Thesis: Ph. D., Massachusetts Institute of Technology, Department of Nuclear Engineering, 1977 / Bibliography : leaves 169-175. / Ph. D. / Ph. D. Massachusetts Institute of Technology, Department of Nuclear Engineering

Master’s thesis focuses on the history and current progress in research of molten salt reactors around the world, with an emphasis placed on the properties of molten salts and the problems associated with their use. In relation to the practical part, one chapter is devoted to the creation of input file in the MCNP software. The practical part deals with neutron activation analysis of graphite prism experiment, which is filled with powder NaCl salt. This experiment is focused on the effect of salt on neutron flux with different energy levels. The whole problem was also simulated in the MCNP environment along with the experiment. At the end of the thesis, the individual methods are compared and evaluated.

Archaeologists widely argue that Fremont potters from the Parowan Valley, in southwestern Utah, manufactured Snake Valley pottery. For my thesis, I examined Snake Valley Black-on-gray rim sherds using neutron activation analysis, oxidation analysis, metric data, and statistical methods. I compared my results on Snake Valley Black-on-gray sherds from three archaeological sites within the Parowan Valley (Paragonah, Parowan, and Evans Mound) to my results on Snake Valley Black-on-gray sherds recovered from three archaeological sites over 250 kilometers to the north (South Temple, Block 49, and Wolf Village). I argue that the Snake Valley Black-on-gray ceramics from the northern sites are tradewares selected from the Parowan Valley sites. My research expands on the limited knowledge of the painted variety of Snake Valley pottery; as well as provides insight into the overall understanding of Snake Valley Black-on-gray distribution among different geographical regions within the Fremont culture.

<p>Neutron Activation Analysis (NAA) is a non-invasive method for assessing the qualitative and quantitative elemental composition of a sample. One application of this technique is in-vivo quantification of specific elements in the human body. An important element in terms of human exposure assessment is Manganese (Mn). Mn is the fourth most usedindustrial metal and can be an  inhalation  exposure  hazard  specifically  for  welders.  Over  exposure  to  Mn  can  lead  to neurological degeneration issues similar to Parkinson’s disease. It has been found that bone is a good  biomarker  for  Mnas  Mn  is  deposited  in  the  bone  and  remains  for  long  periods  of  time,allowing  for  an  assay  to  reveal  long  term  exposure  information.  The  method  of  using  NAA  to quantify levels of Mn in-vivo using the bones in the human hand is being explored in this work.The  NAA  system  used,  involves  a  deuterium-deuterium  neutron  generator  and  an  N-type  High Purity Germanium Detector. It is critical to have the performance of the entire system characterized using phantoms and cadaver bones before the system can be used for in-vivo measurements. The goal of this work is to determine the neutron yield of the generator system, the neutron and photon dose  received  by  a  sample,  the  detection  limit  of  Mn  with  this  system,  and  to  evaluate  the  Mn detection capability of the systemusing cadaver bones from occupationally exposed Mn miners. The parameters were determined through a combination of simulation with Monte Carlo N-Particle Code  (MCNP),  experiments  using  Mn  doped  bone  phantoms  and  cadaver  bones,  and  various dosimetry  tools such  as  TLDs  and  EPDs.  The  neutron  yieldfor the  D-D  109M  generator  wasestimated to be2.24E+09+/-2.15E+07neutrons per secondfor this work. The Mn detection limit for the system was estimatedto be 0.442 ppm. The equivalent dose received by the sampleduring the standard 10-minute irradiation was estimated to be 8.45 +/-2.05rem. The results found for the human cadaver bones weremixed. It was found that the system was able to successfully detect Mn incadaver bones. Unexpectedly, however, three of the samples showed little to no Ca signal.In addition, significant amounts of soft tissue and bone marrow exist in the samples.Thereforethe Mn concentration in the bones was not able to be accurately estimated. A relative metric of Mn concentration  was  used  instead  and  showed  a  slight  positive  increase  from  the  unexposed  to exposed samples but was not statistically significant.</p>

Archaeologists widely argue that Fremont potters from the Parowan Valley, in southwestern Utah, manufactured Snake Valley pottery. For my thesis, I examined Snake Valley Black-on-gray rim sherds using neutron activation analysis, oxidation analysis, metric data, and statistical methods. I compared my results on Snake Valley Black-on-gray sherds from three archaeological sites within the Parowan Valley (Paragonah, Parowan, and Evans Mound) to my results on Snake Valley Black-on-gray sherds recovered from three archaeological sites over 250 kilometers to the north (South Temple, Block 49, and Wolf Village). I argue that the Snake Valley Black-on-gray ceramics from the northern sites are tradewares selected from the Parowan Valley sites. My research expands on the limited knowledge of the painted variety of Snake Valley pottery; as well as provides insight into the overall understanding of Snake Valley Black-on-gray distribution among different geographical regions within the Fremont culture.

