WorldWideScience

Sample records for nano-alluminized propellants comparison

  1. Propeller-Shaped ZnO Nano structures Obtained by Chemical Vapor Deposition: Photoluminescence and Photo catalytic Properties

    International Nuclear Information System (INIS)

    Wang, S.L.; Zhu, H.W.; Li, P.G.; Tang, W.H.

    2012-01-01

    Propeller-shaped and flower-shaped ZnO nano structures on Si substrates were prepared by a one-step chemical vapor deposition technique. The propeller-shaped ZnO nano structure consists of a set of axial nano rod (50 nm in tip, 80 nm in root and 1μm in length), surrounded by radial-oriented nano ribbons (20-30 nm in thickness and 1.5μm in length). The morphology of flower-shaped ZnO nano structure is similar to that of propeller-shaped ZnO, except the shape of leaves. These nano rods leaves (30?nm in diameter and 1-1.5μm in length) are aligned in a radial way and pointed toward a common center. The flower-shaped ZnO nano structures show sharper and stronger UV emission at 378 nm than the propeller-shaped ZnO, indicating a better crystal quality and fewer structural defects in flower-shaped ZnO. In comparison with flower-shaped ZnO nano structures, the propeller-shaped ZnO nano structures exhibited a higher photo catalytic property for the photo catalytic degradation of Rhodamine B under UV-light illumination.

  2. Research on the combustion properties of propellants with low content of nano metal powders

    Energy Technology Data Exchange (ETDEWEB)

    Zhi, Jiang; Shu-Fen, Li [Department of Chemical Physics, University of Science and Technology of China, Hefei 230026 (China); Feng-Qi, Zhao; Zi-Ru, Liu; Cui-Mei, Yin; Yang, Luo; Shang-Wen, Li [Xi' an Modern Chemistry Research Inst., Xi' an 710065 (China)

    2006-04-15

    A comparison of various experimental results for combustionrelated properties evaluation, including burning rates, deflagration heat, flame structures and thermal decomposition properties, of AP/RDX/Al/HTPB composite propellants containing nano metal powders is presented. The thermal behavior of n-Al (nano grain size aluminum) and g-Al (general grain size aluminum i.e., 10 {mu}m) heated in air was also investigated by thermogravimetry. The burning rates results indicate that the usage of bimodal aluminum distribution with the ratio around 4: 1 of n-Al to g-Al or the addition of 2% nano nickel powders (n-Ni) will improve the burning behavior of the propellant, while the usage of grading aluminum powders with the ratio 1: 1 of n-Al to g-Al will impair the combustion of the propellant. Results show that n-Al and n-Ni both have a lower heating capacity, lower ignition threshold and shorter combustion time than g-Al. In addition n-Al is inclined to burn in single particle form. And the thermal analysis results show that n-Ni can catalyze the thermal decomposition of AP in the propellant. The results also confirm the high reactivity of n-Al, which will lead to a lower reaction temperature and rather higher degree of reaction ratio as compared with g-Al in air. All these factors will influence the combustion of propellants. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  3. Effect of the Dispersibility of Nano-CuO Catalyst on Heat Releasing of AP/HTPB Propellant

    International Nuclear Information System (INIS)

    Yang, Y.; Yu, X.; Wang, J.; Wang, Y.

    2011-01-01

    Kneading time is adjusted to change the dispersibility of nano-CuO in AP/HTPB (Ammonia Perchlorate/Hydroxyl-Terminated Polybutadiene) composite propellants. Nano-CuO/AP is prepared to serve as the other dispersing method of nano-CuO, named pre dispersing procedure. Several kinds of heat releasing, thermal decomposition by DSC, combustion heat in oxygen environment, and explosion heat in nitrogen environment, are characterized to learn the effect of dispersibility of nano-CuO catalyst on heat releasing of propellants. With pre-dispersing procedures, thermal decomposition temperature of nano-CuO/AP and its propellant are about 25 degree C and 8.6 degree C lower than that of AP simple mixed with nano-CuO and its propellant, respectively. Comparing propellant with simple mixed nano-CuO kneading 3 hours, combustion heat and explosion heat of propellant with nano-CuO/AP increase about 1.4% and 1.7%, respectively. However, because of the breaking of nano-CuO/AP structure during kneading procedure, combustion heat and explosion heat of all the samples are decreased with the increase of kneading time after 3 hours.

  4. Cu–Co–O nano-catalysts as a burn rate modifier for composite solid propellants

    Directory of Open Access Journals (Sweden)

    D. Chaitanya Kumar Rao

    2016-08-01

    Full Text Available Nano-catalysts containing copper–cobalt oxides (Cu–Co–O have been synthesized by the citric acid (CA complexing method. Copper (II nitrate and Cobalt (II nitrate were employed in different molar ratios as the starting reactants to prepare three types of nano-catalysts. Well crystalline nano-catalysts were produced after a period of 3 hours by the calcination of CA–Cu–Co–O precursors at 550 °C. The phase morphologies and crystal composition of synthesized nano-catalysts were examined using Scanning Electron Microscope (SEM, Energy Dispersive Spectroscopy (EDS and Fourier Transform Infrared Spectroscopy (FTIR methods. The particle size of nano-catalysts was observed in the range of 90 nm–200 nm. The prepared nano-catalysts were used to formulate propellant samples of various compositions which showed high reactivity toward the combustion of HTPB/AP-based composite solid propellants. The catalytic effects on the decomposition of propellant samples were found to be significant at higher temperatures. The combustion characteristics of composite solid propellants were significantly improved by the incorporation of nano-catalysts. Out of the three catalysts studied in the present work, CuCo-I was found to be the better catalyst in regard to thermal decomposition and burning nature of composite solid propellants. The improved performance of composite solid propellant can be attributed to the high crystallinity, low agglomeration and lowering the decomposition temperature of oxidizer by the addition of CuCo-I nano-catalyst.

  5. Differential scanning calorimetric study of HTPB based composite propellants in presence of nano ferric oxide

    Energy Technology Data Exchange (ETDEWEB)

    Patil, Prajakta R.; Krishnamurthy, V.N.; Joshi, Satyawati S. [Department of Chemistry, University of Pune, Pune 411007 (India)

    2006-12-15

    A comparative study of the thermal decomposition of ammonium perchlorate (AP)/hydroxy terminated polybutadiene (HTPB) based composite propellants has been carried out in presence and absence of nano iron oxide at different heating rates in a dynamic nitrogen atmosphere using differential scanning calorimetry. The pronounced effect was a lowering of the high temperature decomposition by 49 C. A higher heat release up to 40% was observed in presence of nano ferric oxide (3.5 nm). The kinetic parameters were evaluated using the Kissinger method. The increase of the rate constant in the catalyzed propellant confirmed the enhancement of the catalytic activity of ammonium perchlorate. The scanning electron micrographs of nano Fe{sub 2}O{sub 3} incorporated in HTPB revealed a well-separated characteristic necklace-like structure of {alpha}-Fe{sub 2}O{sub 3} particles at high magnification. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  6. High burn rate solid composite propellants

    Science.gov (United States)

    Manship, Timothy D.

    High burn rate propellants help maintain high levels of thrust without requiring complex, high surface area grain geometries. Utilizing high burn rate propellants allows for simplified grain geometries that not only make production of the grains easier, but the simplified grains tend to have better mechanical strength, which is important in missiles undergoing high-g accelerations. Additionally, high burn rate propellants allow for a higher volumetric loading which reduces the overall missile's size and weight. The purpose of this study is to present methods of achieving a high burn rate propellant and to develop a composite propellant formulation that burns at 1.5 inches per second at 1000 psia. In this study, several means of achieving a high burn rate propellant were presented. In addition, several candidate approaches were evaluated using the Kepner-Tregoe method with hydroxyl terminated polybutadiene (HTPB)-based propellants using burn rate modifiers and dicyclopentadiene (DCPD)-based propellants being selected for further evaluation. Propellants with varying levels of nano-aluminum, nano-iron oxide, FeBTA, and overall solids loading were produced using the HTPB binder and evaluated in order to determine the effect the various ingredients have on the burn rate and to find a formulation that provides the burn rate desired. Experiments were conducted to compare the burn rates of propellants using the binders HTPB and DCPD. The DCPD formulation matched that of the baseline HTPB mix. Finally, GAP-plasticized DCPD gumstock dogbones were attempted to be made for mechanical evaluation. Results from the study show that nano-additives have a substantial effect on propellant burn rate with nano-iron oxide having the largest influence. Of the formulations tested, the highest burn rate was a 84% solids loading mix using nano-aluminum nano-iron oxide, and ammonium perchlorate in a 3:1(20 micron: 200 micron) ratio which achieved a burn rate of 1.2 inches per second at 1000

  7. Innovative boron nitride-doped propellants

    Directory of Open Access Journals (Sweden)

    Thelma Manning

    2016-04-01

    Full Text Available 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.

  8. Towards biocompatible nano/microscale machines: self-propelled catalytic nanomotors not exhibiting acute toxicity

    Science.gov (United States)

    Khim Chng, Elaine Lay; Zhao, Guanjia; Pumera, Martin

    2014-01-01

    Recent advances in nanotechnology have led to the evolution of self-propelled, artificial nano/microjet motors. These intelligent devices are considered to be the next generation self-powered drug delivery system in the field of biomedical applications. While many studies have strived to further improve the various properties of these devices such as their efficiency, performance and power, little attention has been paid to the actual biocompatibility of nanojets in vivo. In this paper, we will present for the first time the investigation of the toxicity effects of nanojets on the viability of human lung epithelial cells (A549 cells). From the 24 h and 48 h post-exposure studies, it is clearly shown that the nanojets we used in our work has negligible influence on the cell viability across all the concentrations tested. As such, the toxicity profile of our nanojets have been shown to be neither dose- nor time-dependent. This is strongly indicative of the benign nature of our nanojets, which is of paramount significance as it is the first step towards the applications of nano/micromotors in real-world practical medical devices.

  9. New Propellants and Cryofuels

    Science.gov (United States)

    Palasezski, Bryan; Sullivan, Neil S.; Hamida, Jaha; Kokshenev, V.

    2006-01-01

    The proposed research will investigate the stability and cryogenic properties of solid propellants that are critical to NASA s goal of realizing practical propellant designs for future spacecraft. We will determine the stability and thermal properties of a solid hydrogen-liquid helium stabilizer in a laboratory environment in order to design a practical propellant. In particular, we will explore methods of embedding atomic species and metallic nano-particulates in hydrogen matrices suspended in liquid helium. We will also measure the characteristic lifetimes and diffusion of atomic species in these candidate cryofuels. The most promising large-scale advance in rocket propulsion is the use of atomic propellants; most notably atomic hydrogen stabilized in cryogenic environments, and metallized-gelled liquid hydrogen (MGH) or densified gelled hydrogen (DGH). The new propellants offer very significant improvements over classic liquid oxygen/hydrogen fuels because of two factors: (1) the high energy-release, and (ii) the density increase per unit energy release. These two changes can lead to significant reduced mission costs and increased payload to orbit weight ratios. An achievable 5 to 10 percent improvement in specific impulse for the atomic propellants or MGH fuels can result in a doubling or tripling of system payloads. The high-energy atomic propellants must be stored in a stabilizing medium such as solid hydrogen to inhibit or delay their recombination into molecules. The goal of the proposed research is to determine the stability and thermal properties of the solid hydrogen-liquid helium stabilizer. Magnetic resonance techniques will be used to measure the thermal lifetimes and the diffusive motions of atomic species stored in solid hydrogen grains. The properties of metallic nano-particulates embedded in hydrogen matrices will also be studied and analyzed. Dynamic polarization techniques will be developed to enhance signal/noise ratios in order to be able to

  10. Nano and micro architectures for self-propelled motors

    International Nuclear Information System (INIS)

    Parmar, Jemish; Ma, Xing; Katuri, Jaideep; Simmchen, Juliane; Stanton, Morgan M; Trichet-Paredes, Carolina; Soler, Lluís; Sanchez, Samuel

    2015-01-01

    Self-propelled micromotors are emerging as important tools that help us understand the fundamentals of motion at the microscale and the nanoscale. Development of the motors for various biomedical and environmental applications is being pursued. Multiple fabrication methods can be used to construct the geometries of different sizes of motors. Here, we present an overview of appropriate methods of fabrication according to both size and shape requirements and the concept of guiding the catalytic motors within the confines of wall. Micromotors have also been incorporated with biological systems for a new type of fabrication method for bioinspired hybrid motors using three-dimensional (3D) printing technology. The 3D printed hybrid and bioinspired motors can be propelled by using ultrasound or live cells, offering a more biocompatible approach when compared to traditional catalytic motors. (focus issue paper)

  11. Nano Engineered Energetic Materials (NEEM)

    Science.gov (United States)

    2011-01-12

    Dryer, FL; Aksay, IA, Functionalized Graphene Sheet Colloids for Enhanced Fuel/Propellant Combustion, ACS NANO 3, 13, 3945-3954, 2009. 16. Weismiller...loading) which was not observed in other heterogeneous mixtures. Additional details on nano fuels (including graphene ) with liquid oxidizers can be...to the high reflectance of some samples black high temperature spray paint was used on ends of the samples to decrease ignition delay times and

  12. Comparison on exfoliated graphene nano-sheets and triturated graphite nano-particles for mode-locking the Erbium-doped fibre lasers

    Science.gov (United States)

    Yang, Chun-Yu; Lin, Yung-Hsiang; Wu, Chung-Lun; Cheng, Chih-Hsien; Tsai, Din-Ping; Lin, Gong-Ru

    2018-06-01

    Comparisons on exfoliated graphene nano-sheets and triturated graphite nano-particles for mode-locking the Erbium-doped fiber lasers (EDFLs) are performed. As opposed to the graphite nano-particles obtained by physically triturating the graphite foil, the tri-layer graphene nano-sheets is obtained by electrochemically exfoliating the graphite foil. To precisely control the size dispersion and the layer number of the exfoliated graphene nano-sheet, both the bias of electrochemical exfoliation and the speed of centrifugation are optimized. Under a threshold exfoliation bias of 3 volts and a centrifugation at 1000 rpm, graphene nano-sheets with an average diameter of 100  ±  40 nm can be obtained. The graphene nano-sheets with an area density of 15 #/µm2 are directly imprinted onto the end-face of a single-mode fiber made patchcord connector inside the EDFL cavity. Such electrochemically exfoliated graphene nano-sheets show comparable saturable absorption with standard single-graphene and perform the self-amplitude modulation better than physically triturated graphite nano-particles. The linear transmittance and modulation depth of the inserted graphene nano-sheets are 92.5% and 53%, respectively. Under the operation with a power gain of 21.5 dB, the EDFL can be passively mode-locked to deliver a pulsewidth of 454.5 fs with a spectral linewidth of 5.6 nm. The time-bandwidth product of 0.31 is close to the transform limit. The Kelly sideband frequency spacing of 1.34 THz is used to calculate the chirp coefficient as  ‑0.0015.

  13. Perancangan Propeler Self-Propelled Barge

    Directory of Open Access Journals (Sweden)

    Billy Teguh kurniawan

    2013-03-01

    Full Text Available Makalah ini menyampaikan suatu penelitian tentang perancangan propeler yang optimal beserta pemilihan daya mesin yang efisien pada self-propelled barge dengan memperhitungkan besarnya nilai tahanan dari barge tersebut. Dengan penambahan sistem propulsi, diharapkan barge dapat beroperasi dengan lebih efisien dibandingkan saat barge beroperasi menggunakan sistem towing atau ditarik tug boat. Perhitungan tahanan barge dilakukan menggunakan metode Holtrop dan Guldhammer-Harvald sehingga dapat diperhi-tungkan geometri dan jenis propeler yang optimal beserta daya mesin yang efisien untuk barge. Propeler yang dianalisis adalah propeler tipe B-Troost Series, sedangkan variasi yang dilakukan untuk perencanaan propeler pada kajian ini adalah variasi putaran propeler pada rentang antara 310-800 rpm, serta variasi jumlah daun pada rentang tiga, empat, lima, dan enam. Besarnya nilai tahanan self-propelled barge untuk metode Holtrop adalah 105.91 kilonewton, sedangkan hasil per-hitungan dari metode Guldhammer-Harvald didapatkan nilai sebesar 109.14 kilonewton. Tipe propeler yang dipilih setelah dilakukan uji kavitasi adalah tipe Troost Series B4-40, dengan diameter sebesar 2.1 m, efisiensi sebesar 0.421, pitch ratio se-besar 0.591, dengan putaran propeler 400 rpm. Daya mesin yg dibutuhkan barge pada kondisi maksimum (BHPMCR sebesar 1669.5 HP. Dengan mempertimbangkan daya tersebut, maka dipilih mesin jenis Caterpillar tipe Marine 3516B yang mem-punyai daya maksimum sebesar 1285 kilowatt atau 1722.5 horsepower dengan putaran mesin sebesar 1200 rpm

  14. EFD and CFD Characterization of a CLT Propeller

    Directory of Open Access Journals (Sweden)

    Daniele Bertetta

    2012-01-01

    Full Text Available In the present paper an experimental and numerical analysis of an unconventional CLT propeller is carried out. Two different numerical approaches, a potential panel method and an RANSE solver, are employed. Cavitation tunnel experiments are carried out in order to measure, as usual, thrust, torque, and cavity extension for different propeller working points. Moreover, LDV measurements are performed to have a deep insight into the complex wake behind the propeller and to analyze the dynamics of generated tip vortexes. The numerical/experimental analysis and comparison of results highlight the peculiarities of this kind of propellers, the possibility to increase efficiency and reduce cavitation risk, in order to exploit the design approaches already well proven for conventional propellers also in the case of these unconventional geometries.

  15. Comparison of FSE T2 W PROPELLER and 3D-FIESTA of 3 T MR for the internal auditory canal.

    Science.gov (United States)

    Wu, Hai-Bo; Yuan, Hui-Shu; Ma, Furong; Zhao, Qiang

    The study compared the use of periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) technique fast spin echo (FSE) T2 W and the sequence of three-dimensional fast imaging employing steady-state acquisition (3D-FIESTA) technique in the MRI of the internal auditory canal for overall image quality improvement. One hundred thirty-two patients undergoing FSE T2 W PROPELLER and 3D-FIESTA examinations of the internal auditory canal were included. All examinations were performed at 3.0 T with comparison of a sagittal oblique FSE T2 W sequence with the PROPELLER technique to 3D-FIESTA in the same reconstructed orientation with PROPELLER. Image quality was evaluated by two radiologists using a 4-point scale. The Wilcoxon signed rank test was used to compare the data of the two techniques. The image quality of FSE T2 W PROPELLER was significantly improved compared to the reconstructed images of 3D-FIESTA. Observer 1: median FSE T2 W with PROPELLER, 4 [mean, 3.455] versus median reconstructed 3D-FIESTA, 3 [mean, 3.15], (PW with PROPELLER, 4 [mean, 3.47] versus median reconstructed 3D-FIESTA, 3 [mean, 3.25], (PW PROPELLER technique for MRI of internal auditory canal reduced uncertainty caused by motion artifact and improved the quality of the image compared to the reconstructed 3D-FIESTA. It was affected by different parameters including the blade width, echo train length (ETL). This is explained by data oversampling at the center region of k-space, which requires additional imaging time over conventional MRI techniques. Increasing blade was expected to improve motion correction effects but also the signal-to-noise ratio. ETL increases the image sharpness and the overall image quality. Copyright © 2016. Published by Elsevier Inc.

  16. ISO 15859 Propellant and Fluid Specifications: A Review and Comparison with Military and NASA Specifications

    Science.gov (United States)

    Greene, Ben; McClure, Mark B.; Baker, David L.

    2006-01-01

    This work presents an overview of the International Organization for Standardization (ISO) 15859 International Standard for Space Systems Fluid Characteristics, Sampling and Test Methods Parts 1 through 13 issued in June 2004. These standards establish requirements for fluid characteristics, sampling, and test methods for 13 fluids of concern to the propellant community and propellant characterization laboratories: oxygen, hydrogen, nitrogen, helium, nitrogen tetroxide, monomethylhydrazine, hydrazine, kerosene, argon, water, ammonia, carbon dioxide, and breathing air. A comparison of the fluid characteristics, sampling, and test methods required by the ISO standards to the current military and NASA specifications, which are in use at NASA facilities and elsewhere, is presented. Many ISO standards composition limits and other content agree with those found in the applicable parts of NASA SE-S-0073, NASA SSP 30573, military performance standards and details, and Compressed Gas Association (CGA) commodity specifications. The status of a current project managed at NASA Johnson Space Center White Sands Test Facility (WSTF) to rewrite these documents is discussed.

  17. The world of Nano

    International Nuclear Information System (INIS)

    Noh, Seung Jeong; Hyun, Jun Won; An, Yong Hyeon; Lee, Sung Uk; Jee, Hye Gu; Kim, Young Seon

    2006-07-01

    The contents of this book are the beginning of nano technology, definition of nano, commercialization of nano technology, prospect of nano technology, survive with nano t-, development strategy of n-t in the U.S, and Japan, Korea, and other countries, comparison of development strategy of n-t among each country, various measurement technology for practical n-t, scanning tunneling microscopy, nano device, carbon nano tube, nano belt and nano wire, application of sensor in daily life, energy, post-Genome period and using as medicine with nano bio technology.

  18. Study of nano-nitramine explosives: preparation, sensitivity and application

    Directory of Open Access Journals (Sweden)

    Jie Liu

    2014-06-01

    Full Text Available Nano-nitramine explosives (RDX, HMX, CL-20 are produced on a bi-directional grinding mill. The scanning electron microscope (SEM observations show that the prepared particles are semi-spherical, and the narrow size distributions are characterized using the laser particle size analyzer. Compared with the micron-sized samples, the nano-products show obvious decrease in friction and impact sensitivities. In the case of shock sensitivities, nano-products have lower values by 59.9% (RDX, 56.4% (HMX, and 58.1% (CL-20, respectively. When nano-RDX and nano-HMX are used in plastic bonded explosives (PBX as alternative materials of micron-sized particles, their shock sensitivities are significantly decreased by 24.5% (RDX and 22.9% (HMX, and their detonation velocities are increased by about 1.7%. Therefore, it is expected to promote the application of nano-nitramine explosives in PBXs and composite modified double-based propellants (CMDBs so that some of their properties would be improved.

  19. Influence of Propulsion Type on the Stratified Near Wake of an Axisymmetric Self-Propelled Body

    Directory of Open Access Journals (Sweden)

    Matthew C. Jones

    2018-05-01

    Full Text Available To better understand the influence of swirl on the thermally-stratified near wake of a self-propelled axisymmetric vehicle, three propulsor schemes were considered: a single propeller, contra-rotating propellers (CRP, and a zero-swirl, uniform-velocity jet. The propellers were modeled using an Actuator-Line model in an unsteady Reynolds-Averaged Navier–Stokes simulation, where the Reynolds number is R e L = 3.1 × 10 8 using the freestream velocity and body length. The authors previously showed good comparison to experimental data with this approach. Visualization of vortical structures shows the helical paths of blade-tip vortices from the single propeller as well as the complicated vortical interaction between contra-rotating blades. Comparison of instantaneous and time-averaged fields shows that temporally stationary fields emerge by half of a body length downstream. Circumferentially-averaged axial velocity profiles show similarities between the single propeller and CRP in contrast to the jet configuration. Swirl velocity of the CRP, however, was attenuated in comparison to that of the single propeller case. Mixed-patch contour maps illustrate the unique temperature distribution of each configuration as a consequence of their respective swirl profiles. Finally, kinetic and potential energy is integrated along downstream axial planes to reveal key differences between the configurations. The CRP configuration creates less potential energy by reducing swirl that would otherwise persist in the near wake of a single-propeller wake.

  20. Experimental research on air propellers

    Science.gov (United States)

    Durand, William F

    1918-01-01

    The purposes of the experimental investigation on the performance of air propellers described in this report are as follows: (1) the development of a series of design factors and coefficients drawn from model forms distributed with some regularity over the field of air-propeller design and intended to furnish a basis of check with similar work done in other aerodynamic laboratories, and as a point of departure for the further study of special or individual types and forms; (2) the establishment of a series of experimental values derived from models and intended for later use as a basis for comparison with similar results drawn from certain selected full-sized forms and tested in free flight.

  1. Effect of Propellant Composition to the Temperature Sensitivity of Composite Propellant

    International Nuclear Information System (INIS)

    Aziz, Amir; Mamat, Rizalman; Amin, Makeen; Wan Ali, Wan Khairuddin

    2012-01-01

    The propellant composition is one of several parameter that influencing the temperature sensitivity of composite propellant. In this paper, experimental investigation of temperature sensitivity in burning rate of composite propellant was conducted. Four sets of different propellant compositions had been prepared with the combination of ammonium perchlorate (AP) as an oxidizer, aluminum (Al) as fuel and hydroxy-terminated polybutadiene (HTPB) as fuel and binder. For each mixture, HTPB binder was fixed at 15% and cured with isophorone diisocyanate (IPDI). By varying AP and Al, the effect of oxidizer- fuel mixture ratio (O/F) on the whole propellant can be determined. The propellant strands were manufactured using compression molded method and burnt in a strand burner using wire technique over a range of pressure from 1 atm to 31 atm. The results obtained shows that the temperature sensitivity, a, increases with increasing O/F. Propellant p80 which has O/F ratio of 80/20 gives the highest value of temperature sensitivity which is 1.687. The results shows that the propellant composition has significant effect on the temperature sensitivity of composite propellant

  2. Catalytic micromotor generating self-propelled regular motion through random fluctuation

    Science.gov (United States)

    Yamamoto, Daigo; Mukai, Atsushi; Okita, Naoaki; Yoshikawa, Kenichi; Shioi, Akihisa

    2013-07-01

    Most of the current studies on nano/microscale motors to generate regular motion have adapted the strategy to fabricate a composite with different materials. In this paper, we report that a simple object solely made of platinum generates regular motion driven by a catalytic chemical reaction with hydrogen peroxide. Depending on the morphological symmetry of the catalytic particles, a rich variety of random and regular motions are observed. The experimental trend is well reproduced by a simple theoretical model by taking into account of the anisotropic viscous effect on the self-propelled active Brownian fluctuation.

  3. Studies of pellet acceleration with arc discharge heated propellants

    International Nuclear Information System (INIS)

    Schuresko, D.D.

    1985-01-01

    An arc discharge has been utilized to heat gaseous propellants in a pneumatic pellet gun. A cylindrical arc chamber is interposed between the propellant inlet valve and the gun breech and fitted with a ceramic insert for generating swirl in the incoming gas stream. The arc is initiated after the propellant valve opens and the breech pressure starts to rise; a typical discharge lasts 300 microseconds with peak currents u to 2 kA at arc voltages ranging from 100 to 400 V. The system is instrumented with piezoelectric pressure transducers at the propellant valve outlet, gun breech, and gun muzzle. The gun has been operated with 4 mm diameter polyurethane foam pellets (density = 0.14 g/cm 3 ), a 40 cm-long barrel, and various gas propellants at pressures exceeding 70 bar. At I/sub arc/ = 1 kA, V/sub arc/ = 200 V, with helium propellant, the arc produces a 2 to 3 fold prompt increase in P/sub breech/ and a delayed increase in P/sub muzzle/; the pellets exit the gun from 0.5 to 1.0 ms earlier than with the gas alone at 40% higher speeds. Comparisons with the so-called ideal gun theory and with full one-dimensional hydrodynamic calculations of the pellet acceleration will be presented

  4. Studies of pellet acceleration with arc discharge heated propellants

    International Nuclear Information System (INIS)

    Schuresko, D.D.

    1986-01-01

    An arc discharge has been utilized to heat gaseous propellants in a pneumatic pellet gun. A cylindrical arc chamber is interposed between the propellant inlet valve and the gun breech and fitted with a ceramic insert for generating swirl in the incoming gas stream. The arc is initiated after the propellant valve opens and the breech pressure starts to rise; a typical discharge lasts 300 microseconds with peak currents up to 2 kA at arc voltages ranging from 100-400 V. The system is instrumented with piezoelectric pressure transducers at the propellant valve outlet, gun breech, and gun muzzle. The gun has been operated with 4 mm diameter polyurethane foam pellets (density = 0.14 g/cm 3 ), a 40 cm-long barrel, and various gas propellants at pressures exceeding 70 bar. At I/sub arc/ = 1 kA, V/sub arc/ = 200 V, with helium propellant, the arc produces a 2-3 fold prompt increase in P/sub breech/ and a delayed increase in P/sub muzzle/; the pellets exit the gun from 0.5-1.0 ms earlier than with the gas alone at 40% higher speeds. Comparisons with the so-called ideal gun theory and with full one-dimensional hydrodynamic calculations of the pellet acceleration will be presented

  5. Tip-modified Propellers

    DEFF Research Database (Denmark)

    Andersen, Poul

    1999-01-01

    The paper deals with tip-modified propellers and the methods which, over a period of two decades, have been applied to develop such propellers. The development is driven by the urge to increase the efficiency of propellers and can be seen as analogous to fitting end plates and winglets to aircraft...... propeller, have efficiency increases of a reasonable magnitude in both open-water and behind-ship conditions....

