Life Cycle costing as part of design for environment environmental business cases

Background  In developing products various requirements have to be integrated including functionality, quality, affordability as well as environmental aspects. Often conflicting requirements have to be fulfilled. Therefore, multi-dimensional decision support approaches are necessary. Methods  Here, one approach is to relate the conflicting requirements to each other. Life Cycle Costing (LCC) has the potential to support the trade-off between some environmental targets and overall affordability targets by including all monetary flows along the product life cycle (going beyond the well-known costs of ownership by integrating also long-term use and end-of-life costs). Those solutions can be identified that (a) have the highest efficiencies (where do we get most environmental improvements per Ϊ and (b) have the highest affordability for the customer along the life cycle. Furthermore, on-costs in the design phase can be justified in terms of future savings either for the customer or for the recycling of the products. These represent real business cases for environmental actions. Three types of environmental business cases can be differentiated. Results and Discussion  This paper presents various examples where LCC is integrated into product design. However, there are a number of open issues in the implementation of LCC within real product development including data availability and uncertainty (future costs/ savings), level of discounting, accounting and compensation. Various internal case studies done in the last years showed that already few changes in the costs structure can significantly affect the identi-fied future costs. Recommendation and Outlook  Uncertainties in LCC are higher than in LCA and highest when applied in the stage of product develop-ment, i.e. used to support DfE action. As a consequence, the result-ing figures can only be seen as directional. Therefore, the use of LCC in Design for Environment cannot be recommended without major restrictions in terms of guidance, experience/training. The link-age between LCC and DfE can either be established via (1) experts supporting design teams or (2) as part of a DfE tool. The DfE tool has to include detailed guidance for interpretation, and its application should be based on a solid training for DfE engineers.     

Structured population on two patches: modeling dispersal and delay

We derive from the age-structured model a system of delay differential equations to describe the interaction of spatial dispersal (over two patches) and time delay (arising from the maturation period). Our model analysis shows that varying the immature death rate can alter the behavior of the homogeneous equilibria, leading to transient oscillations around an intermediate equilibrium and complicated dynamics (in the form of the coexistence of possibly stable synchronized periodic oscillations and unstable phase-locked oscillations) near the largest equilibrium.     

A survey of flagellate diversity at four deep-sea hydrothermal vents in the Eastern Pacific Ocean using structural and molecular approaches

Eighteen strains of flagellated protists representing nine species were isolated and cultured from four deep-sea hydrothermal vents: Juan de Fuca Ridge (2,200 m), Guaymas Basin (2,000 m), 21 degrees N (2,550 m) and 9 degrees N (2,000 m). Light and electron microscopy were used to identify flagellates to genus and, when possible, species. The small subunit ribosomal RNA genes of each vent species and related strains from shallow-waters and the American Type Culture Collection were sequenced then used for comparative analysis with database sequences to place taxa in an rDNA tree. The hydrothermal vent flagellates belonged to six different taxonomic orders: the Ancyromonadida, Bicosoecida, Cercomonadida, Choanoflagellida, Chrysomonadida, and Kinetoplastida. Comparative analysis of vent isolate and database sequences resolved systematic placement of some well-known species with previously uncertain taxonomic affinities, such as Ancyromonas sigmoides, Caecitellus parvulus, and Massisteria marina. Many of these vent isolates are ubiquitous members of marine, freshwater, and terrestrial ecosystems worldwide, suggesting a global distribution of these flagellate species.     

GRAZING OPTIMIZATION,NUTRIENT CYCLING,AND SPATIAL HETEROGENEITY OF PLANT‐HERBIVORE INTERACTIONS: SHOULD A PALATABLE PLANT EVOLVE?

Abstract.— Can the evolution of plant defense lead to an optimal primary production? In a general theoretical model, Loreau (1995) and de Mazancourt et al. (1998, 1999) have shown that herbivory could increase primary production up to a moderate rate of grazing intensity through recycling of a limiting nutrient, provided several conditions are fulfilled. In the present paper, we assume: (1) grazing intensity is controlled by plants through their level of palatability; and (2) plant fitness is determined by its productivity. We explore the conditions under which such an optimal production may be reached through natural selection. We model two competing plant types that differ only in palatability and are distributed in a patchy landscape determined by the plant‐herbivore interaction. Patch size is determined by herbivore behavior: herbivores recycle nutrient homogeneously within patches, but recycle nutrient proportionally to consumption between patches. The model shows that a strategy of intermediate palatability can be adaptive in response to a small herbivore that lives on and recycles nutrient around one or a few individual plants. For moderately small herbivores, plant palatability may evolve towards one of two local convergent strategies, depending on the initial conditions. For medium‐ to large‐sized herbivores, the nonpalatable strategy is always selected. We discuss the functional and evolutionary implications of these results, and suggest that the traditional dichotomy describing antagonistic and mutualistic interactions may be misleading.     

