allowable rate
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Author(s):  
Halyna Tatarchenko

The problem of building an ecologically clean city is considered, taking into account the basic principles of its construction, maintenance, zoning of ecological functions and, at the same time, the need to maintain sustainable development. Calculations of the concentration of emissions of nitrogen oxides in fourteen transport nodes - intersections of the main roads of the city were carried out, the dispersion of the distribution of impurities in the atmosphere was determined. On the basis of the criterion of the traffic intensity of vehicles, the zoning of the territory around the intersections of the main roads of the city was proposed according to the level of atmospheric air pollution with nitrogen oxides: safe zones, where the content of nitrogen oxides is less than the average daily maximum permissible concentrations (maximum allowable concentration = 0.04 mg/m3); zones of low safety, where the content of nitrogen oxides is less than the maximum one-time maximum permissible concentration (maximum allowable concentration = 0.4 mg/m3); hazardous zones, where the level is higher than the maximum allowable concentration, constant monitoring and special treatment facilities are needed. The calculation of the traffic intensity of vehicles, which is necessary to achieve the maximum allowable rate for nitrogen oxide emissions, and the ratio between the substances. Sanitary protection zones-territories around the main hubs, where nitrogen oxides have a harmful effect on the environment and human health, have been calculated. It was revealed that the predominant north-western direction of winds leads to an increase in the territory of pollution up to 850 m, if the highway has eight lanes. A conceptual model of the transition to clean air in urbanized areas is proposed, according to which, in fact, it is necessary to solve the problems of coexistence and protection: - a person who seeks to live comfortably, and comfort requires constant progress and at the same time preserving his health; - transport, which is associated with the need to quickly move goods and services, requires sustainable economic development and leads to climate change; - the environment, the state of which under anthropogenic influence is deteriorating against the background of intensification of natural disasters.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chengcheng Xu ◽  
Chuiyu Lu ◽  
Jianhua Wang

AbstractWater inflow forecast is influenced by many factors and yields uncertain results. To more accurately predict the magnitude of water inflow and quantitatively define the corresponding response in the parameter change interval, this study combined a non-probabilistic set theory and uncertainty analysis to derive an equation for the confined water inflow. Using mining area data and comparing the calculation of upper and lower boundary limits obtained by a Monte Carlo method, results of the confined water inflow equation were calculated with relative errors of 5% and 10%. When corresponding to the rate of change of the variable parameter, the results showed that under the same error conditions, the allowable rate of change when calculating the minimum value using Eq. A was greater than when using Eq. B, and the maximum value using Eq. B yielded a greater allowable rate of change than the maximum value calculated by Eq. A. Thus, the obtained rate of change for Eq. A is indicative of the lower limit, and Eq. B is conducive to the calculation of the upper limit of mine water inflow.


Plant Disease ◽  
2020 ◽  
Vol 104 (5) ◽  
pp. 1400-1406 ◽  
Author(s):  
David H. Gent ◽  
Mary Block ◽  
Briana J. Claassen

Phosphonate (phosphite; HPO3−2) is fungicidal against oomycetes and certain other organisms. The Fungicide Resistance Action Committee has deemed phosphonate to be at low risk of resistance development, and reduced sensitivity to phosphonate has been reported only occasionally in plant pathogens. Reduced sensitivity to the fungicide fosetyl-Al was documented in the hop downy mildew pathogen, Pseudoperonospora humuli, in the early 2000s, but disease caused by insensitive isolates could still be managed commercially if the fungicide rate was doubled from 2.24 to 4.48 kg/ha. In this research, we document the occurrence of isolates of P. humuli in Oregon that possess even higher levels of insensitivity to fosetyl-Al and other phosphonate fungicides. The median estimated effective concentration required to reduce infection by 50% (EC50) for isolates collected from two farms reporting disease control failures was 2.7% (vol/vol) phosphonate (range = 1.6 to 164.2), which was 1.6 times (range = 0.9 to 96.0) the maximum labeled rate of the phosphonate fungicide utilized. In contrast, the median EC50 for isolates obtained from experimental plots that have received only a single application of a phosphonate fungicide was 0.6% (vol/vol) phosphonate (range = 0.11 to 2.3) or 0.3 times the maximum allowable rate. Sensitivity of isolates to a phosphorous acid fungicide, fosetyl-Al, and a plant nutrient product containing an unspecified level of phosphorous acid were linearly related. Insensitivity to the maximum allowable rate of a phosphorous acid fungicide was widespread within and among hop farms in Oregon. Among 54 isolates assayed for phosphonate insensitivity, 96% had EC50 values that exceeded the maximum allow rate of the fungicide used in the assays. Field studies conducted in 2 years further demonstrated that a phosphorous fungicide, a nutrient product containing phosphorous acid, and fosetyl-Al failed to provide commercially acceptable suppression of downy mildew when applied at the maximum allowable rates and even double these rates, whereas fungicides with different modes of action provided 91% or greater disease control. The whole of this research indicates that P. humuli has been selected to tolerate fosetyl-Al and other phosphonate fungicides at rates four times greater than those used earlier to obtain satisfactory suppression of downy mildew. This finding has implications for management of the disease not only in Oregon but also, in other production regions should insensitive isolates be introduced on infected planting material.


