Neighbor effect, plants

Trace amounts of chlorine suppress the total oxidation. This effect was discovered inadvertently when the selectivity of the process in an industrial plant rose spontaneously from one day to the other. Analysis of the catalyst revealed traces of chlorine, originating from a newly commissioned neighboring chlorine plant. Consequently, small amounts of a chlorine-containing compound, such as ethylene dichloride, are nowadays added to the feed. 

The beneficial effect of chlorine was discovered inadvertently in a plant in France, when the selectivity for ethylene epoxide rose spontaneously one day. Analysis of the catalyst revealed the presence of chlorine, which originated from a neighboring chlorine plant and entered the ethylene oxide reactor together with oxygen from the air. 

One of the most serious stressors to personnel working in many chemical processes is the perception of danger by the workers arising from ineffective control and supervision of these systems. Despite the fact that modem plants are equipped with automated protection systems, there is always some perception of potential risk in their operation. Serious threats can be posed not only for those within the plant, but also for the neighboring public. An environment that is perceived as being highly dangerous will increase the stress experienced by the workers and may have a detrimental effect on their performance. 

Significant levels of herbicides have also been detected in rivers, although these are usually transitory. Heavy rainfall can move herbicides from agricultural land to nearby ditches and streams due to runoff, and in soils that are high in clay, percolation of water occurs through deep fissures with consequent movement into neighboring water courses. Such events under extreme weather conditions are likely to have contributed to the pulses of herbicide contamination observed in some rivers. Questions have been asked about possible effects of such episodic pollution on populations of aquatic plants. 

Once the general area for the plant has been determined, the effect of neighboring industries should be considered when picking the specific site. Their presence may indicate an increased corrosion rate. To illustrate the magnitude of this, Table 2-5 gives the corrosion rates for unpainted carbon steel and zinc for six different locations in Pennsylvania. 

We also found that the response of the plant to the caterpillar spit is systemic (31). Thus, not only the damaged leaves but the entire plant produces and releases volatile compounds when one or more leaves are attacked by caterpillars. Dicke et al. (7) had earlier found a similar effect in that undamaged leaves of a spider mite-injured plant attracted predatory mites. This systemic effect could be very significant in terms of enabling the natural enemies to locate their victims. It makes the plant under attack stand out from its neighbors and act as a beacon to foraging natural enemies. 

Flowers must be pollinated for fruit to form (see alsop.290). Some apples are "self-fertile"— pollination is achieved by bees flying from flower to flower on the same tree. Others cannot set a crop on their own and need to be planted within bee-flying distance of another cultivar that is both compatible and in flower at the same time. Your neighbors yard is usually close enough. A crab apple can also make an effective pollinator. 

The secretion of secondary metabolites to the apoplast is another way to circumvent the toxic effects of some plant natural products. Plants use this mechanism especially in root cells. Then, they can interact with neighboring plants (allelopathy) or modify soil environment to promote... 

Control analysis and control system design for chemical and petroleum processes have traditionally followed the unit operations approach" (Stephanopoulos, 1983). First, all of the control loops were established individually for each unit or piece of equipment in the plant. Then the pieces were combined together into an entire plant. This meant that any conflicts among the control loops somehow had to be reconciled. The implicit assumption of this approach was that the sum of the individual parts could effectively comprise the whole of the plant s control system. Over the last few decades, process control researchers and practitioners have developed effective control schemes for many of the traditional chemical unit operations. And for processes where these unit operations are arranged in series, each downstream unit simply sees disturbances from its upstream neighbor. 

Dry tundra may be regulated differently because the low soil water content might limit decomposition (Ileal et al., 1981 Ober-bauer et al. 1996). However, it is uncertain to what extent observed low rates of CO2 fluxes in dry tundra are due to reduced respiration in microorganisms versus that in plants (Illeris and Jonasson, 1999). In spite of this uncertainty, it appears that predicted changed climatic conditions in the Arctic (IPCC, 1996) can lead to both decreased and increased C sequestration by different arctic ecosystems. It also appears that the same change of environmental conditions may have different effects across ecosystem types and could even lead to different directions of the changes in C balance between neighboring systems. 

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