferred in zebrafish. Objectives: In the present study we investigated interaction energies between TBECH diastereomers (alpha, beta, gamma, and delta) and the hAR, and their ability to activate the receptor and induce prostatespecific antigen (PSA) expression in vitro. Methods: We performed computational modeling to determine interaction energies between the ligand and the AR ligand-binding site, and measured in vitro competitive binding assays for AR by polarization fluorometry analysis. We used enzyme-linked immunosorbent assays to determine PSA activity in LNCaP and HepG2 cells. Results: We found the gamma and delta diastereomers to be more potent activators of hAR than the alpha and beta diastereomers, which was confirmed in receptor binding studies. All TBECH diastereomers induced PSA expression in LNCaP cells even though the AR present in these cells is mutated (T877A). Modeling studies of LNCaP AR revealed that TBECH diastereomers bound to the receptor with a closer distance to the key amino acids in the ligand-binding domain, indicating stronger binding to the mutated receptor. Conclusions: The present study demonstrates the ability of TBECH to activate the hAR, indicating that it is a potential endocrine disruptor. [ABSTRACT FROM AUTHOR]