  6. Book Review: Nano physics & Nano technology

    Directory of Open Access Journals (Sweden)

    Abdolkhaled Zaree

    2012-12-01

    Full Text Available During last decades, there are a lot of emphases on studying material behavior in atomic scale. In most scientific and engineering fields, one can see the effect of nanotechnology. The aim of nanoscience is to design and fabrication of new and applicable materials. Nowadays, Nano is a popular science which chemists, physicist, doctors, engineers, financial managers and environment's fans for creating a good life via nanoscience have a great cooperation with each others. Materials in nano scale such as nanotubes and nanowires have extraordinary properties which by optimization of these properties in nano scale and then develop these properties to macro scale, they've been challenging issues. For instance, materials in nano scale improve mechanical properties of polymers and metallic materials via nano particles and on the other hand by producing a thin film on surfaces improve surface hardening. Besides, nanotechnology is in hi-tech industries such as magnetic devices, surface coating, and biomaterial, material having sensors, polymers, gels, ceramics and intelligent membrane. Nano-carbon tubes are considered intelligent due to the fact that they couple electrochemical and elastic properties simultaneously, hence have greater activation energy density in comparison with other intelligent materials. Studying nanoscience is important because it causes the life to be better. Future Materials and structures will have a lot of outstanding properties. Intelligent machines can repair, recycle and reconstruct themselves. All these features are only possible in nano zone. Nano in engineering science can provide the possibility of making light missiles for exploring space. The reduced weight can be achieved by replacing traditional materials with hybrid nanocomposites.

  7. Gun barrel erosion - Comparison of conventional and LOVA gun propellants

    NARCIS (Netherlands)

    Hordijk, A.C.; Leurs, O.

    2006-01-01

    The research department Energetic Materials within TNO Defence, Security and Safety is involved in the development and (safety and insensitive munitions) testing of conventional (nitro cellulose based) and thermoplastic elastomer (TPE) based gun propellants. Recently our testing capabilities have

  8. Investigation on the wake evolution of contra-rotating propeller using RANS computation and SPIV measurement

    Directory of Open Access Journals (Sweden)

    Kwang-Jun Paik

    2015-05-01

    Full Text Available The wake characteristics of Contra-Rotating Propeller (CRP were investigated using numerical simulation and flow measurement. The numerical simulation was carried out with a commercial CFD code based on a Reynolds Averaged Navier-Stokes (RANS equations solver, and the flow measurement was performed with Stereoscopic Particle Image Velocimetry (SPIV system. The simulation results were validated through the comparison with the experiment results measured around the leading edge of rudder to investigate the effect of propeller operation under the conditions without propeller, with forward propeller alone, and with both forward and aft propellers. The evolution of CRP wake was analyzed through velocity and vorticity contours on three transverse planes and one longitudinal plane based on CFD results. The trajectories of propeller tip vortex core in the cases with and without aft propeller were also compared, and larger wake contraction with CRP was confirmed.

  9. KAPPEL Propeller. Development of a Marine Propeller with Non-planar Lifting Surfaces

    DEFF Research Database (Denmark)

    Kappel, J.; Andersen, Poul

    2002-01-01

    The principle of non-planar lifting surfaces is applied to the design of modern aircraft wings to obtain better lift to drag ratios. Whereas a pronounced fin or "winglet" at the wingtip has been developed for aircraft, the application of the non-planar principle to marine propellers, dealt...... with in this paper, has led to the KAPPEL propeller with blades curved towards the suction side integrating the fin or winglet into the propeller blade. The combined theoretical, experimental and practical approach to develop and design marine propellers with non-planar lifting surfaces has resulted in propellers...

  10. Longitudinal aerodynamic characteristics of light, twin-engine, propeller-driven airplanes

    Science.gov (United States)

    Wolowicz, C. H.; Yancey, R. B.

    1972-01-01

    Representative state-of-the-art analytical procedures and design data for predicting the longitudinal static and dynamic stability and control characteristics of light, propeller-driven airplanes are presented. Procedures for predicting drag characteristics are also included. The procedures are applied to a twin-engine, propeller-driven airplane in the clean configuration from zero lift to stall conditions. The calculated characteristics are compared with wind-tunnel and flight data. Included in the comparisons are level-flight trim characteristics, period and damping of the short-period oscillatory mode, and windup-turn characteristics. All calculations are documented.

  11. Evaluation of the adsorption capacity of nano-graphene and nano-graphene oxide for xylene removal from air and their comparison with the standard adsorbent of activated carbon to introduce the optimized one

    Directory of Open Access Journals (Sweden)

    Akram Tabrizi

    2016-06-01

    Full Text Available Introduction: Volatile organic compounds from industrial activities are one of the most important pollutants released into the air and have adverse effects on human and environment. Therefore, they should be removed before releasing into atmosphere. The aim of the study was to evaluate xylene removal from air by nano-grapheme and nano-graphene oxide in comparison with activated carbon adsorbent. Material and Method:  After preparing adsorbents of activated carbon, nano-graphene, and nano-graphene oxide, experiments adsorption capacity in static mode (Batch were carried out in a glass vial. Some variables including contact time, the amount of adsorbent, the concentration of xylene, and the temperature were studied. Langmuir absorption isotherms were used in order to study the adsorption capacity of xylene on adsorbents. Moreover, sample analysis was done by gas chromatography with Flame Ionization Detector (GC-FID. Results: The adsorption capacities of activated carbon, nano-graphene oxide and nano-graphene for removal of xylene were obtained 349.8, 14.5, and 490 mg/g, respectively. The results of Scanning Electron Microscope (SEM for nano-graphene and nano-graphene oxide showed particle size of less than 100 nm. While, the results of Transmission Electron Microscope (TEM showed particle size of 45nm for nano-graphene and 65 nm for nano-graphene oxide. Also, X-Ray Diffraction (XRD showed cube structure of nano-adsorbents. Conclusion: In constant humidity, increase in exposure time and temperature caused an increase in the adsorption capacity. The results revealed greater adsorption capacity of xylene removal for nano-graphene compared to the activated carbon, and nano-graphene oxide.

  12. IMPACT OF SOME GEOMETRICAL ASPECTS ON THE TANDEM CO-ROTATING PROPELLER HYDRODYNAMIC CHARACTERISTICS

    Directory of Open Access Journals (Sweden)

    Boucetta Djahida

    2017-01-01

    Full Text Available In the present paper, a numerical simulation based on Kω-SST turbulence model has been carried out to determine the tandem propeller hydrodynamic characteristics in non-cavitating viscous flow by using the commercial code Fluent. As the first step, the numerical approach has been applied to the case of single propeller and the comparison with experiment results was in a good agreement. Next, the effects of axial and angular displacement as well as the diameter ratio between the tandem propellers have been investigated. This part of the study reveals that the tandem with idem propeller diameters is strongly recommended to assure more advantages. Furthermore, the tandem geometry corresponding to the axial displacement equal to 0.6D seems to be the best configuration and the open water performances remain almost unchanged with the variation of angular displacement. On the other hand, details of the mutual interaction between tandem propellers were also given by showing pressure contours, streamlines and thrust coefficient. Globally, this study illustrates the advantages of replacing single propellers by tandem solution.

  13. An Experimental Study on the aerodynamic and aeroacoustic performances of Maple-Seed-Inspired UAV Propellers

    Science.gov (United States)

    Hu, Hui; Ning, Zhe

    2016-11-01

    Due to the auto-rotating trait of maple seeds during falling down process, flow characteristics of rotating maple seeds have been studied by many researchers in recent years. In the present study, an experimental investigation was performed to explore maple-seed-inspired UAV propellers for improved aerodynamic and aeroacoustic performances. Inspired by the auto-rotating trait of maple seeds, the shape of a maple seed is leveraged for the planform design of UAV propellers. The aerodynamic and aeroacoustic performances of the maple-seed-inspired propellers are examined in great details, in comparison with a commercially available UAV propeller purchased on the market (i.e., a baseline propeller). During the experiments, in addition to measuring the aerodynamic forces generated by the maple-seed-inspired propellers and the baseline propeller, a high-resolution Particle Image Velocimetry (PIV) system was used to quantify the unsteady flow structures in the wakes of the propellers. The aeroacoustic characteristics of the propellers are also evaluated by leveraging an anechoic chamber available at the Aerospace Engineering Department of Iowa State University. The research work is supported by National Science Foundation under Award Numbers of OSIE-1064235.

  14. Hull-Propeller Interaction and Its Effect on Propeller Cavitation

    DEFF Research Database (Denmark)

    Regener, Pelle Bo

    In order to predict the required propulsion power for a ship reliably and accurately, it is not sufficient to only evaluate the resistance of the hull and the propeller performance in open water alone. Interaction effects between hull and propeller can even be a decisive factor in ship powering...... prediction and design optimization. The hull-propeller interaction coefficients of effective wake fraction, thrust deduction factor, and relative rotative efficiency are traditionally determined by model tests. Self-propulsion model tests consistently show an increase in effective wake fractions when using...... velocities. This offers an opportunity for additional insight into hull-propeller interaction and the propeller’s actual operating condition behind the ship, as the actual (effective) inflow is computed. Self-propulsion simulations at model and full scale were carried out for a bulk carrier, once...

  15. Are nano-composites and nano-ionomers suitable for orthodontic bracket bonding?

    Science.gov (United States)

    Uysal, Tancan; Yagci, Ahmet; Uysal, Banu; Akdogan, Gülsen

    2010-02-01

    The aim of this study was to test nano-composite (Filtek Supreme Plus Universal) and a newly introduced nano-ionomer (Ketac N100 Light Curing Nano-Ionomer) restorative to determine their shear bond strength (SBS) and failure site locations in comparison with a conventional light-cure orthodontic bonding adhesive (Transbond XT). Sixty freshly extracted human maxillary premolar teeth were arbitrarily divided into three equal groups. The brackets were bonded to the teeth in each group with different composites, according to the manufacturers' instructions. The SBS values of the brackets were recorded in Megapascals (MPa) using a universal testing machine. Adhesive remnant index scores were determined after failure of the brackets. The data were analysed using analysis of variance, Tukey honestly significant difference, and chi-square tests. The results demonstrated that group 1 (Transbond XT, mean: 12.60 +/- 4.48 MPa) had a higher SBS than that of group 2 (nano-composite, mean: 8.33 +/- 5.16 MPa; P nano-ionomer, mean: 6.14 +/- 2.12 MPa; P Nano-composites and nano-ionomers may be suitable for bonding since they fulfil the previously suggested SBS ranges for clinical acceptability, but they are inferior to a conventional orthodontic composite.

  16. The influence of the choice of propeller design tool on propeller performance

    OpenAIRE

    Skåland, Edvard Knutsen

    2016-01-01

    In this master thesis different propeller design and analysis methods are presented and compared in terms of the accuracy and computational efficiency of their theory. These methods include lifting line, vortex lattice lifting surface and panel methods. A propeller design program based on lifting line theory was developed by the author. This program has been used together with the propeller design programs OpenProp and AKPD to make six propeller designs. The designs are based o...

  17. Discharge characteristics of an ablative pulsed plasma thruster with non-volatile liquid propellant

    Science.gov (United States)

    Ling, William Yeong Liang; Schönherr, Tony; Koizumi, Hiroyuki

    2017-07-01

    Pulsed plasma thrusters (PPTs) are a form of electric spacecraft propulsion. They have an extremely simple structure and are highly suitable for nano/micro-spacecraft with weights in the kilogram range. Such small spacecraft have recently experienced increased growth but still lack suitable efficient propulsion systems. PPTs operate in a pulsed mode (one discharge = one shot) and typically use solid polytetrafluoroethylene (PTFE) as a propellant. However, new non-volatile liquids in the perfluoropolyether (PFPE) family have recently been found to be promising alternatives. A recent study presented results on the physical characteristics of PFPE vs. PTFE, showing that PFPE is superior in terms of physical characteristics such as its resistance to carbon deposition. This letter will examine the electrical discharge characteristics of PFPE vs. PTFE. The results demonstrate that PFPE has excellent shot-to-shot repeatability and a lower discharge resistance when compared with PTFE. Taken together with its physical characteristics, PFPE appears to be a strong contender to PTFE as a PPT propellant.

  18. Chemical energy powered nano/micro/macromotors and the environment.

    Science.gov (United States)

    Moo, James Guo Sheng; Pumera, Martin

    2015-01-02

    The rise of miniaturized artificial self-powered devices, demonstrating autonomous motion, has brought in new considerations from the environmental perspective. This review addresses the interplay between these nano/micro/macromotors and the environment, recent advances, and their applications in pollution management. Such self-propelled devices are able to actuate chemical energy into mechanical motion in situ, adding another powerful dimension towards solving environmental problems. Use of synthetic nano/micro/macromotors has demonstrated potential in environmental remediation, both in pollutant removal and contaminant degradation, owing to motion-induced mixing. At the same time, the chemical environment exerts influence on the locomotion of the motors. These sensitized self-powered devices demonstrate capabilities for being deployed as sensors and their chemotactic behaviors show efficacy to act as first responders towards a chemical leakage. Thus, the notion of a self-propelling entity also entails further investigation into its inherent toxicity and possible implications as a pollutant. Future challenges and outlook of the use of these miniaturized devices are discussed, with specific regard to the fields of environmental remediation and monitoring, as we move towards their wider acceptance. We believe that these tiny machines will stand up to the task as solutions for environmental sustainability in the 21st century. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Nano medicine in Action: An Overview of Cancer Nano medicine on the Market and in Clinical Trials

    International Nuclear Information System (INIS)

    Wang, R.; Billone, P.S.; Mullett, W.M.

    2013-01-01

    Nano medicine, defined as the application of nano technology in the medical field, has the potential to significantly change the course of diagnostics and treatment of life-threatening diseases, such as cancer. In comparison with traditional cancer diagnostics and therapy, cancer nano medicine provides sensitive cancer detection and/or enhances treatment efficacy with significantly minimized adverse effects associated with standard therapeutics. Cancer nano medicine has been increasingly applied in areas including nano drug delivery systems, nano pharmaceuticals, and nano analytical contrast reagents in laboratory and animal model research. In recent years, the successful introduction of several novel nano medicine products into clinical trials and even onto the commercial market has shown successful outcomes of fundamental research into clinics. This paper is intended to examine several nano medicines for cancer therapeutics and/or diagnostics-related applications, to analyze the trend of nano medicine development, future opportunities, and challenges of this fast-growing area.

  20. Comparison of Antimicrobial Properties of Nano Quinolone with its Microscale Effects

    Science.gov (United States)

    Behbahani, G. Rezaie; Sadr, M. Hossaini; Nabipour, H.; Behbahani, H. Rezaei; Vahedpour, M.; Barzegar, L.

    2013-06-01

    Nano nalidixic acid was prepared by ultrasonic method in carbon tetrachloride. Nano nalidixic acid (quinolone antibiotic) was characterized by X-ray diffraction (XRD), infrared spectroscopy (IR) and scanning electron microscope (SEM). The antibacterial activities of nano nalidixic acid were tested against microorganisms and compared with the microscale drug. The results show that nano nalidixic acid has good inhibitory properties against two Gram-positive species, Staphylococcus aureus and Bacillus subtilis. Nano nalidixic acid also showed good antifungal activity against Candida albicans. Nano nalidixic acid can be injected into the human body as a decontaminating agent to prevent the growth of harmful microorganisms more effectively than the micro-sized drug.

  1. Evaluation of icing drag coefficient correlations applied to iced propeller performance prediction

    Science.gov (United States)

    Miller, Thomas L.; Shaw, R. J.; Korkan, K. D.

    1987-01-01

    Evaluation of three empirical icing drag coefficient correlations is accomplished through application to a set of propeller icing data. The various correlations represent the best means currently available for relating drag rise to various flight and atmospheric conditions for both fixed-wing and rotating airfoils, and the work presented here ilustrates and evaluates one such application of the latter case. The origins of each of the correlations are discussed, and their apparent capabilities and limitations are summarized. These correlations have been made to be an integral part of a computer code, ICEPERF, which has been designed to calculate iced propeller performance. Comparison with experimental propeller icing data shows generally good agreement, with the quality of the predicted results seen to be directly related to the radial icing extent of each case. The code's capability to properly predict thrust coefficient, power coefficient, and propeller efficiency is shown to be strongly dependent on the choice of correlation selected, as well as upon proper specificatioon of radial icing extent.

  2. Development and implementation of a propeller test capability for GL-10 "Greased Lightning" propeller design

    Science.gov (United States)

    Duvall, Brian Edward

    Interest in small unmanned aerial vehicles has increased dramatically in recent years. Hybrid vehicles which allow forward flight as a fixed wing aircraft and a true vertical landing capability have always had applications. Management of the available energy and noise associated with electric propeller propulsion systems presents many challenges. NASA Langley has developed the Greased Lightning 10 (GL-10) vertical takeoff, unmanned aerial vehicle with ten individual motors and propellers. All are used for propulsion during takeoff and contribute to acoustic noise pollution which is an identified nuisance to the surrounding users. A propeller test capability was developed to gain an understanding of how the noise can be reduced while meeting minimum thrust requirements. The designed propeller test stand allowed for various commercially available propellers to be tested for potential direct replacement of the current GL-10 propellers and also supported testing of a newly designed propeller provided by the Georgia Institute of Technology. Results from the test program provided insight as to which factors affect the noise as well as performance characteristics. The outcome of the research effort showed that the current GL-10 propeller still represents the best choice of all the candidate propellers tested.

  3. Numerical Prediction of Magnetic Cryogenic Propellant Storage in Reduced Gravity

    Science.gov (United States)

    Marchetta, J. G.; Hochstein, J. I.

    2002-01-01

    Numerical Prediction of Magnetic Cryogenic Propellant Storage in Reduced strong evidence that a magnetic positioning system may be a feasible alternative technology for use in the management of cryogenic propellants onboard spacecraft. The results of these preliminary studies have indicated that further investigation of the physical processes and potential reliability of such a system is required. The utility of magnetic fields as an alternative method in cryogenic propellant management is dependent on its reliability and flexibility. Simulations and experiments have previously yielded evidence in support of the magnetic positive positioning (MPP) process to predictably reorient LOX for a variety of initial conditions. Presently, though, insufficient evidence has been established to support the use of magnetic fields with respect to the long-term storage of cryogenic propellants. Current modes of propellant storage have met with a moderate level of success and are well suited for short duration missions using monopropellants. However, the storage of cryogenic propellants warrants additional consideration for long-term missions. For example, propellant loss during storage is due to vaporization by incident solar radiation and the vaporized ullage must be vented to prevent excessive pressurization of the tank. Ideally, positioning the fluid in the center of the tank away from the tank wall will reduce vaporization by minimizing heat transfer through the tank wall to the liquid. A second issue involves the capability of sustaining a stable fluid configuration at tank center under varying g-levels or perturbations propellant storage. Results presented herein include comparisons illustrating the influence of gravity, fluid volume, and the magnetic field on a paramagnetic fluid, LOX. The magnetic Bond number is utilized as predictive correlating parameter for investigating these processes. A dimensionless relationship between the Bom and Bo was sought with the goal of

  4. Propellers in Saturn's rings

    Science.gov (United States)

    Sremcevic, M.; Stewart, G. R.; Albers, N.; Esposito, L. W.

    2013-12-01

    Theoretical studies and simulations have demonstrated the effects caused by objects embedded in planetary rings. Even if the objects are too small to be directly observed, each creates a much larger gravitational imprint on the surrounding ring material. These strongly depend on the mass of the object and range from "S" like propeller-shaped structures for about 100m-sized icy bodies to the opening of circumferential gaps as in the case of the embedded moons Pan and Daphnis and their corresponding Encke and Keeler Gaps. Since the beginning of the Cassini mission many of these smaller objects (~data from Cassini Ultraviolet Imaging Spectrograph (UVIS) and Imaging Science Subsystem (ISS) experiments. We show evidence that B ring seems to harbor two distinct populations of propellers: "big" propellers covering tens of degrees in azimuth situated in the densest part of B ring, and "small" propellers in less dense inner B ring that are similar in size and shape to known A ring propellers. The population of "big" propellers is exemplified with a single object which is observed for 5 years of Cassini data. The object is seen as a very elongated bright stripe (40 degrees wide) in unlit Cassini images, and dark stripe in lit geometries. In total we report observing the feature in images at 18 different epochs between 2005 and 2010. In UVIS occultations we observe this feature as an optical depth depletion in 14 out of 93 occultation cuts at corrotating longitudes compatible with imaging data. Combining the available Cassini data we infer that the object is a partial gap located at r=112,921km embedded in the high optical depth region of the B ring. The gap moves at Kepler speed appropriate for its radial location. Radial offsets of the gap locations in UVIS occultations are consistent with an asymmetric propeller shape. The asymmetry of the observed shape is most likely a consequence of the strong surface mass density gradient, as the feature is located at an edge between

  5. Quadcopter thrust optimization with ducted-propeller

    Directory of Open Access Journals (Sweden)

    Kuantama Endrowednes

    2017-01-01

    Full Text Available In relation to quadcopter body frame model, propeller can be categorized into propeller with ducted and without ducted. This study present differences between those two using CFD (Computational Fluid Dynamics method. Both categories utilize two blade-propeller with diameter of 406 (mm. Propeller rotation generates acceleration per time unit on the volume of air. Based on the behavior of generated air velocity, ducted propeller can be modeled into three versions. The generated thrust and performance on each model were calculated to determine the best model. The use of ducted propeller increases the total weight of quadcopter and also total thrust. The influence of this modeling were analyzed in detail with variation of angular velocity propeller from 1000 (rpm to 9000 (rpm. Besides the distance between propeller tip and ducted barrier, the size of ducted is also an important part in thrust optimization and total weight minimization of quadcopter.

  6. Mars Ascent Vehicle-Propellant Aging

    Science.gov (United States)

    Dankanich, John; Rousseau, Jeremy; Williams, Jacob

    2015-01-01

    This project is to develop and test a new propellant formulation specifically for the Mars Ascent Vehicle (MAV) for the robotic Mars Sample Return mission. The project was initiated under the Planetary Sciences Division In-Space Propulsion Technology (ISPT) program and is continuing under the Mars Exploration Program. The two-stage, solid motor-based MAV has been the leading MAV solution for more than a decade. Additional studies show promise for alternative technologies including hybrid and bipropellant options, but the solid motor design has significant propellant density advantages well suited for physical constraints imposed while using the SkyCrane descent stage. The solid motor concept has lower specific impulse (Isp) than alternatives, but if the first stage and payload remain sufficiently small, the two-stage solid MAV represents a potential low risk approach to meet the mission needs. As the need date for the MAV slips, opportunities exist to advance technology with high on-ramp potential. The baseline propellant for the MAV is currently the carboxyl terminated polybutadiene (CTPB) based formulation TP-H-3062 due to its advantageous low temperature mechanical properties and flight heritage. However, the flight heritage is limited and outside the environments, the MAV must endure. The ISPT program competed a propellant formulation project with industry and selected ATK to develop a new propellant formulation specifically for the MAV application. Working with ATK, a large number of propellant formulations were assessed to either increase performance of a CTPB propellant or improve the low temperature mechanical properties of a hydroxyl terminated polybutadiene (HTPB) propellant. Both propellants demonstrated potential to increase performance over heritage options, but an HTPB propellant formulation, TP-H-3544, was selected for production and testing. The test plan includes propellant aging first at high vacuum conditions, representative of the Mars transit

  7. Functional Nano fibers: Production and Applications

    International Nuclear Information System (INIS)

    Khatri, Z.; Kim, I.S.; Kim, S.H.

    2016-01-01

    Nano fibers are lighter material with higher surface area in comparison to polymeric film. The ease of producing functional nano fiber is another advantage over many nano materials. Functional nano fiber in particular has attained a greater interest in recent years. The applications of functional nano fibers are increasing in various technical fields such as water filter membranes, tissue engineering, biosensors, drug delivery systems, wound dressings, catalysis, antibacterial. This special issue is comprised of well-selective articles that discuss production of functional nano fibers their applications in different emerging fields. M. Zhang et al. have presented exciting work on drug delivery using nano fibers. They used collagen that was extracted from abandoned Rana chensinensis skin in northeastern China via an acid enzymatic extraction method. They demonstrated two different nano fiber-vancomycin (VCM) systems, that is, VCM blended nano fibers and core-shell nano fibers with VCM in the core, and both systems sustained control release for a period of 80 hours. Another work was presented by R. Takai et al. on blood purification using composite nano fibers. About 10% of the population worldwide is affected by chronic kidney disease (CKD). The authors developed nano fiber meshes zeolite-polymer composite nano fibers for efficient adsorption of creatinine, which is a simpler and more accessible method for hemodialysis (HD) patients.

  8. Comparison between properties of polyurethane nano composites prepared by two different methods

    International Nuclear Information System (INIS)

    Barmar, M.; Barikani, M.; Fereidoonnia, M.

    2009-01-01

    In this work, a thermoplastic polyurethane elastomer model based on polytetramethylene glycol. toluene diisocyanate and 1,4-butanediol was selected and synthesized. According to this model two types of polyurethane nano composites were prepared by in situ polymerization and melt intercalation procedures. The organo-modified nano clay was used in nano composites samples in 0.4 weight percent level. The prepared nano composites were studied by WAXD, tensile and thermal analysis. Thermal properties of the nano composites were higher than those of pure polyurethane elastomers. Nano composites prepared via melt intercalation method showed a lower tensile strength and hardness than those prepared through in situ polymerization method

  9. Comparison of Benzene & Toluene removal from synthetic polluted air with use of Nano photocatalyticTiO2/ ZNO process.

    Science.gov (United States)

    Gholami, Mitra; Nassehinia, Hamid Reza; Jonidi-Jafari, Ahmad; Nasseri, Simin; Esrafili, Ali

    2014-02-05

    Mono aromatic hydrocarbons (BTEX) are a group of hazardous pollutants which originate from sources such as refineries, gas, and oil extraction fields, petrochemicals and paint and glue industries.Conventional methods, including incineration, condensation, adsorption and absorption have been used for removal of VOCs. None of these methods is economical for removal of pollutants of polluted air with low to moderate concentrations. The heterogeneous photocatalytic processes involve the chemical reactions to convert pollutant to carbon dioxide and water. The aim of this paper is a comparison of Benzene & Toluene removal from synthetic polluted air using a Nano photocatalytic TiO2/ ZNO process. The X-ray diffraction (XRD) patterns showed that Nano crystals of TiO2 and ZNO were in anatase and rutile phases. Toluene & benzene were decomposed by TiO2/ ZNO Nano photocatalyst and UV radiation. Kruskal-wallis Test demonstrated that there are significant differences (pvalue UV intensity and decreasing initial concentrations. Effect of TiO2/ZNO Nano photocatalyst on benzene is less than that on toluene. In this research, Toluene & benzene removal by TiO2/ZNO and UV followed first-order reactions.

  10. Propeller rotation noise due to torque and thrust

    Science.gov (United States)

    Deming, Arthur F

    1940-01-01

    Sound pressure of the first four harmonics of rotation from a full-scale two-blade propeller were measured and are compared with values calculated from theory. The comparison is made (1) for the space distribution with constant tip speed and (2) for fixed space angles with variable tip speed. A relation for rotation noise from an element of radius developed by Gutin is given showing the effect of number of blades on the rotation noise.

  11. Preparation and Characterization of Pyrotechnics Binder-Coated Nano-Aluminum Composite Particles

    Science.gov (United States)

    Ye, Mingquan; Zhang, Shuting; Liu, Songsong; Han, Aijun; Chen, Xin

    2017-07-01

    The aim of this article is to protect the activity of nano-aluminum (Al) particles in solid rocket propellants and pyrotechnics. The morphology, structure, active aluminum content, and thermal and catalytic properties of the coated samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetry-differential scanning calorimetry (TG-DSC), and oxidation-reduction titration methods. The results indicated that nano-Al particles could be effectively coated with phenolic resin (PF), fluororubber (Viton B), and shellac through a solvent/nonsolvent method. The energetic composite particles have core-shell structures and the thickness of the coating film is about 5-15 nm. Analysis of the active Al content revealed that Viton B coating had a much better protective effect. The TG-DSC results showed that the energy amount and energy release rate of PF-, Viton B-, and shellac-coated Al particles were larger than those of the raw nano-Al particles. The catalytic effects of coated Al particles on the thermal decomposition of ammonium perchlorate (AP) were better than those of raw nano-Al particles, and the effect of shellac-coated Al particles was significantly better than that of Viton B-coated Al particles.

  12. NanoSail - D Orbital and Attitude Dynamics

    Science.gov (United States)

    Heaton, Andrew F.; Faller, Brent F.; Katan, Chelsea K.

