Plant ageing system factors

Water Chemistry of Nuclear Reactor Systems, Bournemouth, UK, 1989, Vol. 1, p. 43-47 Hecht, G. Occupational exposures in LWR plants built by Siemens/KWU including service. Paper presented at the Internat. Workshop on New Developments in Occupational Dose Control and ALARA Implementation at Nuclear Power Plants and Similar Facilities. Brookhaven National Laboratory, Upton, N. Y, 1989 Marchl, T., Riess, R. Reducing the cobalt inventory in Siemens PWRs. Paper presented at the EPRI Radiation Field Control Seminar, Seattle, Wash., USA, 1993 Ocken, H. Radiation control to improve nuclear power plant availability. Proc. Intemat. Conf Nuclear Power Plant Aging, Availabilty Factor and Reliability Analysis, San Diego, Calif, 1985, p. 593-600... 

Natural products can be used as plant extracts with pharmacological activity (e.g., Mangifera indica L., vallerian, aloe, Cratoxylum pruniflorum, microporous zeolite), excipient for direct compression or granulation (chitin, chitosan, and dextran), and controlled-release systems (cellulose and native dextran). For natural products the most important factor is the standardization of the extract because properties such as the amount of active substance can be changed from batch to batch. Factors such as the origin of the extract, geographic zone, and age of the tree could affect the properties of natural extracts. 

The toxins selected for discussion in this section are found in plants that are not consumed as part of normal diets. The plants discussed are those most commonly identified in acute, systemic poisonings. These poisonings can be quite severe, although variability in the concentration of toxic chemicals may occur between and within plant species due to factors such as age and part of plant, season, and growth conditions. Historically, the use of plants has ranged from medicinal to homicidal purposes. The list of poisonous plants is extensive and varied, and can not be fully covered in this text. Human... 

Recent investigations indicate that the failure to obtain a positive chemotropic response may be an artifact. Failure to observe chemotropism may result from interference by pollen tube growth inhibitors, a factor causing negative chemotropism, by inherent errors in the surface test method, by the existence of genetically controlled incompatibility systems, and by factors of age of tissues and other characteristics of the plants. 

Cancer is a term commonly used for diseases in which abnormal cells divide uncontrollably and invade other tissues. Cancer cells can spread to other parts of the body through the blood and lymph systems. Cancer is not just one disease but many diseases. There are more than 100 different t3 pes of cancer, hence, the complexity of cancer treatment. It is the second leading cause of death worldwide after heart disease, and its risk and incidence increase with patient age (www. cancer.gov). In addition to genetic factors, enviromnental and nutritional factors play a main role in cancer etiology. In westernized countries, breast, prostate, and colon-rectum cancers predominate because diets are usually rich in animal-source foods and refined carbohydrates and deficient in plant foods. Conversely, in developing countries, where diets are largely based on cereal/starchy foods, esophageal, stomach, and liver cancers are more incident [127]. 

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