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1.
Purpose

A review of LCA process datasets is an important element of quality assurance for databases and for other systems to provide LCA datasets. Somewhat surprisingly, a broadly accepted and applicable set of criteria for a review of LCA process datasets was lacking so far. Different LCA databases and frameworks are proposing and using different criteria for reviewing datasets. To close this gap, a set of criteria for reviewing LCA dataset has been developed within the Life Cycle Initiative.

Methods

Previous contributions to LCA dataset review have been analysed for a start, from ISO and various LCA databases. To avoid somewhat arbitrary review criteria, four basic rules are proposed which are to be fulfilled by any dataset. Further, concepts for assessing representativeness and relevance are introduced into the criteria set from established practices in statistics and materiality. To better structure the criteria and to ease their application, they are grouped into clusters. A first version of the developed review criteria was presented in two workshops with database providers and users on different levels of experience, and draft versions of the criteria were shared within the initiative. The current version of the criteria reflects feedback received from various stakeholders and has been applied and tested in a review for newly developed datasets in Brazil, Malaysia and Thailand.

Results and discussion

Overall, 14 criteria are proposed, which are organised in clusters. The clusters are goal, model, value, relevance and procedure. For several criteria, a more science-based definition and evaluation is proposed in comparison to ‘traditional’ LCA. While most of the criteria depend on the goal and scope of dataset development, a core set of criteria are seen as essential and independent from specific LCA modelling. For all the criteria, value scales are developed, typically using an ordinal scale, following the pedigree approach.

Conclusions

Review criteria for LCI datasets are now defined based on a stringent approach. They aim to be globally acceptable, considering also database interoperability and database management aspects, as well as feedback received from various stakeholders, and thus close an important gap in LCA dataset quality assurance. The criteria take many elements of already existing criteria but are the first to fully reflect the implications of the ISO data quality definition, and add new concepts for representativeness and relevance with the idea to better reflect scientific practice outside of the LCA domain. A first application in a review showed to be feasible, with a level of effort similar to applying other review criteria. Aspects not addressed yet are the review procedure and the mutual recognition of dataset reviews, and their application for a very high number of datasets.

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3.
Accelerated nitrogen inputs — A new problem or a new perspective?   总被引:3,自引:0,他引:3  
This paper considers whether new problems are arising in forest ecosystems due to increased levels of inorganic N deposition from the atmosphere, or whether there are no new problems, just a change of perception. Deposition of N has indeed increased. Wet deposition rates are reasonably quantified, but the rates of dry deposition to forests are largely unknown. Current transport and deposition models are probably under-estimating N deposition to forests. Consideration of possible effects of enhanced N deposition reveals with varying degrees of certainty that there may be effects due to high N in biomass, high uptake rates, leaching of nitrate and consequent acidification, and an overall increase in N availability. Forest ecosystems are not well-enough understood to set a critical load for N deposition, but enough is known to define some upper limits.  相似文献   

4.
Increasing evidence suggests that the eukaryotic cell cycle is controlled at several checkpoints by different members of a novel class of protein kinase, the cyclin-dependent kinases. To phosphorylate their substrates, these enzymes bind to proteins of the cyclin family--proteins that are synthesized and degraded at specific points in each cell cycle. The most well known of these kinases is the 34 kDa product of the cdc2 gene in fission yeast, p34cdc2; however, several putative cyclin-dependent kinases have now been cloned or identified. Some of these closely resemble p34cdc2. Here we review these new proteins, their potential roles in the cell cycle and the cyclins with which they may interact.  相似文献   

5.
Life cycle assessment of aquaculture systems—a review of methodologies   总被引:1,自引:0,他引:1  

Purpose  

As capture fishery production has reached its limits and global demand for aquatic products is still increasing, aquaculture has become the world’s fastest growing animal production sector. In attempts to evaluate the environmental consequences of this rapid expansion, life cycle assessment (LCA) has become a frequently used method. The present review of current peer-reviewed literature focusing on LCA of aquaculture systems is intended to clarify the methodological choices made, identify possible data gaps, and provide recommendations for future development within this field of research. The results of this review will also serve as a start-up activity of the EU FP7 SEAT (Sustaining Ethical Aquaculture Trade) project, which aims to perform several LCA studies on aquaculture systems in Asia over the next few years.  相似文献   

6.

Background, aim, and scope  

During the last decades, the electronics industry has undergone tremendous changes due to intense research leading to advanced technology development. Multiple life cycle assessment (LCA) studies have been performed on the environmental implications of consumer electronics. The aim of this review is to assess the consistency between different LCA studies for desktop computers, laptop computers, mobile phones and televisions (TVs).  相似文献   

7.

Purpose

Light-emitting diode (LED) technology is increasingly being used for general lighting. Thus, it is timely to study the environmental impacts of LED products. No life cycle assessments (LCA) of recessed LED downlight luminaires exist in the literature, and only a few assessments of any type of LED light source (component, lamp and luminaire) are available.

