bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of the Thermal Response of Munitions in Storage Exposed to Real and Arbitrary Weather Conditions
Authors: Blecker Ken , Hadim Hamid 
Published: January 2016

AbstractThe objective of this investigation is to characterize the thermal response of stored munitions exposed to real weather conditions in order to validate current test procedures as well as develop the ability to provide an estimate of the thermal exposure over the lifecycle of a munition. Currently, the thermal history of munitions in storage cannot be determined without continuous monitoring of individual items and there is no method to provide a detailed estimate of the exposure by analyzing existing data when continuous data was not collected. This work describes the experimental and initial numerical investigations of instrumented munitions in storage to characterize their thermal response. The numerical model has the capability to validate broad trends observed from the experimental data. For this investigation, data is being collected through field experiments of inert munitions instrumented with thermocouples that are collocated near a weather station. Data from field experiments are used to develop and validate the numerical model. The numerical model will save time and resources in future investigations of the thermal exposure of munitions in storage as well as advance the understanding of the implications of selecting a long term storage environment. At a fundamental research level, this work contributes to the advances in combined heat transfer by natural convection and radiation inside a 3D enclosure combined with external forced convection and radiation. The numerical model includes several features including heat transfer to the enclosure by solar radiation, conduction, and forced convection, heat transfer between the enclosure container walls and the projectiles by radiation, conduction, and natural convection, heat transfer within the projectile by conduction, distributed thermal energy storage in projectiles, and transient temperature boundary condition at the enclosure walls.
Thermoanalytical Investigation of Some Binary Pyrotechnic Mixtures of Ammonium Azide as Chemical Gas Generating Systems
Authors: Hosseini Seyed Ghorban , Eslami Abbas 
Published: January 2016

AbstractThe conventional NaN3/oxidants gas generator pyrotechnic mixtures suffer from leaving undesirable solid residues. The presented investigation aimed to overcome this problem through mixing of NH4N3 particles with some metallic components, and to introduce some new gas generator pyrotechnic mixtures. In this work, volatile ammonium azide particles were initially stabilized via microencapsulation technique, and blended with Zr, Ti, ZrH2, and TiH2 powders to produce different gas generation mixtures. Thermal properties and kinetic parameters of these pyrotechnic mixtures were investigated by using thermal analysis (TG/DTA and DSC) techniques. The apparent activation energy (E), ΔG#, ΔH#, ΔS#, and critical ignition temperature (Tb) of the ignition processes of the mixtures were obtained from the DSC experiments. Among the investigated mixtures, NH4N3/ZrH2 composition was found to show desirable efficiency, and also it can be considered as a safe pyrotechnic composition for gas generation property, due to its moderate ignition temperature.
Effects of Aluminum Content on TNT Detonation and Aluminum Combustion using Electrical Conductivity Measurements
Authors: Zhou Zhen Qing , Nie Jian Xing , Zeng Liang , Jin Zhao Xin , Jiao Qing Jie 
Published: January 2016

AbstractTo improve the understanding how aluminum contributes in non‐ideal explosive mixtures, cast‐cured formulations were analyzed in a series of electrical conductivity experiments. Five types of TNT‐based aluminized explosives, with aluminum mass fractions from 0 % to 20 % were considered in this study. The electrical conductivity of the detonation products in aluminized explosives was measured using an improved conductivity measurement method. The conductivity measurement results show that the detonation process of TNT‐based aluminized explosives can be divided into two stages: the first stage is the detonation reaction of TNT, and the second stage is the combustion reaction of aluminum with the detonation products. In the first stage, the duration of the TNT detonation increases with increased aluminum content; examination of the peak conductivities of the explosives with various aluminum contents indicated that a higher aluminum content is associated with a lower peak conductivity. Additionally, the ignition time of Al in the second stage is also determined. This work not only presents a means for studying the detonation process of aluminized explosives at 0–2.21 μs, but it also verified the relationship between the aluminum content and electrical conductivity in detonation products.
Characterization of Granular and Polymer‐Embedded RDX Grades: Floret Tests
Authors: van der Heijden Antoine E. D. M. , Bouma Richard H. B. 
Published: January 2016