2020 ◽  
Vol 27 (4) ◽  
pp. 805-831
Author(s):  
Matthew Gould ◽  
Matthew D. Rablen

AbstractTax authorities worldwide are implementing voluntary disclosure schemes to recover tax on offshore investments. The US and UK, in particular, have implemented such schemes in response to bulk acquisitions of information on offshore holdings, recent examples of which are the “Paradise” and “Panama” papers. Schemes offer affected investors the opportunity to make a voluntary disclosure, with reduced fine rates for truthful disclosure. Might such incentives, once anticipated by investors, simply encourage evasion in the first place? We characterize the investor/tax authority game with and without a scheme, allowing for the possibility that some offshore investment has legitimate economic motives. We show that a scheme increases net expected tax revenue, decreases illegal offshore investment and increases onshore investment, but could either increase or decrease legal offshore investment. The optimal disclosure scheme offers maximal incentives for truthful disclosure by imposing the minimum allowable rate of fine.


Author(s):  
Douglas G. MacMartin ◽  
Ken Caldeira ◽  
David W. Keith

Solar geoengineering has been suggested as a tool that might reduce damage from anthropogenic climate change. Analysis often assumes that geoengineering would be used to maintain a constant global mean temperature. Under this scenario, geoengineering would be required either indefinitely (on societal time scales) or until atmospheric CO 2 concentrations were sufficiently reduced. Impacts of climate change, however, are related to the rate of change as well as its magnitude. We thus describe an alternative scenario in which solar geoengineering is used only to constrain the rate of change of global mean temperature; this leads to a finite deployment period for any emissions pathway that stabilizes global mean temperature. The length of deployment and amount of geoengineering required depends on the emissions pathway and allowable rate of change, e.g. in our simulations, reducing the maximum approximately 0.3°C per decade rate of change in an RCP 4.5 pathway to 0.1°C per decade would require geoengineering for 160 years; under RCP 6.0, the required time nearly doubles. We demonstrate that feedback control can limit rates of change in a climate model. Finally, we note that a decision to terminate use of solar geoengineering does not automatically imply rapid temperature increases: feedback could be used to limit rates of change in a gradual phase-out.


2000 ◽  
Vol 15 (2) ◽  
pp. 449-457 ◽  
Author(s):  
J. H. Song ◽  
J. R. G. Evans ◽  
M. J. Edirisinghe ◽  
E. H. Twizell

A model that finds the maximum permissible heating rate for pyrolysis of ceramic moldings is extended to produce multi-segment temperature–time profiles to minimize the binder removal time. The degradation of the polymer and the diffusion of degradation products in solution to the free surface in a cylinder containing 50 vol% alumina and polyalphamethylstyrene is considered. The theory has previously been validated experimentally for fixed heating rates for cylindrical and flat plate geometries and for overpressure debinding. The extended model, presented here, calculates the vapor pressure of monomer over solution and modifies the heating rate to keep this just below ambient pressure. In this way, the temperature follows the maximum allowable rate at each stage to prevent boiling and hence the incidence of defects.


Author(s):  
Wodek Gawronski

Abstract The LQG controllers, designed for the NASA Deep Space Network antennas have small tracking errors and are resistant to wind disturbances. However, during antenna slewing, they induce limit cycling caused by the violation of the antenna rate and acceleration limits. This problem can be avoided by introduction of a command that does not exceed the limits. The command preprocessor presented in this paper generates a command that is equal to the original command if the latter does not exceed the limits, and varies with the maximal (or minimal) allowable rate and acceleration if the limits are met or exceeded. It is comparatively simple since it requires only knowledge of the command at the current and the previous time instants, while other known preprocessors require knowledge of the terminal state and the acquisition time. Thus, the presented preprocessor is more suitable for implementation. In this article analysis of the preprocessor is presented. Also the performances of the preprocessor itself, and of the antenna with the preprocessor is illustrated with typical antenna commands.


1975 ◽  
Vol 14 (3) ◽  
pp. 417-431 ◽  
Author(s):  
B. Roberts† ◽  
E. R. Priest

The standard model for fast magnetic-field reconnexion (Petschek 1964) is qualitatively valid, despite numerous criticisms of its quantitative details. It contains four slow magnetohydrodynamic shock waves, which radiate from a central diffusion region. On the basis of Petschek's rough analysis, it is generally stated that, for large values of the magnetic Reynolds number Rm, reconnexion can occur at a rate no faster than a fraction π/(4 log Rm) of the Alfvén speed. Alternative models of the region outside that of diffusion have been put forward by Yeh & Axford (1970), whose general solutions Vasyliusnas (1975) proved invalid, and by Sonnerup (1970), whose model is mathematically useful, but of limited practical applicability. But their results suggest that reconnexion can occur at any rate whatsoever, with the diffusion-region dimensions responding accordingly. The present paper analyses the external region for Petschek's mechanism in greater detail than hitherto, with the object of deciding whether or not there is a maximum rate. The inclinations of the shock waves are calculated as a function of the fluid speed ve at large distances, which is taken as a measure of the reconnexion rate. It is found that, in agreement with Petschek's rough analysis, there is indeed an upper limit on the allowable rate of magnetic-field reconnexion. Its variation with Rm is calculated, and it is shown, for log10 Rm ≫1, to be approximately 20% of Petschek's value. Typical values are 0·10vAe for Rm = 10·2 and 0·02vAe for Rm = 106. (vAe is the Alfvén speed at large distances from the diffusion region.)


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