Proactive behavior (self‐initiated and future‐oriented actions to bring about change) has largely positive consequences for organizationally oriented outcomes such as job performance. Yet the outcomes of proactivity from a well‐being perspective have not been clearly considered. Drawing on self‐determination theory and the stressor‐detachment model, we propose two distinct paths by which proactivity affects individuals' daily well‐being. The first path is an energy‐generating pathway in which daily proactive behavior enhances end‐of‐work‐day vitality via perceived competence. The second is a strain pathway in which daily proactive behavior generates anxiety at work, which undermines the process of detachment from work. We argue that these pathways are shaped by the extent to which supervisors are prone to blaming employees for their mistakes (punitive supervision). We tested this model using a sample of 94 employees who completed surveys three times a day for between 5 and 7 days. Our multilevel analyses provide support for the proposed dual‐pathway model and suggest differential well‐being outcomes of daily proactive work behavior. Overall, when an individual behaves proactively at work, they are more likely to experience higher levels of daily perceived competence and vitality. However, these positive effects can exist in parallel with daily negative effects on end‐of‐workday anxiety, and hence bedtime detachment, but only when the supervisor is perceived to be punitive about mistakes. 相似文献
The management of solid waste is changing. The traditional approach based on landfilling of mixed refuses is shifting toward
a system based on the at-source sorting of waste into specific fractions. The biological treatment of the organic fraction
is considered to be an appropriate form of disposal not only for the “traditional≓ feedstock such as food scraps and vegetable
and garden waste, but also for biodegradable packaging, when not recyclable in other ways. Any change from a complex system
to another is difficult since many factors are to be organized and optimized. Industry must develop and manufacture compostable
products, municipalities must build composting plants and organize source-separated collection, and regulatory bodies must
define widely acceptable criteria of compostability. In Europe, the European Union has assigned the last task to the CEN,
to provide common criteria and avoid hindrance to commercial exchanges. In Italy the UNI, the national standardization organization,
has produced a working document to contribute to the discussion on the European level. In this paper the UNI scheme is described.
A condensed version of this paper was presented by one of the authors (F.D.I.) at the 5th annual meeting of the BEDP Society,
held in Nashville, September 22–26, 1996, during a session covering International Standards for Biodegradation Testing. 相似文献
Two typical waters from thermal springs of Montecatini Terme-used as therapeutical beverages-exhibit a small complexing capacity towards Cu2+. By differential pulse anodic stripping voltammetry the following values were found: 0.46 μmol 1-1 and 0.10 μmol 1-1, respectively for Regina and Rinfresco waters.
Owing to the presence of a small amount of complexed copper in the original samples, the complexing capacity has to be regarded as residual capacity. In bottled waters from the same springs no complexing capacity was detected. Values of formation constants for copper complexes are given. No residual complexing capacity for Cu2+ was displayed for Tamerici and Tettuccio thermal waters. 相似文献
This paper reports the results of a study using lichens as biomonitors to investigate the environmental distribution of uranium and other trace elements at selected Kosovo sites. The results suggested that the use of depleted uranium (DU) ammunitions in Kosovo did not cause a diffuse environmental contamination in such a way to have caused a detectable U enrichment in lichens. Also isotopic (235)U/(238)U measurements did not indicate the presence of DU particles in lichens. The present results also provided no indication of intense environmental contamination by the other trace elements analyzed, with the exception of Kosovska Mitrovica, where a diffuse environmental contamination by several heavy elements such as Pb, Zn, As and Cd was found. 相似文献
Hexactinellids (glass sponges) are an understudied class with syncytial organization and poor procariotic associations, thought to lack defensive secondary metabolites. Poriferans, though, are outstanding sources of bioactive compounds; nonetheless, a growing suspicion suggests that many of these chemicals could be symbiont-derived. In Polar latitudes, sponges are readily invaded by diatoms, which could provide natural products. Hexactinellids are typical of deep waters; but in Antarctica, they dominate the upper shelf providing shelter and food supply to many opportunistic mesograzers and macroinvertebrates, which exert strong ecological pressures on them. Aiming to examine the incidence of defensive activities of hexactinellids against consumption, feeding experiments were conducted using their lipophilic fractions. Antarctic hexactinellid and demosponge extracts were tested against the asteroid Odontaster validus and the amphipod Cheirimedon