AbstractIn an attempt to further contribute to the characterization of explosive compositions, small scale Floret tests were performed using four RDX grades, differing in product quality. A Floret test provides a measure – by indentation of a copper block – of detonation spreading or the initiability and shock wave divergence and is applied in particular to explosives used in initiation trains. Both as‐received RDX and PBXs (based on the AFX‐757 composition, a hard target penetrator explosive) containing these RDX grades were tested in the Floret test set‐up. It was found that the Floret test method, when applied to granular, as‐received RDX, was not able to discriminate between the overall RDX product qualities on the basis of the resulting volume of the indentation in the copper block. For the Floret test data of the PBX samples, a division into two parts, where one of the RDX lots shows a lower dent volume compared to the other RDX lots tested. Based on the results presented in this paper with granular RDX and a PBX composition and earlier results with a different type of PBX (based on PBXN‐109, an insensitive high explosive used in a wide range of munitions), the Floret test could be developed into a screening test for shock sensitivity and product quality, without the need for complex and large volume casting of specific PBX compositions.
Synthesis of CL‐20 by a Greener Method Using Nitroguanidine/HNO3
Authors: Bayat Yadollah , Hajighasemali Fatemeh 
Published: January 2016

AbstractCL‐20 is a nitramine applied in both explosives and propellants. The traditional nitrolysis of tetraacetyldibenzylhexaazaisowurtzitane (TADB), as the key precursor for the synthesis of CL‐20, requires the use of N2O4/HNO3/H2SO4 (so‐called mixed acid) which has its drawbacks, especially at industrial scales. Herein, the nitrolysis of TADB with a one pot method was investigated using nitroguanidine (NQ) and guanidinium nitrate (GN)/HNO3 as new system for the synthesis of CL‐20. Positive features of these nitro‐debenzylation/nitro‐deacetylation methods include lack of mixed acids, simple work‐up and less hazardous reagents. The maximum yield of reaction (72 %) was obtained under optimized conditions (NQ (3.48 mmol) and TADB (0.58 mmol) in 98 % HNO3 (5 mL) at 85 °C and 24 h).
Comparison of the peptide binding preferences of three closely related TRAF paralogs: TRAF2, TRAF3, and TRAF5
Authors: Foight Glenna Wink , Keating Amy E. 
Published: January 2016

AbstractTumor necrosis factor receptor‐associated factors (TRAFs) constitute a family of adapter proteins that act in numerous signaling pathways important in human biology and disease. The MATH domain of TRAF proteins binds peptides found in the cytoplasmic domains of signaling receptors, thereby connecting extracellular signals to downstream effectors. Beyond several very general motifs, the peptide binding preferences of TRAFs have not been extensively characterized, and differences between the binding preferences of TRAF paralogs are poorly understood. Here we report a screening system that we established to explore TRAF peptide‐binding specificity using deep mutational scanning of TRAF‐peptide ligands. We displayed single‐ and double‐mutant peptide libraries based on the TRAF‐binding sites of CD40 or TANK on the surface of Escherichia coli and screened them for binding to TRAF2, TRAF3, and TRAF5. Enrichment analysis of the library sequencing results showed differences in the permitted substitution patterns in the TANK versus CD40 backgrounds. The three TRAF proteins also demonstrated different preferences for binding to members of the CD40 library, and three peptides from that library that were analyzed individually showed striking differences in affinity for the three TRAFs. These results illustrate a previously unappreciated level of binding specificity between these close paralogs and demonstrate that established motifs are overly simplistic. The results from this work begin to outline differences between TRAF family members, and the experimental approach established herein will enable future efforts to investigate and redesign TRAF peptide‐binding specificity.
Monitoring structural evolution of organosilicate species during sol–gel processes by electrospray ionization mass spectrometry
Authors: Li Jun , Chen Lei 
Published: January 2016