    2013-01-01

    NanoSail-D unfurled January 20th, 2011 and successfully demonstrated the deployment and deorbit capability of a solar sail in low Earth orbit. The orbit was strongly perturbed by solar radiation pressure, aerodynamic drag, and oblate gravity which were modeled using STK HPOP. A comparison of the ballistic coefficient history to the orbit parameters exhibits a strong relationship between orbital lighting, the decay rate of the mean semi-major axis and mean eccentricity. A similar comparison of mean solar area using the STK HPOP solar radiation pressure model exhibits a strong correlation of solar radiation pressure to mean eccentricity and mean argument of perigee. NanoSail-D was not actively controlled and had no capability on-board for attitude or orbit determination. To estimate attitude dynamics we created a 3-DOF attitude dynamics simulation that incorporated highly realistic estimates of perturbing forces into NanoSail-D torque models. By comparing the results of this simulation to the orbital behavior and ground observations of NanoSail-D, we conclude that there is a coupling between the orbit and attitude dynamics as well as establish approximate limits on the location of the NanoSail-D solar center of pressure. Both of these observations contribute valuable data for future solar sail designs and missions.

  13. Development of HAN-based Liquid Propellant Thruster

    Science.gov (United States)

    Hisatsune, K.; Izumi, J.; Tsutaya, H.; Furukawa, K.

    2004-10-01

    Many of propellants that are applied to the conventional spacecraft propulsion system are toxic propellants. Because of its toxicity, considering the environmental pollution or safety on handling, it will be necessary to apply the "green" propellant to the spacecraft propulsion system. The purpose of this study is to apply HAN based liquid propellant (LP1846) to mono propellant thruster. Compared to the hydrazine that is used in conventional mono propellant thruster, HAN based propellant is not only lower toxic but also can obtain higher specific impulse. Moreover, HAN based propellant can be decomposed by the catalyst. It means there are the possibility of applying to the mono propellant thruster that can leads to the high reliability of the propulsion system.[1],[2] However, there are two technical subjects, to apply HAN based propellant to the mono propellant thruster. One is the high combustion temperature. The catalyst will be damaged under high temperature condition. The other is the low catalytic activity. It is the serious problem on application of HAN based propellant to the mono propellant thruster that is used for attitude control of spacecraft. To improve the catalytic activity of HAN based propellant, it is necessary to screen the best catalyst for HAN based propellant. The adsorption analysis is conducted by Monte Carlo Simulation to screen the catalyst metal for HAN and TEAN. The result of analysis shows the Iridium is the best catalyst metal for HAN and TEAN. Iridium is the catalyst metal that is used at conventional mono propellant thruster catalyst Shell405. Then, to confirm the result of analysis, the reaction test about catalyst is conducted. The result of this test is the same as the result of adsorption analysis. That means the adsorption analysis is effective in screening the catalyst metal. At the evaluating test, the various types of carrier of catalyst are also compared to Shell 405 to improve catalytic activity. The test result shows the

  14. 14 CFR 35.23 - Propeller control system.

    Science.gov (United States)

    2010-01-01

    ... propeller effect under the intended operating conditions. (4) The failure or corruption of data or signals... corruption of airplane-supplied data does not result in hazardous propeller effects. (e) The propeller... effect. (2) Failures or malfunctions directly affecting the propeller control system in a typical...

  15. Functionally Graded Materials using Plasma Spray with Nano Structured Ceramic

    International Nuclear Information System (INIS)

    Sioh, E L; Tok, A I Y

    2013-01-01

    In this paper, nano structured FGM was fabricated using DC plasma spray technique. Nano structured and micro structured powder were used as the feeding powder with steel substrate. The spray parameters was optimized and characterisation of nano-ceramic FGM and micro-ceramic FGM were done using bending test and micro-hardness test. Experimental results have shown that the nano-structured FGM exhibit 20% improvement flexure strength and 10% in hardness. A comparison was made between sintered micro ceramic tile and nano ceramic FGM using simple drop test method.

  16. Hydrodynamics of Ship Propellers

    DEFF Research Database (Denmark)

    Breslin, John P.; Andersen, Poul

    This book deals with flows over propellers operating behind ships, and the hydrodynamic forces and moments which the propeller generates on the shaft and on the ship hull.The first part of the text is devoted to fundamentals of the flow about hydrofoil sections (with and without cavitation...... of an intermittently cavitating propeller in a wake and the pressures and forces it exerts on the shaft and on the ship hull is examined. A final chapter discusses the optimization of efficiency of compound propulsors. The authors have taken care to clearly describe physical concepts and mathematical steps. Appendices...

  17. Study on the Effect of Heat Treatment on Physical Properties of Poplar and Beech Woods Impregnated with Nano-Copper and Nano-Silver

    Directory of Open Access Journals (Sweden)

    Hassan Siahposht

    2012-06-01

    Full Text Available Present study conducted to review effects of heat treatment on weight loss, water adsorption, and thickness swelling of poplar (Populus nigra and beech (Fagus oreintalis woods impregnated with nano-copper and nano-silver. Specimens werepressur (2.5 bar impregnated with 400 PPM water-based solution of nano-copper and nano-silver particles in a pressure vessel. For heat treatment, nano-cupper,  nano-silver impregnated and control specimens, were heat treated at 145°C temperature for 24 hours. Water absorption and thickness swelling decreased in heat treated and nano-heat treated specimens and this decrease in specimens impregnated with nano-copper and nano-silver was more obvious than in heat treated control specimens. The reasons were the degradation in crystal sections of celluloses chains and the ink variation of wood polymers. On the other hand, a comparison between heat treated and nano- heat treated specimens has shown weight loss further in nano-heat treated specimens. This shows that retent nano-copper and nano-silver by impregnation facilitates heat transfer in wood; and it may increase the process of degradation and pyrolysis of wood structures in inner parts of specimens.

  18. A comparison of nano bentonite and some nano chemical additives to improve drilling fluid using local clay and commercial bentonites

    Directory of Open Access Journals (Sweden)

    Nada S. Al-Zubaidi

    2017-09-01

    In the second part, a commercial bentonite was used and mixed with nano commercial bentonite and nano chemical materials (MgO, TiO2, and graphene at 0.005, 0.01, 0.05, 0.1, 0.2 and 0.4 wt% concentrations. The results showed that nano commercial bentonite gives the same filtration behavior of graphene, whereas, the plastic viscosity, yield point and apparent viscosity were the same when using nano commercial bentonite, TiO2 and graphene. The best results were obtained with MgO addition, whereby the filter loss decreased to 35% with a higher value of yield point.

  19. Solid propellant impact tests

    International Nuclear Information System (INIS)

    Snow, E.C.

    1976-03-01

    Future space missions, as in the past, call for the continued use of radioisotopes as heat sources for thermoelectric power generators. In an effort to minimize the risk of radioactive contamination of the environment, a complete safety analysis of each such system is necessary. As a part of these analyses, the effects on such a system of a solid propellant fire environment resulting from a catastrophic launch pad abort must be considered. Several impact tests were conducted in which either a simulant MHW-FSA or a steel ball was dropped on the cold, unignited or the hot, burning surface of a block of UTP-3001 solid propellant. The rebound velocities were measured for both surface conditions of the propellant. The resulting coefficient of restitution, determined as the ratio of the components of the impact and rebound velocities perpendicular to the impact surface of the propellant, were not very dependent on whether the surface was cold or hot at the time of impact

  20. Propeller and inflow vortex interaction : vortex response and impact on the propeller performance

    NARCIS (Netherlands)

    Yang, Y.; Zhou, T; Sciacchitano, A.; Veldhuis, L.L.M.; Eitelberg, G.

    2016-01-01

    The aerodynamic operating conditions of a propeller can include complex situations where vorticity from sources upstream can enter the propeller plane. In general, when the vorticity enters in a concentrated form of a vortex, the interaction between the vortex and blade is referred to as

  1. Assessment of CF lung disease using motion corrected PROPELLER MRI: a comparison with CT

    Energy Technology Data Exchange (ETDEWEB)

    Ciet, Pierluigi [General Hospital Ca' Foncello, Radiology Department, Treviso (Italy); Sophia Children' s Hospital, Pediatric Pulmonology Erasmus MC, Rotterdam (Netherlands); Erasmus MC, Radiology, Rotterdam (Netherlands); Serra, Goffredo; Catalano, Carlo [University of Rome ' ' Sapienza' ' , Radiology, Rome (Italy); Bertolo, Silvia; Morana, Giovanni [General Hospital Ca' Foncello, Radiology Department, Treviso (Italy); Spronk, Sandra [Erasmus MC, Radiology, Rotterdam (Netherlands); Erasmus MC, Epidemiology, Rotterdam (Netherlands); Ros, Mirco [Ca' Foncello Hospital, Pediatrics, Treviso (Italy); Fraioli, Francesco [University College London (UCL), Institute of Nuclear Medicine, London (United Kingdom); Quattrucci, Serena [University of Rome Sapienza, Pediatrics, Rome (Italy); Assael, M.B. [Azienda Ospedaliera di Verona, Verona CF Center, Verona (Italy); Pomerri, Fabio [University of Padova, Department of Medicine-DIMED, Padova (Italy); Tiddens, Harm A.W.M. [Sophia Children' s Hospital, Pediatric Pulmonology Erasmus MC, Rotterdam (Netherlands); Erasmus MC, Radiology, Rotterdam (Netherlands)

    2016-03-15

    To date, PROPELLER MRI, a breathing-motion-insensitive technique, has not been assessed for cystic fibrosis (CF) lung disease. We compared this technique to CT for assessing CF lung disease in children and adults. Thirty-eight stable CF patients (median 21 years, range 6-51 years, 22 female) underwent MRI and CT on the same day. Study protocol included respiratory-triggered PROPELLER MRI and volumetric CT end-inspiratory and -expiratory acquisitions. Two observers scored the images using the CF-MRI and CF-CT systems. Scores were compared with intra-class correlation coefficient (ICC) and Bland-Altman plots. The sensitivity and specificity of MRI versus CT were calculated. MRI sensitivity for detecting severe CF bronchiectasis was 0.33 (CI 0.09-0.57), while specificity was 100 % (CI 0.88-1). ICCs for bronchiectasis and trapped air were as follows: MRI-bronchiectasis (0.79); CT-bronchiectasis (0.85); MRI-trapped air (0.51); CT-trapped air (0.87). Bland-Altman plots showed an MRI tendency to overestimate the severity of bronchiectasis in mild CF disease and underestimate bronchiectasis in severe disease. Motion correction in PROPELLER MRI does not improve assessment of CF lung disease compared to CT. However, the good inter- and intra-observer agreement and the high specificity suggest that MRI might play a role in the short-term follow-up of CF lung disease (i.e. pulmonary exacerbations). (orig.)

  2. Assessment of CF lung disease using motion corrected PROPELLER MRI: a comparison with CT

    International Nuclear Information System (INIS)

    Ciet, Pierluigi; Serra, Goffredo; Catalano, Carlo; Bertolo, Silvia; Morana, Giovanni; Spronk, Sandra; Ros, Mirco; Fraioli, Francesco; Quattrucci, Serena; Assael, M.B.; Pomerri, Fabio; Tiddens, Harm A.W.M.

    2016-01-01

    To date, PROPELLER MRI, a breathing-motion-insensitive technique, has not been assessed for cystic fibrosis (CF) lung disease. We compared this technique to CT for assessing CF lung disease in children and adults. Thirty-eight stable CF patients (median 21 years, range 6-51 years, 22 female) underwent MRI and CT on the same day. Study protocol included respiratory-triggered PROPELLER MRI and volumetric CT end-inspiratory and -expiratory acquisitions. Two observers scored the images using the CF-MRI and CF-CT systems. Scores were compared with intra-class correlation coefficient (ICC) and Bland-Altman plots. The sensitivity and specificity of MRI versus CT were calculated. MRI sensitivity for detecting severe CF bronchiectasis was 0.33 (CI 0.09-0.57), while specificity was 100 % (CI 0.88-1). ICCs for bronchiectasis and trapped air were as follows: MRI-bronchiectasis (0.79); CT-bronchiectasis (0.85); MRI-trapped air (0.51); CT-trapped air (0.87). Bland-Altman plots showed an MRI tendency to overestimate the severity of bronchiectasis in mild CF disease and underestimate bronchiectasis in severe disease. Motion correction in PROPELLER MRI does not improve assessment of CF lung disease compared to CT. However, the good inter- and intra-observer agreement and the high specificity suggest that MRI might play a role in the short-term follow-up of CF lung disease (i.e. pulmonary exacerbations). (orig.)

  3. Advanced vectorial simulation of VCSELs with nano structures invited paper

    DEFF Research Database (Denmark)

    Chung, Il-Sug; Mørk, Jesper

    2009-01-01

    The single-mode properties and design issues of three vertical-cavity surface-emitting laser (VCSEL) structures incorporating nano structures are rigorously investigated. Nano structuring enables to deliver selective pumping or loss to the fundamental mode as well as stabilizing the output...... polarization state. Comparison of three vectorial simulation methods reveals that the modal expansion method is suitable for treating the nano structured VCSEL designs....

  4. Characteristics of a non-volatile liquid propellant in liquid-fed ablative pulsed plasma thrusters

    Science.gov (United States)

    Ling, William Yeong Liang; Schönherr, Tony; Koizumi, Hiroyuki

    2017-02-01

    In the past several decades, the use of electric propulsion in spacecraft has experienced tremendous growth. With the increasing adoption of small satellites in the kilogram range, suitable propulsion systems will be necessary in the near future. Pulsed plasma thrusters (PPTs) were the first form of electric propulsion to be deployed in orbit, and are highly suitable for small satellites due to their inherent simplicity. However, their lifetime is limited by disadvantages such as carbon deposition leading to thruster failure, and complicated feeding systems required due to the conventional use of solid propellants (usually polytetrafluoroethylene (PTFE)). A promising alternative to solid propellants has recently emerged in the form of non-volatile liquids that are stable in vacuum. This study presents a broad comparison of the non-volatile liquid perfluoropolyether (PFPE) and solid PTFE as propellants on a PPT with a common design base. We show that liquid PFPE can be successfully used as a propellant, and exhibits similar plasma discharge properties to conventional solid PTFE, but with a mass bit that is an order of magnitude higher for an identical ablation area. We also demonstrate that the liquid PFPE propellant has exceptional resistance to carbon deposition, completely negating one of the major causes of thruster failure, while solid PTFE exhibited considerable carbon build-up. Energy dispersive X-ray spectroscopy was used to examine the elemental compositions of the surface deposition on the electrodes and the ablation area of the propellant (or PFPE encapsulator). The results show that based on its physical characteristics and behavior, non-volatile liquid PFPE is an extremely promising propellant for use in PPTs, with an extensive scope available for future research and development.

  5. Thermoluminescence properties of micro and nano structure hydroxyapatite after gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Shafaei, Mostafa; Ziaie, Farhood; Hajiloo, Nahid [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of). Radiation Application Research School

    2016-12-15

    The goal of this study is to compare the thermoluminescence properties of nano and micro structure hydroxyapatite. Nano structure hydroxyapatite was synthesized via hydrolysis method, while the micro structure one was from Merck Company. X-ray diffraction and fourier transform infrared spectroscopy were used to determine the crystal structure and chemical composition of the hydroxyapatite samples. Particles sizes of each sample were estimated using Scherer equation and transmission electron microscopy system. Thermoluminescence properties of the samples were investigated under gamma irradiation. The glow curves of micro and nano structure samples show a peak at 150 C and 200 C, respectively. Thermoluminescence responses of both the samples were linear in the range of 25 - 1 000 Gy where, nano structure sample show a greater slope and stronger linearity in comparison to the micro sample. The results show that the thermoluminescence response of micro sample faded rapidly in comparison to the nano sample due to the existence of the peak at higher temperature.

  6. Cavitation simulation on marine propellers

    DEFF Research Database (Denmark)

    Shin, Keun Woo

    Cavitation on marine propellers causes thrust breakdown, noise, vibration and erosion. The increasing demand for high-efficiency propellers makes it difficult to avoid the occurrence of cavitation. Currently, practical analysis of propeller cavitation depends on cavitation tunnel test, empirical...... criteria and inviscid flow method, but a series of model test is costly and the other two methods have low accuracy. Nowadays, computational fluid dynamics by using a viscous flow solver is common for practical industrial applications in many disciplines. Cavitation models in viscous flow solvers have been...... hydrofoils and conventional/highly-skewed propellers are performed with one of three cavitation models proven in 2D analysis. 3D cases also show accuracy and robustness of numerical method in simulating steady and unsteady sheet cavitation on complicated geometries. Hydrodynamic characteristics of cavitation...

  7. Single-layer nano-carbon film, diamond film, and diamond/nano-carbon composite film field emission performance comparison

    International Nuclear Information System (INIS)

    Wang, Xiaoping; Wang, Jinye; Wang, Lijun

    2016-01-01

    A series of single-layer nano-carbon (SNC) films, diamond films, and diamond/nano-carbon (D/NC) composite films have been prepared on the highly doped silicon substrate by using microwave plasma chemical vapor deposition techniques. The films were characterised by scanning electron microscopy, Raman spectroscopy, and field emission I-V measurements. The experimental results indicated that the field emission maximum current density of D/NC composite films is 11.8–17.8 times that of diamond films. And the field emission current density of D/NC composite films is 2.9–5 times that of SNC films at an electric field of 3.0 V/μm. At the same time, the D/NC composite film exhibits the advantage of improved reproducibility and long term stability (both of the nano-carbon film within the D/NC composite cathode and the SNC cathode were prepared under the same experimental conditions). And for the D/NC composite sample, a high current density of 10 mA/cm"2 at an electric field of 3.0 V/μm was obtained. Diamond layer can effectively improve the field emission characteristics of nano-carbon film. The reason may be due to the diamond film acts as the electron acceleration layer.

  8. Thermal Vacuum Test Correlation of a Zero Propellant Load Case Thermal Capacitance Propellant Gauging Analytical Model

    Science.gov (United States)

    Mckim, Stephen A.

    2016-01-01

    This thesis describes the development and correlation of a thermal model that forms the foundation of a thermal capacitance spacecraft propellant load estimator. Specific details of creating the thermal model for the diaphragm propellant tank used on NASA's Magnetospheric Multiscale spacecraft using ANSYS and the correlation process implemented are presented. The thermal model was correlated to within plus or minus 3 degrees Celsius of the thermal vacuum test data, and was determined sufficient to make future propellant predictions on MMS. The model was also found to be relatively sensitive to uncertainties in applied heat flux and mass knowledge of the tank. More work is needed to improve temperature predictions in the upper hemisphere of the propellant tank where predictions were found to be 2 to 2.5 C lower than the test data. A road map for applying the model to predict propellant loads on the actual MMS spacecraft toward its end of life in 2017-2018 is also presented.

  9. Efficacy of periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) for shoulder magnetic resonance (MR) imaging

    Energy Technology Data Exchange (ETDEWEB)

    Nagatomo, Kazuya, E-mail: nkgzmyn.1103@gmail.com [Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Yabuuchi, Hidetake, E-mail: h-yabu@med.kyushu-u.ac.jp [Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Yamasaki, Yuzo, E-mail: yyama@radiol.med.kyushu-u.ac.jp [Department of Clinical Radiology, Graduate of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Narita, Hiroshi, E-mail: hiroshi.narita.ty@hitachi.com [Hitachi Medical Corporation, 3-26-29 Hakataekimae, Hakata-ku, Fukuoka 812-0011 (Japan); Kumazawa, Seiji, E-mail: s_kmzw@hs.med.kyushu-u.ac.jp [Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Kojima, Tsukasa, E-mail: k.tsukasa.0910@gmail.com [Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Sakai, Noriyuki, E-mail: noriyuki.sakai0602@gmail.com [Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Masaki, Masahumi, E-mail: m-masaki@kimura-hosp.or.jp [Department of Radiology, Kimura Hospital, 2-13-19 Chiyo, Hakata-ku, Fukuoka 812-0044 (Japan); Kimura, Hiroshi, E-mail: h-kimura@kimura-hosp.or.jp [Department of Surgery, Kimura Hospital, 2-13-19 Chiyo, Hakata-ku, Fukuoka 812-0044 (Japan)

    2016-10-15

    Objectives: To elucidate the utility of PROPELLER for motion artefact reduction on shoulder MRI and to examine the influence of streak artefacts on diagnosis of clinical images. Methods: 15 healthy volunteers and 48 patients underwent shoulder MRI with/without PROPELLER (coronal oblique proton density-fast spin echo [PD-FSE], sagittal oblique T2-FSE). In a volunteer study, all sequences were performed in both static and exercise-loaded conditions. Two radiologists graded artefacts and delineation of various anatomical structures in the volunteer study and motion and streak artefacts in the clinical study. Mean scores were compared between sequences with/without PROPELLER. In the clinical study, mean scores of motion artefacts were compared with mean scores of streak artefacts. Wilcoxon signed-rank test was used for all comparisons. Results: In both studies, PROPELLER significantly reduced motion artefacts (P < 0.05). In the volunteer study, it significantly improved delineations in sagittal oblique images in the exercise-loaded condition (P < 0.05). In the clinical study, streak artefacts appeared dominantly on images with PROPELLER (P < 0.05), but influenced diagnosis to a lesser extent than motion artefacts. Conclusion: PROPELLER can reduce motion artefacts in shoulder MRI. While it does cause streak artefacts, it affects diagnosis to a lesser extent.

  10. Homogenization Issues in the Combustion of Heterogeneous Solid Propellants

    Science.gov (United States)

    Chen, M.; Buckmaster, J.; Jackson, T. L.; Massa, L.

    2002-01-01

    We examine random packs of discs or spheres, models for ammonium-perchlorate-in-binder propellants, and discuss their average properties. An analytical strategy is described for calculating the mean or effective heat conduction coefficient in terms of the heat conduction coefficients of the individual components, and the results are verified by comparison with those of direct numerical simulations (dns) for both 2-D (disc) and 3-D (sphere) packs across which a temperature difference is applied. Similarly, when the surface regression speed of each component is related to the surface temperature via a simple Arrhenius law, an analytical strategy is developed for calculating an effective Arrhenius law for the combination, and these results are verified using dns in which a uniform heat flux is applied to the pack surface, causing it to regress. These results are needed for homogenization strategies necessary for fully integrated 2-D or 3-D simulations of heterogeneous propellant combustion.

  11. Drag and Torque on Locked Screw Propeller

    Directory of Open Access Journals (Sweden)

    Tomasz Tabaczek

    2014-09-01

    Full Text Available Few data on drag and torque on locked propeller towed in water are available in literature. Those data refer to propellers of specific geometry (number of blades, blade area, pitch and skew of blades. The estimation of drag and torque of an arbitrary propeller considered in analysis of ship resistance or propulsion is laborious. The authors collected and reviewed test data available in the literature. Based on collected data there were developed the empirical formulae for estimation of hydrodynamic drag and torque acting on locked screw propeller. Supplementary CFD computations were carried out in order to prove the applicability of the formulae to modern moderately skewed screw propellers.

  12. Noise from Two-Blade Propellers

    Science.gov (United States)

    Stowell, E Z; Deming, A F

    1936-01-01

    The two-blade propeller, one of the most powerful sources of sound known, has been studied with the view of obtaining fundamental information concerning the noise emission. In order to eliminate engine noise, the propeller was mounted on an electric motor. A microphone was used to pick up the sound whose characteristics were studied electrically. The distribution of noise throughout the frequency range, as well as the spatial distribution about the propeller, was studied. The results are given in the form of polar diagrams. An appendix of common acoustical terms is included.

  13. Natural convection in nano-fluids: Are the thermophoresis and Brownian motion effects significant in nano-fluid heat transfer enhancement?

    International Nuclear Information System (INIS)

    Haddad, Zoubida; Abu-Nada, Eiyad; Oztop, Hakan F.; Mataoui, Amina

    2012-01-01

    Natural convection heat transfer and fluid flow of CuO-Water nano-fluids is studied using the Rayleigh-Benard problem. A two component non-homogenous equilibrium model is used for the nano-fluid that incorporates the effects of Brownian motion and thermophoresis. Variable thermal conductivity and variable viscosity are taken into account in this work. Finite volume method is used to solve governing equations. Results are presented by streamlines, isotherms, nano-particle distribution, local and mean Nusselt numbers and nano-particle profiles at top and bottom side. Comparison of two cases as absence of Brownian and thermophoresis effects and presence of Brownian and thermophoresis effects showed that higher heat transfer is formed with the presence of Brownian and thermophoresis effect. In general, by considering the role of thermophoresis and Brownian motion, an enhancement in heat transfer is observed at any volume fraction of nano-particles. However, the enhancement is more pronounced at low volume fraction of nano-particles and the heat transfer decreases by increasing nano-particle volume fraction. On the other hand, by neglecting the role of thermophoresis and Brownian motion, deterioration in heat transfer is observed and this deterioration elevates by increasing the volume fraction of nano-particles. (authors)

  14. Propeller Flaps: A Literature Review.

    Science.gov (United States)

    Sisti, Andrea; D'Aniello, Carlo; Fortezza, Leonardo; Tassinari, Juri; Cuomo, Roberto; Grimaldi, Luca; Nisi, Giuseppe

    2016-01-01

    Since their introduction in 1991, propeller flaps are increasingly used as a surgical approach to loss of substance. The aim of this study was to evaluate the indications and to verify the outcomes and the complication rates using this reconstructing technique through a literature review. A search on PubMed was performed using "propeller flap", "fasciocutaneous flap", "local flap" or "pedicled flap" as key words. We selected clinical studies using propeller flaps as a reconstructing technique. We found 119 studies from 1991 to 2015. Overall, 1,315 propeller flaps were reported in 1,242 patients. Most frequent indications included loss of substance following tumor excision, repair of trauma-induced injuries, burn scar contractures, pressure sores and chronic infections. Complications were observed in 281/1242 patients (22.6%) occurring more frequently in the lower limbs (31.8%). Partial flap necrosis and venous congestion were the most frequent complications. The complications' rate was significantly higher in infants (70 years old) but there was not a significant difference between the sexes. Trend of complication rate has not improved during the last years. Propeller flaps showed a great success rate with low morbidity, quick recovery, good aesthetic outcomes and reduced cost. The quality and volume of the transferred soft tissue, the scar orientation and the possibility of direct donor site closure should be considered in order to avoid complications. Indications for propeller flaps are small- or medium-sized defects located in a well-vascularized area with healthy surrounding tissues. Copyright © 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  15. Disposal of Liquid Propellants

    Science.gov (United States)

    1990-03-13

    propellant includes an oxi- dizer (hydroxylammoniuin nitrate), a fuel (triethanolammonium nitrate), and water . In an- ticipation of widespread (both...are also included. 20. DISTRIBUTION/ AVAILABILIT ’." OF ABMTRACT 21 ABSTRACT SECURITY CLASSIF.CATICIN IUNCLASSIFIEDIUNLIMITED 0 SAME AS RPT. 0 OTIC...trieth- anolammoiur nitrate), anG water . In anticipation of widespread (both conti- nental U.S. and abroac) use of the propellant, USATHAMA began a

  16. A theoretical and experimental investigation of propeller performance methodologies

    Science.gov (United States)

    Korkan, K. D.; Gregorek, G. M.; Mikkelson, D. C.

    1980-01-01

    This paper briefly covers aspects related to propeller performance by means of a review of propeller methodologies; presentation of wind tunnel propeller performance data taken in the NASA Lewis Research Center 10 x 10 wind tunnel; discussion of the predominent limitations of existing propeller performance methodologies; and a brief review of airfoil developments appropriate for propeller applications.

  17. Comparison of Corrosion Behavior of Electrochemically Deposited Nano-Cobalt-Coated Ni Sheet

    Directory of Open Access Journals (Sweden)

    Nasser Al-Aqeeli

    2013-01-01

    Full Text Available Corrosion behavior of nano-coblat-coated Ni sheet was compared with pure Ni and 20% Fe-Ni alloy sheet using potentiodynamic polarization and linear polarization technique in 0.1 M NaCl solution at room temperature. Results showed that corrosion resistance properties of nano-Co-coated Ni sheet were almost same as that of pure Ni sheet, however corrosion resistance of 20% Fe-Ni sheet was decreased significantly. Pitting potential of 20% Fe-Ni sheet was subsequently decreased as compared to pure Ni sheet as well as nano-cobalt-coated Ni sheet. SEM/EDS analysis of the corroded surfaces showed that both pure Ni and nano-coblat-coated Ni sheet did not show any appreciable corrosion however significant corrosion was observed in the case of 20% Fe-Ni sheet.

  18. Cavitation noise studies on marine propellers

    Science.gov (United States)

    Sharma, S. D.; Mani, K.; Arakeri, V. H.

