Benefits of Residual Aluminum in Ductile Iron

Two main chemistry systems of micro-inclusions can be identified in ductile iron: Ca-S-X and Mg-Si-O-X with the majority of the inclusions regardless of treatment type and location being of the second type, silicates. Laboratory investigations have shown that simple silicates were present in the matrix, while more complex silicates were present in conjunction with graphite, probably acting as graphite nucleation sites. In these more complex silicates, elevated levels of Al, Ca, Ce and La were typical. Comparing micro-particles embedded in iron matrix and graphite nodules of iron treated with pure Mg-metal and iron treated with MgFeSi alloy showed a higher amount of complex silicates with elevated Al-levels in the iron treated with MgFeSi. Further laboratory investigation was undertaken to explore which source of Al and which range of residual Al would have a favorable impact on the graphite nucleation in ductile iron. The work showed that a residual aluminum of 0.005 to 0.020 wt.% appears to be beneficial for improving ductile iron solidification characteristics without the incidence of pinholes. Greatest benefits were achieved when introducing the Al into the iron via an inoculant late during processing or via a pre-conditioner to the base iron. Al added via the MgFeSi provided less benefit. Some case studies illustrating the effect of Al in ductile iron are also presented, as Al-containing pre-conditioner or/and Al-bearing, FeSi inoculant application.     

The Rengen Grassland Experiment: soil contamination by trace elements after 65 years of Ca,N, P and K fertiliser application

The Rengen Grassland Experiment (RGE) was established in the Eifel Mts. (Germany) on a low productive Nardetum in 1941. Since then, the following fertiliser treatments have been applied along with a two cut system: unfertilised control, Ca, CaN, CaNP, CaNP–KCl and CaNP–K₂SO₄ with basic slag (syn. Thomas phosphate) as the only P fertiliser. The effect of long-term fertilisation on plant-available (extracted with 0.01 mol l⁻¹ CaCl₂), easily-mobilisable (extracted with 0.05 mol l⁻¹ EDTA), potentially-mobilisable (extracted with 2 mol l⁻¹ HNO₃) and total concentrations of trace elements (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) in the top 0–10 and 10–20 cm of soil were investigated in 2006. According to redundancy analysis (RDA), the effect of treatment on the concentrations of risk elements was significant and explained 82.3 and 90.6% of the variability in the data in the 0–10 and 10–20 cm soil layers, respectively. Basic slag supplied the soil with considerable amounts of As, Cr, Cu, Fe, Mn and Zn. Following 65 years of fertiliser application the concentrations of risk elements in the soil profile had increased substantially, especially with basic slag. However, threshold limits for total trace element concentration in soil permitted by Czech national legislation were exceeded only in the case of As. The increase in plant-available As concentrations was most critical as it increased the potential uptake of As by plants in plots fertilised with P. Although P treatments received more than 300 g of Cr ha⁻¹ annually, no effect on plant-available Cr soil content was detected. This contrasted with the accumulation of total Cr in the 0–10 and 10–20 cm soil layers. Furthermore, plant availability of Cd, Fe, Mn and Zn was affected by soil pH and generally decreased with the application of quick lime. Plant availability of these elements was not correlated with amounts supplied by fertilisers.     

Sex-Related Differences in Murine Models of Chemically Induced Pulmonary Fibrosis

We developed two models of chemically induced chronic lung injury and pulmonary fibrosis in mice (intratracheally administered hydrochloric acid (HCl) and intratracheally administered nitrogen mustard (NM)) and investigated male–female differences. Female mice exhibited higher 30-day survival and less weight loss than male mice. Thirty days after the instillation of either HCl or NM, bronchoalveolar lavage fluid displayed a persistent, mild inflammatory response, but with higher white blood cell numbers and total protein content in males vs. females. Furthermore, females exhibited less collagen deposition, milder pulmonary fibrosis, and lower Ashcroft scores. After instillation of either HCl or NM, all animals displayed increased values of phosphorylated (activated) Heat Shock Protein 90, which plays a crucial role in the alveolar wound-healing processes; however, females presented lower activation of both transforming growth factor-β (TGF-β) signaling pathways: ERK and SMAD. We propose that female mice are protected from chronic complications of a single exposure to either HCl or NM through a lesser activation of TGF-β and downstream signaling. The understanding of the molecular mechanisms that confer a protective effect in females could help develop new, gender-specific therapeutics for IPF.     

