Allocation in recycling systems

‘Design for Recycling’ and dematerialization by enhancing the durability of products are major aspects of the quest for sustainable products. This article presents an LCA-based model for the integrated analyses of the product chain, its recycling systems, and its waste treatment systems at the ‘End of Life’ stage. The model is an extension of the EVR (Eco-costs/Value Ratio) model which has been published in this journal (Vogtländer et al. 2001), but can also be applied to other life cycle interpretation models, since the model as such is not restricted to the use of the eco-costs as a single indicator. The model has been developed to evaluate the design alternatives of complex products like buildings and cars. These products comprise several subsystems, each with its own special solution at the End of Life stage: Extending of the product life, object renovation, re-use of components, re-use of materials, useful application of waste materials, immobilization with and without useful applications, incineration with and without energy recovery, land fill. Since complex product systems always comprise a combination of these design alternatives, a methodology is given to calculate and allocate the eco-costs of the total system in order to select the best solution for sustainability. The methodology is characterized by:

1. A main allocation model of the recycling flow based on physical relationships,
2. a strict separation of the market value, the costs and the ecocosts in the system,
3. a main allocation model for extension of lifetime based on ‘depreciation of eco-costs’, parallel to economic depreciation.

     

Hierarchical Perception of Stimuli During Case Construction in the Bagworm Moth Eumeta crameri (Lepidoptera: Psychidae)

We studied case construction behavior of bagworm moth, Eumeta crameri (Lepidoptera: Psychidac) in the host plant, Acacia nilotica, at two sites. At the time of the study, Site A had 1-year-old A. nilotica saplings only, whereas Site B had full grown trees. The larva of bagworm moth used either thorns or cut-twigs or both as the materials for building its case. It renovated its case three times, and during each instance it increased the volume of its case by replacing older thorns or cut-twigs by newer and longer ones. However, it exhibited a spectacular predilection for thorns, irrespective of the sites, during the first-instar stage of its development. Thereafter, at Site A it used exclusively cut-twigs, whereas at Site B it preferably used thorns provided they were available in the range of the required length and within the threshold distance. It appears that the bagworm has an ability to process thorn length and distance signals hierarchically to fulfill its priority, that is, case building. Thus it optimizes time and energy expenditures during the period of its larval growth leading to pupation by toggling its preference between thorns and cut-twigs.     

几丁糖膜的研究进展

几丁糖膜的基础性研究报道较多,但还未形成产品。本文主要综述了目前国内外几丁糖膜在创伤敷料、术后防粘连、硬膜修复等方面的作用及制备,为进一步形成产品作指导。     

Naturalistic Exhibits May be More Effective Than Traditional Exhibits at Improving Zoo-Visitor Attitudes toward African Apes

Zoos play a unique role in wildlife conservation, particularly in the area of conservation education. Because of their popularity and flagship status for broader conservation issues, great apes may prove to be one of the most important educational conduits in zoos. In 2002, we surveyed knowledge of and attitudes toward African apes in visitors to the Lester E. Fisher Great Ape House (GAH) at Lincoln Park Zoo in Chicago, IL, USA. In the current study, we replicated the survey to document attitudes to and knowledge of the newly renovated and naturalistic Regenstein Center for African Apes (RCAA) and compared results. We found RCAA was no more effective than GAH in increasing visitor knowledge about apes, although visitors answered more questions correctly upon exit than on entrance in both buildings. We did find, however, that RCAA was more effective than GAH at improving visitor attitudes toward chimpanzees. Specifically, upon exiting, RCAA visitors showed increased naturalistic attitudes and reduced utilitarian attitudes toward chimpanzees. Exhibiting apes in naturalistic settings may therefore be an effective way to increase visitor concern for apes in nature and in zoos. Zoos and aquariums investing in new, naturalistic ape exhibits with the aim to educate about, provide emotional connections to, improve attitudes toward, and ultimately increase conservation of apes, need to then critically evaluate whether the actual effect of the designed environment on visitors—above and beyond intended benefits for the animals—is commensurate with the investment. The broader impacts of even small shifts in visitor attitude in the right direction could be significant. These findings may vary across species and settings, however, and should be assessed accordingly.     