RationaleElectrospray ionization mass spectrometry (ESI‐MS) has been employed to study species distribution in controlled acid‐catalyzed hydrolysis and condensation of (3‐chloropropyl)trimethoxysilane (CPTMS), which is frequently used in the synthesis of hybrid silica‐based materials.MethodsThe conditions of analysis for reaction products, i.e. organosilicate oligomers, were optimized by using various capillary temperatures and solute concentrations. The structures of organosilicate oligomers were shown to vary with reaction duration and the molar ratio of water to siloxane (r), with multiple types of oligomers attributed to linear, cyclic and hydroxylated species.ResultsThe evolution of oligomeric structures was elucidated from the ESI‐MS spectra. The number and intensity of cyclic oligomers increase with an increase in the r‐value or reaction length, at the expense of linear species, indicating the trend to formation of cross‐linked polysiloxane structures.ConclusionsOverall, this work demonstrates that ESI‐MS is an indispensable tool for the comprehensive characterization of the correlation between properties and structure of hybrid silica‐based materials. Copyright © 2016 John Wiley & Sons, Ltd.
Rapid detection of water buffalo ricotta adulteration or contamination by matrix‐assisted laser desorption/ionisation time‐of‐flight mass spectrometry
Authors: Russo Rosita , Rega Camilla , Chambery Angela 
Published: January 2016

RationaleThe improvement and development of novel technologies and analytical tools are an important first line of defence for both detecting and deterring food frauds. In order to protect the authenticity of traditional foods and safeguard geographical indications and traditional specialities at European level, Protected Designation of Origin (PDO) legislation has been introduced as a guarantee of quality (Council Regulation ECC 2081/92). Dairy products, especially those certified as PDO products, are amongst the most common targets of fraudulent activities. Recently, the buffalo ricotta, a dairy product exclusively made with buffalo milk and produced in the same geographical area of most widely known buffalo mozzarella, has gained PDO recognition.MethodsIn the present work, a fast and simple matrix‐assisted laser desorption/ionisation time‐of‐flight mass spectrometry (MALDI‐TOFMS)‐based methodology has been developed for detecting the adulteration or contamination of buffalo ricotta with bovine milk.ResultsWe optimized a fast procedure for digesting milk proteins and identified a novel specific proteotypic marker, corresponding to region 149‐162 of β‐lactoglobulin, as highly diagnostic for the presence of cow milk within ricotta matrices.ConclusionsBy exploiting the advantages of MALDI‐TOFMS, the proposed methodology represents a useful tool for the assessment of buffalo ricotta authenticity and to guarantee the PDO certification against frauds. Copyright © 2016 John Wiley & Sons, Ltd.
Deamidation reactions of protonated asparagine and glutamine investigated by ion spectroscopy
Authors: Kempkes Lisanne J. M. , Martens Jonathan K. , Grzetic Josipa , Berden Giel , Oomens Jos 
Published: January 2016

RationaleDeamidation of Asn and Gln residues is a primary route for spontaneous post‐translational protein modification. Several structures have been proposed for the deamidation products of the protonated amino acids. Here we verify these structures by ion spectroscopy, as well as the structures of parallel and sequential fragmentation products.MethodsInfrared ion spectroscopy using the free electron laser FELIX has been applied to the reaction products from deamidation of protonated glutamine and asparagine in a tandem mass spectrometer. IR spectra were recorded over the 800–1900 cm−1 spectral range by infrared multiple‐photon dissociation (IRMPD) spectroscopy. Molecular structures of the fragment ions are derived from comparison of the experimental spectra with spectra predicted for different candidate structures by density functional theory (DFT) calculations.Results[AsnH+ – NH3]+ is found to possess a 3‐aminosuccinic anhydride structure protonated on the amino group. The dissociation reaction involving loss of H2O and CO forms a linear immonium ion. For [GlnH+–NH3]+, the N‐terminal nitrogen acts as the nucleophile leading to an oxo‐proline product ion structure. For [GlnH+–NH3]+, a sequential loss of [CO + H2O] is found, leading to a pyrolidone‐like structure. We also confirm by IR spectroscopy that dehydration of protonated aspartic acid (AspH+) and glutamic acid (GluH+) leads to identical structures as to those found for the loss of NH3 from AsnH+ and GlnH+.ConclusionsThe structure determined for AsnH+ is in agreement with the suggested structure derived from measured and computed activation energies. IR ion spectra for the NH3‐loss product from GlnH+ establish that a different reaction mechanism occurs for this species as compared to AsnH+. For both amino acids, loss of NH3 occurs from the side chain. Copyright © 2016 John Wiley & Sons, Ltd.
Fukushima Daiichi reactor source term attribution using cesium isotope ratios from contaminated environmental samples
Authors: Snow Mathew S. , Snyder Darin C. , Delmore James E. 
Published: January 2016

