Tri-n-octylphosphine oxide and tris (2-ethylhexyl) phosphine oxide complexes of uranyl nitrate

Thesis (Ph.D.)--Boston UniversityDue to the necessity of recovering uranium from reactor fuels, a number of separation methods have been investigated in recent years. Of these, the method of solvent extraction has proved to be a practical one. Long chain symmetrical phosphine oxides have been shown to extract uranium and a number of other metals under different conditions. It was the object of the present investigation to establish the nature of the species resulting from uranyl nitrate-R3Po (R =alkyl group) interaction. The two phosphine oxides selected for the study were: (i) Tri-n-octylphosphine oxide (TOPO) and (ii) Tris(2-ethylhexyl)phosphine oxide (TEHPO). An attempt was made to obtain pure TEHPO. Though the attempt has not met with complete success, yet significant conclusions concerning the stoichiometry and relative stability of the uranyl nitrate-TEHPO complex could be drawn. [TRUNCATED

Laser powder fusion of H13 tool steel using pulsed Nd:YAG laser

Laser Powder Fusion has been used to explore the possibility of fabricating 3-dimensional parts from Computer Aided Design (CAD) data, using the underlying philosophy of 'Rapid Prototyping' or 'Freeform fabrication' techniques. Such techniques have emerged in the past decade or so, as a revolutionary way of designing and realising products primarily for form, fit and functionality. Applications have evolved in the areas of automotive, aerospace, medicine to name a few. The Laser Powder Fusion technique is characterised by the use of a heat source, like a laser or electron beam used for melting or fusing powder material like metal, polymers etc to the required geometry, by tracing and filling in (or rastering) 2-dimensional contours, line by line, layer upon layer, to obtain the 3D geometry. The motivation for the present work comes from the use of this technique for fabricating components with enhanced functionality, for applications in production and prototype tooling, engine parts etc. [Continues.

Learning to read aloud: A neural network approach using sparse distributed memory

An attempt to solve a problem of text-to-phoneme mapping is described which does not appear amenable to solution by use of standard algorithmic procedures. Experiments based on a model of distributed processing are also described. This model (sparse distributed memory (SDM)) can be used in an iterative supervised learning mode to solve the problem. Additional improvements aimed at obtaining better performance are suggested

WSSL: Weighted Self-supervised Learning Framework For Image-inpainting

Image inpainting is the process of regenerating lost parts of the image. Supervised algorithm-based methods have shown excellent results but have two significant drawbacks. They do not perform well when tested with unseen data. They fail to capture the global context of the image, resulting in a visually unappealing result. We propose a novel self-supervised learning framework for image-inpainting: Weighted Self-Supervised Learning (WSSL) to tackle these problems. We designed WSSL to learn features from multiple weighted pretext tasks. These features are then utilized for the downstream task, image-inpainting. To improve the performance of our framework and produce more visually appealing images, we also present a novel loss function for image inpainting. The loss function takes advantage of both reconstruction loss and perceptual loss functions to regenerate the image. Our experimentation shows WSSL outperforms previous methods, and our loss function helps produce better results.Comment: 9 Pages, document submitted for publication at CGVCVIP 202

Maternal serum selenium as a predictor of preeclampsia

Background: Preeclampsia (PE) is a hypertension disorder condition occurring in 7-10% of all pregnancies. Preeclampsia if unidentified and left untreated is associated with poor maternal and fetal adverse outcomes. The objective of the present study was to characterize maternal serum selenium levels as a predictor of preeclampsia and to correlate dietary selenium intake with serum selenium levels in first trimester of pregnancyMethods: A retrospective case-control study of 107 pregnant women was conducted over 1.5 years at St. John’s Medical College Hospital. On screening for inclusion criteria, at baseline, information on maternal socio-demography, anthropometry, dietary intake and clinical examination was collected. A venous blood sample at baseline and 2nd or 3rdtrimester of pregnancy was collected for estimation of selenium concentrations. Blood pressure was measured at baseline and followed up during pregnancy to select cases and controls. Pregnant women were termed ‘cases’ based on NHBPEP (National High Blood Pressure Education Program) classification and subsequent 22 women with normal blood pressure controlled for age were termed as ‘controls.Results: No statistically significant differences were observed for baseline characteristics, biochemical parameters and blood pressure at recruitment among cases and controls. Cases had significant lower levels of energy (P=0.032) and micronutrients like zinc (P=0.027), selenium (P=0.022), magnesium (P=0.047) at first trimester. The serum selenium levels were significantly higher in cases as compared to the controls (69.2±13.7 vs. 59.6±12.9; P=0.021) at baseline.Conclusions: Our findings suggest that serum selenium levels may not be an independent predictor of preeclampsia. Assessment of other micronutrients, oxidative stress markers and other complementary elements may be useful in predicting preeclampsia

