How do different process options and evaluation settings affect economic and environmental assessments? A case study on methyl methacrylate (MMA) production processes

We present an investigation on how economic and environmental assessment results change when different process options or evaluation settings are considered. As the main case study the production technology of methyl methacrylate (MMA) is investigated. Six commercial processes using different reaction routes are modelled and evaluated with respect to their economic and environmental performance. On these six base case models different process options and evaluation settings are considered and the resulting impacts on the assessment results are quantified. Major findings of the study are that the more decision-variables become fixed, the smaller becomes the impact of the decisions still to be taken—but not only with respect to the economic performance but also with regard to the environmental assessment result. Along the process development steps the potential impacts on the economic and environmental performance decrease to the same degree. The results obtained for the evaluation settings do not show such a systematic pattern as those for the process options. This finding indicates that decision makers face many options in the economic and especially the environmental assessment of chemical processes which might lead to quite different magnitudes in variability due to either the choice of method or the choice of method parameters. This paper demonstrates that the resulting variability might be crucial with respect to the decision making outcome.     

Evaluation of EHS hazard and sustainability metrics during early process design stages using principal component analysis

A principal component analysis (PCA) based methodology accounting for EHS hazard and sustainability metrics has been recently proposed in literature (Srinivasan and Nhan, 2008) to deal with the subjective weighting problem of existing index-based methods. In this study we evaluate the potential use of the PCA-based method during early phases of process design in the problem of selection between various synthesis paths, also called chemical routes, for the production of chemical compounds. The study also focuses on the impact of the methodology settings on the obtained chemical route rankings and their interpretation. Two case studies have been performed regarding the production of 4-(2-methoxyethyl)-phenol (MEP) and methyl methacrylate (MMA) using fifteen different evaluation categories capturing various sustainability metrics. The PCA-based method identified the most promising chemical routes as well as the most important evaluation categories. The necessity for normalization of the raw data was demonstrated, without the method being very sensitive to the type of normalization. Moreover, the effect of the transition approach from chemical step to chemical route scores is discussed. The results of the PCA-based method are also compared with an index-based method (Koller et al., 2000) sharing the same evaluation categories, as well as with other index-based frameworks in order to reveal the extent of similarities.     

Diversity attitudes and norms: the role of ethnic identity and relational demography

This study investigated attitudes and subjective norms related to workplace diversity initiatives and intentions to engage in diversity‐related behaviors in a sample of 852 public service employees. Participants completed a survey measuring behavioral intentions, attitudes, belief‐based norms, ethnic identity achievement, and demographic characteristics. Comparisons were made between people of color and Whites as well as between those with high and low ethnic identity achievement. Results showed a triple interaction among supervisor race, employee race, and employee ethnic identity achievement. Specifically, among people of color with high ethnic identity achievement, having a supervisor of color was more strongly associated with positive views of subjective norms toward inclusive behavior, understanding others, and treating others with respect than among people of color with low ethnic identity achievement. Implications of these findings and directions for future research are discussed. Copyright © 2006 John Wiley & Sons, Ltd.     

Job and industry fit: the effects of age and gender matches on career progress outcomes

Using a sample of 232 MBA alumni, we tested the impact of respondent age, gender, and their interaction on career progress outcomes (managerial level, number of promotions, and salary) and whether age‐ and gender‐type of contexts moderated these relationships. Women's salaries did not increase much with age, whereas men's salaries showed a marked increase with age. We also found a gender × job gender‐type effect on salary, such that women earned somewhat higher salaries in masculine‐typed jobs, while men earned considerably higher salaries in feminine‐typed jobs. In addition, we observed a three‐way interaction between gender, age, and age‐type of industry indicating that younger men received more promotions in old‐typed industries, while younger women received more promotions in young‐typed ones. Results are discussed in light of cognitive matching approaches and status characteristics theory. Copyright © 2004 John Wiley & Sons, Ltd.     

Zentralnervöse Sphingolipid-Speicherkrankheiten

Lysosomal storage disorders are progredient and often fatal diseases most of which result from a pronounced enzyme deficiency. In the case of sphingolipidoses, usually enzymes of sphingolipid catabolism are missing, or only a few percent of normal activity are detectable. For many sphingolipidoses, damage of the central nervous system is characteristic, but neurological and other symptoms can vary greatly, especially in adult variants. This variability is mainly caused by different allelic mutations of the structural genes, resulting in different levels of residual enzyme activity.     

