Using Fission-Track Radiography Coupled with Scanning Electron Microscopy for Efficient Identification of Solid-Phase Uranium Mineralogy at a Former Uranium Pilot Mill (Grand Junction, Colorado)

At a former uranium pilot mill in Grand Junction, Colorado, mine tailings and some subpile sediments were excavated to various depths to meet surface radiological standards, but residual solid-phase uranium below these excavation depths still occurs at concentrations above background. The combination of fission-track radiography and scanning electron microscope energy-dispersive X-ray spectroscopy (SEM-EDS) provides a uniquely efficient and quantitative way of determining mineralogic associations of uranium that can influence uranium mobility. After the creation of sample thin sections, a mica sheet is placed on those thin sections and irradiated in a nuclear research reactor. Decay of the irradiated uranium creates fission tracks that can be viewed with a microscope. The fission-track radiography images indicate thin section sample areas with elevated uranium that are focus areas for SEM-EDS work. EDS spectra provide quantitative elemental data that indicate the mineralogy of individual grains or grain coatings associated with the fission-track identification of elevated uranium. For the site in this study, the results indicated that uranium occurred (1) with coatings of aluminum–silicon (Al/Si) gel and gypsum, (2) dispersed in the unsaturated zone associated with evaporite-type salts, and (3) sorbed onto organic carbon. The Al/Si gel likely formed when low-pH waters were precipitated during calcite buffering, which in turn retained or precipitated trace amounts of Fe, As, U, V, Ca, and S. Understanding these mechanisms can help guide future laboratory and field-scale efforts in determining long-term uranium release rates to groundwater.

Do South African state-owned entities follow the pecking order theory of capital structure?

In corporate finance, the pecking-order theory suggests that companies adhere to a particular financing hierarchy, with internal funding taking preference over external funding, and debt financing taking preference over equity. This paper examines whether South African state-owned entities prioritize their financing sources as predicted by the pecking-order theory. A financing deficit variable comprising various cash flow-based components was used to test the theory. A panel regression model was employed using panel data estimators. Using a cross-section sample of 33 state-owned entities from 1995 to 2018, the study finds no evidence that South African state-owned entities follow a pecking order to finance investment projects. The pecking order theory proposition that costs of adverse selection are dominant for lower levels of leverage provides a reason for the financing deficit coefficient not being close to unity and hence an indication that the SOEs in South Africa do not follow the pecking order behavior in their financing decisions, an indication that South African capital market is still developing.

THE SOCIAL CLASS VARIATION IN HEALTH CARE EXPENDITURE: A CASE STUDY OF KHALLIKOTE BLOCK, GANJAM DISTRICT, ODISHA

This objective carries the primary data collected through a questionnaire from my study area and analyses of the impact of health care on the socio-economic development and the level of living of the social class families compared to other families. This also focuses on the problems and preferences of the health care expenditure burden of social class families. This present study was undertaken to investigate the existing health problems and healthcare practice of the social class (SC, ST, and OBC) communities of Khallikote Block in Ganjam District based on the present scenario, which exists between the SC, ST, and OBC groups. The findings of the study indicated that the demographic profile, socioeconomic status, general health status, but still lack of knowledge as well as poor availability of medical institution people intended to use traditional herbal medicine. The housing status of the social class community households needs to be improved through the help of village Panchayat should be oriented by Indira Awas yojana, and help of the people of construct good houses. It is necessary to provide orientation to village Panchayat about healthy housing and sanitation in the tribal communities. The village must be connected with the provision of “Rural Drinking Water” facilities in the social class village area, and villages to have safe drinking water in the villages as well in the community. The study has the following limitations: The study has depicted the current situation of the Khallikote Block in Odisha; the result may not be relevant to other class of people. The study is limited to a cross-section sample of 348 households of the selected sample villages in Langaleswar and Khojapalli Panchayat. It has been assumed that the respondents are true and honest while filling the questionnaire and there is no bias. Due to time and resource limitations, a full-length survey is not possible with a wider representation of data. Insurgency problem in the state created a problem for data collection from interior parts of the state. Despite these limitations, an attempt has been made to make the study more scientific and reliable by testing the reliability of the primary data. KEYWORDS: Health care expenditure, Income, cross-section sample, Regression, demographic profile.

