Fracture toughness of the lean duplex stainless steel LDX 2101

Fracture toughness testing was performed on the recently developed lean duplex stainless steel LDX 2101 (EN 1.4162, UNS S32101). The results were evaluated by master curve analysis, including deriving a reference temperature. The master curve approach, originally developed for ferritic steels, has been used successfully. The reference temperature corresponds to a fracture toughness of 100 MPa√m, which characterizes the onset of cleavage cracking at elastic or elastic-plastic instabilities. The reference temperature, T ₀, was −112 °C and −92 °C for the base and weld materials, respectively. In addition, the fracture toughness is compared with impact toughness results. Complementary crack tip opening displacements (CTODs) have also been calculated. The toughness properties found in traditional duplex stainless steels (DSS) are generally good. The current study verifies a high fracture toughness for both base and weld materials and for the low alloyed grade LDX 2101. Even though the fracture toughness was somewhat lower than for duplex stainless steel 2205, it is still sufficiently high for most low-temperature applications.     

Concept of decommissioning nuclear plants in the USSR and the COMECON Member-Nations

Journal version of the report to the 5th All-Union Scientific Conference on Shielding Installations from Ionizing Radiation [in Russian], (Protvino, Institute of High-Energy Physics, September, 1989).     

Trace element exposure in the environment from MSW landfill leachate sediments measured by a sequential extraction technique

Dredged leachate sediments from eight MSW landfills were dried and homogenized, and metals sequentially extracted. The concentrations of cadmium (Cd), copper (Cu), chromium (Cr), iron (Fe), lead (Pb), manganese (Mn), nickel (Ni) and zinc (Zn) were found to be similar to those reported for sewage sludge, and generally below the EU limits for use of sludge on agricultural land. Sequential extraction of the samples showed that the largest fractions of the heavy metals were associated with Fe- or Mn-oxides. Cr and Cu were the only metals investigated that were associated with the organic matter in the sediments to any significant extent (2-10% of Cr and 10-28% of Cu). Since the largest fractions of the metals studied were bound to Fe-oxides, and thus had a low mobility, these metals will generally have a low bioavailability under aerobic conditions when present in leachate sediments. This is most likely also valid for particulate matter suspended in MSW landfill leachate and released to the environment, since this is the source of the sediments.     

The creosote content of used railway crossties as compared with European stipulations for hazardous waste

Through the history of railways, wooden crossties impregnated with potentially hazardous creosote tar have supported the rails. With impregnated crossties having a lifespan of approximately 50 years, their creosote content is considered as quite safely stored while in dug-down usage. This situation of relative safety does, however, change into acute risk upon replacement and destruction. Carrying a highly flammable content, creosote crossties discharge a pulse of carcinogenic PAH compounds if burnt as ordinary waste. Safe destruction is therefore required if concentrations exceed a critical limit stipulated by the European Union. Since safe destruction is a process of considerable expense, there is a tendency among financial stakeholders to underestimate the creosote content of used railway crossties. In order to actually test whether concentrations generally exceed the critical limit, a set of used creosote ties was therefore sampled while still situated in the railway embankment. With a standard sum of sixteen PAH compounds used as an expression of their total creosote content, the generic concentration was formally inferred and found to significantly exceed the critical limit. The same applies to the fraction of seven carcinogenic PAH compounds, that alone exceed the stipulated limit for hazardous waste. It was also found that the material of railway embankments, whether or not the crossties were used in switches and/or railway yards, and sample depth within the crossties, has a significant effect on creosote concentrations. Regardless of the status of these factors, the concentrations significantly exceed the critical limit that defines hazardous waste within the European Union.     

