The role of microstructural evolution during spark plasma sintering on the soft magnetic and electronic properties of a CoFe–Al2O3 soft magnetic composite

Journal of Materials Science - For transformers and inductors to meet the world’s growing demand for electrical power, more efficient soft magnetic materials with high saturation magnetic...     

User Survey of Subjective Preference for Street-Lighting Sources

A telephone survey was conducted to assess user subjective preferences for metal halide versus high-pressure sodium lighting used in the Neighborhood Streetlight Demonstration Project conducted by an electric utility company. A variety of univariate and multivariate parametric and nonparametric statistical tests were conducted. This analysis revealed that users rated metal halide higher on color and aesthetic dimensions, they rated metal halide and high-pressure sodium equal in terms of overall satisfaction, and they more frequently named metal halide as the preferred source for a street other than the one they live on. Residents living under metal halide lighting were seen to exhibit more of a loyalty for their source than did high-pressure sodium users. In agreement with previous studies, users' assessment of lighting quantity were uncorrelated with photometric measurements. We conclude that further studies are warranted because these suggested preferences and loyalties, if confirmed, would be important to consider in designing street lighting and in setting street-lighting policy.     

Skin surface microflora of the saddle-back tamarin monkey,Saguinus fuscicollis

The resident skin surface microflora of 12 male and three femaleSaguinus fuscicollis was studied. The suprapubic-circumgenital gland surface and the perirectal area were most heavily colonized (10⁶–10⁸ colony forming units/cm²), but high numbers of organisms were also present on the abdomen, the sternal gland surface, and palms and plantar surfaces. Bacteria were also recovered from hair clippings as well as from shaven skin surface, although at much lower densities (10²–10⁴ colony forming units/cm²). Coagulase negative staphylococci, gram-negative bacteria,Streptococcus species and coryneform bacteria were most dominant.Staphylococcus aureus and species ofBacillus were also present. Fungi, yeast, and dermatophytes were infrequently recovered or completely absent. The microbial flora of these tamarins appears to be closely associated with the secretions of the circumgenital scent gland and would therefore be ideally situated to participate in the generation or modification of chemical signals.     

Effect of film thickness and morphology on the performance of photoelectrochemical cells based on poly(terthiophene)

Photoelectrochemical cells have been fabricated from electrochemically deposited polyterthiophene films. The thickness of the photoactive layer was systematically varied by altering the charge density of the electrodeposited film. The morphology, optical absorption and photovoltaic performance of these devices have been characterised as a function of film thickness in order to gain a better understanding of the structure–function relationships in photoelectrochemical cells. Two distinct growth modes are observed. Initially a compact two-dimensional ‘precursor’ polymer film is formed up to a critical thickness of several hundred nanometres whereupon the growth of a ‘bulk’ three-dimensional film structure occurs. The photovoltaic efficiency of these cells appears to be governed by the ‘precursor’ film, which is characterised by a dense, uniform morphology of polymer of increasing conjugation length. On the other hand, the ‘bulk’ overlayer, which manifests as a nodular and highly cracked surface layer, appears to be primarily responsible for limiting device efficiency.     

Hesperidin Promotes Osteogenesis and Modulates Collagen Matrix Organization and Mineralization In Vitro and In Vivo

This study evaluated the direct effect of a phytochemical, hesperidin, on pre-osteoblast cell function as well as osteogenesis and collagen matrix quality, as there is little known about hesperidin’s influence in mineralized tissue formation and regeneration. Hesperidin was added to a culture of MC3T3-E1 cells at various concentrations. Cell proliferation, viability, osteogenic gene expression and deposited collagen matrix analyses were performed. Treatment with hesperidin showed significant upregulation of osteogenic markers, particularly with lower doses. Mature and compact collagen fibrils in hesperidin-treated cultures were observed by picrosirius red staining (PSR), although a thinner matrix layer was present for the higher dose of hesperidin compared to osteogenic media alone. Fourier-transform infrared spectroscopy indicated a better mineral-to-matrix ratio and matrix distribution in cultures exposed to hesperidin and confirmed less collagen deposited with the 100-µM dose of hesperidin. In vivo, hesperidin combined with a suboptimal dose of bone morphogenetic protein 2 (BMP2) (dose unable to promote healing of a rat mandible critical-sized bone defect) in a collagenous scaffold promoted a well-controlled (not ectopic) pattern of bone formation as compared to a large dose of BMP2 (previously defined as optimal in healing the critical-sized defect, although of ectopic nature). PSR staining of newly formed bone demonstrated that hesperidin can promote maturation of bone organic matrix. Our findings show, for the first time, that hesperidin has a modulatory role in mineralized tissue formation via not only osteoblast cell differentiation but also matrix organization and matrix-to-mineral ratio and could be a potential adjunct in regenerative bone therapies.     

Quantitative determination of the mineral-matter content of coal by a radiofrequency -oxidation technique

The development of a low-temperature (≈150 °C) radiofrequency-oxidation technique as a routine laboratory method for the quantitative determination of the mineral-matter content of coal is described. The main advantage of the method over air-oxidation (370 °C) and acid-extraction methods is that isolation of the unaltered mineral matter permits a more accurate expression of coal analyses on a dry mineral-matter-free basis. Comparison with the air-oxidation method has demonstrated the superiority of the radiofrequency-oxidation method for retention of carbonate and sulphide minerals; reproducibility is generally similar. The radiofrequency-oxidation method yields higher results for the percentage of mineral matter than the air-oxidation method. The differences between the combined water contents of the mineral-matter samples prepared by the two methods indicate that the air-oxidation method partly dehydrates clay minerals and that the radiofrequency-oxidation method produces results closer to the true mineral-matter contents. Other advantages — independence of extra analytical determinations, lower elapsed time and labour costs, applicability to a wider range of coals — are detailed in the Conclusions.