Mary Kathleen Alam

Sandia National Laboratories · Energetics Characterization

1H NMR spectroscopy and chemometric analysis were used to characterize rat urine obtained after chronic exposure to either tributyl phosphate (TBP) or triphenyl phosphate (TPP). In this study, the daily dose exposure was 1.5 mg/kg body weight for TBP, or 2.0 mg/kg body weight for TPP, administered over a 15-week period. Orthogonal signal correction...

Vapor‐deposited hexanitroazobenzene (HNAB) films were observed to form a dense amorphous structure that crystallizes to a mixture of the HNAB‐II polymorph and an unidentified structure over a period ranging from hours to weeks depending on the ambient temperature. Films crystallized at various temperatures were characterized using scanning electron...

Vapor-deposited hexanitroazobenzene (HNAB) has been shown to form an amorphous structure as-deposited that crystallizes over a period ranging from several hours to several weeks, depending on the ambient temperature. Raman spectroscopy and x-ray diffraction were used to identify three distinct phases during the crystallization process: the as-depo...

A slapper detonator which integrally incorporates an optical wavequide structure for determining whether there has been degradation of the explosive in the explosive device that is to be initiated by the detonator. Embodiments of this invention take advantage of the barrel-like character of a typical slapper detonator design. The barrel assembly, b...

Tributyl phosphate (TBP) is a toxic organophosphorous compound widely used in many industrial applications, including significant usage in nuclear processing. The industrial application of this chemical is responsible for occupational exposure and environmental pollution. In this study, (1)H NMR-based metabonomics has been applied to investigate th...

The industrial application of organophosphates provides the opportunity for environmental exposure. While the toxicity of organophosphate compounds has been the target of significant work, studies directed towards the identification of metabolite markers to assess phosphate exposure are more limited. In this study the urine metabolite profiles for...

Tracking nuclear materials production and processing, particularly covert operations, is a key national security concern, given that nuclear materials processing can be a signature of nuclear weapons activities by US adversaries. Covert trafficking can also result in homeland security threats, most notably allowing terrorists to assemble devices su...

Chemometric analysis of nuclear magnetic resonance (NMR) spectroscopy has increased dramatically in recent years. A variety of different chemometric techniques have been applied to a wide range of problems in food, agricultural, medical, process and industrial systems. This article gives a brief review of chemometric analysis of NMR spectral data,...

The introduction of a variance-filter to both direct standardization (DS) and piece-wise direct standardization (PDS) instrumental transfer methods for the analysis of NMR spectral data is described. The variance-filter modification allows for the identification of regions in the NMR spectra that are not adequately represented by the limited number...

Hexanitrostilbene (HNS) is a secondary explosive widely used in a variety of commercial and military applications, due in part to its high heat resistivity. Degradation of HNS is known to occur through exposure to a variety of sources including heat, UV radiation, and certain chemical compounds, all of which may lead to reduced performance. Detecti...

The implementation of direct standardization (DS), piecewise direct standardization (PDS), and double-window piecewise direct standardization (DWPDS) instrumental transfer techniques for high-resolution (1)H NMR spectral data was explored. The ability to transfer a multivariate calibration model developed for a "master or target" NMR instrument con...

We report the application of attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) to interrogate live cells, resting and stimulated with lipopolysaccharide (LPS) and gamma-interferon (INF-γ) over the course of 1 h from a murine macrophage-like cell line. Sub-culturing of the cells directly on the ATR crystal results in im...

Hexanitrostilbene (HNS) is a widely used explosive, due in part to its high thermal stability. Degradation of HNS is known to occur through UV, chemical exposure, and heat exposure, which can lead to reduced performance of the material. Common methods of testing for HNS degradation include wet chemical and surface area testing of the material itsel...

A slapper detonator which integrally incorporates an optical wavequide structure for determining whether there has been degradation of the explosive in the explosive device that is to be initiated by the detonator. Embodiments of this invention take advantage of the barrel-like character of a typical slapper detonator design. The barrel assembly, b...

In an effort to shed additional light on the chemical mechanisms underlying the radiation oxidation of polypropylene (PP), we are using samples having selective 13C isotopic labeling at the three unique sites within the macromolecular structure. After radiation exposure, we applied GC/MS, solid-state 13C NMR, and FTIR to evaluate the applicability...

Studies of gettering reactions of a commercial flashed metal alloy commonly used in vacuum electronics with common gases found in vacuum electronic systems (CO, CO2, CH4, and O2) have been carried out in situ using Fourier transform infrared spectroscopy (FT-IR) to better understand the nature of these reactions as a function of temperature. Flashe...

The sections in this article are Introduction The Study of Human Peripheral Muscle Organ Perfusion and Metabolism Skin Monitoring Tumor Detection Detection of pH in Blood and Tissue Lipids and Proteins Body Composition Conclusion

The application of chemometric or multivariate analysis techniques to nuclear magnetic resonance (NMR) spectroscopic data is reviewed. Descriptions of the different processing and data manipulation procedures being utilized to produce reproducible input data sets for chemometric analysis are discussed. A brief review of some of the standard supervi...

Methods and apparatuses of determining the pH of a sample. A method can comprise determining an infrared spectrum of the sample, and determining the hemoglobin concentration of the sample. The hemoglobin concentration and the infrared spectrum can then be used to determine the pH of the sample. In some embodiments, the hemoglobin concentration can...

The application of chemometric or multivariate analysis techniques to nuclear magnetic resonance (NMR) spectroscopic data is reviewed. Descriptions of the different processing and data manipulation procedures being utilized to produce reproducible input data sets for chemometric analysis are discussed. A brief review of some of the standard supervi...