    1990-04-01

    Experimental observations are described of cavitation inception and noise from five model propellers, three basic and two modified, tested in the open jet section of the Indian Institute of Science high-speed water tunnel facility. Extensive experiments on the three basic propellers of different design, which included visualization of cavitation and measurements of noise, showed that the dominant type of cavitation was in the form of tip vortex cavitation, accompanied by leading edge suction side sheet cavitation in its close vicinity, and the resultant noise depended on parameters such as the advance coefficient, the cavitation number, and the propeller geometry. Of these, advance coefficient was found to have the maximum influence not only on cavitation noise but also on the inception of cavitation. Noise levels and frequencies of spectra obtained from all the three basic propellers at conditions near inception and different advance coefficient values, when plotted in the normalized form as suggested by Blake, resulted in a universal spectrum which would be useful for predicting cavitation noise at prototype scales when a limited extent of cavitation is expected in the same form as observed on the present models. In an attempt to delay the onset of tip vortex cavitation, the blades of two of the three basic propellers were modified by drilling small holes in the tip and leading edge areas. Studies on the modified propellers showed that the effectiveness of the blade modification was apparently stronger at low advance coefficient values and depended on the blade sectional profile. Measurements of cavitation noise indicated that the modification also improved the acoustic performance of the propellers as it resulted in a complete attenuation of the low-frequency spectral peaks, which were prominent with the basic propellers. In addition to the above studies, which were conducted under uniform flow conditions, one of the basic propellers was tested in the simulated

  19. Synthesis of Boron Nano wires, Nano tubes, and Nano sheets

    International Nuclear Information System (INIS)

    Patel, R.B.; Chou, T.; Iqbal, Z.

    2014-01-01

    The synthesis of boron nano wires, nano tubes, and nano sheets using a thermal vapor deposition process is reported. This work confirms previous research and provides a new method capable of synthesizing boron nano materials. The materials were made by using various combinations of MgB 2 , Mg(BH 4 ) 2 , MCM-41, NiB, and Fe wire. Unlike previously reported methods, a nanoparticle catalyst and a silicate substrate are not required for synthesis. Two types of boron nano wires, boron nano tubes, and boron nano sheets were made. Their morphology and chemical composition were determined through the use of scanning electron microscopy, transmission electron microscopy, and electron energy loss spectroscopy. These boron-based materials have potential for electronic and hydrogen storage applications.

  20. Nano-PCMs for passive electronic cooling applications

    Science.gov (United States)

    Colla, L.; Fedele, L.; Mancin, S.; Buonomo, B.; Ercole, D.; Manca, O.

    2015-11-01

    The present work aims at investigating a new challenging use of oxide (TiO2, Al2O3, etc.) nanoparticles to enhance the thermal properties: thermal conductivity, specific heat, and latent heat of pure paraffin waxes to obtain a new class of Phase Change Materials (PCMs), the so-called nano-PCMs. The nano-PCMs were obtained by seeding different amounts of oxide nanoparticles in a paraffin wax having a melting temperature of 45°C. The thermophysical properties such as latent heat and thermal conductivity were then measured to understand the effects of the nanoparticles on the thermal properties of both the solid and liquid PCM. Finally, a numerical comparison between the use of the pure paraffin wax and the nano-PCM in a typical electronics passive cooling device was implemented. Numerical simulations were carried out using the Ansys-Fluent 15.0 code. Results in terms of solid and liquid phase temperatures, melting time and junction temperature were reported. Moreover, a comparison with experimental results was also performed.

  1. Tests on thirteen navy type model propellers

    Science.gov (United States)

    Durand, W F

    1927-01-01

    The tests on these model propellers were undertaken for the purpose of determining the performance coefficients and characteristics for certain selected series of propellers of form and type as commonly used in recent navy designs. The first series includes seven propellers of pitch ratio varying by 0.10 to 1.10, the area, form of blade, thickness, etc., representing an arbitrary standard propeller which had shown good results. The second series covers changes in thickness of blade section, other things equal, and the third series, changes in blade area, other things equal. These models are all of 36-inch diameter. Propellers A to G form the series on pitch ratio, C, N. I. J the series on thickness of section, and K, M, C, L the series on area. (author)

  2. Comparison of the characteristics of granular propellant movement in interior ballistics based on the interphase drag model

    International Nuclear Information System (INIS)

    Jang, Jin Sung; Oh, Seok Hawn; Roh, Tae Seong

    2014-01-01

    Interior ballistics are completed in tens of milliseconds, as are all gun-firing phenomena. Thus, some data cannot be measured directly through experimentation. Therefore, such complex gun-firing phenomena are traditionally clarified by numerical analysis. In the two phase flow of interior ballistics, interphase drag has a strong effect on propellant particle movement. This drag is a momentum sink in the gas phase and a corresponding source of momentum for the solid phase. Previous studies have calculated the drag force on the propellant particles using Ergun's empirical equation, which was developed for a dense bed and relates the drag to the pressure drop through porous media. However, the particulate bed is fluidized in the course of the cycle of interior ballistics, thus indicating that the flow field is ransient with regions of high Reynolds number beyond the range of experimental data. The Ergun equation is examined through a compensation study and calibrated based on the Reynolds number using the numerical method. Moreover, the influence of different drag models on flow behavior and propellant movement in interior ballistics is analyzed.

  3. Nano-technology and nano-toxicology.

    Science.gov (United States)

    Maynard, Robert L

    2012-01-01

    Rapid developments in nano-technology are likely to confer significant benefits on mankind. But, as with perhaps all new technologies, these benefits are likely to be accompanied by risks, perhaps by new risks. Nano-toxicology is developing in parallel with nano-technology and seeks to define the hazards and risks associated with nano-materials: only when risks have been identified they can be controlled. This article discusses the reasons for concern about the potential effects on health of exposure to nano-materials and relates these to the evidence of the effects on health of the ambient aerosol. A number of hypotheses are proposed and the dangers of adopting unsubstantiated hypotheses are stressed. Nano-toxicology presents many challenges and will need substantial financial support if it is to develop at a rate sufficient to cope with developments in nano-technology.

  4. High-Lift Propeller Noise Prediction for a Distributed Electric Propulsion Flight Demonstrator

    Science.gov (United States)

    Nark, Douglas M.; Buning, Pieter G.; Jones, William T.; Derlaga, Joseph M.

    2017-01-01

    Over the past several years, the use of electric propulsion technologies within aircraft design has received increased attention. The characteristics of electric propulsion systems open up new areas of the aircraft design space, such as the use of distributed electric propulsion (DEP). In this approach, electric motors are placed in many different locations to achieve increased efficiency through integration of the propulsion system with the airframe. Under a project called Scalable Convergent Electric Propulsion Technology Operations Research (SCEPTOR), NASA is designing a flight demonstrator aircraft that employs many "high-lift propellers" distributed upstream of the wing leading edge and two cruise propellers (one at each wingtip). As the high-lift propellers are operational at low flight speeds (take-off/approach flight conditions), the impact of the DEP configuration on the aircraft noise signature is also an important design consideration. This paper describes efforts toward the development of a mulit-fidelity aerodynamic and acoustic methodology for DEP high-lift propeller aeroacoustic modeling. Specifically, the PAS, OVERFLOW 2, and FUN3D codes are used to predict the aerodynamic performance of a baseline high-lift propeller blade set. Blade surface pressure results from the aerodynamic predictions are then used with PSU-WOPWOP and the F1A module of the NASA second generation Aircraft NOise Prediction Program to predict the isolated high-lift propeller noise source. Comparisons of predictions indicate that general trends related to angle of attack effects at the blade passage frequency are captured well with the various codes. Results for higher harmonics of the blade passage frequency appear consistent for the CFD based methods. Conversely, evidence of the need for a study of the effects of increased azimuthal grid resolution on the PAS based results is indicated and will be pursued in future work. Overall, the results indicate that the computational

  5. Improve Image Quality of Transversal Relaxation Time PROPELLER and FLAIR on Magnetic Resonance Imaging

    Science.gov (United States)

    Rauf, N.; Alam, D. Y.; Jamaluddin, M.; Samad, B. A.

    2018-03-01

    The Magnetic Resonance Imaging (MRI) is a medical imaging technique that uses the interaction between the magnetic field and the nuclear spins. MRI can be used to show disparity of pathology by transversal relaxation time (T2) weighted images. Some techniques for producing T2-weighted images are Periodically Rotated Overlapping Parallel Lines with Enhanced Reconstruction (PROPELLER) and Fluid Attenuated Inversion Recovery (FLAIR). A comparison of T2 PROPELLER and T2 FLAIR parameters in MRI image has been conducted. And improve Image Quality the image by using RadiAnt DICOM Viewer and ENVI software with method of image segmentation and Region of Interest (ROI). Brain images were randomly selected. The result of research showed that Time Repetition (TR) and Time Echo (TE) values in all types of images were not influenced by age. T2 FLAIR images had longer TR value (9000 ms), meanwhile T2 PROPELLER images had longer TE value (100.75 - 102.1 ms). Furthermore, areas with low and medium signal intensity appeared clearer by using T2 PROPELLER images (average coefficients of variation for low and medium signal intensity were 0.0431 and 0.0705, respectively). As for areas with high signal intensity appeared clearer by using T2 FLAIR images (average coefficient of variation was 0.0637).

  6. Large Propellant Tank Cryo-Cooler (LPTC)

    Data.gov (United States)

    National Aeronautics and Space Administration — In rocket test and launch facilities, cryogenic propellants stored in tanks boils off due to heat leakage, with the following impacts:Ø   Waste, propellants boil off...

  7. Seawater Immersion of GEM II Propellant

    National Research Council Canada - National Science Library

    Merrill, Calude

    1999-01-01

    ... (% AP lost/week aged in seawater) and intercepts that depend on sample size. Friction and impact data on dried aged propellant samples showed no increased burning hazard compared with propellant not exposed to water...

  8. The PROPEL Electrodynamic Tether Demonstration Mission

    Science.gov (United States)

    Bilen, Sven G.; Johnson, C. Les; Wiegmann, Bruce M.; Alexander, Leslie; Gilchrist, Brian E.; Hoyt, Robert P.; Elder, Craig H.; Fuhrhop, Keith P.; Scadera, Michael

    2012-01-01

    The PROPEL ("Propulsion using Electrodynamics") mission will demonstrate the operation of an electrodynamic tether propulsion system in low Earth orbit and advance its technology readiness level for multiple applications. The PROPEL mission has two primary objectives: first, to demonstrate the capability of electrodynamic tether technology to provide robust and safe, near-propellantless propulsion for orbit-raising, de-orbit, plane change, and station keeping, as well as to perform orbital power harvesting and formation flight; and, second, to fully characterize and validate the performance of an integrated electrodynamic tether propulsion system, qualifying it for infusion into future multiple satellite platforms and missions with minimal modification. This paper provides an overview of the PROPEL system and design reference missions; mission goals and required measurements; and ongoing PROPEL mission design efforts.

  9. Comparison of nano-hydroxyapatite and sodium fluoride mouthrinse for remineralization of incipient carious lesions.

    Directory of Open Access Journals (Sweden)

    Roza Haghgoo

    2014-08-01

    Full Text Available Dental caries is an infectious disease that can be prevented in several ways. The aim of this study was to compare the efficacy of sodium fluoride mouthrinse and nano- hydroxyapatite (nano-HA for the remineralization of incipient caries.After obtaining different concentrations of nano-HA (0-2-5-10%, 60 sound premolars fixed in acrylic blocks were coated with nail polish except for one surface. Ten teeth (control group were stored in distilled water and the remaining 50 samples were demineralized by immersion in 13 ml of 0.1 M lactic acid and 0.2% poly acrylic acid for 48 hours. Their microhardness was then measured and compared to that of the control group. Next, the 50 test teeth were randomly divided into 5 groups of group1 (negative, group 2 (2% nano-HA, group 3 (5% nano-HA, group 4(10% nano-HA and group 5 (0.2 NAF mouthrinse. The microhardness of the teeth was measured after 12 hours of immersion in the above-mentioned solutions. Data were analyzed using repeated measures analysis of variance (ANOVA.Microhardness of all samples decreased significantly after immersion in the demineralization solution and increased following immersion in nano-HA and NAF mouthrinses; however, this increase was not statistically significant (P=0.711.Nano-HA and NAF mouthrinses can greatly enhance remineralization and increase tooth microhardness.

  10. 78 FR 4038 - Critical Parts for Airplane Propellers

    Science.gov (United States)

    2013-01-18

    ... manufacturers are not required to provide information concerning propeller critical part design, manufacture, or... engineering, manufacturing, and service management processes should provide clear information for propeller... manufacture critical parts for airplane propellers update their manuals to record engineering, manufacture...

  11. Ionic liquid propellants: future fuels for space propulsion.

    Science.gov (United States)

    Zhang, Qinghua; Shreeve, Jean'ne M

    2013-11-11

    Use of green propellants is a trend for future space propulsion. Hypergolic ionic liquid propellants, which are environmentally-benign while exhibiting energetic performances comparable to hydrazine, have shown great potential to meet the requirements of developing nontoxic high-performance propellant formulations for space propulsion applications. This Concept article presents a review of recent advances in the field of ionic liquid propellants. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Nano technology

    International Nuclear Information System (INIS)

    Lee, In Sik

    2002-03-01

    This book is introduction of nano technology, which describes what nano technology is, alpha and omega of nano technology, the future of Korean nano technology and human being's future and nano technology. The contents of this book are nano period is coming, a engine of creation, what is molecular engineering, a huge nano technology, technique on making small things, nano materials with exorbitant possibility, the key of nano world the most desirable nano technology in bio industry, nano development plan of government, the direction of development for nano technology and children of heart.

  13. Advances in LO2 Propellant Conditioning

    Science.gov (United States)

    Mehta, Gopal; Orth, Michael; Stone, William; Perry, Gretchen; Holt, Kimberly; Suter, John

    1994-01-01

    This paper describes the cryogenic testing and analysis that has recently been completed as part of a multi-year effort to develop a new, more robust and operable LO2 propellant conditioning system. Phase 1 of the program consisted of feasibility demonstrations ot four novel propellant conditioning concepts. A no-bleed, passive propellant conditioning option was shown for the first time to successfully provide desired propellant inlet conditions. The benefits of passive conditioning are reduced operations costs, decreased hardware costs, enhanced operability and increased reliability on future expendable launch vehicles In Phase 2 of the test program, effects of major design parameters were studied and design correlation for future vehicle design were developed. Simultaneously, analytical models were developed and validated. Over 100 tests were conducted with a full-scale feedline using LN2 as the test fluid. A circulation pump provided a range of pressure and flow conditions. The test results showed that the passive propellant conditioning system is insensitive to variations in many of the parameters. The test program provides the validation necessary to incorporate the passive conditioning system into the baseline of future vehicles. Modeling of these systems using computational fluid dynamics seems highly promising.

  14. Nano-swimmers in biological membranes and propulsion hydrodynamics in two dimensions.

    Science.gov (United States)

    Huang, Mu-Jie; Chen, Hsuan-Yi; Mikhailov, Alexander S

    2012-11-01

    Active protein inclusions in biological membranes can represent nano-swimmers and propel themselves in lipid bilayers. A simple model of an active inclusion with three particles (domains) connected by variable elastic links is considered. First, the membrane is modeled as a two-dimensional viscous fluid and propulsion behavior in two dimensions is examined. After that, an example of a microscopic dynamical simulation is presented, where the lipid bilayer structure of the membrane is resolved and the solvent effects are included by multiparticle collision dynamics. Statistical analysis of data reveals ballistic motion of the swimmer, in contrast to the classical diffusion behavior found in the absence of active transitions between the states.

  15. Design and simulation on the morphing composite propeller (Conference Presentation)

    Science.gov (United States)

    Chen, Fanlong; Li, Qinyu; Liu, Liwu; Lan, Xin; Liu, Yanju; Leng, Jinsong

    2017-04-01

    As one of the most crucial part of the unmanned underwater vehicle (UUV), the composite propeller plays an important role on the UUV's performance. As the composite propeller behaves excellent properties in hydroelastic facet and acoustic suppression, it attracts increasing attentions all over the globe. This paper goes a step further based on this idea, and comes up with a novel concept of "morphing composite propeller" (MCP) to improve the performance of the conventional composite propeller (CCP) to anticipate the improved propeller can perform better to propel the UUV. Based on the new concept, a novel MCP is designed. Each blade of the propeller is assembled with an active rotatable flap (ARF) to change the blade's local camber with flap rotation. Then the transmission mechanism (TM) has been designed and housed in the propeller blade to push the ARF. With the ARF rotating, the UUV can be propelled by different thrusts under certain rotation velocities of the propeller. Based on the design, the Fluent is exploited to analyze the fluid dynamics around the propeller. Finally, based on the design and hydrodynamic analysis, the structural response for the novel morphing composite propeller is calculated. The propeller blade is simplified and layered with composite materials. And the structure response of an MCP is obtained with various rotation angle under the hydrodynamic pressure. This simulation can instruct the design and fabrication techniques of the MCP.

  16. EPR dosimetric properties of nano-barium sulfate

    International Nuclear Information System (INIS)

    Aboelezz, E.; Hassan, G.M.; Sharaf, M.A.; El-Khodary, A.

    2015-01-01

    Nano/micro BaSO 4 were prepared through the co-precipitation method to measure ionizing radiation doses using electron paramagnetic resonance (EPR). The nano-BaSO 4 sample was characterized using X-ray diffraction (XRD), and transmission electron microscopy (TEM) techniques. The dose response and fading properties of nano- and micro-phase BaSO 4 were compared in EPR spectra. The prepared nano- and micro-BaSO 4 samples have the same hole and electron centers, which may be attributed to SO 4 − and SO 3 − , respectively. The dosimetric signals for prepared nano- and micro-BaSO 4 have spectroscopic splitting factor (g) with values 2.0025±0.0006 and 2.0027±0.0006, respectively. The nanocrystalline sample has a linear γ-ray dose response over the range 0.4 Gy–1 kGy. The performance parameters which including detection limit and critical level calculated from weighted and unweighted least-squares fitting. The sensitivity of nano-BaSO 4 to γ-ray is one and a half times more than alanine. The lifetime and activation energy for nano-BaSO 4 were estimated by conducting a thermal stability study, and were 5.7±1.1×10 4 years and 0.73±0.14 eV, respectively. The combined and expanded uncertainties accompanying measurements were ±3.89% and ±7.78%, respectively. - Highlights: • Preparation of nano-BaSO 4 using the co-precipitation method. • Study of the dosimetric properties of nano-barium sulfate using the EPR technique. • Comparison between a new EPR dosimeter using nano-materials and standard alanine. • Calculation of the uncertainty budget for nano-BaSO 4

  17. Propeller thrust analysis using Prandtl's lifting line theory, a comparison between the experimental thrust and the thrust predicted by Prandtl's lifting line theory

    Science.gov (United States)

    Kesler, Steven R.

    The lifting line theory was first developed by Prandtl and was used primarily on analysis of airplane wings. Though the theory is about one hundred years old, it is still used in the initial calculations to find the lift of a wing. The question that guided this thesis was, "How close does Prandtl's lifting line theory predict the thrust of a propeller?" In order to answer this question, an experiment was designed that measured the thrust of a propeller for different speeds. The measured thrust was compared to what the theory predicted. In order to do this experiment and analysis, a propeller needed to be used. A walnut wood ultralight propeller was chosen that had a 1.30 meter (51 inches) length from tip to tip. In this thesis, Prandtl's lifting line theory was modified to account for the different incoming velocity depending on the radial position of the airfoil. A modified equation was used to reflect these differences. A working code was developed based on this modified equation. A testing rig was built that allowed the propeller to be rotated at high speeds while measuring the thrust. During testing, the rotational speed of the propeller ranged from 13-43 rotations per second. The thrust from the propeller was measured at different speeds and ranged from 16-33 Newton's. The test data were then compared to the theoretical results obtained from the lifting line code. A plot in Chapter 5 (the results section) shows the theoretical vs. actual thrust for different rotational speeds. The theory over predicted the actual thrust of the propeller. Depending on the rotational speed, the error was: at low speeds 36%, at low to moderate speeds 84%, and at high speeds the error increased to 195%. Different reasons for these errors are discussed.

  18. Comparison of flux motion in type-II superconductors including pinning centers with the shapes of nano-rods and nano-particles by using 3D-TDGL simulation

    International Nuclear Information System (INIS)

    Ito, Shintaro; Ichino, Yusuke; Yoshida, Yutaka

    2015-01-01

    Highlights: • We constructed the 3D-TDGL simulator to calculate the flux motion. • We assumed two superconductors including only nano-rods and only nano-particles. • We succeeded to simulate the flux motion for various magnetic field angles. • If anyone introduce nano-rod, controlling the “single-kink” motion is very important. • The introduction of nano-particles is effective to pin the “single-kink” motion. - Abstract: Time-dependent Ginzburg–Landau (TDGL) equations are very useful method for simulation of the motion of flux quanta in type-II superconductors. We constructed the 3D-TDGL simulator and succeeded to simulate the motion of flux quanta in 3-dimension. We carried out the 3D-TDGL simulation to compare two superconductors which included only pinning centers with the shape of nano-rods and only nano-particle-like pinning centers in the viewpoint of the flux motion. As a result, a motion of “single-kink” caused the whole motion of a flux quantum in the superconductor including only the nano-rods. On the other hand, in the superconductor including the nano-particles, the flux quanta were pinned by the nano-particles in the various magnetic field applied angles. As the result, no “single-kink” occurred in the superconductor including the nano-particles. Therefore, the nano-particle-like pinning centers are effective shape to trap flux quanta for various magnetic field applied angles.

  19. Thermal Vacuum Test Correlation of A Zero Propellant Load Case Thermal Capacitance Propellant Gauging Analytics Model

    Science.gov (United States)

    McKim, Stephen A.

    2016-01-01

    This thesis describes the development and test data validation of the thermal model that is the foundation of a thermal capacitance spacecraft propellant load estimator. Specific details of creating the thermal model for the diaphragm propellant tank used on NASA's Magnetospheric Multiscale spacecraft using ANSYS and the correlation process implemented to validate the model are presented. The thermal model was correlated to within plus or minus 3 degrees Centigrade of the thermal vacuum test data, and was found to be relatively insensitive to uncertainties in applied heat flux and mass knowledge of the tank. More work is needed, however, to refine the thermal model to further improve temperature predictions in the upper hemisphere of the propellant tank. Temperatures predictions in this portion were found to be 2-2.5 degrees Centigrade lower than the test data. A road map to apply the model to predict propellant loads on the actual MMS spacecraft toward its end of life in 2017-2018 is also presented.

  20. Combustion characteristics of SMX and SMX based propellants

    Science.gov (United States)

    Reese, David A.

    This work investigates the combustion of the new solid nitrate ester 2,3-hydroxymethyl-2,3-dinitro-1,4-butanediol tetranitrate (SMX, C6H 8N6O16). SMX was synthesized for the first time in 2008. It has a melting point of 85 °C and oxygen balance of 0% to CO 2, allowing it to be used as an energetic additive or oxidizer in solid propellants. In addition to its neat combustion characteristics, this work also explores the use of SMX as a potential replacement for nitroglycerin (NG) in double base gun propellants and as a replacement for ammonium perchlorate in composite rocket propellants. The physical properties, sensitivity characteristics, and combustion behaviors of neat SMX were investigated. Its combustion is stable at pressures of up to at least 27.5 MPa (n = 0.81). The observed flame structure is nearly identical to that of other double base propellant ingredients, with a primary flame attached at the surface, a thick isothermal dark zone, and a luminous secondary flame wherein final recombination reactions occur. As a result, the burning rate and primary flame structure can be modeled using existing one-dimensional steady state techniques. A zero gas-phase activation energy approximation results in a good fit between modeled and observed behavior. Additionally, SMX was considered as a replacement for nitroglycerin in a double base propellant. Thermochemical calculations indicate improved performance when compared with the common double base propellant JA2 at SMX loadings above 40 wt-%. Also, since SMX is a room temperature solid, migration may be avoided. Like other nitrate esters, SMX is susceptible to decomposition over long-term storage due to the presence of excess acid in the crystals; the addition of stabilizers (e.g., derivatives of urea) during synthesis should be sufficient to prevent this. the addition of Both unplasticized and plasticized propellants were formulated. Thermal analysis of unplasticized propellant showed a distinct melt

  1. Development of a Marine Propeller With Nonplanar Lifting Surfaces

    DEFF Research Database (Denmark)

    Andersen, Poul; Friesch, Jürgen; Kappel, Jens J.

    2005-01-01

    The principle of non-planar lifting surfaces is applied to the design of modern aircraft wings to obtain better lift to drag ratios. Whereas a pronounced fin or winglet at the wingtip has been developed for aircraft, the application of the nonplanar principle to marine propellers, dealt...... with in this paper, has led to the KAPPEL propeller with blades curved toward the suction side integrating the fin or winglet into the propeller blade. The combined theoretical, experimental, and practical approach to develop and design marine propellers with nonplanar lifting surfaces has resulted in propellers...

  2. Changing of ballistic parameters from aged gun propellants

    NARCIS (Netherlands)

    Klerk, W.P.C. de; Driel, C.A. van

    2003-01-01

    The various properties of an SB and a DB gun propellant were investigated before and after artificial ageing. It was found that the decrease of nitrocellulose (NC) molecular weight, due to ageing of gun propellants, leads to a decrease of the mechanical integrity of the propellant grains. The effect

  3. Laser-propelled ram accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Sasoh, A. [Tohoku Univ., Sendai (Japan). Inst. of Fluid Science

    2000-11-01

    The concept of 'laser-propelled ram accelerator (L-RAMAC)' is proposed. Theoretically it is capable of achieving a higher launch speed than that by a chemical ram accelerator because a higher specific energy can be input to the propellant gas. The laser beam is supplied through the muzzle, focused as an annulus behind the base of the projectile. The performance of L-RAMAC is analized based on generalized Rankine-Hugoniot relations, suggesting that a superorbital muzzle speed is achievable out of this device. (orig.)

  4. Propeller installation effects on turboprop aircraft acoustics

    Science.gov (United States)

    Chirico, Giulia; Barakos, George N.; Bown, Nicholas

    2018-06-01

    Propeller installation options for a twin-engined turboprop aircraft are evaluated at cruise conditions, aiming to identify the quieter configuration. Computational fluid dynamics is used to investigate the near-field acoustics and transfer functions are employed to estimate the interior cabin noise. Co-rotating and counter-rotating installation options are compared. The effect of propeller synchrophasing is also considered. The employed method captures the complexity of the acoustic field generated by the interactions of the propeller sound fields among each other and with the airframe, showing also the importance of simulating the whole problem to predict the actual noise on a flying aircraft. Marked differences among the various layouts are observed. The counter-rotating top-in option appears the best in terms of acoustics, the top-out propeller rotation leading to louder noise because of inflow conditions and the occurrence of constructive acoustic interferences. Synchrophasing is shown to be beneficial for co-rotating propellers, specially regarding the interior noise, because of favorable effects in the interaction between the propeller direct sound field and the noise due to the airframe. An angle closer to the maximum relative blade shift was found to be the best choice, yielding, however, higher sound levels than those provided by the counter-rotating top-in layout.

  5. THE PROPELLER AND THE FROG

    International Nuclear Information System (INIS)

    Pan, Margaret; Chiang, Eugene

    2010-01-01

    'Propellers' in planetary rings are disturbances in ring material excited by moonlets that open only partial gaps. We describe a new type of co-orbital resonance that can explain the observed non-Keplerian motions of propellers. The resonance is between the moonlet underlying the propeller and co-orbiting ring particles downstream of the moonlet where the gap closes. The moonlet librates within the gap about an equilibrium point established by co-orbiting material and stabilized by the Coriolis force. In the limit of small libration amplitude, the libration period scales linearly with the gap azimuthal width and inversely as the square root of the co-orbital mass. The new resonance recalls but is distinct from conventional horseshoe and tadpole orbits; we call it the 'frog' resonance, after the relevant term in equine hoof anatomy. For a ring surface density and gap geometry appropriate for the propeller Bleriot in Saturn's A ring, our theory predicts a libration period of ∼4 years, similar to the ∼3.7 year period over which Bleriot's orbital longitude is observed to vary. These librations should be subtracted from the longitude data before any inferences about moonlet migration are made.

  6. Nano Materials

    International Nuclear Information System (INIS)

    Jin, In Ju; Lee, Ik Mo; Kwon, Yeung Gu

    2006-02-01

    This book introduces background of nano science such as summary, plenty room at the bottom, access way to nano technique, nanoparticles using bottom-up method which are a marvel of nature, and modern alchemy : chemical synthesis of artificial nano structure, understanding of quantum mechanics, STM/AFM, nano metal powder, ceramic nanoparticles, nano structure film, manufacture of nanoparticles using reverse micelle method, carbon nano tube, sol-gel material, nano energy material, nano catalyst nano bio material technology and spintronics.

  7. Nano-technology and nano-toxicology

    OpenAIRE

    Maynard, Robert L.

    2012-01-01

    Rapid developments in nano-technology are likely to confer significant benefits on mankind. But, as with perhaps all new technologies, these benefits are likely to be accompanied by risks, perhaps by new risks. Nano-toxicology is developing in parallel with nano-technology and seeks to define the hazards and risks associated with nano-materials: only when risks have been identified they can be controlled. This article discusses the reasons for concern about the potential effects on health of ...

