Stability of SrFeO3-Based Materials in H2O/CO2-Containing Atmospheres at High Temperatures and Pressures

The chemical stability of SrFeO₃-based perovskites in H₂O- and CO₂-containing atmospheres at high temperatures and pressures has been examined. The extent of reaction as a function of p CO₂, p H₂O, temperature, and time has been determined. Either strontium carbonate or Sr(OH)₂·H₂O was observed on sample surfaces after exposure. Observation of two different reaction-rate behaviors could be explained by the formation of different products. The stability of the perovskite has been found to increase when the activity of Sr is decreased. Chemical stability in H₂O/CO₂ is important to understand in order to use these membrane materials for syngas production.     

Chocolate Swelling during Storage Caused by Fat or Moisture Migration

Abstract: Quantification of swelling in dark chocolate subjected to fat or moisture migration was conducted using a new method based on confocal chromatic displacement sensor. The nondestructive method allowed for the height profile of dark chocolate samples to be scanned with a sensitivity of ± 2.8 μm. By performing multiple scans on each sample prior to and after being subjected to fat or moisture migration, the induced swelling could be quantified. Applying the new method on confectionery systems revealed that fat and moisture migration generate different swelling behavior/kinetics in dark chocolate during storage. Moisture migration resulted in a rapid swelling once a water activity of 0.8 was reached in the chocolate, probably by interaction and absorption of moisture by the particulate solids. Fat migration also affected the swelling behavior in chocolate, possibly by inducing phase transitions in the continuous cocoa butter phase. Migrating fat also proved to induce a more pronounced swelling than the same amount of absorbed moisture which further consolidated that the observed swelling caused by fat or moisture migration is a result of significant different mechanisms.     

Quantifying security risk level from CVSS estimates of frequency and impact

Modern society relies on and profits from well-balanced computerized systems. Each of these systems has a core mission such as the correct and safe operation of safety critical systems or innovative and effective operation of e-commerce systems. It might be said that the success of these systems depends on their mission. Although the concept of “well-balanced” has a slightly different meaning for each of these two categories of systems, both have to meet customer needs, deliver capabilities and functions according to expectations and generate revenue to sustain today’s highly competitive market. Tighter financial constraints are forcing safety critical systems away from dedicated and expensive communication regimes, such as the ownership and operation of dedicated communication links, towards reliance on third parties and standardized means of communication. As a consequence, knowledge about their internal structures and operations is more widely and publicly available and this can make them more prone to security attacks. These systems are, therefore, moving towards a remotely exploitable environment and the risks associated with this must be controlled.Risk management is a good tool for controlling risk but it has the inherent challenge of quantitatively estimating frequency and impact in an accurate and trustworthy way. Quantifying the frequency and impact of potential security threats requires experience-based data which is limited and rarely reusable because it involves company confidential data. Therefore, there is a need for publicly available data sources that can be used in risk estimation. This paper presents a risk estimation model that makes use of one such data source, the Common Vulnerability Scoring System (CVSS). The CVSS Risk Level Estimation Model estimates a security risk level from vulnerability information as a combination of frequency and impact estimates derived from the CVSS. It is implemented as a Bayesian Belief Network (BBN) topology, which allows not only the use of CVSS-based estimates but also the combination of disparate information sources and, thus, provides the ability to use whatever risk information that is available. The model is demonstrated using a safety- and mission-critical system for drilling operational support, the Measurement and Logging While Drilling (M/LWD) system.     

Influence of partial acidification of skim milk on ultrafiltration performance and physicochemical properties of the produced streams

The influence of partial acidification of skim milk (SM) using glucono-δ-lactone (GDL), citric acid (CA) or lactic acid (LA), on physicochemical properties (e.g. viscosity and calcium balance) of ultrafiltration (UF) retentates produced at 10 and 55°C was investigated. Ultrafiltration retentates produced using CA showed a significantly lower amount (P < 0.05) of ionic calcium and higher apparent viscosity than GDL and LA. Regardless of the acid used, total calcium concentration and apparent viscosity of streams were modified compared with SM, which impaired UF overall performance. Specifically, CA at 10°C and GDL at 55°C, both reduced the permeate flux when compared to the other acids.     

