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51.
We utilize social learning theory to test the role‐modeling effect of supervisor expediency (i.e., a supervisor's use of unethical practices to expedite work for self‐serving purposes). In particular, we examine the relationship between supervisor expediency and employee expediency, as moderated by leader–member exchange (LMX) and mediated by employee unethical tolerance. We predict that employees are more likely to model their supervisors' expedient behaviors when their relationship is characterized by high‐LMX (a high‐quality exchange relationship that is rich in socioemotional support). Furthermore, we argue that supervisor expediency, especially when LMX is high, influences employees' attitudes of unethical tolerance, which then affects employees' expedient behaviors. Across 2 multisource field studies and a third time‐lagged field study, we found general support for our theoretical predictions. Theoretical and practical implications are discussed.  相似文献   
52.
Several treatment technologies are available for the treatment of palm oil mill wastes. Vermicomposting is widely recognized as efficient, eco-friendly methods for converting organic waste materials to valuable products. This study evaluates the effect of different vermicompost extracts obtained from palm oil mill effluent (POME) and palm-pressed fiber (PPF) mixtures on the germination, growth, relative toxicity, and photosynthetic pigments of mung beans (Vigna radiata) plant. POME contains valuable nutrients and can be used as a liquid fertilizer for fertigation. Mung bean seeds were sown in petri dishes irrigated with different dilutions of vermicomposted POME-PPF extracts, namely 50, 60, and 70% at varying dilutions. Results showed that at lower dilutions, the vermicompost extracts showed favorable effects on seed germination, seedling growth, and total chlorophyll content in mung bean seedlings, but at higher dilutions, they showed inhibitory effects. The carotenoid contents also decreased with increased dilutions of POME-PPF. This study recommends that the extracts could serve as a good source of fertilizer for the germination and growth enhancement of mung bean seedlings at the recommended dilutions.  相似文献   
53.
Photosynthetic acclimation under elevated carbon dioxide (CO2) and/or ozone (O3) has been the topic of discussion in many papers recently. We examined whether or not aspen plants grown under elevated CO2 and/or O3 will acclimate after 11 years of exposure at the Aspen Face site in Rhinelander, WI, USA. We studied diurnal patterns of instantaneous photosynthetic measurements as well as A/Ci measurements monthly during the 2004-2008 growing seasons. Our results suggest that the responses of two aspen clones differing in O3 sensitivity showed no evidence of photosynthetic and stomatal acclimation under either elevated CO2, O3 or CO2 + O3. Both clones 42E and 271 did not show photosynthetic nor stomatal acclimation under elevated CO2 and O3 after a decade of exposure. We found that the degree of increase or decrease in the photosynthesis and stomatal conductance varied significantly from day to day and from one season to another.  相似文献   
54.
CALPUFF is an atmospheric source-receptor model recommended by the U.S. Environmental Protection Agency for use on a case-by-case basis in complex terrain and wind conditions. The ability of the model to provide useful information for exposure assessments in areas with those topographical and meteorological conditions has received little attention. This is an important knowledge gap for use of CALPUFF outside of regulatory applications, such as exposure analyses conducted in support of risk assessments and health studies. We compared deposition of cadmium (Cd), lead (Pb), and zinc (Zn) calculated with CALPUFF as a result of emissions from a zinc smelter with corresponding concentrations of the metals measured in attic dust and soil samples obtained from the surrounding area. On a point-by-point analysis, predictions from CALPUFF explained 11% (lead) to 53% (zinc) of the variability in concentrations measured in attic dust. Levels of heavy metals in soil interpolated to 100 residential addresses from the distribution of concentrations measured in soil samples also agreed well with deposition predicted with CALPUFF: R2 of 0.46, 0.76, and 079 for Pb, Cd, and Zn, respectively. Community-average concentrations of Cd, Pb, and Zn measured in soil were significantly (p < 0.0001) and strongly correlated (R2 ranged from 0.77 to 0.98) with predicted deposition rates. These findings demonstrate that CALPUFF can provide reasonably accurate predictions of the patterns of long-term air pollutant deposition in the near-field associated with emissions from a discrete source in complex terrain. Because deposition estimates are calculated as a linear function of air concentrations, CALPUFF is expected to be reliable model for prediction of long-term average, near-field ambient air concentrations in complex terrain as well.  相似文献   
55.
We assessed confounding of associations between short-term effects of air pollution and health outcomes by influenza using Hong Kong mortality and hospitalization data for 1996–2002.Three measures of influenza were defined: (i) intensity: weekly proportion of positive influenza viruses, (ii) epidemic: weekly number of positive influenza viruses ≥4% of the annual number for ≥2 consecutive weeks, and (iii) predominance: an epidemic period with co-circulation of respiratory syncytial virus <2% of the annual positive isolates for ≥2 consecutive weeks. We examined effects of influenza on associations between nitrogen dioxide (NO2), sulfur dioxide (SO2), particulate matter with aerodynamic diameter ≤10 μm (PM10) and ozone (O3) and health outcomes including all natural causes mortality, cardiorespiratory mortality and hospitalization. Generalized additive Poisson regression model with natural cubic splines was fitted to control for time-varying covariates to estimate air pollution health effects. Confounding with influenza was assessed using an absolute difference of >0.1% between unadjusted and adjusted excess risks (ER%).Without adjustment, pollutants were associated with positive ER% for all health outcomes except asthma and stroke hospitalization with SO2 and stroke hospitalization with O3. Following adjustment, changes in ER% for all pollutants were <0.1% for all natural causes mortality, but >0.1% for mortality from stroke with NO2 and SO2, cardiac or heart disease with NO2, PM10 and O3, lower respiratory infections with NO2 and O3 and mortality from chronic obstructive pulmonary disease with all pollutants. Changes >0.1% were seen for acute respiratory disease hospitalization with NO2, SO2 and O3 and acute lower respiratory infections hospitalization with PM10. Generally, influenza does not confound the observed associations of air pollutants with all natural causes mortality and cardiovascular hospitalization, but for some pollutants and subgroups of cardiorespiratory mortality and respiratory hospitalization there was evidence to suggest confounding by influenza.  相似文献   
56.
Before potential damage to vegetation can be adequately forecast, even after an air pollution alert has been placed in effect, a clear understanding of the interactions of environment on plant sensitivity must be ascertained. This involves detailed study of single factors and then multiple factors using the phytotoxicants in question. Factors studied or suggested include light (quality, intensity, and duration), temperature, carbon dioxide concentration, humidity, wind, soil moisture, soil aeration, nutrient levels, and soil texture. This paper presents a review of the work relating plant injury to specific air pollutants as conditioned by several environmental conditions supported by research on the interactions of ozone with these environmental conditions.  相似文献   
57.
The best method of controlling varnish kettle emissions is by thermal incineration. Two new approaches have been developed; these utilize the integral-blower burner and the non-powered raw gas burner. Both of these new approaches offer significant advantages over conventional methods of incineration. Installation, operating, and maintenance costs are substantially reduced when either approach is utilized.