Flow and fracture of austenitic stainless steels at cryogenic temperatures

In this paper, we have characterized the microstructural evolution and the plastic flow and fracture behaviours of AISI 304L and AISI 316LN stainless steel grades at liquid nitrogen temperature (77 K) and at liquid helium temperature (4 K). Uninterrupted tensile experiments, where the sample is continuously deformed under quasi-static loading conditions until fracture, have been carried out with a Single-Section Sample to obtain the stress-strain characteristics of the two grades. Interrupted tensile experiments, in which the sample is unloaded before fracture, have been performed with a novel Double-Section Sample to later characterize the strain-induced martensitic transformation at different levels of deformation. The content of martensite has been determined post-mortem, using magnetic induction, electron backscatter diffraction and quantitative light optical micrography. The results obtained with the three methods show quantitative agreement, and reveal that the martensitic transformation in AISI 304L occurs faster and to a greater extent than in AISI 316LN both at 77 K and at 4 K. To the authors' knowledge, in this paper we provide the first experimental results for the evolution of the content of strain-induced martensite in AISI 304L and AISI 316LN samples tested at liquid helium temperature. In addition, the experimental data for the evolution of the martensite volume fraction with the strain have been used to identify the temperature-dependent parameters of the martensitic transformation kinetic models proposed by Olson and Cohen (1975) and Garion and Skoczen (2002). Moreover, Mode I fracture tests with fatigue-precracked Compact Samples have been carried out to determine the fracture properties of the two investigated materials using the "resistance curve procedure" (ASTM-E1820-20a, 2020). The crack-growth resistance curves have been obtained with four different methods here referred to as ASTM Compliance Method, W-N Compliance Method, Modified W-N Compliance Method and ASTM Normalization Method, which is an original methodological contribution of this paper. While the four approaches yield similar results for the fracture toughness, only the W-N Compliance Method and the Modified W-N Compliance Method, the latter being proposed in this paper, fulfil all the requirements of the standard ASTM-E1820-20a (2020) so that the calculated fracture toughness can be accepted as a material property. The comparison of results for both materials and testing temperatures shows that the AISI 316LN displays higher fracture toughness than the AISI 304L. Moreover, post-mortem microstructural analysis of the Compact Samples near the fracture surface has revealed that the content of martensite is greater in AISI 304L than in AISI 316LN. Furthermore, for AISI 304L more martensite is formed in the sample tested at 77 K because the plastic deformation near the crack is greater than at 4 K.

Small samples, unreasonable generalizations, and outliers: Gender bias in student evaluation of teaching or three unhappy students?

In a widely cited and widely talked about study, MacNell et al. (2015) [1] examined SET ratings of one female and one male instructor, each teaching two sections of the same online course, one section under their true gender and the other section under false/opposite gender. MacNell et al. concluded that students rated perceived female instructors more harshly than perceived male instructors, demonstrating gender bias against perceived female instructors. Boring, Ottoboni, and Stark (2016) [2] re-analyzed MacNell et al.’s data and confirmed their conclusions. However, the design of MacNell et al. study is fundamentally flawed. First, MacNell et al.’ section sample sizes were extremely small, ranging from 8 to 12 students. Second, MacNell et al. included only one female and one male instructor. Third, MacNell et al.’s findings depend on three outliers – three unhappy students (all in perceived female conditions) who gave their instructors the lowest possible ratings on all or nearly all SET items. We re-analyzed MacNell et al.’s data with and without the three outliers. Our analyses showed that the gender bias against perceived female instructors disappeared. Instead, students rated the actual female vs. male instructor higher, regardless of perceived gender. MacNell et al.’s study is a real-life demonstration that conclusions based on extremely small sample-sized studies are unwarranted and uninterpretable.

Small samples, unreasonable generalizations, and outliers: Gender bias in student evaluation of teaching or three unhappy students?

In a widely cited and widely talked about study, MacNell et al. (2015) examined SET ratings of one female and one male instructor, each teaching two sections of the same online course, one section under their true gender and the other section under false/opposite gender. MacNell et al. concluded that students rated perceived female instructors more harshly than perceived male instructors, demonstrating gender bias against perceived female instructors. Boring, Ottoboni, and Stark (2016) re-analyzed MacNell et al.s data and confirmed their conclusions. However, the design of MacNell et al. study is fundamentally flawed. First, MacNell et al. section sample sizes were extremely small, ranging from 8 to 12 students. Second, MacNell et al. included only one female and one male instructor. Third, MacNell et al.s findings depend on three outliers -- three unhappy students (all in perceived female conditions) who gave their instructors the lowest possible ratings on all or nearly all SET items. We re-analyzed MacNell et al.s data with and without the three outliers. Our analyses showed that the gender bias against perceived female instructors disappeared. Instead, students rated the actual female vs. male instructor higher, regardless of perceived gender. MacNell et al.s study is a real-life demonstration that conclusions based on extremely small sample-sized studies are unwarranted and uninterpretable.