Shinrin-yoku (forest-air bathing and walking) effectively decreases blood glucose levels in diabetic patients

 The influence of ”shinrin-yoku” (forest-air bathing and walking) on blood glucose levels in diabetic patients was examined. Eighty-seven (29 male and 58 female) non-insulin-dependent diabetic patients [61 (SEM 1) years old] participated in the present study. Shinrin-yoku was performed nine times over a period of 6 years. The patients were divided into two parties. They then walked in the forest for 3 km or 6 km according to their physical ability and/or the existence of diabetic complications. The mean blood glucose level after forest walking changed from 179 (SEM 4) mg · 100 ml^–1 to 108 (SEM 2) mg · 100 ml^–1 (P<0.0001). The level of glycated haemoglobin A_1c also decreased from 6.9 (SEM 0.2)% (before the first shinrin-yoku) to 6.5 (SEM 0.1)% (after the last shinrin-yoku; P<0.05). Blood glucose values declined by 74 (SEM 9) mg · 100 ml^–1 and 70 (SEM 4) mg · 100 ml^–1 after short- and long-distance walking respectively. There was no significant difference between these values. Since the forest environment causes changes in hormonal secretion and autonomic nervous functions, it is presumed that, in addition to the increased calorie consumption and improved insulin sensitivity, walking in a forest environment has other beneficial effects in decreasing blood glucose levels. Received: 9 July 1997/Accepted: 20 October 1997     

Pattern and Performance of Understory Bamboos (Chusquea spp.) under Different Canopy Closures in Old-Growth Oak Forests in Costa Rica1

The effect of canopy closure on spatial and morphological patterns of three understory Chusquea species was studied in pristine upper montane oak forests. Plots with either Chusquea talamancenis Widmer & L.G. Clark or C. tomentosa Widmer & L.G. Clark were set out in gaps, under intermediate tree canopy and under closed canopy. The third species Chusquea foliosa L.G. Clark was only found in gap and intermediate canopy sites in the study area. Clumps of all bamboo species tend to be few and large under open conditions and numerous and small under more shady conditions. The larger size of clumps in gaps is reflected in the number of culms per clump, the diameter of the culms and, as a consequence, clump basal area, clump crown area, and biomass (index of plant volume) compared to intermediate and closed canopy. The smaller clump density in gaps compared to closed canopy implies that there is more intraspecific competition and density dependent mortality (self-thinning effect) when a bamboo species is dominant under favourable light conditions. Parameters of performance like culm length, number of nodes per culm, number and length of primary branches, and number of branch nodes seem not to be affected by the light regime, unlike total number of branches, total branch length, and the branching pattern. Species differ in their response to the light environment: C. tomentosa and C. foliosa have a higher degree of morphological plasticity than C. talamancensis, which in turn, appears to be more shade tolerant. No difference between species has been found regarding their contribution to vegetation, parameters reflecting abundance per unit area (site clump area, site crown area and site index of clump volume) were similar for all three species.     

A field study of nitrogen dynamics and spring barley growth as affected by the quality of incorporated residues from white clover and ryegrass

Biofumigation refers to the suppression of soil-borne pests and pathogens by biocidal compounds released by Brassicaceous green manure and rotation crops when glucosinolates (GSLs) in their tissues are hydrolysed. We investigated the effect of environment and ontogeny on the GSL production, and thus biofumigation potential, of eight entries from five Brassica species. The environments included autumn and spring sown field plots (FA and FS) and potted plants grown under ambient conditions (PAM) or in a temperature controlled glasshouse at 20 °C/12 °C (PTC). GSL concentration was measured in the root and shoot tissue at buds-raised, flowering and maturity. Of particular interest was the suitability of the pot-grown plants for screening large numbers of brassicas for GSL production. The type of GSLs present in the tissues and their relative proportions remained relatively constant across environments and at different growth stages, with the exception of an increase in indolyl GSLs in the FS environment suspected of being induced by insect attack. Total GSL concentration generally declined from buds-raised to flowering in all environments, and was lowest at maturity. The exceptions were B. campestris, which had higher GSL concentration at flowering than at buds-raised, and the PTC environment in which most species also showed an increase at flowering. Despite GSL types and their proportions remaining relatively constant, the total GSL concentration in the root and shoot tissue of all entries varied significantly with environment (3–10-fold) and was generally ranked FS>PAM>FA>PTC. Interactions between species and environments meant that the ranking of the Brassica entries for total shoot and root GSL concentration changed with environment. However within three entries from B. napus, the ranking was consistent across the environments. The added effect of environment on phenological development and biomass production further influenced GSL production (the product of GSL concentration and biomass) on a ground area basis. The results suggest that glasshouse environments can be used to determine the types and proportions of GSLs present, and to rank entries within, but not between species for the total concentration in the tissues. However the influence of the environment on both GSL concentration and biomass production suggests that an accurate estimate of GSL production on a ground area basis to assess biofumigation potential will require measurement in the target environment.     

