Environmental Bottlenecks Research Articles

Avaliação ambiental estratégica no setor elétrico brasileiro: um estudo de potencialidade

DestaquesA Avaliação Ambiental Estratégica (AAE) possibilita uma visão abrangente das implicações ambientais e sociais de propostas de Planos, Políticas e Programas (PPP) aplicadas a diversas atividades setoriais. No Brasil, é possível identificar gargalos associados ao planejamento do setor elétrico, principalmente em relação ao processo de licenciamento ambiental. Assim, há potencial significativo para aplicação de AAE neste contexto, desde que sejam consideradas as características brasileiras de desenvolvimento.ObjetivosO objetivo deste artigo é identificar e avaliar como ocorre a inclusão da variável ambiental no planejamento do setor elétrico brasileiro e, então, verificar a aplicabilidade da AAE no âmbito deste planejamento. MetodologiaPara o desenvolvimento deste trabalho, utilizou-se a metodologia de pesquisa bibliográfica de abordagem qualitativa. Especificamente, foram consultadas publicações existentes, como artigos científicos, monografias, dissertações, teses e publicações oficiais. Destaca-se a utilização do “Guia de boas práticas para Avaliação Ambiental Estratégica - orientações metodológicas” e o “Plano Decenal de Expansão de Energia 2024”.ResultadosO principal resultado alcançado por este trabalho foi o desenvolvimento de formas de adaptação da AAE no Brasil, a partir de considerações sobre as singularidades da realidade brasileira em cada estágio de desenvolvimento da AAE. Com base nesta adaptação, concluiu-se que a AAE pode contribuir significativamente para um processo decisório ambiental e sustentável no planejamento do setor elétrico brasileiro, inclusive sanando gargalos do licenciamento ambiental.Limitações da InvestigaçãoO principal limitante da pesquisa e seus resultados é a subjetividade dos processos políticos de planejamento no país, os quais impactam diretamente nos estágios de desenvolvimento da AAE.Implicações PráticasO estudo identifica real potencial de AAE no Brasil, e apresenta direcionamentos e recomendações para a criação de um modelo brasileiro de AAE no setor elétrico.Originalidade/ValorO artigo traz recomendações para adaptação de uma metodologia de AAE aplicável ao setor elétrico brasileiro, considerando suas singularidades.

Environmental bottlenecks in children’s genetic potential for adult socio-economic attainments: Evidence from a health shock

This paper explores gene–environment interactions—interactions between family environments and children’s genetic predispositions—in determining educational attainment. The central question is whether poor childhood family environments reduce children’s ability to leverage their genetic gifts to achieve high levels of educational attainment—are there important ‘bottlenecks’ for poor children? The multigenerational information and genetic data contained in the United States’ Health and Retirement Study are used to separate two mechanisms for intergenerational transmission of socio-economic status: genetic endowments and family environments. Using parental in utero exposure to the 1918–19 influenza pandemic as a source of quasi-experimental variation in family environments (that did not affect children’s genetic endowments), I estimate interactions between parental investments and children’s genetic potential. The main finding suggests that girls with high genetic potential whose fathers were exposed to influenza face reduced educational attainments—a gene–environment interaction—but there is no similar effect for boys.

Environmental Bottlenecks on Children's Genetic Potential for Adult Socioeconomic Attainments: Evidence from a Health Shock

This paper explores gene-environmental interactions between family environments and children’s genetic scores in determining educational attainment. The central question is whether poor childhood family environments reduce the ability for children to leverage their genetic gifts to achieve high levels of educational attainments. The multigenerational information and genetic data contained in the Health and Retirement Study is used to separate two mechanisms of intergenerational transmission of socioeconomic status – genetic endowments and family environments. Using parental in utero exposure to the 1918/1919 influenza pandemic as a source of quasi-experimental variation to family environments (but not affecting children’s genetic endowments), this paper estimates interactions between parental investments and children’s genetic potential. The main finding suggests that girls with high genetic potential whose fathers were exposed to influenza face reduced educational attainments – a gene-environment interaction – but there is no similar effect for boys.

