A sustainable method for optimizing product design with trade-off between life cycle cost and environmental impact

In today’s competitive market, corporations have learned that taking sustainability issues into account can significantly improve their public image. Modern producers therefore must simultaneously reduce the environmental impact of their products and make economic gains. Therefore, making trade-offs between economic and environmental issues is required to ensure a company’s continuity. In doing so, companies have attached a great deal of importance to the new product design phase. However, optimization at the design stage becomes very complex for a product with a large number of parts, which can have several design alternatives with similar forms and functionality, but different costs and environmental impacts. In the automobile, shipbuilding and aircraft industries, if the conventional complete enumeration method is applied, the time required for selecting the optimal combination of design alternatives with respect to life cycle cost and environmental impact may exceed a human’s natural life span. To overcome this limitation, this paper introduces an optimization method for use as a design aid tool that enables a designer to assess the life cycle cost and environmental impact of his/her design very early in the product development process. To support the developed method, an illustration is provided using a case study on a locally manufactured automobile.     

Assessment of physicochemical characteristics of Ganga Canal water quality in Uttarakhand

Assessment of physicochemical parameters of Ganga Canal water was carried out during 2012–2013 at Haridwar (Uttarakhand) with two different sites, i.e., Bhimgoda Barrage (site 1—control site) and Bahadrabad (site 2—contaminated site), where canal water flows with loads of pollution from highly commercial and industrial areas. During investigation, maximum turbidity (287.72 ± 56.28 JTU), total solids (1167.60 ± 303.90 mg l^?1), free CO₂ (1.88 ± 0.22 mg l^?1), total hardness (60.14 ± 1.13 mg l^?1), pH (7.1 ± 0.13), nitrate (0.048 ± 0.010), nitrite (0.019 ± 0.001), biochemical oxygen demand (2.866 ± 1.098), chemical oxygen demand (6.8 ± 2.61) and phosphate (0.087 ± 0.015), while minimum velocity (1.71 ± 0.19 ms^?1), transparency (0.12 ± 0.08 m) and dissolved oxygen (7.95 ± 0.44 mg l^?1) were recorded in monsoon season at site 2 in comparison with site 1. The mean values of these parameters were compared with WHO and ISI standards and found significant differences (p < 0.05) in the mean values of turbidity, total solids, pH, dissolved oxygen, free CO₂ and total hardness with sampling sites. The turbidity of both the sites 1 and 2 was recorded above the permissible limit. Turbidity of site 2 is much higher than of site 1, so it is counted as more polluted. The values of the studied parameters were more during monsoon season and summer season at site 2 as compared to site 1. The results indicated that most of the physicochemical parameters from Ganga Canal system were within or at periphery in comparison with permissible limit of ISI and WHO for drinking water and therefore may be suitable for domestic purposes, but it requires perceptible consideration due to intense changes in climate and increase in pollution.     

The effects of pesticide mixtures on degradation of pendimethalin in soils

Most agronomic situations involve a sequence of herbicide, fungicide, and insecticide application. On the other hand, use of pesticidal combinations has become a standard practice in the production of many agricultural crops. One of the most important processes influencing the behavior of a pesticide in the environment is its degradation in soil. It is known that due to several pesticide applications in one vegetation season, the pesticide may be present in mixtures with other pesticides or xenobiotics in soil. This study examines the role which a mixture of chemicals plays in pesticide degradation. The influence of other pesticides on the rate of pendimethalin (PDM) degradation in soil was measured in controlled conditions. Mixtures of PDM with mancozeb or mancozeb and thiamethoxam significantly influenced the degradation of pendimethalin under controlled conditions. The second type of mixtures, with metribuzin or thiamethoxam, did not affect the behavior of pendimethalin in soil. Also, we determined the influence of water content on the rate of pendimethalin degradation alone in two soils and compared it to the rate in three pesticide mixtures. We compared two equations to evaluate the predictors of the rate of herbicide dissipation in soil: the first-order kinetic and the non-linear empirical models. We used the non-linear empirical model assuming that the degradation rate of a herbicide in soil is proportional to the difference of the observed concentration of herbicide in soil at time and concentration of herbicide in the last day of measurement.     

Navigating the Perfect Storm: Research Strategies for Socialecological Systems in a Rapidly Evolving World

The ‘Perfect Storm’ metaphor describes a combination of events that causes a surprising or dramatic impact. It lends an evolutionary perspective to how social-ecological interactions change. Thus, we argue that an improved understanding of how social-ecological systems have evolved up to the present is necessary for the modelling, understanding and anticipation of current and future social-ecological systems. Here we consider the implications of an evolutionary perspective for designing research approaches. One desirable approach is the creation of multi-decadal records produced by integrating palaeoenvironmental, instrument and documentary sources at multiple spatial scales. We also consider the potential for improved analytical and modelling approaches by developing system dynamical, cellular and agent-based models, observing complex behaviour in social-ecological systems against which to test systems dynamical theory, and drawing better lessons from history. Alongside these is the need to find more appropriate ways to communicate complex systems, risk and uncertainty to the public and to policy-makers.     

The use of food waste-based diets and Napier grass to culture grass carp: growth performance and contaminants contained in cultured fish

The present study used commercial feeds, food waste feeds, Napier grass, and mixed feeds (food waste feed to Napier grass ratio, 1:10) to feed grass carp (Ctenopharyngodon idellus). The results indicated that grass carp fed with food waste feeds and mix feeds achieved growth performance (based on specific growth rate and feed conversion ratio) that was similar to commercial feeds (p?>?0.05). Concentrations of metalloid/metals in food waste feeds and polycyclic aromatic hydrocarbons (PAHs) in Napier grass were relatively higher than other types of fish feeds (p?<?0.05). However, most of the metalloid/metals and PAH levels in fish fed with four types of fish feeds were not significantly different (p?>?0.05). These findings show that food waste feeds are suitable for using in the production of fish feed and Napier grass can be served as supplemental feeds for grass carp, and hence reducing the production cost.     

