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591.
This paper reports the findings of a two‐wave longitudinal study investigating relationships between organizational and individual career management activities and organizational commitment in the early years of graduate careers. Several hypotheses are tested and receive mixed support. High organizational commitment predicts the practice of career management activities by graduates to further their career within the organization while low commitment is closely associated with behaviour aimed at furthering the career outside the organization. Graduates who manage their own careers also receive more career management help from their employer. This suggests that there may be the potential for employers to create a ‘virtuous circle’ of career management in which individual and organizational activities complement each other. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
592.
Previous studies relating forest presence to stream acidity and aluminium concentration were based on small numbers of catchments, often precluding the elimination of confounding influences on stream chemistry, such as geology or soil type. Spatial patterns in aluminium and pH data from 113 Welsh catchments of contrasting land use were therefore analysed in three different ranges of acid sensitivity (< 10, 10-15, 15-25 mg CaCO(3) litre(-1) total hardness). In each range, pH declined and aluminium increased significantly with increasing percentage forest cover. There was no evidence that the relationships reflected a spurious effect of forest location. Where aluminium concentrations were elevated under forest in a sub-set of 13 streams, aluminium was present predominantly in the labile form, most toxic to fish. Regressions of pH and aluminium on percentage forest cover provide a useful method of assessing the amount of forest in Welsh catchments which might give rise to given chemical conditions (e.g. pH <6, Al > 80 microg litre(-1)), though some difficulties are likely in accurately specifying the conditions desirable for fish or other biota. 相似文献
593.
594.
James T. Brown Jr. 《Environment international》1981,6(1-6)
An experimental study has been undertaken at the Colorado School of Mines to evaluate the feasibility of using condensational enlargement to enhance the collection efficiency of existing dust control technologies for sub-micron particulates. Although the study was begun to consider the problem of respirable dust control in the underground coal mine environment, this enhancement technique shows promise for a more general class of applications. In the experiments to be reported on, particulates are injected into a continuous flow thermal diffusion chamber and subjected to varying environmental conditions; saturation ratio (rel. humidity), temperature, and residence time were the parameters. The results show that condensation on a dust nucleus (≈0.1 micron) can bring it to a size of several microns in a sufficiently short period of time as to indicate engineering applicability of the concept. 相似文献
595.
Ivan Kuneš Martin Baláš Tereza Koňasová Ondřej Špulák Vratislav Balcar Kateřina Bednářová Millerová Dušan Kacálek Michal Jakl Daniel Zahradník Jan Vítámvás Jaroslava Št́astná Jana Jaklová Dytrtová 《Environmental management》2014,54(6):1421-1433
The article summarizes outcomes of a biomass study conducted in a young speckled alder plantation on a cold mountain site. At this location, the previously existing old forest was clear felled because of damage from air pollution, and present-day surface humus is in need of restoration. The intention of this study was to quantify the biomass and nutrients accumulated by alders and their components and assess whether the initial fertilization resulted in increased biomass production and nutrient accumulation in the biomass. Besides the control, two fertilized treatments were installed. In the surface treatment (SUT), the amendment was applied as a base dressing in small circles around trees. In the planting-hole treatment (PHT), the amendment was incorporated into soil inside the planting holes. Five growth seasons after planting and fertilization, six alders from each treatment were harvested including roots. Their biomass was quantified and analyzed for macroelements. The greatest pool of dry mass (DM) was branches in the control and stem wood in the fertilized treatments. The greatest pools of macroelements were leaves and branches. The most pronounced effects of fertilization were recorded in the DM and consequently in the absolute quantities of nutrients. The DM of an average tree in the control, SUT, and PHT was 85, 226, and 231 g, respectively. The absolute contents of nutrients per tree in the fertilized treatments showed the following increases, as compared with the control: (N) 2.5–2.6 times; (P) 1.6–2.4 times; (K) 1.8–2.1 times; and (Mg) 1.8–2.0 times, respectively. Speckled alder responded positively to fertilization. 相似文献
596.