Comparative life cycle assessment of real pilot reactors for microalgae cultivation in different seasons

Microalgae are promising natural resources for biofuels, chemical, food and feed products. Besides their economic potential, the environmental sustainability must be examined. Cultivation has a significant environmental impact that depends on reactor selection and operating conditions. To identify the main environmental bottlenecks for scale-up to industrial facilities this study provides a comparative life cycle assessment (LCA) of open raceway ponds and tubular photobioreactors at pilot scale. The results are based on experimental data from real pilot plants operated in summer, fall and winter at AlgaePARC (Wageningen, The Netherlands). The energy consumption for temperature regulation presented the highest environmental burden. The production of nutrients affected some categories. Despite limited differences compared to the vertical system, the horizontal PBR was found the most efficient in terms of productivity and environmental impact. The ORP was, given the Dutch climatic conditions, only feasible under summer operation. The results highlight the relevance of LCA as a tool for decision-making in process design. Weather conditions and availability of sources for temperature regulation were identified as essential factors for the selection of geographic locations and for microalgal cultivation systems based on environmental criteria. Simulation of large-scale reactors with optimized temperature regulation systems lead to environmental improvements and energy demand reductions ranging from 17% up to 90% for systems operated in favorable summer conditions.

Identification of environmental bottleneck using Bayesian Networks: a case study of an Indian pig iron manufacturing organization

Environmentally conscious manufacturing has become a global attention for the iron and steel manufacturers to prevent global warming and climate change while making money. Iron and steel sector is considered as one of the most polluting sectors in the world. It is also one of the most energy intensive industries. During pig iron manufacturing, there is a number of steps that affect the environment emitting different pollutants. While some step(s) may be considered critical to damage the environment among all the steps, some pollutant(s) may be considered critical to affect the environment among all the pollutants. This paper proposes environmental bottleneck to consider critical step and critical pollutant simultaneously. Unless environmental bottleneck is improved, environmental performance of the entire manufacturing process may not improve significantly even if other processes (i.e. other than environmental bottleneck) are taken care of. Thus, environmental bottleneck must be taken care of properly by the manufacturing organization to enable environmentally conscious manufacturing. Hence, a method should be developed to identify environmental bottleneck. Current research work uses Bayesian Networks (BN) to identify environmental bottleneck. The contribution of the paper is to identify the environmental bottleneck for an Indian pig iron manufacturing organization. Results suggest that carbon monoxide (CO) emission from the blast furnace is the environmental bottleneck for the current pig iron manufacturing organization. Hence, proper precautions should be considered to control the CO emission from the blast furnace.

CMD

Limited main memory size is considered as one of the major bottlenecks in virtualization environments. Content-Based Page Sharing (CBPS) is an efficient memory deduplication technique to reduce server memory requirements, in which pages with same content are detected and shared into a single copy. As the widely used implementation of CBPS, Kernel Samepage Merging (KSM) maintains the whole memory pages into two global comparison trees (a stable tree and an unstable tree). To detect page sharing opportunities, each tracked page needs to be compared with pages already in these two large global trees. However since the vast majority of compared pages have different content with it, that will induce massive futility comparisons and thus heavy overhead. In this paper, we propose a lightweight page Classification-based Memory Deduplication approach named CMD to reduce futile page comparison overhead meanwhile to detect page sharing opportunities efficiently. The main innovation of CMD is that pages are grouped into different classifications based on page access characteristics. Pages with similar access characteristics are suggested to have higher possibility with same content, thus they are grouped into the same classification. In CMD, the large global comparison trees are divided into multiple small trees with dedicated local ones in each page classification. Page comparisons are performed just in the same classification, and pages from different classifications are never compared (since they probably result in futile comparisons). The experimental results show that CMD can efficiently reduce page comparisons (by about 68.5%) meanwhile detect nearly the same (by more than 98%) or even more page sharing opportunities.