铁还原菌在水资源再生与能源转化领域的研究进展

铁还原菌是一种典型的异化金属还原菌,广泛分布于海洋沉积物、陆地深地层等自然环境,该类细菌可以将铁氧化物中的Fe(Ⅲ)还原为Fe(Ⅱ),在铁、碳的生物地球化学铁循环中发挥重要作用。铁还原菌的末端电子不局限于Fe(Ⅲ),还可以是其他高价金属、有机污染物,可用于土壤、地下水的污染修复和毒性削减。在微生物电化学系统中,铁还原菌氧化有机物产生的电子直接传递给电极,可以产生电能。基于这种独特的胞外电子传递方式,衍生出了微生物燃料电池、微生物电解池、微生物脱盐电池、微生物燃料电池耦合芬顿反应以及光催化微生物燃料电池,常用于微生物发电、生物传感器、生物制氢、定向发酵、海水淡化、生物脱盐和污染物分解矿化。本文从异化铁还原菌的代谢机制、微生态作用、环境修复、水资源再生与能源转化四个方面,综述了铁还原菌的作用原理及国内外研究现状,分析论述了目前亟需解决的关键问题和未来的研究方向,以期为铁还原菌的基础理论研究和应用技术研发提供参考。     

Restoration of Native Warm Season Grassland Species in a Tall Fescue Pasture Using Prescribed Fire and Herbicides

Pastures dominated by tall fescue (Schedonorus phoenix (Scop.) Holub) cover much of the eastern United States, and there are increasing efforts to restore native grassland plant species to some of these areas. Prescribed fire and herbicide are frequently used to limit the growth of tall fescue and other non‐natives, while encouraging native grasses and forbs. A fungal endophyte, commonly present in tall fescue, can confer competitive advantages to the host plant, and may play a role in determining the ability of tall fescue plants to persist in pastures following restoration practices. We compared vegetation composition among four actively restored subunits of a tall fescue pasture (each receiving different combinations of prescribed fire and/or herbicide) and a control. We also measured the rate of endophyte infection in tall fescue present within each restoration treatment and control to determine if restoration resulted in lower tall fescue cover but higher endophyte infection rates (i.e. selected for endophyte‐infected individuals). Tall fescue cover was low in all restoration treatments and the control (1.1–17.9%). The control (unmanaged) had higher species richness than restoration treatments and plant community composition was indicative of succession to forest. Restoration practices resulted in higher cover of native warm season grasses, but in some cases also promoted a different undesirable species. We found no evidence of higher fungal endophyte presence in tall fescue following restoration, as all subunits had low endophyte infection rates (2.2–9.3%). Restoration of tall fescue systems using prescribed fire and herbicide may be used to promote native grassland species.     

Dynamic Eco-Efficiency Projections for Construction and Demolition Waste Recycling Strategies at the City Level

In this article we have elaborated a consistent framework for the quantification and evaluation of eco‐efficiency for scenarios for waste treatment of construction and demolition (C&D) waste. Such waste systems will play an increasingly important role in the future, as there has been for many years, and still is, a significant net increase in stock in the built environment. Consequently, there is a need to discuss future waste management strategies, both in terms of growing waste volumes, stricter regulations, and sectorial recycling ambitions, as well as a trend for higher competition and a need for professional and optimized operations within the C&D waste industry. It is within this framework that we develop and analyze models that we believe will be meaningful to the actors in the C&D industry. Here we have outlined a way to quantify future C&D waste generation and have developed realistic scenarios for waste handling based on today's actual practices. We then demonstrate how each scenario is examined with respect to specific and aggregated cost and environmental impact from different end‐of‐life treatment alternatives for major C&D waste fractions. From these results, we have been able to suggest which fractions to prioritize, in order to minimize cost and total environmental impact, as the most eco‐efficient way to achieve an objective of overall system performance.     

杂交冬瓜创伤周皮结构的切片观察

报道了长沙市蔬菜研究所培育的杂交冬瓜果实在表层和深度损伤后,形成的新保护组织－创伤周皮的结构。这是一种由伤口邻近的薄壁细胞脱分化形成的木栓形成层及其分裂形成的木栓和栓内层,即再生的周皮,这种自我修复能力有效地防止了冬瓜组织受伤后的病菌侵染。     

高职农业类专业微生物技术课程教学改革与实践

微生物技术在现代农业的生态、绿色发展中扮演着重要的作用。在分析了农业转型升级对高技术技能型农业人才的需求之后,课程组在教学实践中根据校企合作单位反馈,对微生物技术课程内容进行了优化。落实课程立德树人的目标,按照素能共育的教育理念,遵循理实一体、线上线下混合的教学模式,探索课程改革,更好地提升农业专业学生的专业技能与职业素养,服务现代农业。     

Projection of Construction and Demolition Waste in Norway

Current waste generation from the construction and demolition industry (C&D industry) in Norway is about 1.25 million tonnes per year. This article presents a procedure for projection of future waste amounts by estimating the activity level in the C&D industry, determining specific waste generation factors related to this activity, and finally calculating projections on flows of waste materials leaving the stocks in use and moving into the waste management system. This is done through a simple model of stocks and flows of buildings and materials. Monte Carlo simulation is used in the calculations to account for uncertainties related to the input parameters in order to make the results more robust. The results show a significant increase in C&D waste for the years to come, especially for the large fractions of concrete/bricks and wood. These projections can be a valuable source of information to predict the future need for waste treatment capacity, the dominant waste fractions, and the challenges in future waste handling systems. The proposed method is used in a forthcoming companion article for eco-efficiency modeling within an evaluation of a C&D waste system.