Effects of Interface Roughness on Residual Stresses in Thermal Barrier Coatings

Using a newly developed object-oriented finite-element analysis method, both an actual microstructure and model microstructures of a plasma-sprayed thermal barrier coating system were numerically simulated to analyze the full-field residual stresses of this coating system. Residual stresses in the actual microstructure were influenced by both the irregular top-coat/bond-coat interface and cracks in the top coat. By treating the microcracked top coat as a more-compliant solid microstructure, the effects of the irregular interface on residual stresses were examined. These results then could be compared to results that have been obtained by analyzing a model microstructure with a sinusoidal interface, which has been considered by some earlier investigators.     

Implications of climate change predictions for UK cropping and prospects for possible mitigation: a review of challenges and potential responses

The UK, like the rest of the world, is confronting the impacts of climate change. Further changes are expected and they will have a profound effect on agriculture. Future crop production will take place against increasing CO₂ levels and temperatures, decreasing water availability, and increasing frequency of extreme weather events. This review contributes to research on agricultural practices for climate change, but with a more regional perspective. The present study explores climate change impacts on UK agriculture, particularly food crop production, and how to mitigate and build resilience to climate change by adopting and/or changing soil management practices, including fertilisation and tillage systems, new crop adoption and variety choice. Some mitigation can be adopted in the shorter term, such as changes in crop type and reduction in fertiliser use, but in other cases the options will need greater investment and longer adaptation period. This is the case for new crop variety development and deployment, and possible changes to soil cultivations. Uncertainty of future weather conditions, particularly extreme weather, also affect decision‐making for adoption of practices by farmers to ensure more stable and sustainable production. Even when there is real potential for climate change mitigation, it can sometimes be more difficult to accomplish with certainty on‐farm. Better future climate projections and long‐term investments will be required to create more resilient agricultural systems in the UK in the face of climate change challenges. © 2016 Society of Chemical Industry     

Identification of Thiols in Yellow Onion (Allium cepa L.) Using Solvent Vented Large Volume Injection GC‐MS

Thiols are often highly odor active molecules and as such can significantly contribute to aroma while being present at extremely low concentrations. This paper details the identification of thiols in yellow onion juice by solvent extraction followed by thiol enrichment using a mercuric agarose gel column. Due to the inherent thermal instability and low concentrations of thiols in onion, chromatographic analysis utilized larger volume solvent elimination injections. New sulfur compounds in onion included 1,1‐propanedithiol, bis‐(1‐sulfanylpropyl)‐sulfide, 1‐methylsulfanyl‐1‐propanethiol, 1‐propylsulfanyl‐1‐propanethiol, and 1‐allylsulfanyl‐1‐propanethiol. A discussion on the potential route of formation for each compound is included along with the orthonasal and retronasal evaluations of the synthesized molecules. This work investigated and identified 5 newly identified compounds present in onions that can impart onion character at low concentrations levels.     

Reformulated gasoline: Cleaner air on the road to nowhere

U.S. legislation taking effect in 1995 and requiring the sale of cleaner reformulated gasoline in heavily polluted areas provides limited environmental benefits, but it fails to take into account the world's dwindling reserves of oil, the eroding economics of using oil, and the political and military costs of maintaining access to non-domestic supplies. In contrast, natural gas offers greater emissions reductions than reformulated gasoline, at lower fuel costs and with greater domestic supply and energy security. In the long term, the expansion of the infrastructure that would support natural gas vehicles could facilitate the transition to hydrogen which, when produced from renewable resources, could become the optimum fuel for a sustainable transportation energy economy.     

Phagocytosis and serum susceptibility of Escherichia coil cultured in iron-deplete and iron-replete media