An analysis of segregation-induced changes in grain boundary cohesion in bcc iron

We thoroughly compare available experimental as well as theoretical values of the strengthening/embrittling energy of numerous solutes at grain boundaries in α-iron and assess their reliability. The strengthening/embrittling energy is displayed according to its relationship to the difference of corresponding sublimation enthalpies of the host and the solute as well as with regard to the position of the solute in the Periodic Table.     

Frequency properties of on-die power distribution network in VLSI circuits

The local voltage fluctuations in the supply and ground grids triggered by on-die logic cell switching in VLSI devices have been experimentally studied. The results show that these fluctuations have a resonant-like form i.e., the on-die power grid should be described as an RLC circuit. The studies reveal that the active element (i.e., CMOS logic cell) affects the frequency properties of power supply and ground grids during its switching (as opposed to before or after switching). It is demonstrated that the frequency properties of the both grids are inter-related via the interconnecting active elements.     

A View on Human Goal-Directed Activity and the Construction of Artificial Intelligence

Although activity aimed at the construction of artificial intelligence started about 60 years ago however, contemporary intelligent systems are effective in very narrow domains only. One of the reasons for this situation appears to be serious problems in the theory of intelligence. Intelligence is a characteristic of goal-directed systems and two classes of goal-directed systems can be derived from observations on animals and humans, one class is systems with innately and jointly determined goals and means. The other class contains systems that are able to construct arbitrary goals and means. It is suggested that the classes (that implicitly underlie most models of artificial intelligence) are insufficient to explain human goal-directed activity. A broader approach to goal-directed systems is considered. This approach suggests that humans are goal-directed systems that jointly synthesize arbitrary goals and means. Neural and psychological data favoring this hypothesis and its experimental validation are considered. A simple computer model based on the idea of joint synthesis to simulate goal-directed activity is presented. The usage of the idea of joint synthesis for the construction of artificial intelligence is discussed.     

Microwave pulses compressed in a barrel-shaped resonator with screw corrugation

The microwave pulse compressor proposed previously [1], having the form of an oversized waveguide resonator with a screw-corrugated inner surface, was constructed and experimentally tested. A fivefold compression of microwave pulses with a 70% efficiency was obtained in a 3-cm wavelength range.     

Decay of end effects in graphite/epoxy bolted joints

Almost all analyses of large structures neglect local effects due to the application of loads and due to the transfer of loads between structural elements. In recent years, however, the use in aircraft structures of highly anisotropic materials, such as graphite/epoxy, has motivated more detailed studies of the applicability of Saint-Venant's principle.

In this paper in graphite/epoxy is analysed using the finite element method (FEM). The influence of anisotropy and transition from a thicker to a thinner laminate cross-section (ply-drop) is investigated. The characteristic decay length which is large for highly anisotropic materials is lessened by a change in thickness.     

A Novel Three-Dimensional Hydrogel-Based Microarray Platform

Three dimensional (3D) microarrays utilizing hydrogel matrixes are becoming increasingly attractive as a desired format for bio-analysis. These materials offer significant advantages as a scaffolding for capture agents over more conventional two dimensional (2D) printed formats in both captures per site and the ability to provide an environment more closely resembling that of a free solution. Biocept has developed a flexible three dimensional polyethylene glycol (PEG) polymer based platform suitable for a variety of biological assays. This novel approach is simple, biocompatible and provides a high degree of reproducibility and very low variability in the final array.     

General purpose software for probability computations—A virtual machine approach

The application of probability techniques in structural engineering has seen ample development in the last decade. Yet, the software used for engineering probability computations often lacks generality. The functional needs to be satisfied by general purpose software for engineering applications of probability methods are presented. An analysis of these needs suggests a software design philosophy based on the concept of a software virtual machine for probability computations. The virtual machine architecture and software design are explained. An example problem, in seismic risk analysis, solved with software based on this design is described.