RationaleSource term attribution of environmental contamination following the Fukushima Daiichi Nuclear Power Plant (FDNPP) disaster is complicated by a large number of possible similar emission source terms (e.g. FDNPP reactor cores 1–3 and spent fuel ponds 1–4). Cesium isotopic analyses can be utilized to discriminate between environmental contamination from different FDNPP source terms and, if samples are sufficiently temporally resolved, potentially provide insights into the extent of reactor core damage at a given time.MethodsRice, soil, mushroom, and soybean samples taken 100–250 km from the FDNPP site were dissolved using microwave digestion. Radiocesium was extracted and purified using two sequential ammonium molybdophosphate‐polyacrylonitrile columns, following which 135Cs/137Cs isotope ratios were measured using thermal ionization mass spectrometry (TIMS). Results were compared with data reported previously from locations to the northwest of FDNPP and 30 km to the south of FDNPP.Results135Cs/137Cs isotope ratios from samples 100–250 km to the southwest of the FDNPP site show a consistent value of 0.376 ± 0.008. 135Cs/137Cs versus 134Cs/137Cs correlation plots suggest that radiocesium to the southwest is derived from a mixture of FDNPP reactor cores 1, 2, and 3. Conclusions from the cesium isotopic data are in agreement with those derived independently based upon the event chronology combined with meteorological conditions at the time of the disaster.ConclusionsCesium isotopic analyses provide a powerful tool for source term discrimination of environmental radiocesium contamination at the FDNPP site. For higher precision source term attribution and forensic determination of the FDNPP core conditions based upon cesium, analyses of a larger number of samples from locations to the north and south of the FDNPP site (particularly time‐resolved air filter samples) are needed. Published in 2016. This article is a U.S. Government work and is in the public domain in the USA.
Analysis of nitrogen‐based explosives with desorption atmospheric pressure photoionization mass spectrometry
Authors: Kauppila T. J. , Flink A. , Pukkila J. , Ketola R. A. 
Published: January 2016

RationaleFast methods that allow the in situ analysis of explosives from a variety of surfaces are needed in crime scene investigations and home‐land security. Here, the feasibility of the ambient mass spectrometry technique desorption atmospheric pressure photoionization (DAPPI) in the analysis of the most common nitrogen‐based explosives is studied.MethodsDAPPI and desorption electrospray ionization (DESI) were compared in the direct analysis of trinitrotoluene (TNT), trinitrophenol (picric acid), octogen (HMX), cyclonite (RDX), pentaerythritol tetranitrate (PETN), and nitroglycerin (NG). The effect of different additives in DAPPI dopant and in DESI spray solvent on the ionization efficiency was tested, as well as the suitability of DAPPI to detect explosives from a variety of surfaces.ResultsThe analytes showed ions only in negative ion mode. With negative DAPPI, TNT and picric acid formed deprotonated molecules with all dopant systems, while RDX, HMX, PETN and NG were ionized by adduct formation. The formation of adducts was enhanced by addition of chloroform, formic acid, acetic acid or nitric acid to the DAPPI dopant. DAPPI was more sensitive than DESI for TNT, while DESI was more sensitive for HMX and picric acid.ConclusionsDAPPI could become an important method for the direct analysis of nitroaromatics from a variety of surfaces. For compounds that are thermally labile, or that have very low vapor pressure, however, DESI is better suited. Copyright © 2016 John Wiley & Sons, Ltd.
Invasive tracheobronchial aspergillosis progressing from bronchial to diffuse lung parenchymal lesions
Authors: Ohta Hiromitsu , Yamazaki Susumu , Miura You , Kanazawa Minoru , Sakai Fumikazu , Nagata Makoto 
Published: January 2016