  8. Energy coefficients for a propeller series

    DEFF Research Database (Denmark)

    Olsen, Anders Smærup

    2004-01-01

    The efficiency for a propeller is calculated by energy coefficients. These coefficients are related to four types of losses, i.e. the axial, the rotational, the frictional, and the finite blade number loss, and one gain, i.e. the axial gain. The energy coefficients are derived by use...... of the potential theory with the propeller modelled as an actuator disk. The efficiency based on the energy coefficients is calculated for a propeller series. The results show a good agreement between the efficiency based on the energy coefficients and the efficiency obtained by a vortex-lattice method....

  9. Solid propellant processing factor in rocket motor design

    Science.gov (United States)

    1971-01-01

    The ways are described by which propellant processing is affected by choices made in designing rocket engines. Tradeoff studies, design proof or scaleup studies, and special design features are presented that are required to obtain high product quality, and optimum processing costs. Processing is considered to include the operational steps involved with the lining and preparation of the motor case for the grain; the procurement of propellant raw materials; and propellant mixing, casting or extrusion, curing, machining, and finishing. The design criteria, recommended practices, and propellant formulations are included.

  10. 14 CFR 25.907 - Propeller vibration and fatigue.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller vibration and fatigue. 25.907... vibration and fatigue. This section does not apply to fixed-pitch wood propellers of conventional design. (a... propeller to show that failure due to fatigue will be avoided throughout the operational life of the...

  11. 14 CFR 23.907 - Propeller vibration and fatigue.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller vibration and fatigue. 23.907... General § 23.907 Propeller vibration and fatigue. This section does not apply to fixed-pitch wood... evaluation of the propeller to show that failure due to fatigue will be avoided throughout the operational...

  12. CFD simulation on Kappel propeller with a hull wake field

    DEFF Research Database (Denmark)

    Shin, Keun Woo; Andersen, Poul; Møller Bering, Rasmus

    2013-01-01

    Marine propellers are designed not for the open-water operation, but for the operation behind a hull due to the inhomogeneous hull wake and thrust deduction. The adaptation for the hull wake is important for the propulsive efficiency and cavitation risk especially on single-screw ships. CFD...... simulations for a propeller with a hull model have showed acceptable agreement with a model test result in the thrust and torque (Larsson et al. 2010). In the current work, a measured hull wake is applied to the simulation instead of modelling a hull, because the hull geometry is mostly not available...... for propeller designers and the computational effort can be reduced by excluding the hull. The CFD simulation of a propeller flow with a hull wake is verified in order to use CFD as a propeller design tool. A Kappel propeller, which is an innovative tip-modified propeller, is handled. Kappel propellers...

  13. Experimental study of high-speed counter-rotation propeller on low speed wind range; Dojiku hantengata kosoku propeller no teisokuiki ni okeru fudo jikken

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Collaborative research was conducted by National Aerospace Laboratory and Japan Aircraft Development Company in the period of fiscal 1988-1992 into methods for testing aircraft with advanced propeller in low-speed wind tunnel. The propulsion efficiency of the currently available high-bypass turbofan engine is approximately 60% in the vicinity of Mach number 0.85. Propeller-driven aircraft, whose propulsion efficiency is as high as 80% in the low Mach number domain, are scarcely in practical use in the domain of Mach number 0.75 or higher. There are studies reported abroad as well as in Japan for the propeller-driven aircraft to enjoy higher propeller propulsion efficiency even in the vicinity of Mach number 0.8 by modifying the propeller diameter, number of blades, and blade sections, etc. This paper describes the experimental research into the high-speed counter-rotation propeller. A counter-rotation propeller 0.3m in diameter and provided with coaxially arranged 8times2 SR-2 blades is evaluated for pitch angles during the takeoff and landing modes, for thrust characteristics at the pitch angle for the cruising mode, and for propeller backwash and noise. 15 refs., 72 figs., 9 tabs.

  14. Technology of foamed propellants

    Energy Technology Data Exchange (ETDEWEB)

    Boehnlein-Mauss, Jutta; Kroeber, Hartmut [Fraunhofer Institut fuer Chemische Technologie ICT, Pfinztal (Germany)

    2009-06-15

    Foamed propellants are based on crystalline explosives bonded in energetic reaction polymers. Due to their porous structures they are distinguished by high burning rates. Energy content and material characteristics can be varied by using different energetic fillers, energetic polymers and porous structures. Foamed charges can be produced easily by the reaction injection moulding process. For the manufacturing of foamed propellants a semi-continuous remote controlled production plant in pilot scale was set up and a modified reaction injection moulding process was applied. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  15. Carbon nano tubes embedded in polymer nano fibers

    International Nuclear Information System (INIS)

    Dror, Y.; Kedem, S.; Khalfin, R.L.; Paz, Y.; Cohenl, Y.; Salalha, Y.; Yarin, A.L.; Zussman, A.

    2004-01-01

    Full Text: The electro spinning process was used successfully to embed Multi-walled carbon nano tubes (MWCNTs) and single-walled carbon nano tubes (SWCNTs) in a matrix of poly(ethylene oxide) (PEO) forming composite nano fibers. Initial dispersion of SWCNTs in water was achieved by the use of an amphphilic alternating copolymer of styrene and sodium maleate. MWNT dispersion was achieved by ionic and nonionic surfactants. The distribution and conformation of the nano tubes in the nano fibers were studied by transmission electron microscopy (TEM). Oxygen plasma etching was used to expose the nano tubes within the nano fibers to facilitate direct observation. Nano tube alignment within the nano fibers was shown to depend strongly on the quality of the initial dispersions. Well-dispersed and separated nano tubes were embedded in a straight and aligned form while entangled non-separated nano tubes were incorporated as dense aggregates. X-ray diffraction demonstrated a high degree of orientation of the PEO crystals in the electro spun nano fibers with embedded SWCNTs, whereas incorporation of MVCNTs had a detrimental effect on the polymer orientation. Composite polymer nano fibers containing dispersed phases of nanometric TiO 2 particles and MWCNTs were also prepared electro spinning. In this case, the polymer matrix was poly(acrylonitrile) (PAN). The morphology and possible applications of these composite nano fibers will be discussed

  16. A comparison study of polymer/cobalt ferrite nano-composites synthesized by mechanical alloying route

    Directory of Open Access Journals (Sweden)

    Sedigheh Rashidi

    2015-12-01

    Full Text Available In this research, the effect of different biopolymers such as polyethylene glycol (PEG and polyvinylalcohol (PVA on synthesis and characterization of polymer/cobalt ferrite (CF nano-composites bymechanical alloying method has been systematically investigated. The structural, morphological andmagnetic properties changes during mechanical milling were investigated by X-ray diffraction (XRD,Fourier transform infrared spectroscopy (FTIR, transmission electron microscopy (TEM, fieldemission scanning electron microscopy (FESEM, and vibrating sample magnetometer techniques(VSM, respectively. The polymeric cobalt ferrite nano-composites were obtained by employing atwo-step procedure: the cobalt ferrite of 20 nm mean particle size was first synthesized by mechanicalalloying route and then was embedded in PEG or PVA biopolymer matrix by milling process. Theresults revealed that PEG melted due to the local temperature raise during milling. Despite thisphenomenon, cobalt ferrite nano-particles were entirely embedded in PEG matrix. It seems, PAV is anappropriate candidate for producing nano-composite samples due to its high melting point. InPVA/CF nano-composites, the mean crystallite size and milling induced strain decreased to 13 nm and0.48, respectively. Moreover, milling process resulted in well distribution of CF in PVA matrix eventhough the mean particle size of cobalt ferrite has not been significantly affecetd. FTIR resultconfirmed the attachment of PVA to the surface of nano-particles. Magnetic properties evaluationshowed that saturation magnetization and coercivity values decreased in nano-composite samplecomparing the pure cobalt ferrite.

  17. Comparison of model propeller tests with airfoil theory

    Science.gov (United States)

    Durand, William F; Lesley, E P

    1925-01-01

    The purpose of the investigation covered by this report was the examination of the degree of approach which may be anticipated between laboratory tests on model airplane propellers and results computed by the airfoil theory, based on tests of airfoils representative of successive blade sections. It is known that the corrections of angles of attack and for aspect ratio, speed, and interference rest either on experimental data or on somewhat uncertain theoretical assumptions. The general situation as regards these four sets of corrections is far from satisfactory, and while it is recognized that occasion exists for the consideration of such corrections, their determination in any given case is a matter of considerable uncertainty. There exists at the present time no theory generally accepted and sufficiently comprehensive to indicate the amount of such corrections, and the application to individual cases of the experimental data available is, at best, uncertain. While the results of this first phase of the investigation are less positive than had been hoped might be the case, the establishment of the general degree of approach between the two sets of results which might be anticipated on the basis of this simpler mode of application seems to have been desirable.

  18. Study of thermal properties and the dispersion state of nano composites epoxy/clay

    International Nuclear Information System (INIS)

    Paz, Juliana D.; Bertholdi, Jonas; Toledo, Tais C.; Folgueras, Marilena V.; Pezzin, Sergio H.; Coelho, Luiz A.F.

    2011-01-01

    This work investigates an exfoliation/intercalation of nano clays in an epoxy resin by means of x-rays diffraction, scanning electronic microscopy, thermal gravimetric analysis and dilatometric analysis. A comparison of two techniques for preparing nano composites is addressed: mechanical stirring and sonication. X-rays analysis showed that an exfoliation/intercalation is occurring in some samples. TG analysis indicated and increase in thermal stability of the nano composites compared to the neat resin. Finally, dilatometric analysis indicates and increase in Tg for nano composites compared to the neat resin. (author)

  19. Comparison of Therapeutic Effect of Anti-Cryptosporidium Nano-Nitazoxanide (NTZ with Free form of this Drug in Neonatal Rat

    Directory of Open Access Journals (Sweden)

    F. Sedighi

    2016-07-01

    Full Text Available Introduction & Objective: Cryptosporidiosis caused by Cryptosporidium, which is a protozoan parasite, has a worldwide distribution. The infection is through fecal-oral route, direct or indi-rect contact, food or water. The treatment of cryptosporidiosis is difficult and the anti-parasitic agents are not effective. The purpose of this study was encapsulation of nitazoxanide in solid lipid nano-particles (SLN and investigation of its anti-Cryptosporidium effect and its comparison with free drug in the neonatal rat. Materials & Methods: Nitazoxanide was encapsulated by HPH method with 2 mg/Kg concentra-tion in SLN nanoparticles. The oocysts were collected from calves and purified by sucrose floatation. A total of 72 Wistar neonatal rats were categorized in 6 groups of 12 rats including four infected groups treated by free drug, encapsulated nano drug, colloidal carriers without drug (SLN and olive oil; an infected control group and a healthy control group that received PBS. 5 × 105 of oocyts inoculated orally into the sample groups. Finally, intestine of each rat was homogenized in PBS by rotor and the homogenized material was passed through a sieve. Then, floated oocysts in sucrose solution were counted by hemocytometer. Results: Treatment by nitazoxanide significantly decreased the number of parasites in the treatment groups. This decrease at day 6 was more than day 3. Nano nitazoxanide had more effects on parasites than free drug. This difference at day 3 of treatment was not significant (p= 0.182 but at day 6 was statistically significant (P< 0.001. Conclusion: Using nano-nitazoxanide could be a more effective way in the treatment of Cryp-tosporidium infections. (Sci J Hamadan Univ Med Sci 2016; 23 (2:134-140

  20. Experimental and Computational Modal Analyses for Launch Vehicle Models considering Liquid Propellant and Flange Joints

    Directory of Open Access Journals (Sweden)

    Chang-Hoon Sim

    2018-01-01

    Full Text Available In this research, modal tests and analyses are performed for a simplified and scaled first-stage model of a space launch vehicle using liquid propellant. This study aims to establish finite element modeling techniques for computational modal analyses by considering the liquid propellant and flange joints of launch vehicles. The modal tests measure the natural frequencies and mode shapes in the first and second lateral bending modes. As the liquid filling ratio increases, the measured frequencies decrease. In addition, as the number of flange joints increases, the measured natural frequencies increase. Computational modal analyses using the finite element method are conducted. The liquid is modeled by the virtual mass method, and the flange joints are modeled using one-dimensional spring elements along with the node-to-node connection. Comparison of the modal test results and predicted natural frequencies shows good or moderate agreement. The correlation between the modal tests and analyses establishes finite element modeling techniques for modeling the liquid propellant and flange joints of space launch vehicles.

  1. The screw propeller

    Science.gov (United States)

    Larrabee, E. E.

    1980-07-01

    Marine and air screw propellers are considered in terms of theoretical hydrodynamics as developed by Joukowsky, Prandtl, and Betz. Attention is given to the flow around wings of finite span where spanwise flow exists and where lift and the bound vorticity must all go smoothly to zero at the wing tips. The concept of a trailing vortex sheet made up of infinitesimal line vortexes roughly aligned with the direction of flight is discussed in this regard. Also considered is induced velocity, which tends to convect the sheet downward at every stage in the roll-up process, the vortex theory of propellers and the Betz-Prandtl circulation distribution. The performance of the Gossamer Albatross and of a pedal-driven biplane called the Chrysalis are also discussed.

  2. Hemodynamic effects of aerosol propellants. I. Cardiac depression in the dog.

    Science.gov (United States)

    Simaan, J A; Aviado, D M

    1975-11-01

    The inhalation of fluorocarbons caused a depression of myocardial contractility, aortic hypotension, a decrease in cardiac output and an increase in pulmonary vascular resistance. The minimal concentrations that elicited these changes are as follows: 1% trichlorofluoromethane (FC11); 2.5% dichlorotetrafluoroethane (FC114); and 10% dichlorodifluoromethane (FC12). Inhalation of 20% octafluorocyclobutane (FC318) and difluoroethane (FC152a) did not influence these hemodynamic parameters. As in previous comparisons, the most widely used aerosol propellants are potentially cardiotoxic in the anesthetized dog.

  3. Investigation on utilization of liquid propellant in ballistic range experiments

    Energy Technology Data Exchange (ETDEWEB)

    Saso, Akihiro; Oba, Shinji; Takayama, Kazuyoshi [Tohoku University, Sendai (Japan)

    1999-10-31

    Experiments were conducted in a ballistic range using a HAN (hydroxylammonium nitrate)-based liquid monopropellant, LP1846. In a 25-mm-bore single-stage gun, using bulk-loaded propellant of 10 to 35 g, a muzzle speed up to 1.0 km/s was obtained. Time variations of propellant chamber pressures and in-tube projectile velocity profiles were measured. The liquid propellant combustion was initiated accompanying a delay time which was created due to the pyrolysis of the propellant. In order to obtain reliable ballistic range performance, the method of propellant loading was revealed to be critical. Since the burning rate of the liquid propellant is relatively low, the peak acceleration and the muzzle speed strongly depend on the rupture pressure of a diaphragm that was inserted between the launch tube and the propellant chamber. (author)

  4. Burning properties and mechanical integrity of aged gun propellants

    NARCIS (Netherlands)

    Driel, C.A. van; Klerk, W.P.C. de

    2017-01-01

    Conventional gun propellants exhibit the phenomenon of nitrocellulose (NC) decomposition. Besides an effect on thermal stability of propellants, decomposition of NC has an effect on the mechanical integrity of the propellant grains. Enhanced grain fracture may lead to unacceptable changes of the

  5. Experimental Research on Air Propellers III

    Science.gov (United States)

    Durand, W F; Lesley, E P

    1920-01-01

    Report presents the results of wind tunnel tests of propellers that examined the influence of the following characteristics: (1) nominal pitch ratio 1.3 combined with a certain number of the more common or standard forms and proportions; (2) driving face slightly rounded or convex; (3) change in the location of the maximum thickness ordinate of the blade section; (4) pushing forward the leading edge of the blade, thus giving a rounded convex surface on the leading side of the driving face. (5) a series of values for the constant "angle of attack" in forming propellers with radially increasing pitch. In accordance with these purposes tests were carried out on 28 propellers.

  6. Shuttle APS propellant thermal conditioner study

    Science.gov (United States)

    Pearson, W. E.

    1971-01-01

    A study program was performed to allow selection of thermal conditioner assemblies for superheating O2 and H2 at supercritical pressures. The application was the auxiliary propulsion system (APS) for the space shuttle vehicle. The O2/H2 APS propellant feed system included propellant conditioners, of which the thermal conditioner assemblies were a part. Cryogens, pumped to pressures above critical, were directed to the thermal conditioner assembly included: (1) a gas generator assembly with ignition system and bipropellant valves, which burned superheated O2 and H2 at rich conditions; (2) a heat exchanger assembly for thermal conditioning of the cryogenic propellant; and (3) a dump nozzle for heat exchanger exhaust.

  7. Heat transfer in heterogeneous propellant combustion systems

    International Nuclear Information System (INIS)

    Brewster, M.Q.

    1992-01-01

    This paper reports that heat transfer plays an important role in several critical areas of heterogeneous, solid-propellant combustion systems. These areas include heat feedback to the propellant surface, heat transfer between burning aluminum droplets and their surroundings, heat transfer to internal insulation systems, and heat transfer to aft-end equipment. Gas conduction dominates heat feedback to the propellant surface in conventional ammonium perchlorate (AP) composite propellants, although particle radiative feedback also plays a significant role in combustion of metalized propellants. Particle radiation plays a dominant role in heat transfer to internal insulation, compared with that of convection. However, conduction by impingement of burning aluminum particles, which has not been extensively studied, may also be significant. Radiative heat loss plays an important role in determining the burning rate of molten aluminum particles due to a highly luminous, oxide particle-laden, detached flame envelope. Radiation by aluminum oxide smoke particles also plays a dominant role in heat transfer from the exhaust plume to aft-end equipment. Uncertainties in aluminum oxide particle-size distribution and optical properties still make it difficult to predict radiative plume heat transfer accurately from first principles

  8. Highly miniaturized FEEP propulsion system (NanoFEEP) for attitude and orbit control of CubeSats

    Science.gov (United States)

    Bock, Daniel; Tajmar, Martin

    2018-03-01

    A highly miniaturized Field Emission Electric Propulsion (FEEP) system is currently under development at TU Dresden, called NanoFEEP [1]. The highly miniaturized thruster heads are very compact and have a volume of less than 3 cm3 and a weight of less than 6 g each. One thruster is able to generate continuous thrust of up to 8 μN with short term peaks of up to 22 μN. The very compact design and low power consumption (heating power demand between 50 and 150 mW) are achieved by using Gallium as metal propellant with its low melting point of approximately 30 °C. This makes it possible to implement an electric propulsion system consisting of four thruster heads, two neutralizers and the necessary electronics on a 1U CubeSat with its strong limitation in space, weight and available power. Even formation flying of 1U CubeSats using an electric propulsion system is possible with this system, which is shown by the example of a currently planned cooperation project between Wuerzburg University, Zentrum fuer Telematik and TU Dresden. It is planned to use the NanoFEEP electric propulsion system on the UWE (University Wuerzburg Experimental) 1U CubeSat platform [2] to demonstrate orbit and two axis attitude control with our electric propulsion system NanoFEEP. We present the latest performance characteristics of the NanoFEEP thrusters and the highly miniaturized electronics. Additionally, the concept and the current status of a novel cold neutralizer chip using Carbon Nano Tubes (CNTs) is presented.

  9. Comparison between Fluoride and Nano-hydroxyapatite in Remineralizing Initial Enamel Lesion: An in vitro Study.

    Science.gov (United States)

    Daas, Issa; Badr, Sherine; Osman, Essam

    2018-03-01

    The aim of this study was to compare the effectiveness of nano-hydroxyapatite (nano-HAP) paste and fluoride varnish in remineralizing initial enamel lesion in young permanent teeth and their ability to resist secondary caries under dynamic pH cycling quantitatively and qualitatively. Initial caries-like lesions were artificially developed on 45 specimens. Specimens were divided into three groups: (1) Control (without treatment), (2) fluoride varnish (3M ESPE), and (3) nano-HAP paste (Desensibilize Nano P). The nano-HAP paste was applied twice separated by one pH cycle, and the varnish was applied only once followed by 7 days of pH cycling. All specimens were examined using DIAGNOdent® pen (KaVo, Germany), and a representative specimen was randomly selected from each group for qualitative evaluation using scanning electron microscope (SEM) at four stages: Baseline, after lesion formation, immediately after remineralization, and after pH cycling. Data were statistically analyzed with Statistical Package for the Social Sciences (SPSS), version 20. The degree of demineralization was significantly elevated in control group; however, no significant difference was found between fluoride varnish group and nano-HAP paste group (p Nano-HAP paste showed promising long-term protective effect in terms of surface depositions and maintaining a smooth surface compared with fluoride varnish. Based on the findings of this study, nano-HAP paste might be recommended as alternative remineralizing agent with lower fluoride concentration than fluoride varnish that could be beneficial for children, pregnant females, and those who are at high risk of dental fluorosis.

  10. Development of hydrazinium nitroformate based solid propellants

    NARCIS (Netherlands)

    Schöyer, H.F.R.; Schnorhk, A.J.; Korting, P.A.O.G.; Lit, P.J. van; Mul, J.M.; Gadiot, G.; Meulenbrugge, J.J.

    1995-01-01

    The development of new high-performance propellant combinations requires the establishment of safety and handling characteristics and thermodynamic decomposition and explosive properties. This paper addresses the early development phases of a new composite solid propellant based on HNF as oxidizer

  11. Hydroformylation of 1-Hexene over Rh/Nano-Oxide Catalysts

    Directory of Open Access Journals (Sweden)

    Sari Suvanto

    2013-03-01

    Full Text Available The effect of nanostructured supports on the activity of Rh catalysts was studied by comparing the catalytic performance of nano- and bulk-oxide supported Rh/ZnO, Rh/SiO2 and Rh/TiO2 systems in 1-hexene hydroformylation. The highest activity with 100% total conversion and 96% yield of aldehydes was obtained with the Rh/nano-ZnO catalyst. The Rh/nano-ZnO catalyst was found to be more stable and active than the corresponding rhodium catalyst supported on bulk ZnO. The favorable morphology of Rh/nano-ZnO particles led to an increased metal content and an increased number of weak acid sites compared to the bulk ZnO supported catalysts. Both these factors favored the improved catalytic performance. Improvements of catalytic properties were obtained also with the nano-SiO2 and nano-TiO2 supports in comparison with the bulk supports. All of the catalysts were characterized by scanning electron microscope (SEM, inductively coupled plasma mass spectrometry (ICP-MS, BET, powder X-ray diffraction (PXRD and NH3- temperature-programmed desorption (TPD.

  12. In-Space Propellant Production Using Water

    Science.gov (United States)

    Notardonato, William; Johnson, Wesley; Swanger, Adam; McQuade, William

    2012-01-01

    A new era of space exploration is being planned. Manned exploration architectures under consideration require the long term storage of cryogenic propellants in space, and larger science mission directorate payloads can be delivered using cryogenic propulsion stages. Several architecture studies have shown that in-space cryogenic propulsion depots offer benefits including lower launch costs, smaller launch vehicles, and enhanced mission flexibility. NASA is currently planning a Cryogenic Propellant Storage and Transfer (CPST) technology demonstration mission that will use existing technology to demonstrate long duration storage, acquisition, mass gauging, and transfer of liquid hydrogen in low Earth orbit. This mission will demonstrate key technologies, but the CPST architecture is not designed for optimal mission operations for a true propellant depot. This paper will consider cryogenic propellant depots that are designed for operability. The operability principles considered are reusability, commonality, designing for the unique environment of space, and use of active control systems, both thermal and fluid. After considering these operability principles, a proposed depot architecture will be presented that uses water launch and on orbit electrolysis and liquefaction. This could serve as the first true space factory. Critical technologies needed for this depot architecture, including on orbit electrolysis, zero-g liquefaction and storage, rendezvous and docking, and propellant transfer, will be discussed and a developmental path forward will be presented. Finally, use of the depot to support the NASA Science Mission Directorate exploration goals will be presented.

  13. Influence of nano-material on the expansive and shrinkage soil behavior

    International Nuclear Information System (INIS)

    Taha, Mohd Raihan; Taha, Omer Muhie Eldeen

    2012-01-01

    This paper presents an experimental study performed on four types of soils mixed with three types of nano-material of different percentages. The expansion and shrinkage tests were conducted to investigate the effect of three type of nano-materials (nano-clay, nano-alumina, and nano-copper) additive on repressing strains in compacted residual soil mixed with different ratios of bentonite (S1 = 0 % bentonite, S2 = 5 % bentonite, S3 = 10 % bentonite, and S4 = 20 % bentonite). The soil specimens were compacted under the condition of maximum dry unit weight and optimum water content (w opt ) using standard compaction test. The physical and mechanical results of the treated samples were determined. The untreated soil values were used as control points for comparison purposes. It was found that with the addition of optimum percentage of nano-material, both the swell strain and shrinkage strain reduced. The results show that nano-material decreases the development of desiccation cracks on the surface of compacted samples without decrease in the hydraulic conductivity.

  14. Numerical Analysis of Ice Impacts on Azimuth Propeller

    Science.gov (United States)

    2013-09-01

    uniformity as one solid object, though the built-on process is recognized as well. The number of blades for this propeller varies to control cavitation ...Figure 7). The CRP allows the hydrodynamic advantage of regaining lost rotational energy from the first propeller, which is the conventional...it speeds flow through and accelerates it past the propellers. Decelerating duct slows the flow and allows for greatly reduced cavitation and

  15. Methodological comparison on hybrid nano organic solar cell fabrication

    Science.gov (United States)

    Vairavan, Rajendaran; Hambali, Nor Azura Malini Ahmad; Wahid, Mohamad Halim Abd; Retnasamy, Vithyacharan; Shahimin, Mukhzeer Mohamad

    2018-02-01

    The development of low cost solar cells has been the main focus in recent years. This has lead to the generation of photovoltaic cells based on hybrid of nanoparticle-organic polymer materials. This type of hybrid photovoltaic cells can overcome the problem of polymeric devices having low optical absorption and carrier mobilities. The hybrid cell has the potential of bridging the efficiency gap, which in present in organic and inorganic semiconductor materials. This project focuses on obtaining an hybrid active layer consisting of nanoparticles and organic polymer, to understand the parameter involved in obtaining this active layer and finally to investigate if the addition of nano particles in to the active layer could enhance the output of the hybrid solar cell. The hybrid active layer have will be deposited using the spin coating technique by using CdTe, CdS nano particles mixed with poly (2-methoxy,5-(2-ethyl-hexyloxy)-p-phenylvinylene)MEH-PPV.

  16. AN AIRPLANE WITH UNCONVENTIONALLY PLACED PROPELLER POWER UNIT

    Directory of Open Access Journals (Sweden)

    Jan Červinka

    2017-02-01

    Full Text Available The significance of the influence of operating propellers on the aircraft aerodynamic characteristics is well-known. Wind tunnel testing of an airplane model with operating propellers is a complex task regarding the required similarity of the full-scale and the model case. Matching sufficient similarity in axial and rotational velocities in the propeller slipstream is the primordial condition for the global aerodynamic similarity of the windtunnel testing. An example of the model power units with related devices is presented. Examples of the wind tunnel testing results illustrate the extent of the propeller influence on aerodynamic characteristics of an aircraft of unconventional configuration with power units positioned at the fuselage afterbody.

  17. Green plasticizers for multibase gun propellants (Lecture)

    NARCIS (Netherlands)

    Schoolderman, C.; Driel, C.A. van; Zebregs, M.

    2007-01-01

    TNO Defence, Security and Safety has a long history of research on gun propellants. Areas investigated are formulating (new ingredients, optimization), manufacturing, charge design and lifetime assessment [1,2,3,4,5]. In conventional propellants inert plasticizers are used to alter performance,

  18. Small-Scale Shock Testing of Propellants and Ingredients

    National Research Council Canada - National Science Library

    Dawley, S

    2004-01-01

    .... The use of small-scale gap testing to evaluate the shock sensitivity of individual propellant ingredients and propellant formulations is a valuable method for experimentally establishing shock...

  19. Effects of superhydrophobic surface on the propeller wake

    Science.gov (United States)

    Choi, Hongseok; Lee, Jungjin; Park, Hyungmin

    2017-11-01

    This study investigates the change in propeller wake when the superhydrophobic surface is applied on the propeller blade. The propeller rotates in a quiescent water tank, facing its bottom, with a rotational Reynolds number of 96000. To measure the three-dimensional flow fields, we use stereo PIV and a water prism is installed at the camera-side tank wall. Two cameras are tilted 30 degrees from the normal axis of the tank wall, satisfying schiempflug condition. Superhydrophobic surface is made by coating hydrophobic nanoparticles on the propeller blade. Measurements are done on two vertical planes (at the center of propeller hub and the blade tip), and are ensemble averaged being classified by blade phase of 0 and 90 degrees. Velocity fluctuation, turbulent kinetic energy, and vorticity are evaluated. With superhydrophobic surface, it is found that the turbulence level is significantly (20 - 30 %) reduced with a small penalty (less than 5%) in the streamwise momentum (i.e., thrust) generation. This is because the cone shaped propeller wake gets narrower and organized vortex structures are broken with the superhydrophobic surfaces. More detailed flow analysis will be given. Supported by NRF (NRF-2016R1C1B2012775, NRF-2016M2B2A9A02945068) programs of Korea government.

