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Enhanced propellant performance via environmentally friendly curable surface coating

Defence Technology（防务技术） 2017年第3期13卷 131-142页

作者： Thelma Manning Jeffrey Wyckoff Kenneth Klingaman Viral Panchal eugene rozumov John Bolognini Ming Wang Young Subhash Patel US Army RDECOM ARDEC Picatinny Arsenal Polymer Processing Institute

Surface coating of granular propellants is widely used in a multiplicity of propellants for small, medium and large caliber ammunition. All small caliber ball propellants exhibit burning progressivity due to application of effective deterrent coatings. Large perforated propellant grains have also begun utilizing plasticizing and impregnated deterrent coatings with the purpose of increasing charge weights for greater energy and velocity for the projectile. The deterrent coating and impregnation process utilizes volatile organic compounds(VOCs) and hazardous air pollutants(HAPs) which results in propellants that need to be forced air dried which impacts air quality. Propellants undergo temperature fluctuations during their life. Diffusion coefficients vary exponentially with variations in temperature. A small temperature increase can induce a faster migration, even over a short period of time, which can lead to large deviations in the concentration. This large concentration change in the ammunition becomes a safety or performance liability. The presence of both polymeric deterrents and nitroglycerin(NG) in the nitrocellulose matrix and organic solvents leads to higher diffusion rates. This results in continued emissions of VOCs and HAPs. Conventional polymers tend to partition within the propellant matrix. In other words,localized mixing can occur between the polymer and underlying propellant. This is due to solvent induced softening of the polymer vehicle over the propellant grain. In effect this creates a path where migration can occur. Since nitrate esters, like NG, are relatively small, it can exude to the surface and create a highly unstable and dangerous situation for the warfighter. Curable polymers do not suffer from this partitioning due to "melting" because no VOC solvents are present. They remain surface coated. The small scale characterization testing, such as closed bomb testing, small scale sensitivity, thermal stability,and chemical compatibility, will

关键词：推进剂性能表面涂层可固化环境友好挥发性有机化合物有害空气污染物大口径弹药硝酸纤维素

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Innovative boron nitride-doped propellants

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Defence Technology（防务技术） 2016年第2期12卷 69-80页

作者： Thelma MANNING Richard FIELD Kenneth KLINGAMAN Michael FAIR John BOLOGNINI Robin CROWNOVER Carlton P.ADAM Viral PANCHAL eugene rozumov Henry GRAU Paul MATTER Michael BEACHY Christopher HOLT Samuel SOPOK USA rmy RDECOM ARDEC Picatinny Arsenal NJ USA pH Matter LLC Columbus OH USA Benet Laboratory Watervliet NY USA

The U.S. military has a need for more powerful propellants with balanced/stoichiometric amounts of fuel and oxidants. However, balanced and more powerful propellants lead to accelerated gun barrel erosion and markedly shortened useful barrel life. Boron nitride(BN) is an interesting potential additive for propellants that could reduce gun wear effects in advanced propellants(US patent pending 2015-026P). Hexagonal boron nitride is a good lubricant that can provide wear resistance and lower flame temperatures for gun barrels. Further, boron can dope steel, which drastically improves its strength and wear resistance, and can block the formation of softer carbides. A scalable synthesis method for producing boron nitride nano-particles that can be readily dispersed into propellants has been developed. Even dispersion of the nano-particles in a double-base propellant has been demonstrated using a solvent-based processing approach. Stability of a composite propellant with the BN additive was verified. In this paper, results from propellant testing of boron nitride nano-composite propellants are presented, including closed bomb and wear and erosion testing. Detailed characterization of the erosion tester substrates before and after firing was obtained by electron microscopy,inductively coupled plasma and x-ray photoelectron spectroscopy. This promising boron nitride additive shows the ability to improve gun wear and erosion resistance without any destabilizing effects to the propellant. Potential applications could include less erosive propellants in propellant ammunition for large, medium and small diameter fire arms.

关键词：复合推进剂六角氮化硼硼掺杂创新型 X射线光电子能谱仪电感耦合等离子体腐蚀测试仪合成方法

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Formulation development and characterization of cellulose acetate nitrate based propellants for improved insensitive munitions properties

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Defence Technology（防务技术） 2014年第2期10卷 92-100页

作者： Thelma MANNING Jeffrey WYCKOFF Carlton ADAM eugene rozumov Kenneth KLINGAMAN Viral PANCHAL Joseph LAQUIDARA Mike FAIR John BOLOGNINI Keith LUHMANN Steve VELARDE Christine KNOTT Stephanie M.PIRAINO Kevin BOYD US Army RDECOM ARDECPicatinny Arsenal Alliiant Tech ATK RAFPRD AAP Naval Surface Warhead Center Indian Head Army Research Laboratory Aberdeen Proving Ground