Flexible patterns in energy savings: heterothermy in primates

AbstractHeterothermy is an energy‐saving strategy usually employed in response to environmental bottlenecks, which is common in almost all mammalian orders. Within the order primates, heterothermy has been physiologically confirmed only in the family Cheirogaleidae (Cheirogaleus, Microcebus, Allocebus, Mirza) of the Malagasy lemurs, and the southern lesser bushbaby (Galago moholi) of the family Galagonidae. These closely related species employ a spectrum of daily torpor, prolonged torpor and obligate hibernation under tropical, but nevertheless seasonal and energetically demanding conditions. There is a remarkable physiological flexibility in regard to their thermoregulatory adaptations not only between species of the same genera within one habitat, but also between populations of the same species, within populations and even within the same individual, permitting immediate responses in seasonal and unpredictable environments, and possibly aiding these species to master challenges of globally changing climatic conditions. Whereas heterothermy is a flexible, but regular seasonal response in the Cheirogaleidae, it is only used as a last emergency strategy in G. moholi. In the other primate species, there is either no or only anecdotal evidence of only minor reductions in metabolic rate, presumably rather reflecting pronounced circadian cycles in body temperature, or local heterothermy. Maybe because of their relatively high degree of sociality and larger body sizes, behavioural and ecological adaptations to seasonality are selected for in other primates.

Eco-friendly manufacturing strategies for simultaneous consideration between productivity and environmental performances: a case study on a printed circuit board manufacturing

Manufacturing firms are constantly seeking to improve productivity in various activities, such as throughput, on-time delivery, and customer service. However, recently, the Korean government has strongly enforced environmental regulations to reduce the risk of pollutant emissions that violate the climate change convention. As a result, most firms are now attempting to maximize their own productivity while satisfying the environmental regulations mandated by government policies. In this study, a new framework that combines simulation and the Taguchi technique is proposed for the green process design based on the production lines of manufacturing firms. The simulation model is designed for identifying the production bottleneck process in terms of productivity, which has an effect on all processes during the production process and on the environmental bottleneck process caused by violating the environmental regulations. In the simulation analysis, we obtain the productivity and environmental performance by adjusting the lower and upper bounds of the control variables. The Taguchi method with the grey relational analysis is also utilized to determine the best strategy to meet the optimal productivity within a range of satisfying the environmental regulation of pollutant emission concentration among the experimental sets. To validate our research framework, a case study of the PCB manufacturing process was conducted. The case study determined that the best way (A3B3C1) involved the operating strategy with the lowest conveyor speed in the scrubbing and DES process and the fastest conveyor speed in the oxide process, which can reduce approximately 28.38% and 28.81% of the emissions concentration of hydrogen chloride and dust, respectively, in comparison with the current operating strategy (baseline).

Pollutant in palm oil production process

Palm oil mill effluent (POME) is a by-product of the palm industry and it releases large amounts of greenhouse gases (GHGs). Water systems are also contaminated by POME if it is released into nonstandard ponds or rivers where it endangers the lives of fish and water fowl. In this paper, the environmental bottlenecks faced by palm oil production were investigated by analyzing the data collected from wet extraction palm oil mills (POMs) located in Malaysia. Strategies for reducing pollution and technologies for GHG reduction from the wet extraction POMs were also proposed. Average GHG emissions produced from processing 1 ton of crude palm oil (CPO) was 1100 kg CO2eq. This amount can be reduced to 200 kg CO2eq by capturing biogases. The amount of GHG emissions from open ponds could be decreased from 225 to 25 kg CO2eq/MT CPO by covering the ponds. Installation of biogas capturing system can decrease the average of chemical oxygen demand (COD) to about 17,100 mg/L and stabilizing ponds in the final step could decrease COD to 5220 mg/L. Using a biogas capturing system allows for the reduction of COD by 80% and simultaneously using a biogas capturing system and by stabilizing ponds can mitigate COD by 96%. Other ways to reduce the pollution caused by POME, including the installation of wet scrubber vessels and increasing the performance of biogas recovery and biogas upgrading systems, are studied in this paper.Implications: Around 0.87 m3 POME is produced per 1 ton palm fruit milled. POME consists of around 2% oil, 2–4% suspended solid, 94–96% water. In palm oil mills, more than 90% of GHGs were emitted from POME. From 1 ton crude palm oil, 1100 kg CO2eq GHGs are generated, which can be reduced to 200 kg CO2eq by installation of biogas capturing equipment.