  20. Supercritical Fluid Processing of Propellant Polymers

    Science.gov (United States)

    1991-01-01

    of insoluble material present in the polymeric neopentyl glycol azelate (NPGA) binder. Laub (2) summarizes (from Refs 3 & 4) the various polymeric...binders used in composite propellant formulations for DOD missile systems. e.g., these include: polyneopentyl glycol azelate (NPGA) in HAWK. hydroxy...systems. Composite smokeless propellants containing polyethylene glycol (PEG), polyethylene glycol adepate (PEGA) and polycaprolactone are currently under

  1. HMX based enhanced energy LOVA gun propellant

    Energy Technology Data Exchange (ETDEWEB)

    Sanghavi, R.R. [High Energy Materials Research Laboratory, Pune 411021 (India)]. E-mail: sanghavirr@yahoo.co.uk; Kamale, P.J. [High Energy Materials Research Laboratory, Pune 411021 (India); Shaikh, M.A.R. [High Energy Materials Research Laboratory, Pune 411021 (India); Shelar, S.D. [High Energy Materials Research Laboratory, Pune 411021 (India); Kumar, K. Sunil [High Energy Materials Research Laboratory, Pune 411021 (India); Singh, Amarjit [High Energy Materials Research Laboratory, Pune 411021 (India)

    2007-05-08

    Efforts to develop gun propellants with low vulnerability have recently been focused on enhancing the energy with a further improvement in its sensitivity characteristics. These propellants not only prevent catastrophic disasters due to unplanned initiation of currently used gun propellants (based on nitrate esters) but also realize enhanced energy levels to increase the muzzle velocity of the projectiles. Now, in order to replace nitroglycerine, which is highly sensitive to friction and impact, nitramines meet the requirements as they offer superior energy due to positive heat of formation, typical stoichiometry with higher decomposition temperatures and also owing to negative oxygen balance are less sensitive than stoichiometrically balanced NG. RDX has been widely reported for use in LOVA propellant. In this paper we have made an effort to present the work on scantily reported nitramine HMX based LOVA gun propellant while incorporating energetic plasticizer glycidyl azide polymer to enhance the energy level. HMX is known to be thermally stable at higher temperature than RDX and also proved to be less vulnerable to small scale shaped charge jet attack as its decomposition temperature is 270 deg. C. HMX also offers improved impulse due to its superior heat of formation (+17 kcal/mol) as compared to RDX (+14 kcal/mol). It has also been reported that a break point will not appear until 35,000 psi for propellant comprising of 5 {mu}m HMX. Since no work has been reported in open literature regarding replacement of RDX by HMX, the present studies were carried out.

  2. Structural, Magnetic, and Transport Properties of Polymer-Nano ferrite Composites

    International Nuclear Information System (INIS)

    Imam, N.G.G.

    2013-01-01

    In this work, a series of (x) BaTiO 3 / (1-x) Ni 0.5 Zn 0.5 Fe 2 O 4 nano composite samples were prepared using citrate auto combustion and the samples were classified into three groups.In first group: A series of (x) BaTiO 3 / (1-x) Ni 0.5 Zn 0.5 Fe 2 O 4 ; 0.0≤ x ≤ 1.0 were prepared by double sintering technique and citrate auto combustion method in comparison study due to different characterization analysis. The comparison reveals that from X-ray diffraction; all the samples from the two methods formed in single phase in both; cubic spinel structure NiZnFe 2 O 4 (NZF) ferrite and perovskite tetragonal structure BaTiO 3 (BTO).In group two, in another compassion, multiferroic hybrid nano composites based on different polymers as a matrix for the prepared magnetoelectric biferroic nano composite system 0.5 BaTiO 3 / 0.5Ni 0.5 Zn 0.5 Fe 2 O 4 that has been prepared by citrate auto combustion method. Four different polymers namely poly aniline (PANI), polyvinyl acetate (PVAc), Polyvinyl pyrrolidone (PVP), and polyethylene glycol (PEG), with fixed ration (1:1) with respect to the dispersed magnetoelectric nano composite.In group three, the nano composites materials with formula (1-y) [0.5 BaTiO 3 / 0.5 Ni 0.5 Zn 0.5 Fe 2 O 4 ] / (y) (PEG); 0.0 ≤y ≤+ 1.0, have been prepared at room temperature by weight mixing and cold pressing. Physical properties of nano composite materials consisting different ratios of polyethylene glycol were investigated. With the variation of y content, typical magnetic hysteresis loops of nano composites have been observed in the nano composites at room temperature. When PEG content increase, the saturation magnetization decrease. Meanwhile, the coercive force tends to stable. Additionally, the dielectric constant (ε ' ) and dielectric loss factor (ε '' ) of nano composites materials shift toward higher frequency. The value of (ε ' ) decreased with increasing frequency, which indicates that the major contribution

  3. Endocranial anatomy of the charadriiformes: sensory system variation and the evolution of wing-propelled diving.

    Directory of Open Access Journals (Sweden)

    N Adam Smith

    Full Text Available Just as skeletal characteristics provide clues regarding behavior of extinct vertebrates, phylogenetically-informed evaluation of endocranial morphology facilitates comparisons among extinct taxa and extant taxa with known behavioral characteristics. Previous research has established that endocranial morphology varies across Aves; however, variation of those systems among closely related species remains largely unexplored. The Charadriiformes (shorebirds and allies are an ecologically diverse clade with a comparatively rich fossil record, and therefore, are well suited for investigating interspecies variation, and potential links between endocranial morphology, phylogeny, ecology and other life history attributes. Endocranial endocasts were rendered from high resolution X-ray computed tomography data for 17 charadriiforms (15 extant and two flightless extinct species. Evaluation of endocranial character state changes on a phylogeny for Charadriiformes resulted in identification of characters that vary in taxa with distinct feeding and locomotor ecologies. In comparison with all other charadriiforms, stem and crown clade wing-propelled diving Pan-Alcidae displayed compressed semicircular canals, and indistinct occipital sinuses and cerebellar fissures. Flightless wing-propelled divers have relatively smaller brains for their body mass and smaller optic lobes than volant pan-alcids. Observed differences between volant and flightless wing-propelled sister taxa are striking given that flightless pan-alcids continue to rely on the flight stroke for underwater propulsion. Additionally, the brain of the Black Skimmer Rynchops niger, a taxon with a unique feeding ecology that involves continuous forward aerial motion and touch-based prey detection used both at day and night, is discovered to be unlike that of any other sampled charadriiform in having an extremely large wulst as well as a small optic lobe and distinct occipital sinus. Notably, the

  4. Prediction of propeller-induced hull-pressure fluctuations

    NARCIS (Netherlands)

    Van Wijngaarden, H.C.J.

    2011-01-01

    The cavitating propeller often forms the primary source of noise and vibration on board ships. The propeller induces hydroacoustic pressure fluctuations due to the passing blades and, more importantly, the dynamic activity of cavities in the propeller’s immediate vicinity. The accurate prediction of

  5. 75 FR 12148 - Airworthiness Directives; Ontic Engineering and Manufacturing, Inc. Propeller Governors, Part...

    Science.gov (United States)

    2010-03-15

    ... propeller pitch by regulating oil pressure to the propeller pitch change mechanism. Changes in governor oil..., the propeller governor cannot control oil pressure to the propeller pitch control mechanism. This... proposing this AD to prevent loss of propeller pitch control, damage to the propeller governor, and internal...

  6. Self-propelled oil droplets consuming "fuel" surfactant

    DEFF Research Database (Denmark)

    Toyota, Taro; Maru, Naoto; Hanczyc, Martin M

    2009-01-01

    A micrometer-sized oil droplet of 4-octylaniline containing 5 mol % of an amphiphilic catalyst exhibited a self-propelled motion, producing tiny oil droplets, in an aqueous dispersion of an amphiphilic precursor of 4-octylaniline. The tiny droplets on the surface of the self-propelled droplet wer...

  7. MEMS-Based Solid Propellant Rocket Array Thruster

    Science.gov (United States)

    Tanaka, Shuji; Hosokawa, Ryuichiro; Tokudome, Shin-Ichiro; Hori, Keiichi; Saito, Hirobumi; Watanabe, Masashi; Esashi, Masayoshi

    The prototype of a solid propellant rocket array thruster for simple attitude control of a 10 kg class micro-spacecraft was completed and tested. The prototype has 10×10 φ0.8 mm solid propellant micro-rockets arrayed at a pitch of 1.2 mm on a 20×22 mm substrate. To realize such a dense array of micro-rockets, each ignition heater is powered from the backside of the thruster through an electrical feedthrough which passes along a propellant cylinder wall. Boron/potassium nitrate propellant (NAB) is used with/without lead rhodanide/potassium chlorate/nitrocellulose ignition aid (RK). Impulse thrust was measured by a pendulum method in air. Ignition required electric power of at least 3 4 W with RK and 4 6 W without RK. Measured impulse thrusts were from 2×10-5 Ns to 3×10-4 Ns after the calculation of compensation for air dumping.

  8. Nuclear thermal rockets using indigenous Martian propellants

    International Nuclear Information System (INIS)

    Zubrin, R.M.

    1989-01-01

    This paper considers a novel concept for a Martian descent and ascent vehicle, called NIMF (for nuclear rocket using indigenous Martian fuel), the propulsion for which will be provided by a nuclear thermal reactor which will heat an indigenous Martian propellant gas to form a high-thrust rocket exhaust. The performance of each of the candidate Martian propellants, which include CO2, H2O, CH4, N2, CO, and Ar, is assessed, and the methods of propellant acquisition are examined. Attention is also given to the issues of chemical compatibility between candidate propellants and reactor fuel and cladding materials, and the potential of winged Mars supersonic aircraft driven by this type of engine. It is shown that, by utilizing the nuclear landing craft in combination with a hydrogen-fueled nuclear thermal interplanetary vehicle and a heavy lift booster, it is possible to achieve a manned Mars mission in one launch. 6 refs

  9. Comparison of Dorsal Intercostal Artery Perforator Propeller Flaps and Bilateral Rotation Flaps in Reconstruction of Myelomeningocele Defects.

    Science.gov (United States)

    Tenekeci, Goktekin; Basterzi, Yavuz; Unal, Sakir; Sari, Alper; Demir, Yavuz; Bagdatoglu, Celal; Tasdelen, Bahar

    2018-04-09

    Bilateral rotation flaps are considered the workhorse flaps in reconstruction of myelomeningocele defects. Since the introduction of perforator flaps in the field of reconstructive surgery, perforator flaps have been used increasingly in the reconstruction of various soft tissue defects all over the body because of their appreciated advantages. The aim of this study was to compare the complications and surgical outcomes between bilateral rotation flaps and dorsal intercostal artery perforator (DICAP) flaps in the soft tissue reconstruction of myelomeningocele defects. Between January 2005-February 2017, we studied 47 patients who underwent reconstruction of myelomeningocele defects. Patient demographics, operative data, and postoperative data were reviewed retrospectively and are included in the study. We found no statistically significant differences in patient demographics and surgical complications between these two groups; this may be due to small sample size. With regard to complications-partial flap necrosis, cerebrospinal fluid (CSF) leakage, necessity for reoperation, and wound infection-DICAP propeller flaps were clinically superior to rotation flaps. Partial flap necrosis was associated with CSF leakage and wound infection, and CSF leakage was associated with wound dehiscence. Although surgical outcomes obtained with DICAP propeller flaps were clinically superior to those obtained with rotation flaps, there was no statistically significant difference between the two patient groups. A well-designed comparative study with adequate sample size is needed. Nonetheless, we suggest using DICAP propeller flaps for reconstruction of large myelomeningocele defects.

  10. Image based measurement techniques for aircraft propeller flow diagnostics : Propeller slipstream investigations at high-lift conditions and thrust reverse

    NARCIS (Netherlands)

    Roosenboom, E.W.M.

    2011-01-01

    The aim of the thesis is to measure the propeller slipstream properties (velocity and vorticity) and to assess the unsteady and instantaneous behavior of the propeller flow field at high disk loadings, zero thrust and thrust reverse using the image based measurement techniques. Along with its

  11. GISAXS modelling of helium-induced nano-bubble formation in tungsten and comparison with TEM

    International Nuclear Information System (INIS)

    Thompson, Matt; Sakamoto, Ryuichi; Bernard, Elodie; Kirby, Nigel; Kluth, Patrick; Riley, Daniel; Corr, Cormac

    2016-01-01

    Grazing-incidence small angle x-ray scattering (GISAXS) is a powerful non-destructive technique for the measurement of nano-bubble formation in tungsten under helium plasma exposure. Here, we present a comparative study between transmission electron microscopy (TEM) and GISAXS measurements of nano-bubble formation in tungsten exposed to helium plasma in the Large Helical Device (LHD) fusion experiment. Both techniques are in excellent agreement, suggesting that nano-bubbles range from spheroidal to ellipsoidal, displaying exponential diameter distributions with mean diameters μ=0.68 ± 0.04 nm and μ=0.6 ± 0.1 nm measured by TEM and GISAXS respectively. Depth distributions were also computed, with calculated exponential depth distributions with mean depths of 8.4 ± 0.5 nm and 9.1 ± 0.4 nm for TEM and GISAXS. In GISAXS modelling, spheroidal particles were fitted with an aspect ratio ε=0.7 ± 0.1. The GISAXS model used is described in detail. - Highlights: • GISAXS and TEM were used to measure nano-bubble formation in W exposed to He plasma in the large helical device. • Nano-bubbles had an exponential diameter distributions with averages 0.6 ± 0.1 nm and 0.68 ± 0.04 nm measured by GISAXS and TEM. • Nano-bubbles had an exponential depth distributions with average depths of 9.1 ± 0.4 nm and 8.4 ± 0.5 nm for GISAXS and TEM. • The GISAXS model used to analyse diffraction patterns is explained in detail.

  12. GISAXS modelling of helium-induced nano-bubble formation in tungsten and comparison with TEM

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Matt, E-mail: matt.a.thompson@anu.edu.au [Research School of Physics and Engineering, Australian National University, Mills Road, Acton, ACT 2601 (Australia); Sakamoto, Ryuichi [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Bernard, Elodie [Aix-Marseille University, Marseille 13288 (France); Kirby, Nigel [SAXS/WAXS Beamline, Australian Synchrotron, 800 Blackburn Rd, Clayton, VIC, 3168 (Australia); Kluth, Patrick [Research School of Physics and Engineering, Australian National University, Mills Road, Acton, ACT 2601 (Australia); Riley, Daniel [Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232 (Australia); Corr, Cormac [Research School of Physics and Engineering, Australian National University, Mills Road, Acton, ACT 2601 (Australia)

    2016-05-15

    Grazing-incidence small angle x-ray scattering (GISAXS) is a powerful non-destructive technique for the measurement of nano-bubble formation in tungsten under helium plasma exposure. Here, we present a comparative study between transmission electron microscopy (TEM) and GISAXS measurements of nano-bubble formation in tungsten exposed to helium plasma in the Large Helical Device (LHD) fusion experiment. Both techniques are in excellent agreement, suggesting that nano-bubbles range from spheroidal to ellipsoidal, displaying exponential diameter distributions with mean diameters μ=0.68 ± 0.04 nm and μ=0.6 ± 0.1 nm measured by TEM and GISAXS respectively. Depth distributions were also computed, with calculated exponential depth distributions with mean depths of 8.4 ± 0.5 nm and 9.1 ± 0.4 nm for TEM and GISAXS. In GISAXS modelling, spheroidal particles were fitted with an aspect ratio ε=0.7 ± 0.1. The GISAXS model used is described in detail. - Highlights: • GISAXS and TEM were used to measure nano-bubble formation in W exposed to He plasma in the large helical device. • Nano-bubbles had an exponential diameter distributions with averages 0.6 ± 0.1 nm and 0.68 ± 0.04 nm measured by GISAXS and TEM. • Nano-bubbles had an exponential depth distributions with average depths of 9.1 ± 0.4 nm and 8.4 ± 0.5 nm for GISAXS and TEM. • The GISAXS model used to analyse diffraction patterns is explained in detail.

  13. Indentation analysis of nano-particle using nano-contact mechanics models during nano-manipulation based on atomic force microscopy

    International Nuclear Information System (INIS)

    Daeinabi, Khadijeh; Korayem, Moharam Habibnejad

    2011-01-01

    Atomic force microscopy is applied to measure intermolecular forces and mechanical properties of materials, nano-particle manipulation, surface scanning and imaging with atomic accuracy in the nano-world. During nano-manipulation process, contact forces cause indentation in contact area between nano-particle and tip/substrate which is considerable at nano-scale and affects the nano-manipulation process. Several nano-contact mechanics models such as Hertz, Derjaguin–Muller–Toporov (DMT), Johnson–Kendall–Roberts–Sperling (JKRS), Burnham–Colton–Pollock (BCP), Maugis–Dugdale (MD), Carpick–Ogletree–Salmeron (COS), Pietrement–Troyon (PT), and Sun et al. have been applied as the continuum mechanics approaches at nano-scale. In this article, indentation depth and contact radius between tip and substrate with nano-particle for both spherical and conical tip shape during nano-manipulation process are analyzed and compared by applying theoretical, semiempirical, and empirical nano-contact mechanics models. The effects of adhesion force, as the main contrast point in different nano-contact mechanics models, on nano-manipulation analysis is investigated for different contact radius, and the critical point is discussed for mentioned models.

  14. Performance Analysis Rim Driven Propeller as a Propulsor using Open Water Test

    OpenAIRE

    Agoes Santoso; Irfan Syarif Arief; Anggara Tio Kurniawan

    2017-01-01

    The use of duct in propeller is one of the breakthrough in the development of the propeller. Ducting not only claimed to be increasing efficiency of the propeller, but also capable to protect the propeller from impact therefore propeller lifespan is longer. From that idea then RDP is created. RDP propeller blade are designed to be fix at their housing called Rim, in the other word, the driving force came from it’s rim. On current RDP blade used is non-conventional blade. This thesis will disc...

  15. Non-destructive testing of rocket propellant quality using -X-ray radiography

    International Nuclear Information System (INIS)

    Arayaprecha, W.

    1979-01-01

    Currently, X-rays radiography has been used extensively in various industries. In this thesis, X-rays has been used in the study of compaction of rocket propellant. For a rocket, to gain an accurate guidance result, the propellant used must be mixed and compacted thoroughly. The quality control of the production of propellant sticks must be carefully done. In this study of non-destructive quality testing of rocket propellant, at first the ultrasonic rays was used to test its homogeneity. However, because the density of the propellant was too low, the test equipment could not detect any reflected signals from the propellant being tested. Then the new procedure using X-rays radiography was tried. The variables in the test procedure were voltage, amperage and the focal-film distance. Also different types of films were used. The results of this experiment were then used to construct an exposure chart for testing the homogeneity of the rocket propellant. The advantage of this chart is that a tester can use this table with propellant sticks of different sizes if they have similar density to the density specified in the chart. Also, it is not necessary that the mixture of the testing propellant be the same as the ones used to construct this chart

  16. A Simple Method for High-Lift Propeller Conceptual Design

    Science.gov (United States)

    Patterson, Michael; Borer, Nick; German, Brian

    2016-01-01

    In this paper, we present a simple method for designing propellers that are placed upstream of the leading edge of a wing in order to augment lift. Because the primary purpose of these "high-lift propellers" is to increase lift rather than produce thrust, these props are best viewed as a form of high-lift device; consequently, they should be designed differently than traditional propellers. We present a theory that describes how these props can be designed to provide a relatively uniform axial velocity increase, which is hypothesized to be advantageous for lift augmentation based on a literature survey. Computational modeling indicates that such propellers can generate the same average induced axial velocity while consuming less power and producing less thrust than conventional propeller designs. For an example problem based on specifications for NASA's Scalable Convergent Electric Propulsion Technology and Operations Research (SCEPTOR) flight demonstrator, a propeller designed with the new method requires approximately 15% less power and produces approximately 11% less thrust than one designed for minimum induced loss. Higher-order modeling and/or wind tunnel testing are needed to verify the predicted performance.

  17. Spectrum Diagnosis for Fuchsia Plume of Hall Effect Thruster with Xenon as Propellant

    International Nuclear Information System (INIS)

    Yu Daren; Ding Jiapeng; Dai Jingmin

    2006-01-01

    The colour of the Hall effect thruster's plume is often light-green, and sometimes a fuchsia plume appears during experiments. Based on a spectrum and colour analysis, and a comparison with normal plumes, a conclusion is made that the density of the Xe ions and the temperature of electrons are low when the plume appears fuchsia. In this condition, most of the components of the plume are Xe atoms, and the ionization rate of the propellant is low

  18. DES Prediction of Cavitation Erosion and Its Validation for a Ship Scale Propeller

    Science.gov (United States)

    Ponkratov, Dmitriy, Dr

    2015-12-01

    Lloyd's Register Technical Investigation Department (LR TID) have developed numerical functions for the prediction of cavitation erosion aggressiveness within Computational Fluid Dynamics (CFD) simulations. These functions were previously validated for a model scale hydrofoil and ship scale rudder [1]. For the current study the functions were applied to a cargo ship's full scale propeller, on which the severe cavitation erosion was reported. The performed Detach Eddy Simulation (DES) required a fine computational mesh (approximately 22 million cells), together with a very small time step (2.0E-4 s). As the cavitation for this type of vessel is primarily caused by a highly non-uniform wake, the hull was also included in the simulation. The applied method under predicted the cavitation extent and did not fully resolve the tip vortex; however, the areas of cavitation collapse were captured successfully. Consequently, the developed functions showed a very good prediction of erosion areas, as confirmed by comparison with underwater propeller inspection results.

  19. Computer aided design and development of mixed-propeller pumps

    International Nuclear Information System (INIS)

    Bhaoyal, B.C.

    1994-01-01

    This paper deals with the design principle of mixed propeller hydraulic aided by CADD software developed by author for generation of the hydraulic profile of the mixed propeller and diffuser geometry. The design methodology for plotting the vane profile of mixed propeller pump has been discussed in detail with special reference to conformal transformation in cylindrical as well as conical plane. (author). 10 refs., 11 figs

  20. Self-Organization of Motor-Propelled Cytoskeletal Filaments at Topographically Defined Borders

    Directory of Open Access Journals (Sweden)

    Alf Månsson

    2012-01-01

    Full Text Available Self-organization phenomena are of critical importance in living organisms and of great interest to exploit in nanotechnology. Here we describe in vitro self-organization of molecular motor-propelled actin filaments, manifested as a tendency of the filaments to accumulate in high density close to topographically defined edges on nano- and microstructured surfaces. We hypothesized that this “edge-tracing” effect either (1 results from increased motor density along the guiding edges or (2 is a direct consequence of the asymmetric constraints on stochastic changes in filament sliding direction imposed by the edges. The latter hypothesis is well captured by a model explicitly defining the constraints of motility on structured surfaces in combination with Monte-Carlo simulations [cf. Nitta et al. (2006] of filament sliding. In support of hypothesis 2 we found that the model reproduced the edge tracing effect without the need to assume increased motor density at the edges. We then used model simulations to elucidate mechanistic details. The results are discussed in relation to nanotechnological applications and future experiments to test model predictions.

  1. Enhanced propellant performance via environmentally friendly curable surface coating

    Directory of Open Access Journals (Sweden)

    Thelma Manning

    2017-06-01

    Full Text Available 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

  2. Autonomous Propellant Loading Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The AES Autonomous Propellant Loading (APL) project consists of three activities. The first is to develop software that will automatically control loading of...

  3. Investigation and Estimation of Structure of Web from Electro spun Nano fibres

    International Nuclear Information System (INIS)

    Malasauskiene, J.; Milasius, R.

    2013-01-01

    During the electro spinning process the web of nano fibres is manufactured by means of electrostatic forces between two electrodes. The diameters of nano fibres usually differ and they depend on various parameters. The different fineness of fibres influences the structure of the web and herewith the end-use properties of such kind of nano material. Analysis of nano fibres diameters distribution also shows big differences; even more, the distributions are not spread along the normal distribution. Understanding the influence of electro spinning parameters and the reason why the shapes of distributions are so sophisticated is very important. The goal of this paper is to analyse the distribution of diameter and to propose the new criterion for nano fibres diameter comparison and web of nano fibres estimation. In this paper the influence of covering time of support material on structure of PA6.6 nano fibre web has been investigated. It was estimated that this parameter does not have a significant influence on the average diameter of nano fibres, and only the structure of web has been influenced by the changes in covering time. According to the results provided the phenomena of nano fibres sticking on the support material at the time of electro spinning can be proved and explained.

  4. Blade Section Lift Coefficients for Propellers at Extreme Off-Design Conditions

    National Research Council Canada - National Science Library

    Shen, Young

    1997-01-01

    The Propeller Force Module (PFM) code developed by Analytical Methods Inc. (AMI) for calculating propeller side forces during maneuvering simulation studies requires inputs of propeller blade sectional lift, drag, and moment data...

  5. Thermal Decomposition Behaviors and Burning Characteristics of AN/Nitramine-Based Composite Propellant

    Science.gov (United States)

    Naya, Tomoki; Kohga, Makoto

    2015-04-01

    Ammonium nitrate (AN) has attracted much attention due to its clean burning nature as an oxidizer. However, an AN-based composite propellant has the disadvantages of low burning rate and poor ignitability. In this study, we added nitramine of cyclotrimethylene trinitramine (RDX) or cyclotetramethylene tetranitramine (HMX) as a high-energy material to AN propellants to overcome these disadvantages. The thermal decomposition and burning rate characteristics of the prepared propellants were examined as the ratio of AN and nitramine was varied. In the thermal decomposition process, AN/RDX propellants showed unique mass loss peaks in the lower temperature range that were not observed for AN or RDX propellants alone. AN and RDX decomposed continuously as an almost single oxidizer in the AN/RDX propellant. In contrast, AN/HMX propellants exhibited thermal decomposition characteristics similar to those of AN and HMX, which decomposed almost separately in the thermal decomposition of the AN/HMX propellant. The ignitability was improved and the burning rate increased by the addition of nitramine for both AN/RDX and AN/HMX propellants. The increased burning rates of AN/RDX propellants were greater than those of AN/HMX. The difference in the thermal decomposition and burning characteristics was caused by the interaction between AN and RDX.

  6. Process for the leaching of AP from propellant

    Science.gov (United States)

    Shaw, G. C.; Mcintosh, M. J. (Inventor)

    1980-01-01

    A method for the recovery of ammonium perchlorate from waste solid rocket propellant is described wherein shredded particles of the propellant are leached with an aqueous leach solution containing a low concentration of surface active agent while stirring the suspension.

  7. Propeller TAP flap

    DEFF Research Database (Denmark)

    Thomsen, Jørn Bo; Bille, Camilla; Wamberg, Peter

    2013-01-01

    major complications needing additional surgery. One flap was lost due to a vascular problem. Breast reconstruction can be performed by a propeller TAP flap without cutting the descending branch of the thoracodorsal vessels. However, the authors would recommend that a small cuff of muscle is left around...

  8. Structure of Partially Premixed Flames and Advanced Solid Propellants

    National Research Council Canada - National Science Library

    Branch, Melvyn

    1998-01-01

    The combustion of solid rocket propellants of advanced energetic materials involves a complex process of decomposition and condensed phase reactions in the solid propellant, gaseous flame reactions...

  9. Stereospecific Winding of Polycyclic Aromatic Hydrocarbons into Trinacria Propellers.

    Science.gov (United States)

    Mosca, Dario; Stopin, Antoine; Wouters, Johan; Demitri, Nicola; Bonifazi, Davide

    2017-11-02

    The stereospecific trimerization of enantiomerically pure binaphthols with hexakis(bromomethyl)benzene gives access in one step to enantiomerically pure molecular propellers, in which three binaphthyl rings are held together with dioxecine rings. X-ray diffraction analysis revealed that three out the six naphthyl moieties are folded in a (EF) 3 -type arrangement held by three intramolecular C-H⋅⋅⋅π interactions. This slips outward the three remaining naphthyl rings in a blade-like fashion, just like in three-folded propeller components. This peculiar conformation shows striking similarity to the mythological Sicilian symbol of Trinacria, from which the name "trinacria propeller" derives. The propeller conformation is also preserved in chlorinated solutions, as displayed by the presence of a peak at 4.7 ppm typical of an aromatic proton resonance engaged in a C-H⋅⋅⋅π interaction. The denaturation of the propeller-like conformation is obtained at high temperature, corresponding to activation energy for the ring inversion of ca. 18.2 kcal mol -1 . Notably, halide-functionalized molecular propellers exposing I-atoms at the leading and trailing edges could be prepared stereo- and regiospecifically by choosing the relevant iodo-bearing BINOL derivative. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Nonlinear Output Feedback Control of Underwater Vehicle Propellers using Advance Speed Feedback

    DEFF Research Database (Denmark)

    Fossen, T.I.; Blanke, M.