Cellulose acetate nitrate(CAN) was used as an insensitive energetic binder to improve the insensitive munitions(IM) properties of gun propellants to replace the M1 propellant used in 105 mm artillery *** contains the energetic nitro groups found in nitrocellulose(NC),but also acetyl functionalities,which lowered the polymer's sensitivity to heat and shock,and therefore improved its IM properties relative to *** formulation,development and small-scale characterization testing of several CAN-based propellants were *** formulations,using insensitive energetic solid fillers and high-nitrogen modifiers in place of nitramine were *** small scale characterization testing,such as closed bomb testing,small scale sensitivity,thermal stability,and chemical compatibility were *** mechanical response of the propellants under high-rate uni-axial compression at,hot,cold,and ambient temperatures were also *** diameter testing,hot fragment conductive ignition(HFCI) tests were done to evaluate the propellants' responses to thermal and shock *** the propellant chemical composition,theoretical predictions of erosivity were *** the small scale test results were utilized to down-select the promising CAN based formulations for large scale demonstration testing such as the ballistic performance and fragment impact testing in the105 mm M67 artillery charge *** test results completed in the small and large scale testing are discussed.

关键词：硝酸纤维素弹道性能钝感弹药推进剂醋酸纤维素开发配方特性测试

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High quality large single crystals of metal halide perovskites for optoelectronic applications

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Science China Chemistry 2017年第10期60卷 1326-1327页

作者： eugene A.Katz Alexandre Yersin Department of Solar Energy and Environmental Physics J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev Sede Boqer Campus 8499000 Israel Ilse-Katz Institute for Nanoscale Science and Technology Ben-Gurion University of the Negev Beer Sheva 8410501 lsrael

As the technological development of large single-crystalline wafers have revolutionized many industries including electronics and photovoltaics,one can predict that the availability of large single-crystalline perovskite crystals and wafers can revolutionize its broad applications in photodetectors,solar cells,LEDs,lasers,*** 2015,Liu et al.

关键词： crystalline halide perovskite technological electronics inverse optoelectronic wafer availability render

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Alternative kind of hydrogen atoms as a possible explanation for the latest puzzling observation of the 21 cm radio line from the early Universe

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Research in Astronomy and Astrophysics 2020年第7期20卷 172-176页

作者： eugene Oks Physics Department 380 Duncan DriveAuburn UniversityAuburnAL 36849USA

There is a puzzling astrophysical result concerning the latest observation of the absorption profile of the redshifted radio line 21 cm from the early Universe(as described in Bowman et al.). The amplitude of the profile was more than a factor of two greater than the largest predictions. This could mean that the primordial hydrogen gas was much cooler than expected. Some explanations in the literature suggested a possible cooling of baryons either by unspecified dark matter particles or by some exotic dark matter particles with a charge a million times smaller than the electron charge. Other explanations required an additional radio background. In the present paper, we entertain a possible different explanation for the above puzzling observational result: the explanation is based on the alternative kind of hydrogen atoms(AKHA),whose existence was previously demonstrated theoretically, as well as by the analysis of atomic experiments. Namely, the AKHA are expected to decouple from the cosmic microwave background(CMB) much earlier(in the course of the Universe expansion) than usual hydrogen atoms, so that the AKHA temperature is significantly lower than that of usual hydrogen atoms. This seems to lower the excitation(spin) temperature of the hyperfine doublet(responsible for the 21 cm line) sufficiently enough for explaining the above puzzling observational result. This possible explanation appears to be more specific and natural than the previous possible explanations. Further observational studies of the redshifted 21 cm radio line from the early Universe could help to verify which explanation is the most relevant.

关键词： Cosmology:Early Universe explanation of the puzzle of 21cm radio line Galaxies:intergalactic medium Cosmology:observations Cosmology:theory

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Galactic Dark Matter Halos Containing H Ⅰ Regions:A Possible Overestimation of the Column Densities

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Research in Astronomy and Astrophysics 2023年第3期23卷 100-103页

作者： eugene Oks Physics Department Auburn UniversityAuburnAL 36849USA

We analyze how the column density of hydrogen atoms in the HⅠregions,observed in dark matter halos of a number of galaxies,can be *** we study how the determination of the column density of hydrogen atoms from the observed astrophysical data would be affected by the possible presence of the Second Flavor of Hydrogen Atoms(SFHA),whose existence had been previously demonstrated in four different types of atomic experiments and had helped in explaining two puzzling astrophysical observations:the anomalous absorption in the 21 cm line from the early Universe and the smoother,less clumpy distribution of dark matter in the Universe than predicted by Einstein’s *** a model example we demonstrate that the neglect of the SFHA leads to the overestimation of the column density of hydrogen atoms in dark matter halos by about 30%.We perform these relatively simple estimates just to get the message across and to motivate further corresponding theoretical and experimental studies.