Reuse of Electric Motors in Consumer Products

Product takeback calls for sound strategies of product recovery management One such strategy-is the reuse of the components of a product. There are consumer products such as power tools whose most expensive component, the electric motor; offers potential for reuse. Empirical evidence reveals that the lifetime of a motor often exceeds the life-time of the product using it. This article focuses on the reuse of electric motors. For this purpose, a novel circuit was developed that measures, computes, and records parameters strongly correlated with the degradation of a motor during the use stage of the product. This circuit, called electronic data log (EDL), provides valuable insights into the usage patterns of products. The data recorded during the use stage are retrieved after product takeback as a basis for reuse decisions. In this article, the trade-off between higher initial manufacturing cost caused by the EDL and cost savings from the reuse of used motors is analyzed. The problem of misclassifications of used motors is also addressed. It is shown that the return rate of used products is the critical parameter determining the economic efficiency of a motorreuse strategy based on EDLs. The analysis shows that the implementation of EDLs in products as an enabler for motor reuse may be associated with large cost savings     

Effects of overstory and understory vegetation on the understory light environment in mixed boreal forests

Abstract. The percentage of above-canopy Photosynthetic Photon Flux Density (%PPFD) was measured at 0, 50 and 100 cm above the forest floor and above the main understory vegetation in stands of (1) pure Betula papyrifera (White birch), (2) pure Populus tremuloides (Trembling aspen), (3) mixed broad-leaf-conifer, (4) shade-tolerant conifer and (5) pure Pinus banksiana (Jack pine) occurring on both clay and till soil types. %PPFD was measured instantaneously under overcast sky conditions (nine locations within each of 29 stands) and continuously for a full day under clear sky conditions (five locations within each of eight stands). The percentage cover of the understory layer was estimated at the same locations as light measurements. Mean %PPFD varied from 2% at the forest floor under Populus forests to 15% above the understory vegetation cover under Betula forests. Percent PPFD above the understory vegetation cover was significantly higher under shade intolerant tree species such as Populus, Betula and Pinus than under shade tolerant conifers. No significant differences were found in %PPFD above the understory vegetation cover under similar tree species between clay and till soil types. The coefficient of variation in %PPFD measured in the nine locations within each stand was significantly lower under deciduous dominated forests (mean of 19%) than under coniferous dominated forests (mean of 40%). %PPFD measured at the forest floor was positively correlated with %PPFD measured above the understory vegetation and negatively correlated with cumulative total percent cover of the understory vegetation (R² = 0.852). The proportion of sunflecks above 250 and 500 mmol m^–2 s^–1 was much lower and %PPFD in shade much higher under Populus and Betula forests than under the other forests. Differences in the mean, variability and nature of the light environment found among forest and soil types are discussed in relation to their possible influences on tree succession.     

Microhabitat size distribution affects local difference in community structure: Metazoan communities in treeholes

I studied the effect of treehole (microhabitat) size distribution in local habitats on geographic difference in aquatic metazoan community structure by comparing differences between two sites on Iriomote Island, and between Iriomote Island (subtropical) and Tsushima Island (temperate), in southwestern Japan. In treeholes at each local site, the amount of litter, the species richness and total biomass of metazoa were positively correlated with treehole capacity. Between the two sites on Iriomote Island (Shirahama and Komi), the amount of litter, biomass and species number per treehole was greater at Komi where the mean and variance of treehole size were greater, while the dependencies of these parameters on treehole capacity were common to both sites. Total species number was larger at Komi (2 predators and 20 saprophages) than at Shirahama (1 predator and 19 saprophages). Most of the dominant taxa colonized larger treeholes with higher probabilities, although one taxa showed the opposite trend. Treeholes on Tsushima were smaller than those on Iriomote. The metazoan fauna in treeholes consisted of 15 saprophages on Tsushima, being less richer than that on Iriomote Island which had 2 predators and 21 saprophages. However, the dependencies of litter amount and biomass on treehole capacity did not differ significantly between the islands, although treeholes on Iriomote harbored a greater number of species per treehole than those on Tsushima. This study indicated that there are general correlates between community structure within individual treeholes (infracommunity structure) and treehole capacity (microhabitat size). Therefore, microhabitat-size distribution is potentially a significant constraint of local community structure, and its variation may contribute to the variation in local and regional species richness.