When compared to conventional methods, the new approaches achieve an increase of 100% in mixing velocity or turbulence. This results in a reduction of 20% in fuel consumption. Residence time is reduced by 29% via the non-powered raw gas burner approach. An average reduction of 65% is obtained in the length to diameter ratio. Choice of which approach depends upon several factors, primarily the type of fuel available and the minimum oxygen concentration in the fume stream.  相似文献   
58.
Verification of forecasts of COH levels at the Downtown Sampling Station using our objective forecast method developed in conjunction with the Allegheny County Bureau of Air Pollution Control gave excellent results. The next step was to expand the area of forecast coverage.

COH data taken from July 1968 through June 1969 from six sampling stations located roughly in a large concentric arc around the Downtown Station were studied. Three of the stations are located in river valleys near large industrial plants and the other three are located on higher terrain in suburban areas.

COH levels of Low, Moderate, High, and Very High (where Low = 0–0.9, Moderate = 1.0–1.9, High = 2.0–3.0, and Very High = >3.0) were used.

The total number of occurrences of High and Very High COHS at the Downtown Station was 10.7% of the total data sample. This was more than twice the frequency of any of the outlying stations.

An evaluation of the statistical frequencies indicate the Downtown Station can safely be used as a “control station” in forecasting Low or Moderate COH levels for the six surrounding stations. However, the occurrence of High or Very High COH levels at the six outlying stations do not occur with a high enough statistical consistency to be predicted by using the forecast value of the Downtown Station.

The valley stations exhibit the characteristics of separate sub air basins particularly during a period in which morning inversions occur for two or more consecutive days and the average daily wind speed does not exceed 4 m/sec.

The results show it is possible to forecast only Low or Moderate COH levels for each of the six outlying stations by using statistical correlations derived from the Downtown Station. Separate objective forecasts which relate the pollution buildup in each valley sub air basin must be used when High or Very High COHS are forecast at the Downtown Station.  相似文献   
59.
60.
With the development of ambient air quality standards (AAQS), the need arises to describe the characteristics of regional surface air-pollutant concentration frequency distributions. In the evaluation of land use plans, numerous agencies will be concerned with evaluating the effectiveness of emission zoning and/or control actions. On a regional basis, one means of performing this assessment lies in determining the changes in the pollutant frequency distributions resulting from control actions.

This study presents new data concerning the surface air-pollutant concentration frequency distributions observed for area sources and continuous point sources, and compares these distributions with those of the pertinent meteorological variables describing the transport and diffusion of the pollutant. The observed surface air pollutant frequency distributions are compared to those corresponding to simple modeling concepts from either an urban area source or a continuous point source. For an urban source and a relatively inert pollutant like CO, we found that the observed frequency distribution for CO surface air concentration parallels the approximately log-normal frequency distribution of the reciprocal of the wind speed. We show that the constant relating these two well-correlated frequency distributions can be determined either experimentally or with a numerical simulation model of air pollution. The usefulness of numerical models in air pollution is discussed.  相似文献   
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