Infection activates immune response pathways in host macrophages and lymphocytes that might be of sufficient magnitude to facilitate early diagnoses of infections through a host immune biosignature. Attenuated total reflectance (ATR) infrared spectroscopy was used to examine the spectroscopic signatures of living mouse macrophage cells before and a...

The effect of non-exponential and multi-exponential decay or relaxation behavior on the performance of the direct exponential curve resolution algorithm (DECRA) is investigated through a series of numerical simulations. Three different combinations of decay or relaxation behavior were investigated through DECRA analysis of simulated pulse gradient...

The near-infrared (NIR) measurement of blood pH relies on the spectral signature of histidine residing on the hemoglobin molecule. If the amount of hemoglobin in solution varies, the size of the histidine signal can vary depending on changes in either the pH or hemoglobin concentration. Multivariate calibration models developed using the NIR spectr...

Polymeric chemiresistors are a class of chemical sensor that have promise for being practical in situ sensors of volatile organic compounds (VOC) in various environmental monitoring applications. However, these devices may undergo changes in response due to changes in temperature or humidity that must be taken into consideration when developing cal...

Many data analysis algorithms that are currently employed in SAW sensors lack the ability to easily maintain calibration models in the presence of unmodeled interferents or sensor drift. The classical least squares/partial least squares (CLS/PLS) hybrid algorithm is tested in this study for its ability to update calibration models for unmodeled int...

The diffuse reflection (DR) spectrum of a sample consisting of a mixture of rare earth oxides and talc was measured at 2 cm-1 resolution, using five different accessories installed on five different Fourier transform near-infrared (FT-NIR) spectrometers from four manufacturers. Peak positions for 37 peaks were determined using two peak-picking algo...

We employ infrared spectroscopy (IR) with attenuated total reflectance (ATR) as a sampling technique to monitor live and dried RAW cells (a murine macrophage cell line) during activation with g-interferon and lipopolysaccharide. By comparing the spectra of activated cells at various time points to the spectra of healthy control cells, we identify s...

The goal of this LDRD Research project was to provide a preliminary examination of the use of infrared spectroscopy as a tool to detect the changes in cell cultures upon activation by an infectious agent. Due to a late arrival of funding, only 5 months were available to transfer and setup equipment at UTTM,develop cell culture lines, test methods o...

This paper will describe an algorithm for detecting and classifying seismic and acoustic signals for unattended ground sensors. The algorithm must be computationally efficient and continuously process a data stream in order to establish whether or not a desired signal has changed state (turned-on or off). The paper will focus on describing a Fourie...

Multivariate techniques were used to address the quantification of (17)O-nuclear magnetic resonance (NMR) spectra for a series of primary alcohol mixtures. Due to highly overlapping resonances, quantitative spectral evaluation using standard integration and deconvolution techniques proved difficult. Multivariate evaluation of the (17)O-NMR spectral...

This invention relates to methods and apparatus for, preferably, determining non-invasively and in vivo at least two of the five blood gas parameters (i.e., pH, [HCO.sub.3.sup.- ], PCO.sub.2, PO.sub.2, and O.sub.2 sat.) in a human.

Whole blood pH has been determined in vitro by using near-infrared spectroscopy over the wavelength range of 1500 to 1785 nm with multivariate calibration modeling of the spectral data obtained from two different sample sets. In the first sample set, the pH of whole blood was varied without controlling cell size and oxygen saturation (O2 Sat) varia...

Near-infrared spectra (1300â2500 nm) collected from lysed blood solutions were shown to correlate with the pH of the solutions measured potentiometrically. Cross-validated partial least-squares (PLS) models were developed from these spectral data, which provided standard error of prediction (SEP) values below 0.05 pH units for a pH range of 1.0 (6....

Recent investigations by our group have demonstrated that near-infrared spectra collected from lysed blood solutions can be used to create clinically useful partial least squares (PLS) models for pH with standard errors of prediction below 0.05 pH units for a pH range of 1 (6.8 to 7.8). Further work was performed in order to discern the primary sou...

High precision near-infrared spectroscopy in the wavelength region 1100-1800 nm was used to provide data on the intermolecular interactions of alcohols and water. This data can be used to further refine alcohol/water composition diagrams as an aid to understanding gradient elution in reversed-phase chromatography using an alcohol/water mixture as a...

The use of ¹⁷O NMR spectroscopy as a tool to investigate aging in polymer systems has recently been demonstrated. Because the natural abundance of ¹⁷O is extremely low (0.037%), the use of labeled ¹⁷Oâ during the oxidation of polymers produces ¹⁷O NMR spectra whose signals arise entirely from the degradation species (i.e. signals from t...

In order to produce pure polymer streams from post-consumer waste plastics, a quick, accurate and relatively inexpensive method of sorting needs to be implemented. This technology has been demonstrated by using near-infrared spectroscopy reflectance data and neural network classification techniques. Backpropagation neural network routines have been...

Multivariate techniques were used to address the quantification of ¹⁷O-NMR (nuclear magnetic resonance) spectra for a series of primary alcohol mixtures. Due to highly overlapping resonances, quantitative spectral evaluation using standard integration and deconvolution techniques proved difficult. Multivariate evaluation of the ¹⁷O-NMR spectr...

While plastic recycling efforts have expanded during the past several years, the cost of recovering plastics is still a major impediment for recyclers. Several factors contribute to the prohibitive cost of recycled resins, including the present low marketability of products made with mixed recycled materials, and costs of collecting, sorting and re...