Publications by authors named "Jennifer Gottfried"

Article Synopsis
  • * The study reports on molecular ionic ferroelectrics that display both room-temperature ionic conductivity and ferroelectric properties, emphasizing the interaction between these characteristics.
  • * The presence of absorbed water molecules in these ionic ferroelectrics allows for controlled adjustments in polarization, thermal conductivity, and electrical resistivity, demonstrating their potential for multifunctional applications.
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This review will focus on the key steps in the recognition of parotid gland and duct injuries focusing on the important steps needed at the initial assessment. Management planning is presented in the way that trauma surgeons interact with patients, highlighting the important parts of the informed consent conversation followed by the key information that must be communicated to the anesthesia and operating room teams, which ensures proper monitoring and equipment needs are in place. Short-term and long-term outcomes for patients with persistent sequelae of the trauma and their management are reviewed.

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Chemical energy ferroelectrics are generally solid macromolecules showing spontaneous polarization and chemical bonding energy. These materials still suffer drawbacks, including the limited control of energy release rate, and thermal decomposition energy well below total chemical energy. To overcome these drawbacks, we report the integrated molecular ferroelectric and energetic material from machine learning-directed additive manufacturing coupled with the ice-templating assembly.

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Background: Many parents seek otoplasty for their school age children but fear having to undergo general anesthesia (GA). In our experience, otoplasty can safely be performed in an office-based setting under local anesthesia (LA). There is a gap in the literature regarding pediatric otoplasty under LA.

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Chemically driven thermal wave triggers high energy release rate in covalently-bonded molecular energetic materials. Molecular ferroelectrics bridge thermal wave and electrical energy by pyroelectric associated with heating frequency, thermal mass and heat transfer. Herein we design energetic molecular ferroelectrics consisting of imidazolium cations (energetic ion) and perchlorate anions (oxidizer), and describe its thermal wave energy conversion with a specific power of 1.

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From humans to vinegar flies, exposure to diets rich in sugar and fat lowers taste sensation, changes food choices, and promotes feeding. However, how these peripheral alterations influence eating is unknown. Here we used the genetically tractable organism to define the neural mechanisms through which this occurs.

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Optical ignition of solid energetic materials, which can rapidly release heat, gas, and thrust, is still challenging due to the limited light absorption and high ignition energy of typical energetic materials ( e.g., aluminum, Al).

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A new synthesis approach for aluminum particles enables an aluminum core to be passivated by an oxidizing salt: aluminum iodate hexahydrate (AIH). Transmission electron microscopy (TEM) images show that AIH replaces the AlO passivation layer on Al particles that limits Al oxidation. The new core-shell particle reactivity was characterized using laser-induced air shock from energetic materials (LASEM) and results for two different Al-AIH core-shell samples that vary in the AIH concentration demonstrate their potential use for explosive enhancement on both fast (detonation velocity) and slow (blast effects) timescales.

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An 11-year-old Caucasian boy, with a microdeletion in the 1q21.1-q21.2 region, had multiple medical conditions including gastroparesis documented initially at the age of 5.

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The impact of laser-driven flyer plates on energetic materials CL-20, PETN, and TATB has been investigated. Flyer plates composed of 25 μm thick Al were impacted into the energetic materials at velocities up to 1.3 km/s.

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A focused, nanosecond-pulsed laser has been used to ablate, atomize, ionize, and excite milligram quantities of metal-doped energetic materials that undergo exothermic reactions in the laser-induced plasma. The subsequent shock wave expansion in the air above the sample has been monitored using high-speed schlieren imaging in a recently developed technique, laser-induced air shock from energetic materials (LASEM). The method enables the estimation of detonation velocities based on the measured laser-induced air-shock velocities and has previously been demonstrated for organic military explosives.

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Herein we present the preparation and characterization of three new bispyrazolyl-based energetic compounds with great potential as explosive materials. The reaction of sodium 4-amino-3,5-dinitropyrazolate (5) with dimethyl iodide yielded bis(4-amino-3,5-dinitropyrazolyl)methane (6), which is a secondary explosive with high heat resistance (T =310 °C). The oxidation of this compound afforded bis(3,4,5-trinitropyrazolyl)methane (7), which is a combined nitrogen- and oxygen-rich secondary explosive with very high theoretical and estimated experimental detonation performance (V (theor)=9304 m s versus V (exp)=9910 m s ) in the range of that of CL-20.

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Differences in the excitation of non-energetic and energetic residues with a 900 mJ, 6 ns laser pulse (1064 nm) have been investigated. Emission from the laser-induced plasma of energetic materials (e.g.