Mineralized biosignatures in ALH-77005 Shergottite - Clues to Martian Life?

The ALH-77005 Martian meteorite was found in Allan Hills on Antarctica during the Japanese National Institute of Polar Research (1977-1978) mission. One thin section sample was studied by optical microscopy for microtexture and by FTIR-ATR microscopy for interpretation of biogenic minerals and embedded organic materials. The geochemical data (biogenic elements, δ13C) of ALH-77005 meteorite from literature implementing recent results were compared to terrestrial geological samples. The ALH-77005 has poikilitic textures with coarse pyroxenes and brown olivines, and with recrystallized melt pocket. The coarse-grained minerals do not contain any alteration along the grain boundaries. Melt pocket and vicinity of opaque minerals contain biogenic signatures as filamentous, coccoidal forms of iron-oxidizing bacteria. The biosignatures were determined by 1) coccoidal, filamentous forms, 2) presence of embedded organic material, 3) presence of biogenic minerals, like ferrihydrite, goethite, and hematite. The other signatures for biogenicity of this meteorite are strong negative δ13C, enrichment of Fe, Mn, P, Zn in shock melt support scenario. This study proposes presence of microbial mediation on Mars.

Determinants of intellectual capital disclosure: evidence from India

Purpose This paper aims at exploring the extent and determinants of intellectual capital disclosure (ICD) in India. Design/methodology/approach Content of annual reports of 200 firms classified on their market capitalization is analysed using search terms to find out the extent and nature of disclosure. The period of study is 2010-11 and 2013-14. Paired t-test is used to see if there is any significant change in the level of disclosure between two time periods. The various determinants and their impacts are captured using a regression equation. Findings The analysis showed evidence that market capitalization, ownership and age of the firms are the major determinants of ICD in India. Performance, size and type of industry mattered only for large-cap firms. Disclosure levels are seen to increase with market capitalization. Human capital and external capital is highly reported by all categories of firms. The overall disclosure by all categories has significantly increased, whereas that of human capital and external capital has increased significantly only in small-cap and mid-cap firms. Originality/value This paper looks at size, market and performance-related variables and their impact on the extent of disclosure. It takes representative firms from three indices based on their market capitalization and evaluates them, thus making results and findings reliable. This is the first paper which takes a large cross section sample from across 12 sectors and also performs a longitudinal analysis. This paper is of interest to managers of firms who can affect the policies of their firms in making robust changes in disclosure practices.

The study of the mechanical properties of the porous gypsum

The paper presents the laboratory test results of the mechanical properties of porous gypsum. Material for the study was obtained from gypsum Pro-Monta plate of 100mm thick. Based on the compression test of cubic samples, following mechanical properties were determined: compressive strength, Poisson's ratio and Young's modulus. Tensile strength was determined based on three-point bending test of rectangular cross section sample. Also a friction coefficients were investigated as follows: between the smoothed surface of the sample and a fiberboard pad, between a rough surfaces (after cutting) and fiberboard pad. A porosity of the material samples was determined using standard method. The material’s mechanical property values can be useful for modeling destruction and deformation of a porous gypsum undertaken by analytical and numerical methods.

Cross-Section Sample Preparation Method for Imaging Dopant Related Anomalies Using Scanning Probe Microscopy Techniques

Visualization of dopant related anomalies in integrated circuits is extremely challenging. Cleaving of the die may not be possible in practical failure analysis situations that require extensive electrical fault isolation, where the failing die can be submitted of scanning probe microscopy analysis in various states such as partially depackaged die, backside thinned die, and so on. In advanced technologies, the circuit orientation in the wafer may not align with preferred crystallographic direction for cleaving the silicon or other substrates. In order to overcome these issues, a focused ion beam lift-out based approach for site-specific cross-section sample preparation is developed in this work. A directional mechanical polishing procedure to produce smooth damage-free surface for junction profiling is also implemented. Two failure analysis applications of the sample preparation method to visualize junction anomalies using scanning microwave microscopy are also discussed.