Methods

The LCA of a recessed LED downlight luminaire was conducted by using the data from the luminaire manufacturer, laboratory measurements, industry experts and literature. The assessment was conducted using SimaPro LCA software. EcoInvent and European Reference Life Cycle Database were used as the databases. The LCA included a range of environmental impacts in order to obtain a broad overview. The functional unit of the LCA was one luminaire used for 50,000 h. In addition, the sensitivity of the environmental impacts to the life was studied by assessing the LED downlight luminaire of 36,000 h and 15,000 h useful life and to the used energy sources by calculating the environmental impacts using two average energy mixes: French and European.

Results and discussion

The environmental impacts of the LED luminaire were mostly dominated by the energy consumption of the use. However, manufacturing caused approximately 23 % of the environmental impacts, on average. The environmental impacts of manufacturing were mainly due to the driver, LED array and aluminium parts. The installation, transport and end of life had nearly no effect on the total life cycle impacts, except for the end of life in hazardous waste. The life cycle environmental impacts were found to be sensitive to the life of the luminaire. The change from the French to the European average energy mix in use resulted to an even clearer dominance of the use stage.

Conclusions

The case study showed that the environmental impacts of the LED downlight luminaire were dominated by the use-stage energy consumption, especially in the case of the European energy mix in use. Luminous efficacy is, thus, a relatively appropriate environmental indicator of the luminaire. As LED technology possesses generally higher luminous efficacy compared to conventional ones, the LED luminaire is considered to represent an environmentally friendly lighting technology. However, data gaps exist in the data in LED product manufacturing and its environmental impacts. The environmental impacts of different LED products need to be analysed in order to be able to precisely compare the LED technology to the conventional lighting technologies.  相似文献   

8.

Purpose

End-of-life (EoL) modelling in life cycle assessment has already been broadly discussed within several studies. However, no consensus has been achieved on how to model recycling in LCA, even though several approaches have been developed. Within this paper, results arising from the application of two new EoL formulas, the product environmental footprint (PEF) and the multi-recycling-approach (MRA) ones, are compared and discussed. Both formulas consider multiple EoL scenarios such as recycling, incineration and landfill.

Methods

The PEF formula has been developed within the PEF programme whose intent is to define a harmonized methodology to evaluate the environmental performance of products. The formula is based on a 50:50 allocation approach, as burdens and benefits associated with recycling are accounted for a 50% rate. The MRA formula has been developed to change focus from products to materials. Recycling cycles and material losses over time are considered with reference to material pools. Allocation between systems is no longer needed, as the actual number of potential life cycles for a certain material is included in the calculation. Both the approaches have been tested within two case studies.

Results and discussion

Methodological differences could thereof be determined, as well as applicability concerns, due to the type of data required for each formula. As far as the environmental performance is concerned, impacts delivered by MRA are lower than those delivered by PEF for aluminium, while the opposite happens for plastic and rubber due to the higher share of energy recovery accounted in PEF formula. Stainless steel impacts are almost the same.

Conclusions and recommendations

The application of the two formulas provides some inputs for the EoL dilemma in LCA. The use of a wider perspective, better reflecting material properties all over the material life cycle, is of substantial importance to properly represent recycling situations. In MRA, such properties are treated and less data are required compared to the PEF formula. On the contrary, the PEF model better accommodates the modelling of products whose materials, at end of life, can undertake the route of recycling or recovery (or landfill), depending on country-specific EoL management practices. However, its application requires more data.
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9.
10.
Electronegativity is a very useful concept but it is not a physical observable; it cannot be determined experimentally. Most practicing chemists view it as the electron-attracting power of an atom in a molecule. Various formulations of electronegativity have been proposed on this basis, and predictions made using different formulations generally agree reasonably well with each other and with chemical experience. A quite different approach, loosely linked to density functional theory, is based on a ground-state free atom or molecule, and equates electronegativity to the negative of an electronic chemical potential. A problem that is encountered with this approach is the differentiation of a noncontinuous function. We show that this approach leads to some results that are not chemically valid. A formulation of atomic electronegativity that does prove to be effective is to express it as the average local ionization energy on an outer contour of the atom’s electronic density.  相似文献   

11.
12.
The aim of this study was to determine the reference interval of serum cobalt-binding capacity (CoBC), and to estimate the effect of factors unrelated to oxidative modification of serum albumin on this diagnostic marker. Healthy volunteers (n = 194), patients with autoimmune diseases (n = 44) and patients with type 2 diabetes mellitus (n = 50) were enrolled in the study. The regional reference interval was found to be 0,462–0,744 mmol Co2+/L of serum. The study of serum CoBC in patients with autoimmune pathology and type 2 diabetes mellitus has shown that the CoBC level strongly depends on the serum protein profile. Therefore, this test may be used to diagnose the ischemia, although other pathologies associated with changes in the ratio of blood protein fractions can also influence the serum CoBC level.  相似文献   