Considerable environmental bottlenecks for species listed in the Habitats and Birds Directives in the Netherlands

Many habitats and species have their existence threatened, especially in densely populated areas such as Western Europe. To stop the decline of biodiversity, the Natura 2000 network is being set-up. The ultimate objective is to get all habitat types (of Annex I of the Habitats Directive) and species (of Annexes II, III and IV of the Habitats Directive and Annex I of the Birds Directive) in a favourable conservation status. In the Netherlands a national ecological network has been set up for this purpose which includes the designated Natura 2000 sites. The current amount of atmospheric nitrogen deposition, acidification and desiccation were compared with limit values per habitat type for nitrogen deposition load, soil pH and spring groundwater table respectively and subsequently presented together in one map. Fragmentation was tested for 80 species.For two-third of the examined natural surface the critical load for nitrogen deposition is exceeded, desiccation is present in over 90% of the area of groundwater dependent nature. Problems with acidification are less pronounced. Fragmentation is present causing regional problems for up to six species. When the four pressures are combined, about two third of the areas suffer from at least one pressure. Many areas suffer from a combination of nitrogen deposition and desiccation.We conclude that environmental and spatial conditions are insufficient to meet the biodiversity target set by the European Union for the Natura 2000 network, habitat types and species.

A Preliminary Analysis of Land Resource Constraints on Urban Expansion of Beijing Based on Land Supply and Demand

Land resources not only provide support for urban development, but play a feedback and restricting role in unregulated urban growth. Taking Beijing City as an example, this paper analyzes supply and demand relationships and upper limits for the growth of land resources during the process of urban development. By analyzing dominant factors and trends in the demand for land resources, this paper gives preliminary estimates on the minimum size of the land demand in Beijing in view of constructing a World City. According to the basic characteristics of supply and demand relationships for land, current land use in Beijing is confronting a grim situation of conflict between supply and demand. We also point out maximum growth and three types of constraints on land resources. Last, we propose solutions to resource and environmental bottlenecks, and urban disease amid urban development.

BMP Research on ANPSP Control in Middle Region of Zhejiang Province

Agricultural nonpoint source pollution (ANPSP) is an important source for water environment, with its contribution ratio increases year by year. ANPSP becomes the environmental bottleneck factor in restricting agriculture sustainable development and rural modernization. The study was focused on the causes and occurrence of ANPSP in the middle region of Zhejiang province, and introduced some successful governance effect of best management practices (BMP) in developed region. The application of control technologies under BMP guidance were compared and analyzed, among artificial wetland, front library, buffer zone and land-water interlace belt, water and soil conservation, agriculture ecological engineering management and so on. According to the characteristics of different BMP technologies and ANPSP in the middle region of Zhejiang, the regional BMP should be designed for solutions. This research made good sense to promote effective control of ANPSP in middle region of Zhejiang in engineering application.

The influence of canalisation on juvenile salmonid habitat

There have been few mechanistic studies linking local ecological characteristics of streams to morphological pressures. This paper reports the findings of an investigation of the impacts of canalisation on salmonid habitat. Habitat use by Atlantic salmon and brown trout, fry and parr was assessed using Generalised Additive Models (GAMs) based on seasonal electrofishing survey data and output from 2-dimensional hydraulic models. By overlaying the habitat models onto the physical characteristics of the canalised reach, it was possible to determine where and when environmental bottlenecks occurred, and for which species and life stages. The canalised reach was characterised by relatively uniform sedimentary and hydraulic characteristics compared to other reaches. Although it was generally well suited to fry, the lack of coarser substrate and low velocity areas during winter made the canalised reach unfavourable for salmon and trout parr respectively. Given the insights provided by this study, we suggest the approach of combining physical channel characterisation with locally derived seasonal habitat models is well suited to future research focussed on assessing the ecological impact of morphological pressures.

The Study on Adaptive Design of Mountainous Old Campus Space Renovation - A Case Study on Chongqing University

Since the beginning of the 21st century, large-scale extensive expansion of suburb new campus construction has been a kind of abnormal phenomenon in the process of the rapid development of modern higher education. Along with the implementation of land macro-control policies, the old campus space renovation will be the significant direction in campus construction. The complex natural environment and more limited land resources are key factors in mountainous old campus space renovation. Taking Chongqing University as the example, the paper analyzes the relationship of symbiosis, coexistence, mutual prosperity between mankind and the elements in particular mountainous environment. Starting from the whole and harmony, we try to discuss the adaption of mountainous old campus to natural environment, built environment and cultural environment by adopting adaptive methods, so as to maintain its regional character, and guide mountainous campus construction to overcome the environmental bottle-neck. Based on own advantages, the mountainous old campus will develop to be a high efficient, compact and open ecological adaptive campus by continuous effective renovation.