Large eddy simulation of flow and scalar transport in a vegetated channel

Predicting flow and mass transport in vegetated regions has a broad range of applications in ecology and engineering practice. This paper presents large eddy simulation (LES) of turbulent flow and scalar transport within a fully developed open-channel with submerged vegetation. To properly represent the scalar transport, an additional diffusivity was introduced within the canopy to account for the contribution of stem wakes, which were not resolved by the LES, to turbulent diffusion. The LES produced good agreement with the velocity and concentration fields measured in a flume experiment. The simulation revealed a secondary flow distributed symmetrically about the channel centerline, which differed significantly from the circulation in a bare channel. The secondary circulation accelerated the vertical spread of the plume both within and above the canopy layer. Quadrant analysis was used to identify the form and shape of canopy-scale turbulent structures within and above the vegetation canopy. Within the canopy, sweep events contributed more to momentum transfer than ejection events, whereas the opposite occurred above the canopy. The coherent structures were similar to those observed in terrestrial canopies, but smaller in scale due to the constraint of the water surface.     

水浴消解－原子荧光法同时测定污水处理厂污泥中的汞和砷

本文主要介绍了应用双道原子荧光光谱法,采用水浴消解法同时测定污水处理厂污泥中汞和砷的原理和过程。结果表明,该方法具有操作简单、快速省事、灵敏度高、准确度好、节省试剂等优点,是较好的测定方法。     

西安夏季大气亚微米颗粒物化学组成与来源的在线观测研究

西安作为汾渭平原地区最大的城市,大气颗粒物污染形势严峻.2017年夏季期间,在西安市浐灞生态园区运用气溶胶化学组分监测仪,对大气亚微米颗粒物中的非难挥发性组分(NR-PM1)进行了在线监测.观测期间NR-PM1的平均质量浓度为(30.1?±?15.4)μg???m?3.其中有机物含量最高,占NR-PM1总质量浓度的63％,其次为硫酸盐(18％)、铵盐(10％)和硝酸盐(9％).运用正交矩阵因子分析法共解析出两个主要因子,包括烃类有机组分(HOA)和含氧有机组分(OOA),分别占有机物总质量浓度的43％和55％.HOA主要由机动车排放贡献,而OOA主要由气态污染物的二次反应生成.气象因素对NR-PM1的浓度与化学组分的影响较为显著.高硝酸盐阶段发生在高湿、低温条件,可能是由氮氧化物的液相反应产生的.高硫酸盐阶段发生在低湿、高温条件,主要来自于大气光化学反应的贡献.该研究结果为西安及周边地区的空气污染治理决策提供重要的理论依据.     

Comparative study of polyhydroxyalkanoates production from acidified and anaerobically treated brewery wastewater using enriched mixed microbial culture

The production of polyhydroxyalkanoates(PHA) from wastewaters using microbial mixed cultures(MMC) has been attracting increased interest because of PHA's biodegradability characteristics. Production of PHA by an MMC enriched with PHA-accumulating bacteria was compared using anaerobically treated and acidified brewery wastewaters under various feeding strategies, namely pulse and batch feed addition. To obtain an enriched MMC, a sequencing batch reactor was inoculated with activated sludge fed with acetate and subjected to aerobic dynamic feeding. The enriched MMC was able to accumulate PHA up to 72.6% of cell dry weight(CDW) with pulse addition of acetate controlled by the dissolved oxygen(DO) concentration in the reactor. In a batch accumulation experiment with acetate,the PHA content achieved(28.5% CDW) was less than that of the pulse feeding strategy with the same amount of acetate(～2000 mg C/L). Using anaerobically treated and acidified brewery wastewater fed in pulses, the maximum PHA accumulated by the enriched MMC was similar for both wastewaters(45% CDW), in spite of the higher volatile fatty acid concentration in acidified brewery wastewater. The pulse feed addition controlled by the DO concentration was difficult to implement for wastewater as compared to acetate because the difference in DO concentration between substrate availability and depletion was low. For the batch addition of acidified wastewater, a slightly lower PHA content(39%CDW) was obtained. These results show that both brewery wastewaters can be utilized for PHA production with a similar maximum PHA storage capacity.     

Arthropods associated with fungal galls: do large galls support more abundant and diverse inhabitants?

Fungus-induced galls can attract spore-feeding arthropods as well as gall-feeding ones, resulting in diverse communities. Do large fungal galls support more abundant and diverse arthropod communities than small fungal galls? To address this question, we investigated the structure of the arthropod community associated with bud galls induced by the fungus Melanopsichium onumae on the tree species Cinnamomum yabunikkei (Lauraceae) in central Japan. Thirteen species of arthropods were associated with M. onumae galls. Dominant arthropod species were represented by the larvae of a salpingid beetle (a spore feeder), a nitidulid beetle (a spore feeder), a cosmopterigid moth (a spore feeder), an unidentified moth (a gall tissue feeder), and a drosophilid species (a gall tissue feeder). Arthropod abundance and species richness were positively correlated with gall diameter. The majority of the most abundant species were more frequently found in large galls than in small ones, indicating that large fungal galls, which have more food and/or space for arthropods, could support a more abundant and diverse arthropod community.