    1999-01-01

    More accurate propeller shaft speed controllers can be designed by using nonlinear control theory. In this paper, an output feedback controller reconstructing the advance speed (speed of water going into the propeller) from vehicle speed measurements is derived. For this purpose a three-state model...... minimizes thruster losses due to variations in propeller axial inlet flow which is a major problem when applying conventional vehicle-propeller control systems. The proposed controller is simulated for an underwater vehicle equipped with a single propeller. From the simulations it can be concluded...... of propeller shaft speed, forward (surge) speed of the vehicle and axial inlet flow of the propeller is applied. A nonlinear observer in combination with an output feedback integral controller are derived by applying Lyapunov stability theory and exponential stability is proven. The output feedback controller...

  11. Propellant Slosh Force and Mass Measurement

    Directory of Open Access Journals (Sweden)

    Andrew Hunt

    2018-01-01

    Full Text Available We have used electrical capacitance tomography (ECT to instrument a demonstration tank containing kerosene and have successfully demonstrated that ECT can, in real time, (i measure propellant mass to better than 1% of total in a range of gravity fields, (ii image propellant distribution, and (iii accurately track propellant centre of mass (CoM. We have shown that the ability to track CoM enables the determination of slosh forces, and we argue that this will result in disruptive changes in a propellant tank design and use in a spacecraft. Ground testing together with real-time slosh force data will allow an improved tank design to minimize and mitigate slosh forces, while at the same time keeping the tank mass to a minimum. Fully instrumented Smart Tanks will be able to provide force vector inputs to a spacecraft inertial navigation system; this in turn will (i eliminate or reduce navigational errors, (ii reduce wait time for uncertain slosh settling, since actual slosh forces will be known, and (iii simplify slosh control hardware, hence reducing overall mass. ECT may be well suited to space borne liquid measurement applications. Measurements are independent of and unaffected by orientation or levels of g. The electronics and sensor arrays can be low in mass, and critically, the technique does not dissipate heat into the propellant, which makes it intrinsically safe and suitable for cryogenic liquids. Because of the limitations of operating in earth-bound gravity, it has not been possible to check the exact numerical accuracy of the slosh force acting on the vessel. We are therefore in the process of undertaking a further project to (i build a prototype integrated “Smart Tank for Space”, (ii undertake slosh tests in zero or microgravity, (iii develop the system for commercial ground testing, and (iv qualify ECT for use in space.

  12. Simulation study on improving efficiencies of perovskite solar cell: Introducing nano textures on it

    Science.gov (United States)

    Xie, Ziang; Sun, Shuren; Wang, Wei; Qin, Laixiang; Yan, Yu; Hou, Ruixiang; Qin, G. G.

    2018-03-01

    We report that the power conversion efficiencies (PCEs) of the planar CH3NH3PbI3 solar cells (SCs) can be largely improved by fabricating nano textures on the SC surface. With the finite difference time domain (FDTD) method, the ultimate efficiencies of the planar CH3NH3PbI3 SCs with two types of nano textures are investigated: the column-shaped nano hollow (CLNH) array and the cone-shaped nano hollow (CNNH) array. For the nano textured CH3NH3PbI3 SCs with photovoltaic layer depth in the range of 125 nm ∼ 500 nm, when the array period and filling fraction of the nano textures are optimized, in comparison with the planar ones, their PCE increased 42% ∼ 84% for the CLNH textured ones, and 52% ∼ 63% for the CNNH textured ones. As a conclusion, introduction of nano textures on the SC surface is a promising route for improving the PCEs of the perovskite SCs.

  13. Modeling of Unsteady Sheet Cavitation on Marine Propeller Blades

    Directory of Open Access Journals (Sweden)

    Spyros A. Kinnas

    2003-01-01

    Full Text Available Unsteady sheet cavitation is very common on marine propulsor blades. The authors summarize a lifting-surface and a surface-panel model to solve for the unsteady cavitating flow around a propeller that is subject to nonaxisymmetric inflow. The time-dependent extent and thickness of the cavity were determined by using an iterative method. The cavity detachment was determined by applying the smooth detachment criterion in an iterative manner. A nonzeroradius developed vortex cavity model was utilized at the tip of the blade, and the trailing wake geometry was determined using a fully unsteady wake-alignment process. Comparisons of predictions by the two models and measurements from several experiments are given.

  14. DLC nano-dot surfaces for tribological applications in MEMS devices

    Energy Technology Data Exchange (ETDEWEB)

    Singh, R. Arvind; Na, Kyounghwan [Nano-Bio Research Center, Korea Institute of Science and Technology, 39-1, Hawolgok-dong, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Yi, Jin Woo; Lee, Kwang-Ryeol [Computational Science Center, Korea Institute of Science and Technology, 39-1, Hawolgok-dong, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Yoon, Eui-Sung, E-mail: esyoon@kist.re.kr [Nano-Bio Research Center, Korea Institute of Science and Technology, 39-1, Hawolgok-dong, Seongbuk-gu, Seoul 136-791 (Korea, Republic of)

    2011-02-01

    With the invention of miniaturized devices like micro-electro-mechanical systems (MEMS), tribological studies at micro/nano-scale have gained importance. These studies are directed towards understanding the interactions between surfaces at micro/nano-scales, under relative motion. In MEMS devices, the critical forces, namely adhesion and friction restrict the smooth operation of the elements that are in relative motion. These miniaturized devices are traditionally made from silicon (Si), whose tribological properties are not good. In this paper, we present a short investigation of nano- and micro-tribological properties of diamond-like carbon (DLC) nano-dot surfaces. The investigation was undertaken to evaluate the potential of these surfaces for their possible application to the miniaturized devices. The tribological evaluation of the DLC nano-dot surfaces was done in comparison with bare Si (1 0 0) surfaces and DLC coated silicon surfaces. A commercial atomic force microscope (AFM) was used to measure adhesion and friction properties of the test materials at the nano-scale, whereas a custom-built micro-tribotester was used to measure their micro-friction property. Results showed that the DLC nano-dot surfaces exhibited superior tribological properties with the lowest values of adhesion force, and friction force both at the nano- and micro-scales, when compared to the bare Si (1 0 0) surfaces and DLC coated silicon surfaces. In addition, the DLC nano-dot surfaces showed no observable wear at the micro-scale, unlike the other two test materials. The superior tribological performance of the DLC nano-dot surfaces is attributed to their hydrophobic nature and the reduced area of contact projected by them.

  15. DLC nano-dot surfaces for tribological applications in MEMS devices

    International Nuclear Information System (INIS)

    Singh, R. Arvind; Na, Kyounghwan; Yi, Jin Woo; Lee, Kwang-Ryeol; Yoon, Eui-Sung

    2011-01-01

    With the invention of miniaturized devices like micro-electro-mechanical systems (MEMS), tribological studies at micro/nano-scale have gained importance. These studies are directed towards understanding the interactions between surfaces at micro/nano-scales, under relative motion. In MEMS devices, the critical forces, namely adhesion and friction restrict the smooth operation of the elements that are in relative motion. These miniaturized devices are traditionally made from silicon (Si), whose tribological properties are not good. In this paper, we present a short investigation of nano- and micro-tribological properties of diamond-like carbon (DLC) nano-dot surfaces. The investigation was undertaken to evaluate the potential of these surfaces for their possible application to the miniaturized devices. The tribological evaluation of the DLC nano-dot surfaces was done in comparison with bare Si (1 0 0) surfaces and DLC coated silicon surfaces. A commercial atomic force microscope (AFM) was used to measure adhesion and friction properties of the test materials at the nano-scale, whereas a custom-built micro-tribotester was used to measure their micro-friction property. Results showed that the DLC nano-dot surfaces exhibited superior tribological properties with the lowest values of adhesion force, and friction force both at the nano- and micro-scales, when compared to the bare Si (1 0 0) surfaces and DLC coated silicon surfaces. In addition, the DLC nano-dot surfaces showed no observable wear at the micro-scale, unlike the other two test materials. The superior tribological performance of the DLC nano-dot surfaces is attributed to their hydrophobic nature and the reduced area of contact projected by them.

  16. An advanced GAP/AN/TAGN propellant : part 2 : stability and storage life

    Energy Technology Data Exchange (ETDEWEB)

    Judge, M.D. [Bristol Aerospace, Winnipeg, MB (Canada); Badeen, C.M.; Jones, D.E.G. [Natural Resources Canada, Ottawa, ON (Canada). Canadian Explosives Research Laboratory

    2007-07-15

    An advanced solid propellant was characterized. The propellant was based on a glycidyl azide polymer (GAP) energetic binder with an ammonium nitrate (AN) oxidizer, and contained a significant percentage of triaminoguanidine nitrate (TAGN). Raw ingredient accelerating rate calorimetry (ARC) was performed to determine self-heating rates. Thermal stability and heat flow calorimetry tests were also conducted. Ballistic analyses were conducted to determine the propellant's burn rate. The propellant was designed to produce non-toxic and non-acidic exhaust products. Results of the tests indicated that the propellant is safe for prolonged storage. The study demonstrated that propellant samples can be heated to temperatures up to 175 degrees C for several hours without combustion response. A mass loss of 62 per cent was observed at temperatures between 160 and 230 degrees C. The samples ignited almost immediately after being placed in a pre-heated block at temperatures higher than 175 degrees C. The propellant's burn rate was approximately twice that of standard AN propellants. The propellant will be further evaluated as a candidate for the propulsion of tactical rockets and missiles. 17 refs., 4 tabs., 6 figs.

  17. Discovery Of B Ring Propellers In Cassini UVIS, And ISS

    Science.gov (United States)

    Sremcevic, Miodrag; Stewart, G. R.; Albers, N.; Esposito, L. W.

    2012-10-01

    We present evidence for the existence of propellers in Saturn's B ring by combining data from Cassini Ultraviolet Imaging Spectrograph (UVIS) and Imaging Science Subsystem (ISS) experiments. We identify two propeller populations: (1) tens of degrees wide propellers in the dense B ring core, and (2) smaller, more A ring like, propellers populating the inner B ring. The prototype of the first population is an object observed at 18 different epochs between 2005 and 2010. The ubiquitous propeller "S" shape is seen both in UVIS occultations as an optical depth depletion and in ISS as a 40 degrees wide bright stripe in unlit geometries and dark in lit geometries. Combining the available Cassini data we infer that the object is a partial gap embedded in the high optical depth region of the B ring. The gap moves at orbital speed consistent with its radial location. From the radial separation of the propeller wings we estimate that the embedded body, which causes the propeller structure, is about 1.5km in size located at a=112,921km. The UVIS occultations indicate an asymmetric propeller "S" shape. Since the object is located at an edge between high and relatively low optical depth, this asymmetry is most likely a consequence of the strong surface mass density gradient. We estimate that there are possibly dozen up to 100 other propeller objects in Saturn's B ring. The location of the discovered body, at an edge of a dense ringlet within the B ring, suggests a novel mechanism for the up to now illusive B ring irregular large-scale structure of alternating high and low optical depth ringlets. We propose that this B ring irregular structure may have its cause in the presence of many embedded bodies that shepherd the individual B ring ringlets.

  18. Nano- and micro-electromechanical systems fundamentals of nano- and microengineering

    CERN Document Server

    Lyshevski, Sergey Edward

    2005-01-01

    NANOTECHNOLOGY AND MICROTECHNOLOGY (NANO- AND MICRO- SCIENCE, ENGINEERING AND TECHNOLOGY), AND BEYOND Introduction and Overview: From Micro- to Nano- and Beyond to Stringo-Scale Introductory Definitions to the Subjects Current Developments and Needs for Coherent Revolutionary Developments Societal Challenges and Implications NANO- AND MICROSCALE SYSTEMS, DEVICES, AND STRUCTURES Sizing Features: From Micro- to Nano-, and from Nano- to Stringo-Scale MEMS and NEMS Definitions Introduction to Taxonomy of Nano- and Microsystem Synthesis and Design Introduction to Design and Optimization of Nano- and Microsystems in the Behavioral Domain NANO- AND MICROSYSTEMS: CLASSIFICATION AND CONSIDERATION Biomimetics, Biological Analogies,and Design of NEMS and MEMS Micro- and Nanoelectromechanical Systems: Scaling Laws and Mathematical Modeling MEMS Examples and MEMS Architectures Introduction to Microfabrication and Micromachining FUNDAMENTALS OF MICROFABRICATION AND MEMS FABRICATION TECHNOLOGIES Introducti...

  19. Nano dentistry

    International Nuclear Information System (INIS)

    Oh, S.; Park, Y.B.; Kim, S.; Jin, S.

    2014-01-01

    Nano technology in dentistry has drawn many scientists’ and clinicians’ attention to significant advances in the diagnosis, treatment, and prevention of oral disease. Also, nano materials in dentistry have been studied to overcome the physical and chemical characteristics of conventional dental materials. These interesting facts are the motivation of this special issue. The presented issue provides a variety of topics in the field of dentistry such as novel nano filled composite resin, the cytotoxicity of nanoparticles deposited on orthodontic bands, the osseointegration of 3D nano scaffold, and nano surface treated implant.

  20. Propellant selection for ramjets with solid fuel

    Energy Technology Data Exchange (ETDEWEB)

    Schmucker, R H; Lips, H

    1976-03-11

    Ramjet propulsion using solid propellant for post-boost acceleration of missiles exhibits several favorable properties, brought about by heterogeneous combustion. A simplified theory for calculating the performance of possible propellants is presented, and they are classified with respect to maximum fuel-specific impulse. The optimal choice of fuel, from a system standpoint, must consider volume constraints, and defines the requirements for motor geometry.

  1. Exploratory procedures with carbon nanotube-based sensors for propellant degradation determinations

    Science.gov (United States)

    Ruffin, Paul B.; Edwards, Eugene; Brantley, Christina; McDonald, Brian

    2010-04-01

    Exploratory research is conducted at the US Army Aviation & Missile Research, Development, and Engineering Center (AMRDEC) in order to perform assessments of the degradation of solid propellant used in rocket motors. Efforts are made to discontinue and/or minimize destructive methods and utilize nondestructive techniques to assure the quality and reliability of the weaponry's propulsion system. Collaborative efforts were successfully made between AMRDEC and NASA-Ames for potential add-on configurations to a previously designed sensor that AMRDEC plan to use for preliminary detection of off-gassing. Evaluations were made in order to use the design as the introductory component for the determination of shelf-life degradation rate of rocket motors. Previous and subsequent sensor designs utilize functionalized single-walled carbon nano-tubes (SWCNTs) as the key sensing element. On-going research is conducted to consider key changes that can be implemented (for the existing sensor design) such that a complete wireless sensor system design can be realized. Results should be a cost-saving and timely approach to enhance the Army's ability to develop methodologies for measuring weaponry off-gassing and simultaneously detecting explosives. Expectations are for the resulting sensors to enhance the warfighters' ability to simultaneously detect a greater variety of analytes. Outlined in this paper are the preliminary results that have been accomplished for this research. The behavior of the SWCNT sensor at storage temperatures is outlined, along with the initial sensor response to propellant related analytes. Preparatory computer-based programming routines and computer controlled instrumentation scenarios have been developed in order to subsequently minimize subjective interpretation of test results and provide a means for obtaining data that is reasonable and repetitively quantitative. Typical laboratory evaluation methods are likewise presented, and program limitations

  2. Air propellers and their environmental problems on ACV's

    Science.gov (United States)

    Soley, D. H.

    The development of ACV blade protection against erosion, both on the propeller blade faces and leading edge, is considered. Polyurethane spray coating is now the standard protection applied to all Dowty Rotol propellers, with thicknesses from 0.015-0.020 on aircraft, and up to 0.080 on the ACV. The bolt-on guard reduced leading edge replacement time by 50 percent, and makes possible replacement in all weather conditions. Typical damage and repairs to ACV blades are discussed, and the propeller installation on the LCAC craft being built for the U.S. Navy is addressed.

  3. Numerically-based ducted propeller design using vortex lattice lifting line theory

    OpenAIRE

    Stubblefield, John M.

    2008-01-01

    CIVINS (Civilian Institutions) Thesis document This thesis used vortex lattice lifting line theory to model an axisymmetrical-ducted propeller with no gap between the duct and the propeller. The theory required to model the duct and its interaction with the propeller were discussed and implemented in Open-source Propeller Design and Analysis Program (OpenProp). Two routines for determining the optimum circulation distribution were considered, and a method based on calculus of variation...

  4. Advanced technologies available for future solid propellant grains

    Energy Technology Data Exchange (ETDEWEB)

    Thepenier, J. [SNPE Propulsion, St Medard en Jalles (France); Fonblanc, G. [SNPE Propulsion, Vert le Petit (France). Centre de Recherche de Bouchet

    2001-06-01

    Significant advances have been made during the last decade in several fields of solid propulsion: the advances have enabled new savings in the motor development phase and in recurring costs, because they help limit the number of prototypes and tests. The purpose of the paper is to describe the improvements achieved by SNPE in solid grain technologies, making these technologies available for new developments in more efficient and reliable future SRMs: new energetic molecules, new solid propellants, new processes for grain manufacturing, quick response grain design tools associated with advanced models for grain performance predictions. Using its expertise in chemical synthesis, SNPE develops new molecules to fit new energetic material requirements. Tests based on new propellant formulations have produced good results in the propellant performance/safety behavior ratio. New processes have been developed simultaneously to reduce the manufacturing costs of the new propellants. In addition, the grain design has been optimized by using the latest generation of predictive theoretical tools supported by a large data bank of experimental parameters resulting from over 30 years' experience in solid propulsion: computer-aided method for the preliminary grain design; advanced models for SRM operating and performance predictions. All these technologies are available for industrial applications in future developments of solid propellant grains. (author)

  5. Comparison of in vitro biocompatibility of NanoBone(®) and BioOss(®) for human osteoblasts.

    Science.gov (United States)

    Liu, Qin; Douglas, Timothy; Zamponi, Christiane; Becker, Stephan T; Sherry, Eugene; Sivananthan, Sureshan; Warnke, Frauke; Wiltfang, Jörg; Warnke, Patrick H

    2011-11-01

    Scaffolds for bone tissue engineering seeded with the patient's own cells might be used as a preferable method to repair bone defects in the future. With the emerging new technologies of nanostructure design, new synthetic biomaterials are appearing on the market. Such scaffolds must be tested in vitro for their biocompatibility before clinical application. However, the choice between a natural or a synthetic biomaterial might be challenging for the doctor and the patient. In this study, we compared the biocompatibility of a synthetic bone substitute, NanoBone(®) , to the widely used natural bovine bone replacement material BioOss(®) . The in vitro behaviour of human osteoblasts on both materials was investigated. Cell performance was determined using scanning electron microscopy (SEM), cell vitality staining and four biocompatibility tests (LDH, MTT, WST, BrdU). We found that both materials showed low cytotoxicity and good biocompatibility. The MTT proliferation test was superior for Nanobone(®) . Both scaffolds caused only little damage to human osteoblasts and justify their clinical application. However, NanoBone(®) was able to support and promote proliferation of human osteoblasts slightly better than BioOss(®) in our chosen test set-up. The results may guide doctors and patients when being challenged with the choice between a natural or a synthetic biomaterial. Further experiments are necessary to determine the comparison of biocompatibility in vivo. © 2011 John Wiley & Sons A/S.

  6. Anticipated Effectiveness of Active Noise Control in Propeller Aircraft Interiors as Determined by Sound Quality Tests

    Science.gov (United States)

    Powell, Clemans A.; Sullivan, Brenda M.

    2004-01-01

    Two experiments were conducted, using sound quality engineering practices, to determine the subjective effectiveness of hypothetical active noise control systems in a range of propeller aircraft. The two tests differed by the type of judgments made by the subjects: pair comparisons in the first test and numerical category scaling in the second. Although the results of the two tests were in general agreement that the hypothetical active control measures improved the interior noise environments, the pair comparison method appears to be more sensitive to subtle changes in the characteristics of the sounds which are related to passenger preference.

  7. Semiconductor Nano wires and Nano tubes: From Fundamentals to Diverse Applications

    International Nuclear Information System (INIS)

    Xiong, Q.; Grimes, C.A.; Zacharias, M.; Morral, A.F.; Hiruma, K.; Shen, G.

    2012-01-01

    Research in the field of semiconductor nano wires (SNWs) and nano tubes has been progressing into a mature subject with several highly interdisciplinary sub areas such as nano electronics, nano photonics, nano composites, bio sensing, optoelectronics, and solar cells. SNWs represent a unique system with novel properties associated to their one-dimensional (1D) structures. The fundamental physics concerning the formation of discrete 1D subbands, coulomb blockade effects, ballistic transport, and many-body phenomena in 1D nano wires and nano tubes provide a strong platform to explore the various scientific aspects in these nano structures. A rich variety of preparation methods have already been developed for generating well-controlled 1D nano structures and from a broad range of materials. The present special issue focuses on the recent development in the mechanistic understanding of the synthesis, the studies on electrical/optical properties of nano wires and their applications in nano electronics, nano photonics, and solar-energy harvesting. In this special issue, we have several invited review articles and contributed papers that are addressing current status of the fundamental issues related to synthesis and the diverse applications of semiconducting nano wires and nano tubes. One of the papers reviews the progress of the top-down approach of developing silicon-based vertically aligned nano wires to explore novel device architectures and integration schemes for nano electronics and clean energy applications. Another paper reviews the recent developments and experimental evidences of probing the confined optical and acoustic phonon in nonpolar semiconducting (Si and Ge) nano wires using Raman spectroscopy. The paper by K. Hiruma et al. spotlights the III semiconductor nano wires and demonstrates selective-area metal organic vapor phase epitaxy grown GaAs/In(Al)GaAs and InP/InAs/InP nano wires with heterojunctions along their axial and radial directions. The paper

  8. Propellant Gelation for Green In-Space Propulsion, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Concerns in recent years about the toxicity and safe handling of the storable class of propellants have led to efforts in greener monopropellants and bi-propellants....

  9. Modeling Propellant Tank Dynamics

    Data.gov (United States)

    National Aeronautics and Space Administration — The main objective of my work will be to develop accurate models of self-pressurizing propellant tanks for use in designing hybrid rockets. The first key goal is to...

  10. Performance Analysis Rim Driven Propeller as a Propulsor using Open Water Test

    Directory of Open Access Journals (Sweden)

    Agoes Santoso

    2017-12-01

    Full Text Available The use of duct in propeller is one of the breakthrough in the development of the propeller. Ducting not only claimed to be increasing efficiency of the propeller, but also capable to protect the propeller from impact therefore propeller lifespan is longer. From that idea then RDP is created. RDP propeller blade are designed to be fix at their housing called Rim, in the other word, the driving force came from it’s rim. On current RDP blade used is non-conventional blade. This thesis will discuss about design analysis of Kaplan Propeller Kaplan Ka-70 that modified on it’s thickness distribution. On this thesis data that is varied is motor load. Simulation using Open Water Test. The result, highest value of KT and KQ occur on 30% motor load and highest efficiency is 18,338% achieved on 260 Rpm.

  11. Particle swarm optimization: an alternative in marine propeller optimization?

    Science.gov (United States)

    Vesting, F.; Bensow, R. E.

    2018-01-01

    This article deals with improving and evaluating the performance of two evolutionary algorithm approaches for automated engineering design optimization. Here a marine propeller design with constraints on cavitation nuisance is the intended application. For this purpose, the particle swarm optimization (PSO) algorithm is adapted for multi-objective optimization and constraint handling for use in propeller design. Three PSO algorithms are developed and tested for the optimization of four commercial propeller designs for different ship types. The results are evaluated by interrogating the generation medians and the Pareto front development. The same propellers are also optimized utilizing the well established NSGA-II genetic algorithm to provide benchmark results. The authors' PSO algorithms deliver comparable results to NSGA-II, but converge earlier and enhance the solution in terms of constraints violation.

  12. Numerical Prediction of Hydromechanical Behaviour of Controllable Pitch Propeller

    Directory of Open Access Journals (Sweden)

    Saman Tarbiat

    2014-01-01

    Full Text Available The research described in this paper was carried out to predict hydrodynamic and frictional forces of controllable pitch propeller (CPP that bring about fretting problems in a blade bearing. The governing equations are Reynolds-averaged Navier-Stokes (RANS and are solved by OpenFOAM solver for hydrodynamic forces behind the ship’s wake. Frictional forces are calculated by practical mechanical formulae. Different advance velocities with constant rotational speed for blades are used to achieve hydrodynamic coefficients in open water and the wake behind the propeller. Results are compared at four different pitches. Detailed numerical results of 3D modelling of the propeller, hydrodynamic characteristics, and probability of the fretting motion in the propeller are presented. Results show that the probability of the fretting movement is related to the pitch.

  13. Effect of nano-fillers on the thermal conductivity of epoxy composites with micro-Al2O3 particles

    International Nuclear Information System (INIS)

    Gao, Zhifang; Zhao, Lei

    2015-01-01

    Highlights: • Nano-fillers were synthesized by a simple urea process. • Ternary filler system with synthesized nano-hybrid fillers was investigated. • Using of nano-hybrid filler for prevent nanofiller aggregation was presented. - Abstract: Nano-AlN particles, AlN/graphene nano-hybrids (AlN/GE) and AlN/carbon nanotubes nano-hybrids (AlN/CNTs) were prepared. The structures, morphologies of synthesized nano-materials were examined by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results showed that the morphologies of the synthesized nano-materials were obviously different. In addition, the thermal conductivity of epoxy composites could be effectively improved by adding the produced nano-fillers. Especially, the epoxy composite with AlN/GE nano-hybrids had the highest enhancement in thermal conductivity comparison to the pure epoxy. Moreover, the density of epoxy composites with the synthesized nano-fillers was decreased and the corresponding thermal stability was enhanced

  14. Numerical study of hub taper angle on podded propeller performance

    International Nuclear Information System (INIS)

    Islam, M.F.; Veitch, B.; Bose, N.; Liu, P.

    2005-01-01

    Presently, the majority of podded propulsion systems are of the pulling type, because this type provides better hydrodynamic efficiency than the pushing type. There are several possible explanations for the better overall performance of a puller type podded propulsor. One is related to the difference in hub shape. Puller and pusher propellers have opposite hub taper angles, hence different hub and blade root shape. These differences cause changes in the flow condition and possibly influence the overall performance. The current study focuses on the variation in performance of pusher and puller propellers with the same blade sections, but different hub taper angles. A hyperboloidal low order source doublet steady/unsteady time domain panel method code was modified and used to evaluate effects of hub taper angle on the open water propulsive performance of some fixed pitch screw propellers used in podded propulsion systems. The modified code was first validated against measurements of two model propellers in terms of average propulsive performance and good agreement was found. Major findings include significant effects of hub taper angle on propulsive performance of tapered hub propellers and noticeable effects of hub taper angle on sectional pressure distributions of tapered hub propeller blades. (author)

  15. Heterogeneous propellant internal ballistics: criticism and regeneration

    Science.gov (United States)

    Glick, R. L.

    2011-10-01

    Although heterogeneous propellant and its innately nondeterministic, chemically discrete morphology dominates applications, ballisticcharacterization deterministic time-mean burning rate and acoustic admittance measures' absence of explicit, nondeterministic information requires homogeneous propellant with a smooth, uniformly regressing burning surface: inadequate boundary conditions for heterogeneous propellant grained applications. The past age overcame this dichotomy with one-dimensional (1D) models and empirical knowledge from numerous, adequately supported motor developments and supplementary experiments. However, current cost and risk constraints inhibit this approach. Moreover, its fundamental science approach is more sensitive to incomplete boundary condition information (garbage-in still equals garbage-out) and more is expected. This work critiques this situation and sketches a path forward based on enhanced ballistic and motor characterizations in the workplace and approximate model and apparatus developments mentored by CSAR DNS capabilities (or equivalent).

