Product life-cycle implications for remanufacturing strategies

For remanufacturing to be successful, there is a need to gain information on future market needs of remanufactured products, and match this to information on the magnitude of return flows. One of the major issues impacting remanufacturing is in the difficulty of obtaining used products (cores) that are suitable for remanufacturing. The timing and quantity of product returns is dependent on the type of product. Factors such as the mean product lifetime, rate of technical innovation, and failure rate of components all influence the return rate of products from end-of-use and end-of-life. The balance between product returns and demand for remanufactured products is a function of many variables, where the rate of technological innovation and the expected life of a product are the major influencing characteristics. The main contribution of this paper is the support that is provided in different supply and demand situations. By using a product life-cycle perspective, the supply and demand situations can be foreseen, and support given regarding possible strategies in these situations.     

Landfill mining: a critical review of two decades of research

Landfills have historically been seen as the ultimate solution for storing waste at minimum cost. It is now a well-known fact that such deposits have related implications such as long-term methane emissions, local pollution concerns, settling issues and limitations on urban development. Landfill mining has been suggested as a strategy to address such problems, and in principle means the excavation, processing, treatment and/or recycling of deposited materials. This study involves a literature review on landfill mining covering a meta-analysis of the main trends, objectives, topics and findings in 39 research papers published during the period 1988-2008. The results show that, so far, landfill mining has primarily been seen as a way to solve traditional management issues related to landfills such as lack of landfill space and local pollution concerns. Although most initiatives have involved some recovery of deposited resources, mainly cover soil and in some cases waste fuel, recycling efforts have often been largely secondary. Typically, simple soil excavation and screening equipment have therefore been applied, often demonstrating moderate performance in obtaining marketable recyclables. Several worldwide changes and recent research findings indicate the emergence of a new perspective on landfills as reservoirs for resource extraction. Although the potential of this approach appears significant, it is argued that facilitating implementation involves a number of research challenges in terms of technology innovation, clarifying the conditions for realization and developing standardized frameworks for evaluating economic and environmental performance from a systems perspective. In order to address these challenges, a combination of applied and theoretical research is required.     

Associations between CB-153 and p,p'-DDE and hormone levels in serum in middle-aged and elderly men

BACKGROUND: Animal and epidemiologic data indicate that exposure to persistent organochlorine pollutants (POPs) may disrupt the hypothalamus-pituitary-thyroid (HPT) and the hypothalamus-pituitary-gonadal (HPG) axes. We have assessed whether the POP-biomarkers 2,2'4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis(4-chlorophenyl)-ethene (p,p'-DDE) affect thyrotropin (TSH), thyroid hormones, gonadotropins or sex hormone concentrations in men. METHODS: Lipid adjusted serum concentrations of CB-153, and p,p'-DDE, were determined in 196 men (median age 59 years, range 48-82). Hormone analyses in serum were performed with immunoassays. The effect of CB-153 and p,p'-DDE (as continuous or categorized variables) were evaluated by linear regression models, adjusting for potential confounders. RESULTS: There was a significant positive association between p,p'-DDE and TSH. An increase of 100 ng/g lipid of p,p'-DDE corresponded to an increase of 0.03 mU/l (95% Confidence Interval (CI) 0.01, 0.05) in TSH level. The explanatory value (R(2)) of the multivariate model was only 7%. Moreover, there was a significant negative association between p,p'-DDE and estradiol. An increase of 100 ng/g lipid of p,p'-DDE corresponded to a decrease of 0.57 pmol/l (95% CI -1.0, -0.12) in estradiol level. The R(2)-value was only 4%. No associations were observed between any of the POP biomarkers and the other hormones. CONCLUSIONS: The positive association between p,p'-DDE and TSH and the negative association between p,p'-DDE and estradiol, among middle-aged and elderly men, were not accompanied by associations between the POP-markers and thyroxin, testosterone, and gonadotropins, respectively. The results gives some additional support for that POP exposure may affect HPT- and HPG-axes also in humans, but the overall epidemiological data are still not coherent enough to allow any firm conclusions.     

Urban dose rates at Gävle, Göteborg and Lund

Besides gamma rays from ¹³⁷Cs emanating from the Chernobyl accident, gamma rays from natural radionuclides are a dominant source of radiation exposure to the public. Since people spend much more time indoors than outdoors the radiation dose obtained inside dwellings contributes greatly to individual and collective doses. Dose rate measurements were made at 20 locations within the city of Göteborg and at further 22 reference sites within a radius of 100 km. Measurements were also made at Gävle and Lund. The dose rates were measured with RNI intensimeters, TLD (LiF) meters and in in situ measurements using an HPGe. The ground cover was grass, asphalt, concrete slates or paving-stones. The dose rates varied between 0.05 and 0.25 μSv/h. Also performed in different ways, measurements made inside and outside buildings at both Göteborg and Gävle showed inside dose rates higher than outside dose rates.     

