Plant - damage

Injury to plants and vegetation is caused by a variety of factors, of which air pollution is only one. Drought, too much water, heat and cold, hail, insects, animals, disease, and poor soil conditions are some of the other causes of plant injury and possible plant damage (3). Estimates suggest that less than 5% of total crop losses are related to air pollution. Air pollution has a much greater impact on some geographic areas and crops than others. Crop failure can be caused by fumigation from a local air pollution source or by more widespread and more frequent exposure to adverse levels of pollution. 

Table 12-4 are sufficient for an understanding of smog chemistry. The major undesirable components of photochemical smog are NOj, O3, SOj, H2SO4, PAN, and aldehydes. Air quality standards have been established in several countries for SO2, NO2, and O3 H2SO4 contributes to acidic deposition and reduction in visibility and PAN and aldehydes can cause eye irritation and plant damage if their concentrations are sufficiently high. 

In plant health terms, monitoring and measurement both eost money and are only half way to the real objeetive, whieh is the avoidanee of eost and plant damage. Condition management makes proper use of both aetivities and exploits information derived from them to generate money for the plant operator. Good plant eondition management, therefore, should be the objeetive of materials and maehine health speeialists. 

The combinations of failures and non-failed conditions define the state of the pJani at the right branches. The damage associated with these plant damage states are calculated using thermal-hydraulic analyses to determine temperature profiles that are related to critical chemical reactions, explosions and high pressure. These end-states serve as initiators fot breaking confinement that leads to release in the plant and aquatic and atmospheric release outside ol the plant,... 

System event trees connect to the containment event tree with a large number ot sequences fonned by different combinations of events. The number of sequences is made tractable by grouping sequences in release categories - a process called binning. Two approaches to binning are 1) probability screening and 2) plant-damage bins. 

Approach 2 develops groups of system sequences called plant damage bins plant... 

The Important Sequence Model module does sensitivity studies and importance rankings for about a thousand highest frequency sequences. The analyst zooms to the most frequent plant damage category, to the most frequent sequences in that category, to the most important top event, to the most important split fraction, and to the most important cutsets. If sensitivity analysis is needed on the model as a whole, a menu option, "CLONE a Model," makes a copy of the model, c hange,s are made, and results compared. 

This f-M distribution estimates a lower risk from earthquakes because the high intensity earthquakes that exceed the DBA and result in plant damage are in the roll-off region of the curve. Unfortunately, this roll-off at high intensities is not universally accepted by the seismological community (PSA Procedures Guide 11-14)... 

The frequencies of plant damage and public consequence are calculated using plant logic combined with component fragilities. Event and fault trees are constructed to identify tiic accident sequences and the damage that may result from an earthquake. In performing a plant system and accident-sequence analysis, the major differences between seismic and internal events analysis are given in Table 5.1-4... 

Estimate the frequencies of various fire-initiated plant damage states. 

Enter failure probabilities (ones) in the system model to determine the plant damage states as a function of water depth... 

Guides 1.3 and 1.4 which were used by the RSS. The RSS presented results of accident progression and fission products in release categories associated with various plant damage states. 

Category 1. Relea.se of gaseous ammonia primarily from failure of Tank DK-101 by three plant-damage statc.s overpressure, underpressure and seismic load. For all three it was assumed that ... 

Category 2. Release of liquid ammonia from pipe failure for two plant-damage states involved the assumptions ... 

In most engineering applications the supply water is not suitable for immediate use without treatment. It is essential that the method of water treatment selected be the one most suited to the application. If steam is used as the working medium for a process, it is essential that water treatment be used to prevent the precipitation of substances in the water from fouling pipe work and heat exchangers otherwise costly plant damage will result. 

Although the need to properly soften the FW control BW variables such as alkalinity, TDS, and sludge and limit carbonic acid corrosion remains vital, these other problems generally are secondary to effective control over DO. If severe boiler plant damage and system failure are to be avoided, it is necessary to continuously maintain waterside reducing conditions and properly passivated boiler surfaces. 

A pump roller bearing failure in a crude oil refinery initiated the fracture of the motor shaft and the pump bearing bracket. The pump casing then broke, releasing hot oil, which au-toignited. Secondary pipe and flange failures contributed fuel to the fire. Plant damage totaled over 15 million. 

The gases in the ethylene oxide reactor moved into the explosive region while being above the autoignition temperature. A violent explosion occurred, resulting in several injuries and significant plant damage. 

Cress (Lepidium sativum) and radish (Raphanus sativus) are small seeds, quick to germinate and sensitive to phytotoxic (plant damaging) substances like the organic acids temporarily present in immature composts. 

Symptoms During spring and summer, the beetles eat small holes in leaves and stems. A severe attack will check growth and kill young plants. Damage is always worse in dry weather. Larvae feed on plant roots, or in leaf mines. 

The chemistry of the photochemical reaction milieu, including the formation of secondary aerosols, is covered in Chapter 3. Table 6-1 lists the substances that have been identified and associated with the impact of photochemical oxidants on breathing, eye irritation, plant damage, and visibility reduction. It is important to recognize this chemical corn-... 

Many deleterious effects have been associated with photochemically polluted air ozone is deflnitely associated with respiratory problems, plant damage, and material damage PAN has deflnitely been associated with plant damage, and some other members of this class of chemical compounds have been associated with eye irritation the hydroxyl radical is considered to be an important factor in the conversion of gas-phase intermediates to end products, such as sulfur dioxide to particulate sulfate the particulate complex is responsible for haze formation and has also been associated with eye irritation and respiratory effects. The aldehydes have been associated with eye irritation. Ozone and PAN themselves do not cause eye irritation. For purposes of control, much more research is needed, in order to relate the laboratory data about the concentrations of these various materials that have significant effects to their formation in the atmosphere from emission and their atmospheric distribution. The lack of convenient measurement methods has hindered progress in gaining this understanding. 

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