Identification of Cattle-Derived Volatiles that Modulate the Behavioral Response of the Biting Midge <Emphasis Type="Italic">Culicoides nubeculosus</Emphasis>

Identification of host-derived volatiles is an important step towards the development of novel surveillance and control tools for Culicoides biting midges. In this study, we identified compounds from headspace collections of cattle hair and urine that modulate the behavioral response of Culicoides nubeculosus, a research model species with a similar host-range as the vectors of Bluetongue disease and Schmallenberg disease in Europe. Combined gas chromatography and electroantennographic detection (GC-EAD) analysis revealed 23 bioactive compounds, of which 17, together with octanal, were evaluated in a two-choice behavioral assay in the presence of CO_2. Decanal, 2-phenylethanal, 1-octen-3-ol, 2-ethylhexanol, 3-methylindole, phenol, and 3-ethylphenol elicited attraction of host seeking C. nubeculosus, whereas heptanal, octanal, nonanal, 3-propylphenol, and 4-propylphenol inhibited the insects’ attraction to CO₂, when compared to CO₂ alone. 6-Methyl-5-hepten-2-one, 3-methylphenol, 4-methylphenol, and 4-ethylphenol elicited both attraction and inhibition. The behavioral responses were dependent on the concentration tested. Our results show that cattle-derived odors have the potential to be used for the manipulation of the behavior of Culicoides biting midges.     

Application of hazard analysis and critical control point methodology and risk-based grading to consumer food safety surveys

Traditionally, consumer food safety survey responses have been classified as either "right" or "wrong" and food handling practices that are associated with high risk of infection have been treated in the same way as practices with lower risks. In this study, a risk-based method for consumer food safety surveys has been developed, and HACCP (hazard analysis and critical control point) methodology was used for selecting relevant questions. We conducted a nationally representative Web-based survey (n = 2,008), and to fit the self-reported answers we adjusted a risk-based grading system originally developed for observational studies. The results of the survey were analyzed both with the traditional "right" and "wrong" classification and with the risk-based grading system. The results using the two methods were very different. Only 5 of the 10 most frequent food handling violations were among the 10 practices associated with the highest risk. These 10 practices dealt with different aspects of heat treatment (lacking or insufficient), whereas the majority of the most frequent violations involved storing food at room temperature for too long. Use of the risk-based grading system for survey responses gave a more realistic picture of risks associated with domestic food handling practices. The method highlighted important violations and minor errors, which are performed by most people and are not associated with significant risk. Surveys built on a HACCP-based approach with risk-based grading will contribute to a better understanding of domestic food handling practices and will be of great value for targeted information and educational activities.     

Subcritical drying of silica gels

Silica aerogel is a sol-gel prepared material characterized by high porosity and large inner surface area. Aerogels can be prepared with a high transparency and low thermal conductivity, giving a material excellent for application as transparent thermal insulator. The traditional route to prepare silica aerogels is by formation of an alcogel by hydrolysis and condensation of silicon alkoxides followed by supercritical drying in an autoclave at high pressure (–100 atm). Unfortunately, this process is expensive and might be dangerous, so drying methods have been developed that operate under ambient conditions. In previous work, we have shown that gels can be strengthened and stiffened by providing new monomers to the alcogel giving xerogels with similar properties as aerogels by drying at ambient pressure (porosity up to 90%). This method of obtaining ambient pressure dried aerogels will be described and special emphasis will be given on the effect of the initial gel structure on the preparation of the xerogels.     

Determination of ionized magnesium in platelets and correlation with selected variables

We describe a method for determining the intracellular ionized magnesium concentration ([Mg2+]i) in platelets by using the fluorescent probe FURAPTRA. We determined the dissociation constant (KD) of FURAPTRA for Mg2+ (2.26 +/- 0.29 mmol/L), within-day assay variability (CV = 6.8%), among-day intraindividual variability (CV = 11.0%), variability after a 4-h delay in processing the blood specimen (t = 1.2, P >0.2; F = 6.2, P <0.02), and the reference interval (0.23-0.59 mmol/L) for this assay. We also evaluated the correlation between platelet [Mg2+]i and concentrations of selected serum electrolytes, proteins, and total cholesterol; age; body mass index; and gender. Only the inverse correlation between platelet [Mg2+]i and serum total cholesterol concentration in men was significant (r=-0.66, P <0.005).