The susceptibility of Escherichia coli cultured in either iron-deplete or iron-replete media to phagocytosis by bovine neutrophils and the bactericidal activity of bovine serum was tested in vitro. Fourteen E. coli isolates from naturally occurring intramammary infections (IMI) were cultured overnight at 37 degrees C in iron-replete media and iron-deplete media. The iron-replete media were trypticase soy broth or a chemically defined medium. The iron-deplete media were either trypticase soy broth plus 0.2 mM alpha, alpha' dipyridyl and 1mM citrate, or the chemically defined medium plus 0.2 mM alpha, alpha' dipyridyl, and 1 mM citrate. Iron-replenished medium was the chemically defined iron-deplete medium plus 40 mM ferric citrate. Bacteria grown in iron-deplete media were less susceptible to phagocytosis compared with bacteria grown in iron-replete media. Replenishing the chemically defined iron-deplete medium with ferric citrate obliterated the decreased susceptibility to phagocytosis observed in iron-deplete media. The iron availability in media used to culture E. coli before assay did not affect the bactericidal action of either the classical pathway of complement or the antibody independent alternative pathway of complement in serum. The growth of bacteria in iron-deplete medium did not alter the expression of capsule compared with growth in iron-replete medium. Iron availability during culture of E. coli altered the susceptibility of isolates to phagocytosis by neutrophils, but had no effect on the susceptibility of isolates to the bactericidal activity of serum.     

The impact of the Veterans Health Administration (VHA) reorganization on psychology programs: A survey of VHA psychology leaders.

Because the Veterans Health Administration (VHA) is the nation's largest health care system and employer and trainer of psychologists, changes in VHA psychology have implications for the rest of the profession. A national survey of 127 VHA psychology leaders (91% response rate) documented that many psychologists now are managed by a psychiatrist, deliver more outpatient services, and do less personality testing. In the context of a 10% reduction in psychology staffing, morale is rated lower than 2 years earlier. Diversified professional roles are associated with higher status of psychology and management support for mental health programs. Psychologists need to understand and respond adaptively to the organizational and economic forces affecting their practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Arsenic removal by iron-modified activated carbon

Iron-impregnated activated carbons have been found to be very effective in arsenic removal. Oxyanionic arsenic species such as arsenate and arsenite adsorb at the iron oxyhydroxide surface by forming complexes with the surface sites. Our goal has been to load as much iron within the carbon pores as possible while also rendering as much of the iron to be available for sorbing arsenic. Surface oxidation of carbon by HNO3/H2SO4 or by HNO3/KMnO4 increased the amount of iron that could be loaded to 7.6-8.0%; arsenic stayed below 10 ppb until 12,000 bed volumes during rapid small-scale tests (RSSCTs) using Rutland, MA groundwater (40-60 ppb arsenic, and pH of 7.6-8.0). Boehm titrations showed that surface oxidation greatly increased the concentration of carboxylic and phenolic surface groups. Iron impregnation by precipitation or iron salt evaporation was also evaluated. Iron content was increased to 9-17% with internal iron-loading, and to 33.6% with both internal and external iron loading. These iron-tailored carbons reached 25,000-34,000 bed volumes to 10 ppb arsenic breakthrough during RSSCTs. With the 33.6% iron loading, some iron peeled off.     

Continuously extruded micro‐textured polypropylene films

The continuous extrusion of micro‐textured isotactic polypropylene (i‐PP) film and its tribological properties are reported. As analyzed by scanning electron microscopy, a rectangular‐semicircular micro‐patterned die successfully produced extruded cast‐films with hill‐like micro‐texture. Such films displayed static and kinetic coefficients of friction (COF_s and COF_k) values of 0.247 ± 0.028 and 0.245 ± 0.003, respectively, for a steel fixture sliding along the micro‐texture of the film. The equivalent COF_s and COF_k values for non‐textured (NT) films were 0.369 ± 0.036 and 0.340 ± 0.024, respectively, confirming that textured films displayed a reduction in COF of about 30%. For textured and NT films sliding on textured films, the COF_k values were even lower at 0.161 ± 0.013 and 0.113 ± 0.004, which represents about 20–40% reduction as compared with that for the NT‐NT counterparts. Films coated with a silicone lubricant displayed COF_s and COF_k values of 0.334 ± 0.042 and 0.099 ± 0.012, respectively, for NT films sliding over lubricated NT films, and 0.426 ± 0.031 and 0.063 ± 0.006, respectively, for textured films sliding over lubricated textured films. The COF_k values for textured/non‐lubricated films approach those of NT/lubricated films, indicating that micro‐textured polypropylene films may be used in environmentally sensitive applications where lubricants and fluorinated additives may not be used for reducing friction. POLYM. ENG. SCI., 54:2147–2154, 2014. © 2013 Society of Plastics Engineers