Peanut hull pellets as a single use sorbent for the capture of Cu(II) from wastewater 总被引:1,自引:0,他引:1
This paper investigates the ability of peanut hulls and peanut hull pellets to adsorb copper from dilute aqueous metal ion solutions in batch and fixed bed systems. The kinetics of copper uptake onto the media have been investigated in batch systems and the influence of pH and particle size on the rate and extent of copper capture determined. The Langmuir and Freundlich isotherm theories were determined; the Langmuir model was found to best represent the equilibrium isotherm data. In normalized kinetic tests at least 75% of copper removal occurred within the first 20 min; 92% removal was effected within the first 50 min. The rate of uptake was optimum within the pH range 5-7.5, and media capacities remained relatively constant at a pH above 4.0. Bench-scale column studies were performed using peanut hull pellets. The overall capacity of pelletized peanut hulls was higher than for unmodified peanut hulls. Due to their demonstrated ability for Cu(II) uptake and favorable structural characteristics, pelletized peanut hulls could gain use as a low-cost, once-through biomass filter medium for copper-bearing waste streams. 相似文献
597.
Casey L. Brown Sarah E. Reed Matthew S. Dietz Kurt M. Fristrup 《Environmental management》2013,52(5):1262-1270
Noise emanating from human activity has become a common addition to natural soundscapes and has the potential to harm wildlife and erode human enjoyment of nature. In particular, motor vehicles traveling along roads and trails produce high levels of both chronic and intermittent noise, eliciting varied responses from a wide range of animal species. Anthropogenic noise is especially conspicuous in natural areas where ambient background sound levels are low. In this article, we present an acoustic method to detect and analyze motor vehicle noise. Our approach uses inexpensive consumer products to record sound, sound analysis software to automatically detect sound events within continuous recordings and measure their acoustic properties, and statistical classification methods to categorize sound events. We describe an application of this approach to detect motor vehicle noise on paved, gravel, and natural-surface roads, and off-road vehicle trails in 36 sites distributed throughout a national forest in the Sierra Nevada, CA, USA. These low-cost, unobtrusive methods can be used by scientists and managers to detect anthropogenic noise events for many potential applications, including ecological research, transportation and recreation planning, and natural resource management. 相似文献
598.
Andjelka Kelic Zachary A. Collier Christopher Brown Walter E. Beyeler Alexander V. Outkin Vanessa N. Vargas Mark A. Ehlen Christopher Judson Ali Zaidi Billy Leung Igor Linkov 《The Environmentalist》2013,33(4):544-560
Increased reliance on the Internet for critical infrastructure and the global nature of supply chains provides an opportunity for adversaries to leverage dependencies and gain access to vital infrastructure. Traditional approaches to assessing risk in the cyber domain, including estimation of impacts, fall short due to uncertainty in how interconnected systems react to cyber attack. This paper describes a method to represent the pathways of disruption propagation, evaluate the macroeconomic impact of cyber threats and aid in selecting among various cybersecurity policies. Based on state of the art agent-based modeling, multicriteria decision analysis, and macroeconomic modeling tools, this framework provides dynamic macroeconomic, demographic and fiscal insights regarding shocks caused by cyber attacks to the regional economy over time. The interlinkage of these models will provide a robust and adaptive system that allows policy makers to evaluate complex issues such as cybersecurity threats and their impacts on the geopolitical, social, environmental, and macroeconomic landscape. 相似文献
599.
600.
Kate Burningham 《Local Environment》2013,18(1):55-67
During the 1990s the social scientific literature on local opposition to proposed developments has moved from a focus on individual motives to a concern with the social causes and significance of such protest. However, the language of NIMBYism is still widely used by researchers. Drawing on data from a case study of local responses to a proposed new road the central role that the language of NIMBY plays within siting disputes is illustrated, and it is concluded that academics interested in understanding the dynamics and process of local development disputes might usefully study participants' use of NIMBY, but should distance themselves from the activity of attributing NIMBYism to certain parties. In addition those concerned with managing, mediating or resolving local disputes should also steer clear of the language of NIMBY and engage with the diversity and complexity of local concerns and interests. 相似文献