13.
Epiascidiate leaves are those foliar organs whose adaxial (ventral) side is the inside of a tube. Such tubular leaves are found in Nepenthaceae, Sarraceniaceae, Cephalotaceae, and Lentibulariaceae. Throughout botanical history these leaves have received considerable attention because of their bizarre morphology and problems of interpretation. This paper documents the attempts of the last 150 years to correctly understand their organographic nature. All epiascidiate foliar organs are structurally similar in their early ontogeny, each forms a distinctive adaxial outgrowth (Querzone), and the diverse morphologies of the mature organs seem to be modifications upon a similar primordial ground plan. Typologically these leaves are directly related to peltate leaves and phyllodes (non-petiolar,sensu Boke). Except for certain, highly speculative,de novo theories, such as the “foliar runner” theory of Croizat, all misinterpretations of the nature of epiascidiate leaves are directly attribuable to earlier errors in ascertaining the organography of typologically related leaf forms. Accordingly, the sympodial tubular leaf (Roth) is rejected, as is the petiolar nature of tubular leaves (de Candolle). The typological relationships of these leaves to unifacial foliar organs (Troll) seems well substantiated from both an organographic and a histogenetic viewpoint. The peltate carpel theory (?elakovský; Troll) is, in reality, an epiascidiate carpel theory. The idea of a fundamentally tubular carpel seems correct from both a typological and phylogenetic standpoint. To comprehend the various contradictory interpretations which have been used to explain morphologically complex problems, as well as to understand the genesis of morphological theories, it is necessary to acquire an accurate historical perspective of the subject.  相似文献   

14.
The plasma concentration of secretin was measured during a 5-day military training course comprising prolonged physical exercise (35% of max O2 uptake), severe caloric deficiency (approx. 35700 kJ/24 h) and sleep deprivation (only 2 h of sleep as a total during 5 days). 24 subjects were divided into 3 groups, one group was compensated for the caloric deficiency and another group was partly compensated for the sleep deprivation. The results showed that the fasting plasma secretin increased 3–6-fold (from 1.8–3.7 to 13.3–19.1 pmol/l) during the course with small differences in increase between the groups. Ingestion of a mixed meal reduced the fasting plasma secretin by about 40% during the course, while oral glucose reduced the plasma secretin to the concentrations found in the control experiment.The study shows that plasma secretin is increased when man is exposed to prolonged multifactorial stress. Additional food or sleep appears to have small influence on the fasting plasma secretin, but after giving a meal or oral glucose solution the plasma secretin decreases rapidly.  相似文献   

15.
Lavatera andMalva are circumscribed by epicalyx characters, but the distinction is untenable on this basis. Morphological characters and phylogenetic trees from rDNA ITS sequence data indicate the presence of two well-supported species groups different from the traditional genera. One group includes a mixture of closely related species in both genera and forms a more broadly circumscribedMalva, including most disjunctLavatera species—notably four of western North American islands, one Australian and one Canarian species. The other group forms a more narrowly definedLavatera. Another CanarianLavatera species may be a common ancestor to the two groups.  相似文献   

16.
The World Antidoping Agency (WADA) has introduced some changes in the 2012 prohibited list. Among the leading innovations to the rules are that both 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (peroxisome proliferator-activated receptor-δ [PPAR-δ]-5' adenosine monophosphate-activated protein kinase [AMPK] agonist) and GW1516 (PPAR-δ-agonist) are no longer categorized as gene doping substances in the new 2012 prohibited list but as metabolic modulators in the class "Hormone and metabolic modulators." This may also be valid for the angotensin II receptor blocker telmisartan. It has recently been shown that telmisartan might induce similar biochemical, biological, and metabolic changes (e.g., mitochondrial biogenesis and changes in skeletal muscle fiber type) as those reported for the former call of substances. We suspect that metabolic modulators abuse such as telmisartan might become a tangible threat in sports and should be thereby targeted as an important antidoping issue. The 2012 WADA prohibited list does not provide telmisartan for a potential doping drug, but arguments supporting the consideration to include them among "metabolic modulators" are at hand.  相似文献   

17.
18.
The International Journal of Life Cycle Assessment - The aim of this study is to explore the dimensions of sustainability that addressed the most within international standards and thereby present...  相似文献   

19.
The International Journal of Life Cycle Assessment - The increase of shellfish production has raised environmental concerns, i.e., enrichment and redistribution of nutrients and energy consumption....  相似文献   

20.
The inherent interest on the origin of genetic novelties can be traced back to Darwin, But it was not until recently that we were allowed to investigate the fundamental process of origin of new genes by the studies on newly evolved young genes. Two indispensible steps are involved in this process: origin of new gene copies through various mutational mechanisms and evolution of novel functions, which fur-ther more leads to fixation of the new copies within populations. The theoretical framework for the former step formed in 1970s. Ohno proposed gene duplication as the most important mechanism producing new gene copies. He also believed that the most common fate for new gene copies is to become pseudogenes. This classical view was validated and was also challenged by the characterization of the first functional young gene jingwei in Drosophila. Recent genome-wide comparison on young genes of Drosophila has elucidated a compre-hensive picture addressing remarkable roles of various mechanisms besides gene duplication during origin of new genes. Case surveys revealed it is not rare that new genes would evolve novel structures and functions to contribute to the adaptive evolution of organisms.Here, we review recent advances in understanding how new genes originated and evolved on the basis of genome-wide results and ex-perimental efforts on cases, We would finally discuss the future directions of this fast-growing research field in the context of functional genomics era.  相似文献   

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