Determination of antibiotic substances in hospital sewage water using solid phase extraction and liquid chromatography/mass spectrometry and group analogue internal standards

A method for determination of antibiotics in hospital sewage water has been developed and validated. Analogue internal standards for fluoroquinolones, sulfonamides, trimethoprim, beta-lactams (penicillins and cephalosporins), nitroimidazoles and tetracyclines were successfully used for calibration and shown to generally improve precision compared to external calibration. Matrix components caused ion suppression/enhancement effects during the MS detection for all analytes studied. Two effects were observed: general suppression and short-term variations in the MS response. In the hospital sewage water large temporal variations in the analyte concentration were observed during the course of the sampling period (seven grab samples in 13 h). Analyte concentrations varied within the following ranges (in microg l(-1)): ciprofloxacin, 3.6-101.0; metronidazole, 0.1-90.2; sulfamethoxazole, 0.4-12.8; ofloxacin, 0.2-7.6; trimethoprim, 0.6-7.6; and doxycycline, 0.6-6.7.     

Bis(4-chlorophenyl) sulfone (BCPS) in Swedish marine and fresh water wildlife-a screening study

Bis(4-chlorophenyl) sulfone (BCPS) is a high production volume chemical (HPVC) applied in thermostable polymers. BCPS has been detected as an environmental contaminant both in Europe and in North America but it is still not a commonly studied pollutant. In this study, three Baltic Sea fish species; herring (Clupea harengus), salmon (Salmo salar) and perch (Perca fluviatilis) from the Swedish coast, and one inland fish species, arctic char (Salvelinus alpinus), were analysed to screen for the occurrence and distribution of BCPS. Salmon and arctic char, were sampled in the early 1970s as well as the late 1990s. Fish eating grey seal (Halichoerus gryphus) and guillemot (Uria aalge) from the Baltic Sea were included to screen for whether BCPS biomagnify or not. The representativeness of the analysed samples for studying bioaccumulation of environmental pollutants was compared through analysis of two well known persistent and bioaccumulating compounds, 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153), and 4,4'-DDE. Pooled muscle and blubber samples based on 4-10 individuals were used for analysis, as well as individual samples of grey seal blubber. 2,4,4'-Trichlorodiphenyl sulfone, was synthesised and applied as an internal standard. BCPS was detected in all marine samples but in only one of the fresh water fish samples. The highest BCPS concentrations detected, 1600 and 1900 ng/g lipid weighet (l.w.), were found in muscle from Baltic guillemot. The results indicate that BCPS is bioaccumulated in both grey seal and guillemot, and that the guillemot has higher concentrations of BCPS than the grey seal (50-500 ng/g l.w.). The concentrations found in different species of fish from the Baltic Sea ranged between 15-37 ng/g l.w. and lower concentrations were found in freshwater species (n.d.-1.8 ng/g l.w.). The present study shows that BCPS is found in all investigated species of wildlife but, in most species, still at low concentrations. However, the guillemot has levels in the low ppm range indicating a considerable biomagnification of BCPS in this species.     

Simulating solute transport in a structured field soil: uncertainty in parameter identification and predictions

Dual-permeability models have been developed to account for the significant effects of macropore flow on contaminant transport, but their use is hampered by difficulties in estimating the additional parameters required. Therefore, our objective was to evaluate data requirements for parameter identification for predictive modeling with the dual-permeability model MACRO. Two different approaches were compared: sequential uncertainty fitting (SUFI) and generalized likelihood uncertainty estimation (GLUE). We investigated six parameters controlling macropore flow and pesticide sorption and degradation, applying MACRO to a comprehensive field data set of bromide andbentazone [3-isopropyl-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2dioxide] transport in a structured soil. The GLUE analyses of parameter conditioning for different combinations of observations showed that both resident and flux concentrations were needed to obtain highly conditioned and unbiased parameters and that observations of tracer transport generally improved the conditioning of macropore flow parameters. The GLUE "behavioral" parameter sets covered wider parameter ranges than the SUFI posterior uncertainty domains. Nevertheless, estimation uncertainty ranges defined by the 5th and 95th percentiles were similar and many simulations randomly sampled from the SUFI posterior uncertainty domains had negative model efficiencies (minimum of -3.2). This is because parameter correlations are neglected in SUFI and the posterior uncertainty domains were not always determined correctly. For the same reasons, uncertainty ranges for predictions of bentazone losses through drainflow for good agricultural practice in southern Sweden were 27% larger for SUFI compared with GLUE. Although SUFI proved to be an efficient parameter estimation tool, GLUE seems better suited as a method of uncertainty estimation for predictions.     