Some Environmental Bottlenecks to Coal Utilization for Power Generation in Nigeria and Their Corrective Actions

Given the magnitude of the Nigerian coal reserves, the industrialization role coal played in the pre-petroleum era, and the resources conservation consideration dictating that some local resources be used so as to conserve and extend the depletion years of oil and gas, Enugu coal offers a promising alternative solution to Nigeria's power generation. Unfortunately, emissions from coal combination chiefly impose some environmental bottlenecks to coal utilization for power generation. This article reviews the roles of nitrogen oxides and sulfur dioxide emissions as acid gas, as well as the activities of carbon dioxide as both acid gas and greenhouse gas. The article also examines the impact of environmental concern and legislation on the control of combustion emissions. To ensure compliance with legislation and environmental concerns, this paper proposed fluidized bed combustion as the remedy for combustion emissions control. In this regard, two categories of FBC, namely bubbling fluidized bed and circulating fluidized bed combustors, were reviewed in conjunction with their modes of operation in the forms of: • atmospheric fluidized bed combustion and • pressurized fluidized bed combustion. The review showed that the bubbling fluidized beds are more viable for retrofit applications, while the circulating fluidized bed units are more applicable in new plants. Owing to the non inclusion of carbon dioxide parameters in the operating credentials of bubbling fluidized bed and circulating fluidized bed units, some of the known technologies for carbon dioxide scrubbing/removal were suggested as this article will show.

ADAPTATION RATES OF LYTIC VIRUSES DEPEND CRITICALLY ON WHETHER HOST CELLS SURVIVE THE BOTTLENECK

We use a branching process approach to estimate the substitution rate, the rate at which beneficial mutations occur and fix, in populations of lytic viruses whose growth is controlled by periodic population bottlenecks. Our model predicts that substitution rates, and by extension adaptation rates, are profoundly affected by the survival of infected host cells at the bottleneck. In particular, we find that direct transfer (or environmental) bottlenecks, in which some fraction of both free virus and host cells are preserved, are associated with relatively slow adaptation rates for the virus. In contrast, viruses can adapt much more quickly when only free virus is transferred to a new host population, as is typical in an epidemiological setting. Finally, when premature lysis of the host-cell population is induced at the bottleneck, we predict that adaptation rates for the virus will, in general, be faster still. These results hold irrespective of the life-history trait affected by the beneficial mutation. The substitution rates in the presence of environmental bottlenecks are predicted to be as much as an order of magnitude lower than in the other two cases.

The Emerging Property Development Pattern in Greece and its Impact on Spatial Development

Real estate market and property development dynamics in Greece are undergoing some critical changes, exhibiting a new condition which governs the relationship between capital and landed property in the current phase of capitalist development. A key feature of these changes is the formation of a property development pattern which clearly marks a break with the dominant conventional one (structured upon the small-scale owner occupation and the absence of big capital). The potential impact of this new pattern is difficult to assess as yet. Each pattern – the conventional and the newly emerging one – are affecting spatial development differently (in positive or negative terms). As things stand, however, there does appear to be a contradictory coexistence between the two; this is aggravated by inability of state and planning policy, in particular, to actively intervene in the changing spatial economy and society. Thus, there seems to be an inherent risk in the near future of having to cope only with the negative features produced by the two patterns which in a worstcase scenario could result in: continuous urban sprawl, non-planning and environmental degradation, increases in land values, overborrowing, reduction of public space and other socio-economic, functional and environmental bottlenecks.

Scale-dependent associations between native freshwater mussels and invasive Corbicula