Credibility Evaluation of User-generated Content using Novel Multinomial Classification Technique

Awareness about the features of the internet, easy access to data using mobile, and affordable data facilities have caused a lot of traffic on the internet. Digitization came with a lot of opportunities and challenges as well. One of the important advantages of digitization is paperless transactions, and transparency in payment, while data privacy, fake news, and cyber-attacks are the evolving challenges. The extensive use of social media networks and e-commerce websites has caused a lot of user-generated information, misinformation, and disinformation on the Internet. The quality of information depends upon various stages (of information) like generation of information, medium of propagation, and consumption of information. Content being user-generated, information needs a quality assessment before consumption. The loss of information is also necessary to be examined by applying the machine learning approach as the volume of content is extremely huge. This research work focuses on novel multinomial classification (based on multinoulli distribution) techniques to determine the quality of the information in the given content. To evaluate the information content a single algorithm with some processing is not sufficient and various approaches are necessary to evaluate the quality of content.  We propose a novel approach to calculate the bias, for which the Machine Learning model will be fitted appropriately to classify the content correctly. As an empirical study, rotten tomatoes’ movie review data set is used to apply the classification techniques. The accuracy of the system is evaluated using the ROC curve, confusion matrix, and MAP

Validity of a food frequency questionnaire to assess nutritional intake among Sri Lankan adults

Sri Lanka is undergoing nutritional transition and diet-related chronic diseases are emerging as an important health problem. Currently, no validated food frequency questionnaire (FFQ) exists to measure habitual dietary intake of Sri Lankan adults. The purpose of the study is to assess the validity of a semi-quantitative FFQ and 7-day weighed-intake dietary records (7DWR), designed to assess dietary intake among Sri Lankan adults. Dietary intake was measured using both a FFQ and 7DWR. The FFQ consisted of 8 food groups containing the main foods comprising the diet of Sri Lankan adults, a total of 85 items and 12 color photographs to identify serving size. One hundred healthy adults were randomly recruited from a community sample and administrated the FFQ followed by completion of the 7DWR. Paired sample t tests, Pearson’s correlation coefficients, kappa test and Bland–Altman analysis were conducted to determine correlation and the level of agreement for energy and micronutrients. Seventy-seven participants completed both the FFQ and 7DWR. Estimated mean energy intake (SD) from FFQ (1794 ± 398 kcal) and 7DWR (1698 ± 333 kcal, p < 0.001) were significantly different due to a significant overestimation of carbohydrate (11.5 g/day, p < 0.001) and to some extent fat (5.7 g/day, ns). Significant positive correlations (p < 0.05) were found between the FFQ and 7DWR for energy (r = 0.39), carbohydrate (r = 0.47), protein (r = 0.26), fat (r = 0.17) and dietary fiber (r = 0.32). Bland–Altman graphs indicated fairly good agreement between methods with no relationship between bias and average intake of each nutrient examined. Based on these findings, the FFQ appears to be an acceptable tool for assessing the nutrient intake of Sri Lankans and will assist proper categorization of individuals by dietary intake

Galactic synchrotron emissivity measurements between 250° MWA

This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The version of record, H. Su et al, 'Galactic synchrotron emissivity measurements between 250◦ < l < 355◦ from the GLEAM survey with the MWA', MNRAS, 465(3): 3163-3174, first published online 17 November 2016, is available via doi: 10.1093/mnras/stw2959. © : 2016 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.Synchrotron emission pervades the Galactic plane at low radio frequencies, originating from cosmic ray electrons interacting with the Galactic magnetic field. Using a low-frequency radio telescope, the Murchison Widefield Array (MWA), we measure the free-free absorption of this Galactic synchrotron emission by intervening HII regions along the line of sight. These absorption measurements allow us to calculate the Galactic cosmic-ray electron emissivity behind and in front of 47 detected HII regions in the region $250^\circPeer reviewedFinal Published versio