Frontal impact dummy kinematics in oblique frontal collisions: evaluation against post mortem human subject test data

OBJECTIVE: Today, a predominant percentage of vehicles involved in car crashes are exposed to oblique or frontal offset collisions. The aim of this study is to evaluate the 50th percentile male Hybrid III, THOR 99, and THOR Alpha dummies by comparing them with the corresponding kinematics of post mortem human subjects (PMHS) in this type of collision. METHODS: The PMHS data include results from oblique frontal collision tests. They include sled tests with near-side and far-side belt geometries at 15 degrees , 30 degrees , and 45 degrees angles. The test subjects were restrained with a three-point lap-shoulder belt and the Delta V was 30 km/h. RESULTS: The results from the Hybrid III and THOR 99 tests showed that, in most of the test, the head trajectories were an average of approximately 0.1 m shorter than those from equivalent PMHS. The Hybrid III and THOR 99 far-side belt geometry tests showed that the belt remained in place longer on the shoulder of the Hybrid III than on the THOR 99 and the THOR Alpha. This was probably due to a stiffer lumbar spine in the Hybrid III and to a large groove in the steel of the superior surface of the Hybrid III shoulder structure. The THOR 99 escaped from the shoulder belt about 40-50 ms earlier than the THOR Alpha. The results from the THOR Alpha tests show that the head trajectory accorded fairly well with the PMHS data, as long as the shoulder belt did not slip off the shoulder. Although the THOR Alpha shoulder escaped the shoulder belt in the 45 degrees far-side belt geometry, the PMHS did not. This may be due to the THOR Alpha shoulder design, with approximately 0.05 m smaller superior and medial shoulder range-of-motion, in combination with a relatively soft lumbar spine. CONCLUSIONS: The THOR Alpha provides head trajectories similar to those of the PMHS under these loading conditions, provided the shoulder belt remains in position on the shoulder. When the shoulder belt slipped off the dummy shoulder, the head kinematics was altered. The shoulder range-of-motion may be a contributing factor to the overall kinematics of an occupant in oblique frontal impact situations where the occupant moves in a trajectory at an angle from that of the longitudinal direction of the car.     

Screening of environmental pressure from products in the Swedish railway infrastructure: Implications for strategic environmental management

This paper proposes a method to be used in environmental reviews as an initial tool for estimating upstream environmental pressures from material use in organisations dealing mostly with construction materials. Upstream environmental pressures are often omitted in environmental reviews from organisations and instead tend to be site specific, with a limited life-cycle perspective. This paper uses the Swedish National Rail Authority as a case to present the approach. An energy indicator is used to estimate the environmental pressure of material use.In the studied building project, a small set of products contribute to a major part of the material use and the material-related energy use. The energy use is almost exclusively of nonrenewable energy carriers. The three most important products are all homogenous and non-complex, which makes the energy indicator well suited for the analysis. The organisation can use the results to focus on the most important products and also to see which parts of the organisation contribute to the material-related energy use. Rail traffic in Sweden is almost exclusively from non-fossil-based energy carriers. This highlights the importance of the infrastructure to the overall environmental pressure of the railway. Consequently, if road transport were to shift away from fossil fuels, railways earlier environmental advantages would diminish, since research suggests that railway infrastructure is more energy intensive than road infrastructure.     

Decreased emission of nitrous oxide from delivery wards—case study in Sweden

The very potent greenhouse gas nitrous oxide (N₂O) is widely used as a mild anaesthetic for mothers in delivery work in Sweden. As a part of the Stockholm County Council environmental program it was decided in 2002 that the emissions should be drastically reduced. Different ways were theoretically evaluated, and catalytic splitting to nitrogen and oxygen gas (N₂ and O₂) was chosen for a demonstration installation. A Japanese commercial unit for treatment of mixed anaesthetic gases (Anesclean® from Showa Denko K.K.) was thoroughly modified and installed at the Karolinska University Hospital at Huddinge in Stockholm in 2004. The destruction of N₂O was optimised and studied for 2 years. Data from both collection and destruction are given in the article. Of the collected N₂O more than 95% was split to N₂ and O₂ in the very stable system. The overall emission decrease was mainly dependent on the share that could be collected in the specific exhaustion system as compared to the normal room ventilation. Life cycle assessment (LCA) and life cycle costing (LCC) were used to evaluate the actual environmental value and economical cost for the process. Important factors are pointed out.