In North America there is conflicting evidence concerning whether the invasive Asian clam, Corbicula fluminea, and native mussels (Unionidae), can successfully co-exist. One reason underlying disparate conclusions may be the different spatial scales at which data have been collected. We compared the distribution and abundance of native unionid mussels and Corbicula at two spatial scales, stream reaches and 0.25 m 2 patches, within one biogeographic region, the Ouachita Highlands, of the south central U.S. We found that Corbicula abundance was negatively related to native mussel abundance at small spatial scales. While Corbicula densities varied widely in patches without native mussels, and in patches where mussels occurred at low abundance, Corbicula density was never high in patches where mussels were dense. We hypothesize that the likelihood of successful Corbicula invasion decreases with increasing abundance of adult native mussels. Several mechanisms may potentially drive this pattern including lack of space for Corbicula to colonize, physical displacement by actively burrowing mussels, and locally reduced food resources in patches where native mussels are feeding. In addition, Corbicula may be unable to withstand environmental bottlenecks as readily as unionids. When patch-scale density and biomass information were pooled to represent entire stream reaches, the negative relationship between native mussels and Corbicula was no longer as apparent, and there was not a significant relationship between native mussels and Corbicula. These results point to the importance of appropriate sample scale in examining potential associations between species.

Material suppliers and industrial metabolism

Life Cycle Assessment (LCA) is not sufficiently tailored to the analysis of strategic environmental problems of material suppliers. Sustainable development calls for a reduction by a factor of 10 to 20 in the material intensity of the economy, a situation which leads to dramatic shifts in markets for raw materials. Furthermore, a material supplier might have major improvement options in the material's numerous downstream uses. LCAs, however, can't cover these two aspects. An adapted form of Substance Flow Analysis (SFA) may be an answer. This approach defines a system in relation to the flow of a specific material through society. All environmental interventions related to the material are inventoried. An emission evaluation indicates the dominant environmental bottlenecks, given the current market volume of each application of the material. This helps to identify improvement options and strategic choices in market portfolios. Scenario analysis on potential measures can further indicate changes of material flows - and thus markets - in the system. The approach is illustrated with a case study on chlorine.

Crinoid biofacies in Upper Carboniferous cyclothems, midcontinent North America: faunal tracking and the role of regional processes in biofacies recurrence

Abstract Coordinated stasis is a pattern of long-term, multispecies evolutionary and ecological stability bounded by rapid turnover events. One class of models proposed to explain the paleoecological pattern of biofacies stability, typified by ecological locking, states that biotas within habitats become integrated into ecological units that, through population and community-level processes, rebound and persist through short-term disturbances. This high frequency community resilience allows the units to persist through geologic time, tracking their preferred habitats during transgressions and regressions. Because species are tightly woven into the fabric of the ecosystem, there is little opportunity for speciation; this also buffers them against extinction. This ecological locking by ecosystem homeostatic processes produces long intervals of regionally stable biofacies in the fossil record. In these models, the primary structuring mechanisms are at the local, community level, controlled by species autecology, species interactions, and local disturbance regime. An opposing class of models states that species are fundamentally independent and that species interactions are not strong nor spatio-temporally persistent enough to forge communities into integrated units with long-term persistence. Community recurrence would be expected as long as the various habitat types recur in time and space, species autecologies remain stable, the pool of available species remains intact and the recruitment of species into local habitats is not interrupted. The focus of these models is dominantly at the regional level, controlled by biogeographic history and dispersal among, as well as within, communities. The results of this study of crinoids from the Upper Carboniferous Lansing Group of midcontinent North America show that they are distributed among five recurrent paleocommunity types, or biofacies, which are generally arrayed along an onshore-offshore gradient. Two of these biofacies are restricted to the offshore, dysaerobic horizons of the most extensive cyclothem in the group. The other three biofacies recur consistently among the cycles. However, this repeated pattern includes a regionally distributed offshore biofacies, unique to late transgressive deposits, that is not found in analogous regressive deposits. While the distribution of the two shoreward biofacies is consistent with faunal tracking, the recurrence of a biofacies unique to late transgressive horizons is not consistent with an integrated paleocommunity that tracks shifting habitats through transgression and regression. These results favor the alternative models, namely that biofacies develop in place via dispersal from a persistent species pool in response to prevailing environmental conditions. The recurrence of apparently ephemeral biofacies through time underscores the importance of regional processes in controlling local paleocommunity composition. The establishment of refuges, or “source” populations, during environmental bottlenecks (i.e. lowstands) is critical to maintaining the regional species pool through time for continued recruitment into local “sink” paleocommunities during more amenable times (i.e. highstands). Metapopulation dynamics among habitats are equally important in maintaining species within a region through time. Conflicting observations of stochastic (individualistic) and deterministic (integrated) behaviors of the same ecological systems probably result from differences in the scales of analyses and therefore the processes being studied.