关键词： galaxies anomalous estimation

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DES map shows a smoother distribution of matter than expected:a possible explanation

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Research in Astronomy and Astrophysics 2021年第10期21卷 1-4页

作者： eugene Oks Physics Department 380 Duncan DriveAuburn UniversityAuburnAL 36849USA

The largest and most detailed map of the distribution of dark matter in the Universe has been recently created by the Dark Energy Survey(DES)*** distribution was found to be slightly(by a few percent)smoother and less clumpy than predicted by general *** result was considered as a hint of some new physical *** the present paper we offer a relatively simple model that could explain the above result without resorting to any new physical *** model deals with the dynamics of a system consisting of a large number of gravitating neutral particles,whose mass is equal to the mass of hydrogen *** central point of the model is a partial inhibition of the gravitation for a relatively small subsystem of the entire *** would be sufficient for this subsystem to constitute just about a few percent of the total ensemble of particles for explaining the few percent more smooth distribution of dark matter(observed by the DES team)compared to the prediction of general *** most viable candidate for the dark matter particles in this model is the second flavor of hydrogen atoms(SFHA)that has only S-states and therefore does not couple to the electric dipole radiation or even to higher multipole radiation,so that the SFHA is practically *** SFHA has experimental confirmation from atomic experiments,it does not go beyond the Standard Model,it is based on standard quantum mechanics and it explains puzzling astrophysical observations of the redshifted line 21 cm from the early ***,our model explaining the DES result of a little too smooth distribution of dark matter without resorting to any new physical laws seems to be self-consistent.

关键词： (cosmology:)dark matter gravitation atomic processes astroparticle physics

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Reminiscing my sixty year pursuit of the physics of the Sun and the Galaxy

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Research in Astronomy and Astrophysics 2014年第1期14卷 1-14页

作者： eugene N.Parker Department of Physics Department of Astronomy and AstrophysicsUniversity of Chicago

Reminiscing begins with childhood and passes on to student days through graduate school and the first real contact with research. Then early academic posi- tions and stumbling efforts to pursue my ideas. The first significant progress came as a research associate with Prof. W. M. Elsasser at the University of Utah, beginning with an introduction to magnetohydrodynarnics and the generation of the geomagnetic field through induction in the liquid metal core of Earth. A move to the University of Chicago to work with Prof. J. A. Simpson, on the implications of cosmic ray varia- tions and interplanetary magnetic fields, led to the theory of coronal expansion and the solar wind and then to exploring the dynamical effects of cosmic rays on the galactic magnetic field. Spontaneous current sheets and intrinsic rapid reconnection in interlaced magnetic field line topologies were the next big project, leading up to retirement. Finally, it is a pleasure to recall my many associates, whose fresh thinking helped stimulate the daily research activities.

关键词： dynamo -- magnetohydrodynamics -- plasma

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A practical geometrical comparison between free-repelled hydraulic jumps within inclined channels

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Science China(Technological Sciences) 2009年第11期52卷 3363-3367页

作者： John Demetriou eugene Retsinis National Technical University of Athens School of Civil Engineering. JD Research Hydrolab-A non Profit Foundation 12 Polykarpou St. N. Smymi Athens 17123 Greece National Technical University of Athens School of Civil Engineering. 23 Loid Tzortz St. Athens 11744 Greece

In this experimental study a practical geometrical comparison between inclined (angle φ) free and repelled hydraulic jumps (the latter in non prismatic but abruptly expanding channels) is presented, analysed and discussed. For repelled hydraulic jumps a considerable parameter is the expansion ratio r (=channels' width ratio), which here is changing from r =0.5 to r =0.7. The comparison is made with the free jump (in prismatic channel, r =1), in the same ranges of angles φ (0°≤φ≤8°) and Froude numbers (2≤Fr1≤8). A practical arithmetic example is presented to show the behavioral change of conjugate depths, lengths L and depths at 0.5L, in order to receive a comparison among all pertinent geometrical quantities. The present results may be useful for the hydraulic engineering when designing open channels.

关键词： free jumps repelled jumps inclined channels

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Preservation of Linear Constraints in Approximation of Tensors

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Numerical Mathematics(Theory,Methods and Applications) 2009年第4期2卷 421-426页

作者： eugene Tyrtyshnikov Institute of Numerical Mathematics of Russian Academy of Sciences

For an arbitrary tensor(multi-index array) with linear constraints at each direction,it is proved that the factors of any minimal canonical tensor approximation to this tensor satisfy the same linear constraints for t... 详细信息

关键词： Multi-index arrays tensors linear constraints low rank approximation canonicaltensor decomposition multilevel matrices.

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