femoratus as putative sympatric, omnivorous consumers. Hexactinellids yielded greater unpalatable activities towards the amphipod, while no apparent allocation of lipophilic defenses was noted. After chemical analyses on the lipophilic fractions from these Antarctic glass sponges, quite similar profiles were revealed, and no peculiar secondary metabolites, comparable to those characterizing other poriferans, were found. Instead, the lipidic compounds 5α(H)-cholestan-3-one and two glycoceramides were isolated for their particular outspread presence in our samples. The isolated compounds were further assessed in asteroid feeding assays, and their occurrence was evaluated for chemotaxonomical purposes in all the Antarctic samples as well as in glass sponges from other latitudes by NMR and MS. Characteristic sphingolipids are proposed as chemical markers in Hexactinellida, with possible contributions to the classification of this unsettled class. 相似文献
Effective landfill management and operation require an accurate evaluation of the occurrence and extent of odour emission events, which are among the main causes of resident complaints and concerns, in particular in densely urbanised areas. This paper proposes a fuzzy optimal protection system (FOPS) based on fuzzy logic to manage odour production from a municipal solid waste (MSW) landfill. The case study is a MSW landfill in an old quarry site located 6 km north-west of Naples city centre (Italy). The aim is to reduce the odour nuisance in the area surrounding the landfill where there are several sensitive receptors. FOPS is based on logical relationships between local atmospheric dynamics, number and intensity of odour pollution events detected by certain fixed receptors and odour emission rate via an optimal fuzzy approach. Such system allows to start, in real time, established mitigation actions required to further reduce the odorous emissions from the landfill itself (e.g. spraying of perfumed substances and activation of extraction wells), especially when weather conditions might not be favourable and cause by causing a higher odour perception. The fuzzy system was coupled with the air pollutant transport software CALPUFF to simulate the odour dispersion in the considered area taking into account both different odour emission rates and local weather conditions. FOPS results show that this approach can be very useful as, by measuring the odour concentrations, a significant reduction of the odour exceedances over the thresholds fixed, to minimise the olfactory harassment, was observed in the whole area studied.
Environmental Science and Pollution Research - The European Interreg Italy–France 2014–2020 Maritime Project SPlasH! (Stop to Plastics in H2O!) focused on the study of microplastics... 相似文献
The present work deals with a multi-objective optimisation approach to incorporate up-to-date financial models in the multidisciplinary conceptual design of a commercial aircraft. Design optimisations based on financial objective functions are compared to standard performance-based optimal solutions. The main novelty is in the extension of the financial models to the long-term investments of a wider group of stakeholders. The rationale underlying this research stems from two considerations: (i) the environmentally sustainable development of the air transportation system in the next 20 years is subordinate to breakthrough technologies, since the consolidated ones have reached their saturation point; (ii) the economic impacts of highly innovative concepts on the stakeholders chain is still uncertain. The problem is addressed at the conceptual design level and the analysis is performed within a comprehensive multidisciplinary framework, adopting all the technical constraints required in aeronautical design. The Pareto fronts obtained using performance and financial merit factors, reveal that the proposed financial model yields highly efficient, technically sound concepts. The design space point corresponding to the negative cash flows minimum turned out to be very close to the one corresponding to minimum acoustic emissions, confirming that the financial model drives the optimiser towards environment-friendly designs. 相似文献
ABSTRACT: In this paper a numerical model for flood propagation in urban areas is proposed. It has been applied to evaluate flooding hydraulic characteristics in terms of potential flood elevations, depths, and inundated areas. Furthermore, the algorithm efficiency and the consequent reduced computation time allow the use of the hydraulic model as a part of a more complex system for civil protection actions, planning, and management. During flood events, the transportation network plays a main role both in rescuing people when they are more vulnerable and in moving people and materials from and toward affected areas. The reduced efficiency of this transportation network is evaluated based on a least‐flood‐risk path‐finding algorithm. The results of a case study concerning the northern part of the city of Rome, show that the numerical model for unsteady flow in open channel networks achieves the proposed aims. It has proven to be able to describe the flood hydraulic characteristics and to be suitable for real‐time flood emergency management in urban areas. 相似文献