Numerical Model of Sedimentation∕Thickening with Inertial Effects

A numerical model of gravity sedimentation and thickening was developed from the governing two-phase flow equations for the liquid and solid phases. The inertial and gravity terms in the solid and liquid momentum equations were retained in the gravity sedimentation and thickening model. An implicit, space-staggered finite-difference algorithm was developed for the resulting coupled partial differential equations. Constitutive relationships describing the physical properties of the slurry were required to solve the numerical model. These constitutive properties describing the relationship between effective stress and porosity and between permeability and porosity were determined experimentally and by model calibration. The model was calibrated and verified using the data of dynamic porosity profiles of gravity sedimentation and thickening of kaolin suspensions in distilled water.     

Scenarios for the Austrian food chain in 2020 and its landscape impacts

How the future landscape will look depends particularly on the outcome of the socio-economically motivated decisions of farmers, food processors, retailers and consumers, all members of the food supply chain. However, a long-term perspective on the food supply chain and its landscape effects is confronted with a great deal of uncertainty and data constraints. These difficulties can be partly avoided by using the personal judgements of agents whose decisions control the structure of present and future food supply chains. A well-established agent-based method for dealing with and describing variation in the future is the method of scenario planning. The aim of this paper is to present the application of the scenario approach to the Austrian food supply chain in 2020 and its landscape impacts. A critical discussion of the scenarios should reflect their explanatory power regarding future development options for landscapes. The first section of the paper outlines the interactions between society, the food supply chain and the landscape in a conceptual model. It describes the applied scenario technique and the research setting involving agents from agriculture, the food industry, retailing, gastronomy, and consumer organisations. Four scenarios for the food chain in 2020 are presented (Liberal Market Scenario, Protective Policy Scenario, Fast World Scenario, Slow World Scenario) and their respective consequences and strategies are discussed. The scenario technique used is found to be a useful means of gathering and structuring disperse expert knowledge. The paper concludes that—despite some methodological limitations—scenarios can deal with uncertainty concerning the socio-economic driving forces of landscape change and therefore can be used as a preliminary step in formulating robust strategies for landscape management.     

How employees respond to personal offense: The effects of blame attribution, victim status, and offender status on revenge and reconciliation in the workplace.

This study investigated the relationships between blame, victim and offender status, and the pursuit of revenge or reconciliation after a personal offense. Results from a sample of 141 government agency employees showed that blame is positively related to revenge and negatively related to reconciliation. In addition, victim–offender relative status moderated the relation between blame and revenge such that victims who blamed sought revenge more often when the offender's status was lower than their own. The victims' own absolute hierarchical status also moderated this relation such that lower, not higher, status employees who blamed sought revenge more often. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The new injection beamline at VERA

VERA has been operated for 12 years with one 40-cathode SNICS ion source. Since the number of isotopes investigated at VERA increased steadily, we decided to install a second ion source. Due to space restrictions, a new injection line had to be built and merged into the existing one. The major task was to build an electrostatic analyzer assembly to accommodate injection from two ion sources.     

Determination of flow stress properties of machinable materials with help of simple compression and orthogonal machining test

This paper describes a possible method for predicting values of orthogonal metal cutting properties such as shear angle, cutting force etc., on a basis of the well known Hollomon equation, using a simple compression test in order to avoid any cutting experiments. There are two possibilities: the flow stress properties can be obtained from an independent material test; or by measuring the active and passive cutting forces from the orthogonal machining test itself. This paper is concerned with a material flow stress equation, including the effects of strain (ε), strain rate ( ) and temperature (T), which is one of the five equations that have to be solved in simulation analysis with the finite element method. In finding a solution for those five equations, it is necessary to dispose of flow stress properties by rearrangement of the Hollomon equation and so making it usable for cutting process investigation. The rearrangement is described in this paper.     

Soil Degradation of Parthenin—Does it Contradict the Role of Allelopathy in the Invasive Weed Parthenium hysterophorus L.?

The invasive success of Parthenium hysterophorus L. is thought to be partially attributable to allelopathy mediated by the plant metabolite parthenin. To assess the ecological significance of parthenin release from plant material, its persistence and phytotoxicity in soil was studied. Results show parthenin is rapidly degraded with an average DT ₅₀ of 59 h under standard experimental conditions. Degradation was delayed in sterilized soils, at lower soil moisture, and higher parthenin concentrations. Higher temperatures, higher CEC_pot/clay content of soils, soil preconditioning with parthenin, and P. hysterophorus infestation accelerated degradation. Physico-chemical and biological processes are, therefore, expected to govern the fate of parthenin in soil. Parthenin exhibited low soil phytotoxicity and did not accumulate over time. Along with the indicated reduction in bioavailability and development of hormetic effects, results suggest that for parthenin to have detrimental allelopathic effects, it requires high P. hysterophorus densities that result in high soil levels of parthenin and soil conditions that favor the persistence of parthenin. In light of this, the ecological significance of parthenin is discussed.