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611.
Cleaner Production is an organized approach to minimize industrial waste and emissions by increasing the efficiency of the use of materials and energy. It is propagated especially by UNIDO and UNEP as an approach to identify preventive measures to cut on waste and emissions from industrial activities. Case studies conducted by the authors in the last 10 years demonstrate, that in a number of cases water consumption per production unit of industries from the surface treatment sector, from food processing and from the textile industry could be reduced by 30–90%, auxiliary materials consumption could be reduced by 30–50%, and energy consumption of processes could be reduced by 15–25%. All these measures were actually economically beneficial for the companies, most of these measures paid back in less than one year [1].The standard approach to apply Cleaner Production originates from chemical engineering. It follows the steps of: Drawing a process flow sheet – collecting input/output data – doing mass and energy balances – identify sources for waste and emissions – set priorities – identify options. In the process of option generation one generally relies on expert knowledge or on checklists which are available in different manuals or in the best available technology reference (BREF) notes.1 This approach is strong with teams with an (chemical) engineering background.The authors wanted to develop a generic approach for option identification especially for teams with little formal engineering background or teams which have to go beyond their professional experience by using elements of the so-called TRIZ method (Theory of inventive problem solving, or originally Russian: “
” (Teoria reschenija isobretatjelskich sadatsch)). TRIZ offers very strong tools for developing process improvement options on a generic level without specific technological knowledge about the process which shall be improved. The authors have found from their research that especially the concept of the Ideal Final Result, and the Laws of Evolution form a conceptual framework which can aid effectively in the identification of improvement options in a systematic way.  相似文献   
612.
The use of species distribution models (SDMs) to predict potential distributions of species is steadily increasing. A necessary assumption when projecting models throughout space or time is that climatic niches are conservative, but recent findings of niche shifts during biological invasion of particular plant and animal species have indicated that this assumption is not categorically valid. One reason for observed shifts may relate to variable selection for modelling. In this study, we assess differences in climatic niches in the native and invasive ranges of the Greenhouse frog (Eleutherodactylus planirostris). We analyze which variables are more ‘conserved’ in comparison to more ‘relaxed’ variables (i.e. subject to niche shift) and how they influence transferability of SDMs developed with Maxent on the basis of ten bioclimatic layers best describing the climatic requirements of the target species. We focus on degrees of niche similarity and conservatism using Schoener's index and Hellinger distance. Significance of results are tested with null models. Results indicate that the degrees of niche similarity and conservatism vary greatly among the predictive variables. Some shifts can be attributed to active habitat selection, whereas others apparently reflect variation in the availability of climate conditions or biotic interactions between the frogs' native and invasive ranges. Patterns suggesting active habitat selection also vary among variables. Our findings evoke considerable implications on the transferability of SDMs over space and time, which is strongly affected by the choice and number of predictors. The incorporation of ‘relaxed’ predictors not or only indirectly correlated with biologically meaningful predictors may lead to erroneous predictions when projecting SDMs. We recommend thorough assessments of invasive species' ecology for the identification biologically meaningful predictors facilitating transferability.  相似文献   
613.
Testosterone mediates male reproductive trade-offs in vertebrates including mammals. In male edible dormice (Glis glis), reproductivity linked to high levels of testosterone reduces their ability to express torpor, which may be expected to dramatically increase thermoregulatory costs. Aims of this study were therefore to analyse behavioural and physiological consequences of reproductive activity in male edible dormice under ecologically and evolutionary relevant conditions in the field. As we frequently encountered sleeping groups in the field, we hypothesized that social thermoregulation should be an important measure to reduce energy expenditure especially in sexually active male edible dormice. Our results revealed that the occurrence of sleeping groups was negatively influenced by male body mass but not by reproductive status or ambient temperature. In reproductive as in non-reproductive males, the number of individuals huddling together was negatively influenced by their body mass. Thus in general males with a high body mass were sitting in smaller groups than males with a low body mass. However, in reproductive males group size was further negatively affected by ambient temperature and positively by testes size. Thus breeders formed larger sleeping groups at lower ambient temperatures and males with larger testes were found in larger groups than males with smaller testes. Measurements of oxygen consumption demonstrated that grouping behaviour represents an efficient strategy to reduce energy expenditure in edible dormice as it reduced energy requirements by almost 40%. In summary, results of this field study showcase how sexually active male edible dormice may, through behavioural adjustment, counterbalance high thermoregulatory costs associated with reproductive activity.  相似文献   
614.