Instrumental Neutron Activation Analysis was used for this study of stonewares collected from the site of the Buena Vista/Oregon Pottery Company (1866-1890). The results show significant chemical signatures in the samples tested. Thorium/ytterbium and thorium/chromium ratios within their respective ranges of variation demonstrate a relative conformity among all samples of Buena Vista ceramics.

This study has attempted to examine third and fourth century pottery supply in northern England together with other aspects of pottery assemblages in the region. The pottery kilns of the East Yorkshire industries have been characterised by neutron activation analysis which has proved reasonably successful in discriminating between them. Neutron activation analysis has also been utilised to attempt to check visually identified fabric groups and to help isolate other fabrics. This has been of varying success. Quantified data has been collected from 15 sites across the north and the limited published quantitative data have been utilised to examine the distribution, marketing and competition between fabric types in the region. Examination of functional variations through time between different types of site has also been undertaken as has that of variations in the quantity of finewares through time and between different types of site together with an attempt at quantifying decoration and examining trends in this. Pottery supply to the northern frontier area would seem to have been organised by different mechanisms in different periods. In the second century much of the pottery used on the frontier would appear to have been produced by the military themselves whilst in the third century and earlier fourth century free market mechanisms would seem to have operated, but in the late fourth-early fifth centuries some form of 'military contract' would appear to have taken over supply. Functional variations between different types of site have been identified with rural sites, turrets and Signal Stations sharing a major emphasis on the jar as the basic ceramic form and more complex settlement types having more diversified functional groups. The distribution of finewares also seems to be concentrated on more complex settlement types. It is apparent that there are consistent differences between the East Yorkshire region and the rest of the study area which may well reflect differences extending back into the Iron Age. Similarly there seem to be indications of some 'de-Romanisation' in late Roman assemblages but this does not develop in the fifth century, when nearly all the strands of evidence of Romano-British material culture disappear very rapidly. / Science and Engineering Research Council

Alzheimer’s disease accounts for up to 80% of the cases of dementia making it the most common type of dementia. As of 2015, 46.8 million people are suffering from Alzheimer’s disease worldwide with an alarming rate of increase in the onset of the disease. Despite the ongoing research, the true cause of Alzheimer’s disease remains unknown. Aluminum is one of the major environmental toxins linked to the etiology of Alzheimer’s disease. A pilot clinical study for non-invasive measurement of bone aluminum was performed at the in vivo neutron activation analysis facility at McMaster University including 15 Alzheimer’s and 15 control subjects. A significant difference in bone aluminum, relative to calcium, was found between the two groups. Multiple methods of analysis were investigated to determine the method with the lowest minimum detection limit. The method of in vivo neutron activation analysis allows for the simultaneous activation of multiple elements. As such, it was possible to measure the magnesium levels, which has been shown to be involved in Alzheimer’s disease, in the study subjects. The results of bone measurements did not show a significant association between bone magnesium levels and Alzheimer’s disease. Moreover, the short-term kinetic behaviours of sodium and chlorine, both essential for the human body, were studied. The outcome of this study revealed an increase in the biological half-lives of sodium and chlorine with age and a higher variability in Alzheimer’s patients compared to control subjects. Finally, bone samples from parenteral nutrition patients were analyzed to determine their aluminum content for comparison and benchmarking purposes. The present results suggest a possible association between bone aluminum and the presence of Alzheimer’s disease. No such association was found for magnesium or the biological half-lives of sodium and chlorine. The technique of in vivo neutron activation analysis was shown to be a promising tool for measuring bone aluminum and magnesium; however, a better detection limit is required to strengthen the current results. / Dissertation / Doctor of Philosophy (PhD) / Alzheimer’s disease is the most common form of dementia. The cause of Alzheimer’s disease is unknown, but both genetic and environmental factors are known to be involved. Different elements have been studied for their possible role in this disease. Aluminum and to a lesser extent magnesium have been linked to the etiology of Alzheimer’s disease. The current thesis presents the results of a clinical study that utilizes the method of in vivo neutron activation analysis to measure aluminum and magnesium in the hand bone of Alzheimer’s disease and control subjects. In vivo neutron activation analysis is a non-invasive method that uses neutrons to activate elements in the human body and measures the radiation emitted. Different methods of analyzing the resulting data were investigated to find the most suitable analysis approach. The biological half-lives of sodium and chlorine were also measured to investigate their short-term kinetic behaviour and pattern with age.

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