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A series of organic polymers and the military explosive cyclotrimethylenetrinitramine (RDX) were studied using the light emission from a femtosecond laser-induced plasma under an argon atmosphere. The relationship between the molecular structure and plasma emission was established by using the percentages of the atomic species (C, H, N, O) and bond types (C-C, C═C, C-N, and C≡N) in combination with the atomic/molecular emission intensities and decay rates. In contrast to previous studies of organic explosives in which C2 was primarily formed by recombination, for the organic materials in this study the percentage of C-C (and C═C) bonds was strongly correlated to the molecular C2 emission.

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Laser-induced breakdown spectroscopy is a promising approach for explosive residue detection, but several limitations to its widespread use remain. One issue is that the emission spectra of the residues are dependent on the substrate composition because some of the substrate is usually entrained in the laser-induced plasma and the laser-material interaction can be significantly affected by the substrate type. Here, we have demonstrated that despite the strong spectral variation in cyclotrimethylenetrinitramine (RDX) residues applied to various metal substrates, classification of the RDX residue independent of substrate type is feasible.

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Standoff laser induced breakdown spectroscopy (LIBS) has previously been used to classify trace residues as either hazardous (explosives, biological, etc.) or benign. Correct classification can become more difficult depending on the surface/substrate underneath the residue due to variations in the laser-material interaction.

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The feasibility of exploiting plasma chemistry to study the chemical reactions between metallic nanoparticles and molecular explosives such as cyclotrimethylenetrinitramine (RDX) has been demonstrated. This method, based on laser-induced breakdown spectroscopy, involves the production of nanoparticles in a laser-induced plasma and the simultaneous observation of time-resolved atomic and molecular emission characteristic of the species involved in the intermediate chemical reactions of the nanoenergetic material in the plasma. Using this method, it has been confirmed that the presence of aluminum promotes the ejection process of carbon from the intermediate products of RDX.

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The potential of laser-induced breakdown spectroscopy (LIBS) to discriminate biological and chemical threat simulant residues prepared on multiple substrates and in the presence of interferents has been explored. The simulant samples tested include Bacillus atrophaeus spores, Escherichia coli, MS-2 bacteriophage, α-hemolysin from Staphylococcus aureus, 2-chloroethyl ethyl sulfide, and dimethyl methylphosphonate. The residue samples were prepared on polycarbonate, stainless steel and aluminum foil substrates by Battelle Eastern Science and Technology Center.

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In this review we discuss the application of laser-induced breakdown spectroscopy (LIBS) to the problem of detection of residues of explosives. Research in this area presented in open literature is reviewed. Both laboratory and field-tested standoff LIBS instruments have been used to detect explosive materials.

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Recently laser-induced breakdown spectroscopy (LIBS) has been investigated as a potential technique for trace explosive detection. Typically LIBS is performed using nanosecond laser pulses. For this work, we have investigated the use of femtosecond laser pulses for explosive residue detection at two different fluences.

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Laser-induced breakdown spectroscopy (LIBS) was used to discern between two biological agent surrogates (Bacillus atrophaeus and ovalbumin) and potential interferent compounds (mold spores, humic acid, house dust, and Arizona road dust). Multiple linear regression and neural network analysis models were constructed by using B. atrophaeus and ovalbumin spectra, and limits of detection were calculated.

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The performance of a man-portable laser induced breakdown spectrometer was evaluated for the detection of biological powders on indoor office surfaces and wipe materials. Identification of pure unknown powders was performed by comparing against a library of spectra containing biological agent surrogates and confusant materials, such as dusts, diesel soot, natural and artificial sweeteners, and drink powders, using linear correlation analysis. Simple models constructed using a second technique, partial least squares discriminant analysis, successfully identified Bacillus subtilis (BG) spores on wipe materials and office surfaces.

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A technique being evaluated for standoff explosives detection is laser-induced breakdown spectroscopy (LIBS). LIBS is a real-time sensor technology that uses components that can be configured into a ruggedized standoff instrument. The U.

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Laser-induced breakdown spectroscopy (LIBS) is a promising technique for real-time chemical and biological warfare agent detection in the field. We have demonstrated the detection and discrimination of the biological warfare agent surrogates Bacillus subtilis (BG) (2% false negatives, 0% false positives) and ovalbumin (0% false negatives, 1% false positives) at 20 meters using standoff laser-induced breakdown spectroscopy (ST-LIBS) and linear correlation. Unknown interferent samples (not included in the model), samples on different substrates, and mixtures of BG and Arizona road dust have been classified with reasonable success using partial least squares discriminant analysis (PLS-DA).

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Since the Royal Society Discussion Meeting on H3+ in 2000, the laboratory spectroscopy of H3+ has entered a new regime. For the first time, transitions of H3+ above the barrier to linearity have been observed. A highly sensitive near-infrared spectrometer based on a titanium:sapphire laser and incorporating a dual-beam, double-modulation technique with bidirectional optical multi-passing has been developed in order to detect these transitions, which are more than 4600 times weaker than the fundamental band.

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