Two pathways ensuring social harmony

Reproductive division of labour is a characteristic trait of social insects. The dominant reproductive individual, often the queen, uses chemical communication and/or behaviour to maintain her social status. Queens of many social insects communicate their fertility status via cuticle-bound substances. As these substances usually possess a low volatility, their range in queen–worker communication is potentially limited. Here, we investigate the range and impact of behavioural and chemical queen signals on workers of the ant Temnothorax longispinosus. We compared the behaviour and ovary development of workers subjected to three different treatments: workers with direct chemical and physical contact to the queen, those solely under the influence of volatile queen substances and those entirely separated from the queen. In addition to short-ranged queen signals preventing ovary development in workers, we discovered a novel secondary pathway influencing worker behaviour. Workers with no physical contact to the queen, but exposed to volatile substances, started to develop their ovaries, but did not change their behaviour compared to workers in direct contact to the queen. In contrast, workers in queen-separated groups showed both increased ovary development and aggressive dominance interactions. We conclude that T. longispinosus queens influence worker ovary development and behaviour via two independent signals, both ensuring social harmony within the colony.     

Skimming behaviour and spreading potential of Stenus species and Dianous coerulescens (Coleoptera: Staphylinidae)

Rove beetles of the genus Stenus Latreille and the genus Dianous Leach possess pygidial glands containing a multifunctional secretion of piperidine and pyridine-derived alkaloids as well as several terpenes. One important character of this secretion is the spreading potential of its different compounds, stenusine, norstenusine, 3-(2-methyl-1-butenyl)pyridine, cicindeloine, α-pinene, 1,8-cineole and 6-methyl-5-heptene-2-one. The individual secretion composition enables the beetles to skim rapidly and far over the water surface, even when just a small amount of secretion is emitted. Ethological investigations of several Stenus species revealed that the skimming ability, skimming velocity and the skimming behaviour differ between the Stenus species. These differences can be linked to varied habitat claims and secretion saving mechanisms. By means of tensiometer measurements using the pendant drop method, the spreading pressure of all secretion constituents as well as some naturally identical beetle secretions on the water surface could be established. The compound 3-(2-methyl-1-butenyl)pyridine excelled stenusine believed to date to be mainly responsible for skimming relating to its surface activity. The naturally identical secretions are not subject to synergistic effects of the single compounds concerning the spreading potential. Furthermore, evolutionary aspects of the Steninae’s pygidial gland secretion are discussed.     

Effect of host and larval frass volatiles on behavioural response of the old house borer,Hylotrupes bajulus (L.) (Coleoptera: Cerambycidae), in a wind tunnel bioassay

Summary. In a wind tunnel bioassay the effect of three concentrations of natural extracts of (1) Scots pine wood, Pinus sylvestris, and (2) larval frass on the behavioural response of unmated females and males of the old house borer, Hylotrupes bajulus, was tested and compared to the behavioural effects of the male-produced sex pheromone (3R)-3-hydroxy-2-hexanone. The influence on the behaviour of both sexes was found to be equally significant for the two higher concentrated hexane extracts of wood and larval frass. Therefore several synthetic monoterpenes present in the extracts and ethanol were tested at the two higher concentrations (1:100, 1:1000 vol/vol). Among the higher concentrated monoterpenoid hydrocarbons [(+)-α-pinene, (+)-β-pinene, (+)-limonene], only α-pinene increased the activity, orientation towards scent source and interest towards conspecifics. The tests with higher concentrated ethanol and the oxygenated monoterpenes [(-)-verbenone, (-)-trans-pinocarveol, (+)-terpinen-4-ol, (+)-α-terpineol, (-)-myrtenol] revealed that verbenone is the most effective stimulant for the females, followed by trans-pinocarveol, terpinen-4-ol and α-terpineol. For males, terpinen-4-ol was the only mediator significantly inducing attraction and orientation towards the scent source combined with an interest in conspecifics apparent by fighting or courtship behaviour. Males did not respond to verbenone which is a main compound of larval frass. Myrtenol and ethanol were ineffective in both sexes. In fact behavioural observations suggest that the beetles were repelled by the high dose of myrtenol. Using the ten-fold lower dose of the synthetic monoterpenes (1:1000 vol/vol), all semiochemicals except myrtenol lost activity. Myrtenol, however, induced behavioural responses, like increased activity and orientation towards scent source, only at the low concentration. Based on the results, primary attraction of unmated old house borer is probably mediated by monoterpenes of coniferous wood, while secondary attraction to infested wood would occur in response to volatiles of larval frass. Received 5 May 1999; accepted 30 September 1999