AbstractInvasive tracheobronchial aspergillosis that is entirely limited or predominantly confined to tracheobronchial lesions is a relatively rare form of invasive pulmonary aspergillosis. Extended parenchymal opacities that are radiological manifestations of invasive aspergillosis sometimes occur following invasive tracheobronchial aspergillosis. However, it remains unclear whether or not invasive tracheobronchial aspergillosis is the initial stage of invasive pulmonary aspergillosis. A 61‐year‐old woman was admitted because of severe diarrhea and dehydration. Three days after admission, she complained of dyspnea. A computed tomography (CT) scan of the chest showed bronchial wall thickening. She developed respiratory failure despite antibiotic therapy. A CT scan showed obstructions of bronchial lumens and bronchiectasis in the right upper lobe. Aspergillus fumigatus was identified from samples obtained in bronchoscopic examination. Bronchial lesions rapidly progressed to be extended. Aspergillus infection with multiple parenchymal opacities was observed on CT scan. She responded to treatment with antifungal drugs.
Two‐dimensional visualization and measurement of the fetal optic chiasm: improving counseling for antenatal diagnosis of agenesis of the septum pellucidum
Authors: Viñals F. , Ruiz P. , Correa F. , Gonçalves Pereira P. 
Published: January 2016

ABSTRACTObjectiveTo develop an objective method for visualizing and measuring the fetal optic chiasm (OC) using transvaginal two‐dimensional (2D) ultrasound in the coronal plane and to report measurements in fetuses with agenesis of the septum pellucidum (SP).MethodsThis was a prospective cross‐sectional study of 115 morphologically normal fetuses in low‐risk pregnancies, between 21 and 30 weeks' gestation. The OC was measured in a coronal plane at the level of the third ventricle and was seen as a horizontally aligned dumbbell‐shaped structure of moderate echogenicity. In addition, OC measurements from eight fetuses with agenesis of the SP and complete follow‐up were compared with the reference range.ResultsOC measurements were obtained in 110/115 normal fetuses and showed that OC increases linearly with gestational age. Our method of measurement demonstrated good intraobserver repeatability and excellent interobserver reproducibility. Among the eight fetuses with agenesis of the SP, five had normal OC measurements and five had normal vision postnatally. Pregnancy continued to term in all cases and the follow‐up period varied from 6 months to 7 years.ConclusionOur study demonstrates that it is possible to visualize and measure the OC directly on a 2D ultrasound coronal plane. In fetuses with agenesis of the SP, the morphology and width of the OC visual pathway could prove a relevant tool for assessing its development. It would also help in the difficult task of providing antenatal counseling when faced with the diagnosis of agenesis of the SP. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.
Fetal growth is associated with first‐trimester maternal vascular function
Authors: Iacobaeus C. , Kahan T. , Jörneskog G. , Bremme K. , Thorsell M. , Andolf E. 
Published: January 2016

ABSTRACTObjectiveTo investigate the relationship between maternal endothelial function in the first trimester, assessed in both the brachial artery and the forearm skin microcirculation, and fetal growth.MethodsVascular function was assessed in 56 pregnant women during gestational weeks 11–14. Vascular reactivity in the brachial artery was evaluated by postischemic hyperemia‐induced flow‐mediated vasodilatation (FMD) and by vasodilatation following administration of sublingual glyceryl trinitrate (GTN). Forearm skin microcirculation was investigated by laser Doppler perfusion imaging during iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP) to assess endothelium‐dependent and ‐independent microvascular vasodilatation, respectively. Fetal growth was measured at study inclusion and birth‐weight centile was calculated after delivery.ResultsFMD and GTN‐induced vasodilatation were both associated with birth‐weight centile. On multivariate analysis (adjusted for brachial artery diameter at rest, blood pressure, maternal age and heart rate), for FMD β = 1.7 (95% CI, 0.06–3.34), r2 = 0.26 and P = 0.042, and for GTN‐induced vasodilatation β = 2.6 (95% CI, 0.44–4.68), r2 = 0.15 and P = 0.02. Endothelium‐dependent and ‐independent microvascular reactivity were also associated with birth‐weight centile: for ACh β = 7.82 (95% CI, 1.81–13.83), r2 = 0.12 and P = 0.029, and for SNP β = 6.27 (95% CI, 1.20–11.34), r2 = 0.11 and P = 0.016.ConclusionFirst‐trimester maternal vascular dilatation capacity (rather than endothelial function alone) is associated with fetal growth. These findings were consistent in both the brachial artery and the forearm skin microcirculation. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.