Low-temperature alteration reactions on uranium phases may lead to the mobilization of uranium and thereby poses a potential threat to humans living close to uranium-contaminated sites. In this study, the surface alteration of uraninite (UO2) and uranium tetrachloride (UCl4) in air atmosphere was studied by confocal laser scanning microscopy (CLSM) and laser-induced fluorescence spectroscopy using an excitation wavelength of 408 nm. It was found that within minutes the oxidation state on the surface of the uraninite and the uranium tetrachloride changed. During the surface alteration process U(IV) atoms on the uraninite and uranium tetrachloride surface became stepwise oxidized by a one-electron step at first to U(V) and then further to U(VI). These observed changes in the oxidation states of the uraninite surface were microscopically visualized and spectroscopically identified on the basis of their fluorescence emission signal. A fluorescence signal in the wavelength range of 415–475 nm was indicative for metastable uranium(V), and a fluorescence signal in the range of 480–560 nm was identified as uranium(VI). In addition, the oxidation process of tetravalent uranium in aqueous solution at pH 0.3 was visualized by CLSM and U(V) was fluorescence spectroscopically identified. The combination of microscopy and fluorescence spectroscopy provided a very convincing visualization of the brief presence of U(V) as a metastable reaction intermediate and of the simultaneous coexistence of the three states U(IV), U(V), and U(VI). These results have a significant importance for fundamental uranium redox chemistry and should contribute to a better understanding of the geochemical behavior of uranium in nature. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   
615.
Flood disasters have had a devastating effect worldwide over the past century, both in terms of human suffering and material losses. The study of these events and development of more effective adaptation and mitigation policies has become a priority, both in Europe and other parts of the globe. This paper detects and presents the spatial distribution of river flood risks in Europe. The methodology we developed involves an assessment of three key risk components: exposure, vulnerability and hazard. A topography-based flood hazard map of Europe, identifying low-lying areas adjacent to rivers, is presented and used to identify risk, together with land-use data and damage-stage relationship for different land uses. The study covers river flood risk for the entire European continent. This methodology can be used to determine the level of future risk, using the estimations on Hazard, Exposure and Vulnerability from specific climate and economic development models. Annual average flood damage is estimated for European regions, in absolute monetary terms and in % of regional Gross Domestic Product (GDP). The results highlight regions where the threat to the economy from river flood hazard is of major concern.  相似文献   
616.
617.
The stridulation of the giant pill-millipede genus Sphaerotherium from South Africa, one of only three groups of millipedes that produce sounds, was studied. One hundred one stridulation series of a total of nine different species (Sphaerotherium dorsaloide, Sphaerotherium hanstroemi, Sphaerotherium mahaium, Sphaerotherium similare, Sphaerotherium punctulatum, Sphaerotherium convexitarsum, Sphaerotherium dorsale, Sphaerotherium rotundatum, and Sphaerotherium perbrincki) were analyzed. Stridulation sounds are produced only with a special field of ribs on the posterior surface of the posterior telopod, which is actively moved over a field of sclerotized nubs on the inner margin of the anal shield. The Sphaerotherium male usually stridulates only when in contact with a female to initiate mating. This seems to prevent the female from volvating into a ball or stimulate the female to uncoil when already rolled in. The sound analyzes revealed a broad frequency spectrum in all stridulation sounds produced, without obvious differences in frequency distribution among species. However, the temporal pattern of the stridulation varies greatly between species and seems to be species-specific, arguing for a species recognition function of the stridulation during courtship behavior. A single species (S. punctulatum) was found to stridulate during mating while three species also show postcopulatory stridulation. Apparently, pill-millipedes are not capable of acoustic perception, as no hearing organs are known, indicating that the communication is mainly based on perception of temporal vibration patterns, and not of the acoustic signal itself. The need to overcome the rolling-in reflex of the female is developed as a hypothesis why stridulation exists only in millipedes able to coil into a ball, and apparently evolved four times independently in the superorder Oniscomorpha.  相似文献   
618.
This study combines biology and mathematics, showing that a relatively simple question from molecular biology can lead to complicated mathematics. The question is how to calculate the number of theoretically possible aliphatic amino acids as a function of the number of carbon atoms in the side chain. The presented calculation is based on earlier results from theoretical chemistry concerning alkyl compounds. Mathematical properties of this number series are highlighted. We discuss which of the theoretically possible structures really occur in living organisms, such as leucine and isoleucine with a chain length of four. This is done both for a strict definition of aliphatic amino acids only involving carbon and hydrogen atoms in their side chain and for a less strict definition allowing sulphur, nitrogen and oxygen atoms. While the main focus is on proteinogenic amino acids, we also give several examples of non-proteinogenic aliphatic amino acids, playing a role, for instance, in signalling. The results are in agreement with a general phenomenon found in biology: Usually, only a small number of molecules are chosen as building blocks to assemble an inconceivable number of different macromolecules as proteins. Thus, natural biological complexity arises from the multifarious combination of building blocks.  相似文献   
619.
Supply chain and logistics issues of bio-energy production   总被引:1,自引:0,他引:1  
  相似文献   
620.
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