Effects of lactic acid concentration and spray drying conditions on stickiness of acidified skim milk powder

The effects of lactic acid concentration (LA) and spray drying conditions on stickiness of acidified skim milk powder (SMP), which impacts process efficiency and powder properties, were examined using a fully replicated 2^4-1 fractional factorial design. The wall deposition was significantly affected by LA, and yield was positively influenced by the drying temperature difference. Drying temperature difference significantly affected particle size, moisture content and water activity of acidified SMP. Particle size was also significantly influenced by nozzle airflow rate. Moisture content and water activity were significantly affected by LA, while glass transition temperature was only influenced by the outlet temperature.     

Groundwater Contamination from Rural Pit Latrines: Examples from Siberia and Kosova

New hydrogeochemical data from Kosova and southern Siberia agree with previous studies from Botswana and Moldova in suggesting that high densities of pit latrines (and other domestic pollution sources) in rural villages can result in contamination of potable groundwater supplies by microbes and nitrate. Concentrations in excess of 100 mg/l nitrate have been recorded in each of these areas, at which levels small children may be endangered by methaemoglobinaemia. The sanitation and water-supply conditions are believed to be typical of large areas of Eastern Europe and the former Soviet Union. It is likely that poor sanitation and conflict with potable-water supplies are among the main sources of environmental risk to populations in these areas, rather than the industrial and military contamination upon which so many international collaborative programmes have focused.     

Mechanisms and prevention of plant tissue collapse during dehydration: a critical review

The appearance and functional properties are primordial in the quality assessment of semifinished fruit and vegetable products. These properties are often associated with shrunken, shriveled, darkened materials of poor rehydration ability after been subjected to air-drying--the most used drying method in the food industry. Fruits and vegetables are cellular tissues containing gas-filled pores that tend to collapse when subjected to dehydration. Collapse is an overall term that has different meanings and scale-settings in the literature depending on whether the author is a plant physiologist, a food technologist, a chemical engineer, or a material scientist. Some clarifications are given in this particular but wide field. The purpose of this work was to make a state-of-the-art contribution to the structural and textural effects of different types of dehydration on edible plant products and give a basis for preventing this phenomenon. The plant tissue is described, and the primordial role of the cell wall in keeping the structural integrity is emphasized. Water and its functionality at macro and micro levels of the cellular tissue are reviewed as well as its transport during dehydration. The effects of both dehydration and rehydration are described in detail, and the term "textural collapse" is proposed as an alternative to structural collapse.     

Identification and Evaluation of 21 Novel Microsatellite Markers from the Autumnal Moth (Epirrita autumnata) (Lepidoptera: Geometridae)

The autumnal moth (Epirrita autumnata) is a cyclically outbreaking forest Lepidoptera with circumpolar distribution and substantial impact on Northern ecosystems. We have isolated 21 microsatellites from the species to facilitate population genetic studies of population cycles, outbreaks, and crashes. First, PCR primers and PCR conditions were developed to amplify 19 trinucleotide loci and two tetranucleotide loci in six multiplex PCR approaches and then analyzed for species specificity, sensitivity and precision. Twelve of the loci showed simple tandem repeat array structures while nine loci showed imperfect repeat structures, and repeat numbers varied in our material between six and 15. The application in population genetics for all the 21 microsatellites were further validated in 48 autumnal moths sampled from Northern Norway, and allelic variation was detected in 19 loci. The detected numbers of alleles per locus ranged from two to 13, and the observed and expected heterozygosities varied from 0.04 to 0.69 and 0.04 to 0.79, respectively. Evidence for linkage disequilibrium was found for six loci as well as indication of one null allele. We find that these novel microsatellites and their multiplex-PCR assays are suitable for further research on fine- and large-scale population-genetic studies of Epirrita autumnata.     

Studies on two insect pests

Samples of two insect species, the Blossom beetle (Meligethes aeneusF.) and the Turnip seed weevil (Ceuthorrhynchus assimilisPayk.), were taken at various occasions in a winter rape field, both in areas treated with DDT and in areas untreated. As indicated by sweep net samples the DDT treatments caused a considerable reduction in the population level of the Blossom beetle. On the other hand, the treatments were associated with no significant decrease in the abundance of the Turnip seed weevil. Gas chromatography analyses showed large amounts of residue in both species in samples from the DDT‐treated areas. In the Turnip seed weevil, residues were also clearly demonstrated in samples from the areas where no DDT was used. The results indicate that DDT contaminated specimens spread at most to a limited extent in the Blossom beetle, while a movement of contaminated specimens to the untreated areas was evident in the Turnip seed weevil.