  16. Development of strand burner for solid propellant burning rate studies

    International Nuclear Information System (INIS)

    Aziz, A; Mamat, R; Ali, W K Wan

    2013-01-01

    It is well-known that a strand burner is an apparatus that provides burning rate measurements of a solid propellant at an elevated pressure in order to obtain the burning characteristics of a propellant. This paper describes the facilities developed by author that was used in his studies. The burning rate characteristics of solid propellant have be evaluated over five different chamber pressures ranging from 1 atm to 31 atm using a strand burner. The strand burner has a mounting stand that allows the propellant strand to be mounted vertically. The strand was ignited electrically using hot wire, and the burning time was recorded by electronic timer. Wire technique was used to measure the burning rate. Preliminary results from these techniques are presented. This study shows that the strand burner can be used on propellant strands to obtain accurate low pressure burning rate data

  17. Injection dynamics of gelled propellants

    Science.gov (United States)

    Yoon, Changjin

    Gel propellants have been recognized as attractive candidates for future propulsion systems due to the reduced tendency to spill and the energy advantages over solid propellants. One of strong benefits emphasized in gel propellant applications is a throttling capability, but the accurate flow control is more complicated and difficult than with conventional Newtonian propellants because of the unique rheological behaviors of gels. This study is a computational effort directed to enhance understanding of the injector internal flow characteristics for gel propellants under rocket injection conditions. In simulations, the emphasized rheology is a shear-thinning which represents a viscosity decrease with increasing a shear rate. It is described by a generalized Newtonian fluid constitutive equation and Carreau-Yasuda model. Using this rheological model, two injection schemes are considered in the present study: axially-fed and cross-fed injection for single-element and multi-element impinging injectors, respectively. An axisymmetric model is developed to describe the axially-fed injector flows and fully three-dimensional model is utilized to simulate cross-fed injector flows. Under axially-fed injection conditions investigated, three distinct modes, an unsteady, steady, and hydraulic flip mode, are observed and mapped in terms of Reynolds number and orifice design. In an unsteady mode, quasi-periodic oscillations occur near the inlet lip leading mass pulsations and viscosity fluctuations at the orifice exit. This dynamic behavior is characterized using a time-averaged discharge coefficient, oscillation magnitude and frequency by a parametric study with respect to an orifice design, Reynolds number and rheology. As a result, orifice exit flows for gel propellants appear to be significantly influenced by a viscous damping and flow resistance due to a shear thinning behavior and these are observed in each factors considered. Under conditions driven by a manifold crossflow

  18. Propeller efficiency at full scale : measurement system and mathematical model design

    NARCIS (Netherlands)

    Muntean, T.V.

    2012-01-01

    What is propeller efficiency at full scale? This question is asked equally by ship operators and by propeller and propulsion system manufacturers. The question reflects the need to measure propeller efficiency at full physical scale and during regular operation of the vessel. The question has a

  19. Green propellant propulsion concepts for space transportation and technology development needs

    NARCIS (Netherlands)

    Haeseler, D.; Bombelli, V.; Vuillermoz, P.; Lo, R.; Maree, A.G.M.; Caramelli, F.

    2004-01-01

    A study has been performed under contract from ESA/ESTEC identifying the development needs in Europe in the field of new green propellant utilization. Criteria for green propellants are defined and discussed. Promising propellants are identified together with their rating w.r.t. those criteria, in

  20. A Grazing-Incidence Small-Angle X-Ray Scattering View of Vertically Aligned ZnO Nano wires

    International Nuclear Information System (INIS)

    Lavcevic, M.L.; Silovic, L.; Dubcek, P.; Pavlovic, M.; Bernstorff, S.

    2013-01-01

    We report a grazing-incidence small-angle X-ray scattering study of ZnO films with vertically aligned and randomly distributed nano wires, grown through a hydrothermal growth process on nano structured ZnO seeding coatings and deposited by electron beam evaporation on silicon and glass, respectively. The comparison of the scattering patterns of seeding coatings and nano wires showed that the scattering of vertically aligned nano wires exhibited a specific feature: the dominant characteristic of their scattering patterns is the appearance of fine structure effects around the specular peak. These effects were clarified by the combined reflection and scattering phenomena, suggested for the aligned nano wires-substrate system. Furthermore, they enabled the calculation of the average gyration radius of nano wires in horizontal direction. The calculated value was in good agreement with the radii of nano wires estimated by surface electron microscopy. Therefore, the observed feature in the scattering pattern can serve as evidence of the aligned growth of nano wires.

  1. Nano-computed tomography. Technique and applications; Nanocomputertomografie. Technik und Applikationen

    Energy Technology Data Exchange (ETDEWEB)

    Kampschulte, M.; Sender, J.; Litzlbauer, H.D.; Althoehn, U.; Schwab, J.D.; Alejandre-Lafont, E.; Martels, G.; Krombach, G.A. [University Hospital Giessen (Germany). Dept. of Diagnostic and Interventional Radiology; Langheinirch, A.C. [BG Trauma Hospital Frankfurt/Main (Germany). Dept. of Diagnostic and Interventional Radiology

    2016-02-15

    Nano-computed tomography (nano-CT) is an emerging, high-resolution cross-sectional imaging technique and represents a technical advancement of the established micro-CT technology. Based on the application of a transmission target X-ray tube, the focal spot size can be decreased down to diameters less than 400 nanometers (nm). Together with specific detectors and examination protocols, a superior spatial resolution up to 400 nm (10 % MTF) can be achieved, thereby exceeding the resolution capacity of typical micro-CT systems. The technical concept of nano-CT imaging as well as the basics of specimen preparation are demonstrated exemplarily. Characteristics of atherosclerotic plaques (intraplaque hemorrhage and calcifications) in a murine model of atherosclerosis (ApoE{sub (-/-)}/LDLR{sub (-/-)} double knockout mouse) are demonstrated in the context of superior spatial resolution in comparison to micro-CT. Furthermore, this article presents the application of nano-CT for imaging cerebral microcirculation (murine), lung structures (porcine), and trabecular microstructure (ovine) in contrast to micro-CT imaging. This review shows the potential of nano-CT as a radiological method in biomedical basic research and discusses the application of experimental, high resolution CT techniques in consideration of other high resolution cross-sectional imaging techniques.

  2. A review of research in low earth orbit propellant collection

    Science.gov (United States)

    Singh, Lake A.; Walker, Mitchell L. R.

    2015-05-01

    This comprehensive review examines the efforts of previous researchers to develop concepts for propellant-collecting spacecraft, estimate the performance of these systems, and understand the physics involved. Rocket propulsion requires the spacecraft to expend two fundamental quantities: energy and propellant mass. A growing number of spacecraft collect the energy they need to execute propulsive maneuvers in-situ with solar panels. In contrast, every spacecraft using rocket propulsion has carried all of the propellant mass needed for the mission from the ground, which limits the range and mission capabilities. Numerous researchers have explored the concept of collecting propellant mass while in space. These concepts have varied in scale and complexity from chemical ramjets to fusion-driven interstellar vessels. Research into propellant-collecting concepts occurred in distinct eras. During the Cold War, concepts tended to be large, complex, and nuclear powered. After the Cold War, concepts transitioned to solar power sources and more effort has been devoted to detailed analysis of specific components of the propellant-collecting architecture. By detailing the major contributions and limitations of previous work, this review concisely presents the state-of-the-art and outlines five areas for continued research. These areas include air-compatible cathode technology, techniques to improve propellant utilization on atmospheric species, in-space compressor and liquefaction technology, improved hypersonic and hyperthermal free molecular flow inlet designs, and improved understanding of how design parameters affect system performance.

  3. Four-quadrant propeller modeling: A low-order harmonic approximation

    Digital Repository Service at National Institute of Oceanography (India)

    Haeusler, A.J; Saccon, A.; Hauser, J; Pascoal, A.M.; Aguiar, A.P.

    . We explore the connection between the propeller thrust, torque, and efficiency curves and the lift and drag curves of the propeller blades. The model originates from a well-known four-quadrant model, based on a sinusoidal approximation...

  4. Reconstruction of pressure sores with perforator-based propeller flaps.

    Science.gov (United States)

    Jakubietz, Rafael G; Jakubietz, Danni F; Zahn, Robert; Schmidt, Karsten; Meffert, Rainer H; Jakubietz, Michael G

    2011-03-01

    Perforator flaps have been successfully used for reconstruction of pressure sores. Although V-Y advancement flaps approximate debrided wound edges, perforator-based propeller flaps allow rotation of healthy tissue into the defect. Perforator-based propeller flaps were planned in 13 patients. Seven pressure sores were over the sacrum, five over the ischial tuberosity, and one on the tip of the scapula. Three patients were paraplegic, six were bedridden, and five were ambulatory. In three patients, no perforators were found. In 10 patients, propeller flaps were transferred. In two patients, total flap necrosis occurred, which was reconstructed with local advancement flaps. In two cases, a wound dehiscence occurred and had to be revised. One hematoma required evacuation. No further complications were noted. No recurrence at the flap site occurred. Local perforator flaps allow closure of pressure sores without harvesting muscle. The propeller version has the added benefit of transferring tissue from a distant site, avoiding reapproximation of original wound edges. Twisting of the pedicle may cause torsion and venous obstruction. This can be avoided by dissecting a pedicle of at least 3 cm. Propeller flaps are a safe option for soft tissue reconstruction of pressure sores. © Thieme Medical Publishers.

  5. Calculation of marine propeller static strength based on coupled BEM/FEM

    Directory of Open Access Journals (Sweden)

    YE Liyu

    2017-10-01

    Full Text Available [Objectives] The reliability of propeller stress has a great influence on the safe navigation of a ship. To predict propeller stress quickly and accurately,[Methods] a new numerical prediction model is developed by coupling the Boundary Element Method(BEMwith the Finite Element Method (FEM. The low order BEM is used to calculate the hydrodynamic load on the blades, and the Prandtl-Schlichting plate friction resistance formula is used to calculate the viscous load. Next, the calculated hydrodynamic load and viscous correction load are transmitted to the calculation of the Finite Element as surface loads. Considering the particularity of propeller geometry, a continuous contact detection algorithm is developed; an automatic method for generating the finite element mesh is developed for the propeller blade; a code based on the FEM is compiled for predicting blade stress and deformation; the DTRC 4119 propeller model is applied to validate the reliability of the method; and mesh independence is confirmed by comparing the calculated results with different sizes and types of mesh.[Results] The results show that the calculated blade stress and displacement distribution are reliable. This method avoids the process of artificial modeling and finite element mesh generation, and has the advantages of simple program implementation and high calculation efficiency.[Conclusions] The code can be embedded into the code of theoretical and optimized propeller designs, thereby helping to ensure the strength of designed propellers and improve the efficiency of propeller design.

  6. The biochemical effects of nano tamoxifen and some bioactive components in experimental breast cancer.

    Science.gov (United States)

    Ezzat, Afaf; Abdelhamid, Abdou Osman; El Awady, Mostafa K; Abd El Azeem, Amal S; Mohammed, Dina Mostafa

    2017-11-01

    The effect of nano tamoxifen and some bioactive components such as yeast, isoflavone, and silymarin on the level of resistance and prevention of breast cancer progression in experimental animals is the target of this study. Thirty female Sprague-Dawley rats received a single medication dosage of 7,12-dimethylbenz[a]anthracene (DMBA) intragastrically. After fourteen days of DMBA admission, the procedure protocol started out. Finally, all the experimental results evaluated, tabulated and statistically analyzed. The results demonstrated a highly significant elevation in the 8-OHdG level in group 1 (nano yeast) and 3 (nano silymarin) while the results demonstrated a highly significant reduction in group 2 (nano tamoxifen). The apoptosis results demonstrated a significant elevation in group 3 (nano silymarin) where appeared significant reduction in group 4 (nano isoflavone). ErbB-2 results demonstrated a significant elevation in group 2 (nano tamoxifen) and a significant reduction in each of group 3 (nano silymarin) and 4 (nano isoflavone). The lipid peroxide level demonstrated an extremely significant reduction in group 4 (nano isoflavone). And a significant reduction of total antioxidant was observed in group 3 (nano silymarin) in comparison to injected animals control. This may be considered a new vision and strategy to resist breast cancer disease or prevent progression. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  7. Electric Propellant Solid Rocket Motor Thruster Results Enabling Small Satellites

    OpenAIRE

    Koehler, Frederick; Langhenry, Mark; Summers, Matt; Villarreal, James; Villarreal, Thomas

    2017-01-01

    Raytheon Missile Systems has developed and tested true on/off/restart solid propellant thrusters which are controlled only by electrical current. This new patented class of energetic rocket propellant is safe, controllable and simple. The range of applications for this game changing technology includes attitude control systems and a safe alternative to higher impulse space satellite thrusters. Described herein are descriptions and performance data for several small electric propellant solid r...

  8. PENGARUH PENGGUNAAN ENERGY SAVING DEVICE PADA PROPELLER B4 55 DENGAN METODE CFD

    Directory of Open Access Journals (Sweden)

    Andi Trimulyono

    2013-10-01

    Full Text Available Tingginya harga bahan bakar semakin mendorong pelaku industri khususnya pemilik kapal melakukan penghematan konsumsi bahan bakar dan cara yang cukup efektif untuk mengurangi konsumsi bahan bakar tersebut adalah dengan menambah instalasi alat yang disebut Energy Saving Device (ESD pada propeller dengan tujuan meningkatkan efisiensi propulsi.   Beberapa desain  ESD propeller yang telah dikembangkan yakni Ducted Propellers (Kort Nozzel propeller, dan Propeller Boss Cap Fins (PBCF. Perbedaan jenis Energy Saving Device (ESD mengindikasikan perubahan gaya torque dan thrust yang berbeda sehingga penulis disini ingin menganalisa pengaruh instalasi Energy Saving Device (ESD  pada propeller terhadap torque dan thrust yang dihasilkan sehingga dapat diketahui jenis ESD dengan performa paling optimal dengan bantuan paket program CAD (Computer Aided Design serta CFD (Computational Fluid Dynamics. Hasil analisa dengan menggunakan RANS software CFD menunjukkan akibat penambahan instalasi Energy Saving Device (ESD  pada propeller, terjadi perubahan bentuk aliran fluida, yang berpengaruh pula terhadap nilai thrust dan torque yang dihasilkan. Gaya thrust yang terjadi pada pada PBCF Propeller adalah sebesar 8.70E+05 N, dengan Torque 7.18E+05, sedangkan thrust pada Nozzle Propeller adalah sebesar 1.18E+06 dengan Torque 9.86E+05

  9. Engine-propeller power plant aircraft community noise reduction key methods

    Science.gov (United States)

    Moshkov P., A.; Samokhin V., F.; Yakovlev A., A.

    2018-04-01

    Basic methods of aircraft-type flying vehicle engine-propeller power plant noise reduction were considered including single different-structure-and-arrangement propellers and piston engines. On the basis of a semiempirical model the expressions for blade diameter and number effect evaluation upon propeller noise tone components under thrust constancy condition were proposed. Acoustic tests performed at Moscow Aviation institute airfield on the whole qualitatively proved the obtained ratios. As an example of noise and detectability reduction provision a design-and-experimental estimation of propeller diameter effect upon unmanned aircraft audibility boundaries was performed. Future investigation ways were stated to solve a low-noise power plant design problem for light aircraft and unmanned aerial vehicles.

  10. Feasibility Study and Demonstration of an Aluminum and Ice Solid Propellant

    Directory of Open Access Journals (Sweden)

    Timothee L. Pourpoint

    2012-01-01

    Full Text Available Aluminum-water reactions have been proposed and studied for several decades for underwater propulsion systems and applications requiring hydrogen generation. Aluminum and water have also been proposed as a frozen propellant, and there have been proposals for other refrigerated propellants that could be mixed, frozen in situ, and used as solid propellants. However, little work has been done to determine the feasibility of these concepts. With the recent availability of nanoscale aluminum, a simple binary formulation with water is now feasible. Nanosized aluminum has a lower ignition temperature than micron-sized aluminum particles, partly due to its high surface area, and burning times are much faster than micron aluminum. Frozen nanoscale aluminum and water mixtures are stable, as well as insensitive to electrostatic discharge, impact, and shock. Here we report a study of the feasibility of an nAl-ice propellant in small-scale rocket experiments. The focus here is not to develop an optimized propellant; however improved formulations are possible. Several static motor experiments have been conducted, including using a flight-weight casing. The flight weight casing was used in the first sounding rocket test of an aluminum-ice propellant, establishing a proof of concept for simple propellant mixtures making use of nanoscale particles.

  11. Comparison of the mechanical properties between carbon nanotube and nanocrystalline cellulose polypropylene based nano-composites

    International Nuclear Information System (INIS)

    Huang, Jun; Rodrigue, Denis

    2015-01-01

    Highlights: • SWCNT and NCC can effectively improve the mechanical properties of nano-composites. • SWCNT is more effective than NCC to increase modulus and strength. • Longer NCC is more effective to improve the mechanical properties of nano-composites. • It is more economic to use NCC than SWCNT to improve mechanical properties. - Abstract: Using beam and tetrahedron elements to simulate nanocrystalline cellulose (NCC), single wall carbon nanotube (SWCNT) and polypropylene (PP), finite element method (FEM) is used to predict the mechanical properties of nano-composites. The bending, shear and torsion behaviors of nano-composites are especially investigated due to the limited amount of information in the present literature. First, mixed method (MM) and FEM are used to compare the bending stiffness of NCC/PP and SWCNT/PP composites. Second, based on mechanics of materials, the shear moduli of both types of nano-composites are obtained. Finally, fixing the number of fibers and for different volume contents, four NCC lengths are used to determine the mechanical properties of the composites. The bending and shearing performances are also compared between NCC and SWCNT based composites. In all cases, the elastic–plastic analyses are carried out and the stress or strain distributions for specific regions are also investigated. From all the results obtained, an economic analysis shows that NCC is more interesting than SWCNT to reinforce PP

  12. Effect of gamma radiation on properties of a composite rocket propellant

    International Nuclear Information System (INIS)

    Dedgaonkar, V.G.; Pol, V.G.; Navle, P.B.; Ghorpade, V.G.; Wani, V.S.

    2000-01-01

    Gamma radiation was employed for modifying the properties of a composite rocket propellant prepared in a standard way. It was observed that when the same gamma dose was imparted to hydroxy terminated polybutadiene (HTPB) then converted into propellant, the enhancement in the properties was much larger than the irradiated propellant samples. (author)

  13. A Study of Flame Physics and Solid Propellant Rocket Physics

    National Research Council Canada - National Science Library

    Buckmaster, John

    2007-01-01

    ..., the combustion of heterogeneous propellants containing aluminum, the use of a genetic algorithm to optimally define false-kinetics parameters in propellant combustion modeling, the calculation of fluctuations...

  14. Propeller performance analysis using lifting line theory

    OpenAIRE

    Flood, Kevin M.

    2009-01-01

    CIVINS (Civilian Institutions) Thesis document Approved for public release ; distribution is unlimited Propellers are typically optimized to provide the maximum thrust for the minimum torque at a specific number of revolutions per minute (RPM) at a particular ship speed. This process allows ships to efficiently travel at their design speed. However, it is useful to know how the propeller performs during off-design conditions. This is especially true for naval warships whose missions req...

  15. PIV-based load determination in aircraft propellers

    OpenAIRE

    Ragni, D.

    2012-01-01

    The thesis describes the application of particle image velocimetry (PIV) to study the aerodynamic loads of airfoils and aircraft propellers. The experimental work focuses on the development of a measurement procedure to infer the pressure of the flow field from the velocity distribution obtained by PIV velocimetry. The technique offers important advantages in aircraft propellers, since the loads can be locally inspected without the need to install pressure sensors and momentum balances in rot...

  16. Environmental risk assessment of engineered nano-SiO2 , nano iron oxides, nano-CeO2 , nano-Al2 O3 , and quantum dots.

    Science.gov (United States)

    Wang, Yan; Nowack, Bernd

    2018-05-01

    Many research studies have endeavored to investigate the ecotoxicological hazards of engineered nanomaterials (ENMs). However, little is known regarding the actual environmental risks of ENMs, combining both hazard and exposure data. The aim of the present study was to quantify the environmental risks for nano-Al 2 O 3 , nano-SiO 2 , nano iron oxides, nano-CeO 2 , and quantum dots by comparing the predicted environmental concentrations (PECs) with the predicted-no-effect concentrations (PNECs). The PEC values of these 5 ENMs in freshwaters in 2020 for northern Europe and southeastern Europe were taken from a published dynamic probabilistic material flow analysis model. The PNEC values were calculated using probabilistic species sensitivity distribution (SSD). The order of the PNEC values was quantum dots nano-CeO 2  nano iron oxides nano-Al 2 O 3  nano-SiO 2 . The risks posed by these 5 ENMs were demonstrated to be in the reverse order: nano-Al 2 O 3  > nano-SiO 2  > nano iron oxides > nano-CeO 2  > quantum dots. However, all risk characterization values are 4 to 8 orders of magnitude lower than 1, and no risk was therefore predicted for any of the investigated ENMs at the estimated release level in 2020. Compared to static models, the dynamic material flow model allowed us to use PEC values based on a more complex parameterization, considering a dynamic input over time and time-dependent release of ENMs. The probabilistic SSD approach makes it possible to include all available data to estimate hazards of ENMs by considering the whole range of variability between studies and material types. The risk-assessment approach is therefore able to handle the uncertainty and variability associated with the collected data. The results of the present study provide a scientific foundation for risk-based regulatory decisions of the investigated ENMs. Environ Toxicol Chem 2018;37:1387-1395. © 2018 SETAC. © 2018 SETAC.

  17. Cryogenic Propellant Storage and Transfer Technology Demonstration For Long Duration In-Space Missions

    Science.gov (United States)

    Meyer, Michael L.; Motil, Susan M.; Kortes, Trudy F.; Taylor, William J.; McRight, Patrick S.

    2012-01-01

    The high specific impulse of cryogenic propellants can provide a significant performance advantage for in-space transfer vehicles. The upper stages of the Saturn V and various commercial expendable launch vehicles have used liquid oxygen and liquid hydrogen propellants; however, the application of cryogenic propellants has been limited to relatively short duration missions due to the propensity of cryogens to absorb environmental heat resulting in fluid losses. Utilizing advanced cryogenic propellant technologies can enable the efficient use of high performance propellants for long duration missions. Crewed mission architectures for beyond low Earth orbit exploration can significantly benefit from this capability by developing realistic launch spacing for multiple launch missions, by prepositioning stages and by staging propellants at an in-space depot. The National Aeronautics and Space Administration through the Office of the Chief Technologist is formulating a Cryogenic Propellant Storage and Transfer Technology Demonstration Mission to mitigate the technical and programmatic risks of infusing these advanced technologies into the development of future cryogenic propellant stages or in-space propellant depots. NASA is seeking an innovative path for human space exploration, which strengthens the capability to extend human and robotic presence throughout the solar system. This mission will test and validate key cryogenic technological capabilities and has the objectives of demonstrating advanced thermal control technologies to minimize propellant loss during loiter, demonstrating robust operation in a microgravity environment, and demonstrating efficient propellant transfer on orbit. The status of the demonstration mission concept development, technology demonstration planning and technology maturation activities in preparation for flight system development are described.

  18. High-Fidelity Microstructural Characterization and Performance Modeling of Aluminized Composite Propellant

    International Nuclear Information System (INIS)

    Kosiba, Graham D.; Wixom, Ryan R.; Oehlschlaeger, Matthew A.

    2017-01-01

    Image processing and stereological techniques were used to characterize the heterogeneity of composite propellant and inform a predictive burn rate model. Composite propellant samples made up of ammonium perchlorate (AP), hydroxyl-terminated polybutadiene (HTPB), and aluminum (Al) were faced with an ion mill and imaged with a scanning electron microscope (SEM) and x-ray tomography (micro-CT). Properties of both the bulk and individual components of the composite propellant were determined from a variety of image processing tools. An algebraic model, based on the improved Beckstead-Derr-Price model developed by Cohen and Strand, was used to predict the steady-state burning of the aluminized composite propellant. In the presented model the presence of aluminum particles within the propellant was introduced. The thermal effects of aluminum particles are accounted for at the solid-gas propellant surface interface and aluminum combustion is considered in the gas phase using a single global reaction. In conclusion, properties derived from image processing were used directly as model inputs, leading to a sample-specific predictive combustion model.

  19. A Portable Burn Pan for the Disposal of Excess Propellants

    Science.gov (United States)

    2016-06-01

    2013 - 06/01/2016 A Portable Burn Pan for the Disposal of Excess Propellants Michael Walsh USA CRREL USA CRREL 72 Lyme Road Hanover, NH 03755...Army Alaska XRF X-Ray Florescence vii ACKNOWLEDGEMENTS Project ER-201323, A Portable Burn Pan for the Disposal of Gun Propellants, was a very...contamination problem while allowing troops to train as they fight, we have developed a portable training device for burning excess gun propellants. 1.1

  20. Action of colloidal silica films on different nano-composites

    Directory of Open Access Journals (Sweden)

    S. Abdalla

    Full Text Available Nano-composite films have been the subject of extensive work to develop the energy-storage efficiency of electrostatic capacitors. Factors such as polymer purity, nano-particles size, and film morphology drastically affect the electrostatic efficiency of the dielectric material that form an insulating film between conductive electrodes of a capacitor. This in turn affects the energy storage performance of the capacitor. In the present work, we have studied the dielectric properties of 4 high pure amorphous polymer films: polymethylmethacrylate (PMMA, polystyrene, polyimide and poly-4-vinylpyridine. Comparison between the dielectric properties of these polymers has revealed that the higher break down performance is a character of polyimide PI and PMMA. Also, our experimental data shows that adding colloidal silica to PMMA and PI leads to a net decrease in the dielectric properties compared to the pure polymer. Keywords: Dielectric break down, Polymers, Nano-composite, Colloidal silica

  1. Chemical Functionalization, Self-Assembly, and Applications of Nano materials and Nano composites 2014

    International Nuclear Information System (INIS)

    Yan, X.; Jiao, T.; Balan, L.; Chen, X.; Hu, M.Z.; Liu, W.

    2014-01-01

    The growing interests in nano materials and nano composites call for the development of processing techniques to obtain multiple functionalization nano structures and achieve the tailoring of specific features of the nanometer size. Functional nano materials and nano composites will expand the applied range of the original material and at the same time promote the development of inter discipline. Thus, the chemical functionalization and bottom-up assemblies of nano materials and subsequent applications will accelerate the development of nano science and nano technology.

  2. Rapid Synthesis and Characterization of Nano sodalite Synthesized using Rice Husk Ash

    International Nuclear Information System (INIS)

    Siti Haslina Ahmad Rusmili; Zainab Ramli

    2012-01-01

    Rice husk ash (RHA) which contains more than 90 percent silica is proven to be an active silica source in zeolite synthesis. In this study, nano sodalite has been successfully synthesized hydrothermally at 60 degree Celsius using RHA as silica source in alkaline medium at various crystallization times. Commercial fumed silica was used as comparison for the silica source. Analysis by XRD has shown that pure nano sodalite was formed in 3 hours and stable up to more than 24 hours when using RHA as silica source. On the other hand, fumed silica produced pure nano sodalite only at 4 hours while a mixture of zeolites was observed outside this time range. FESEM shows a worm-like morphology of nano sodalite in the size range of 50-100 nm while FTIR shows the formation of aluminosilicates bonds. Analysis on the dissolved silica in the gel reaction mixture demonstrates the decreasing mass of silica after prolong time of crystallization which indicates the consumption of the dissolved silica in crystal growth of nano sodalite. This study shows that RHA is a better silica source in stabilizing the nano sodalite phase in oxide gel reaction mixture as compared to fumed silica. (author)

  3. 14 CFR 35.21 - Variable and reversible pitch propellers.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Variable and reversible pitch propellers. 35.21 Section 35.21 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: PROPELLERS Design and Construction § 35.21 Variable and...

  4. Microleakage under orthodontic bands cemented with nano-hydroxyapatite-modified glass ionomer.

    Science.gov (United States)

    Enan, Enas T; Hammad, Shaza M

    2013-11-01

    To estimate the in vivo effect of nano-hydroxyapatite (HA) modification of banding glass-ionomer cement on microleakage under orthodontic bands. Eighty noncarious premolars scheduled for extraction in 20 orthodontic patients were randomly divided into four groups. Grouping was based on the ratio of nano-HA (0%, 5%, 10%, 15% by weight) added to the luting glass-ionomer cement (GIC) Ketac-Cem, which was used for cementation of prefabricated micro-etched orthodontic bands. Dye penetration method was used for microleakage evaluation at the cement-band and cement-enamel interfaces. Statistical evaluation was performed with a Kruskal-Wallis test and a Mann-Whitney U-test, and a Bonferroni-adjusted significance level was calculated. Bands cemented with conventional GIC showed the highest microleakage scores in comparison to those cemented with nano-HA-modified GIC. No significant difference was found between teeth banded with 10% and 15% modified GIC. Modification of the banding GIC with 15% nano-HA revealed a positive effect on reducing microleakage around orthodontic bands.

  5. Plane boundary effects on characteristics of propeller jets

    Science.gov (United States)

    Wei, Maoxing; Chiew, Yee-Meng; Hsieh, Shih-Chun

    2017-10-01

    The flow properties of a propeller jet in the presence of a plane bed boundary were investigated using the particle image velocimetry technique. Three clearance heights, Z b = 2 D p, D p, and 0.5 D p, where D p = propeller diameter, were used to examine boundary effects on the development of the jet. In each case, the mean flow properties and turbulence characteristics were measured in a larger field of view than those used in past studies. Both the streamwise and transverse flow fields were measured to obtain the three-dimensional characteristics of the propeller jet. Similar to a confined offset jet, the propeller jet also exhibits a wall attachment behavior when it is placed near a plane boundary. As a result, in contrast to its unconfined counterpart, the confined propeller jet features three regions, namely the free jet, impingement and wall jet regions. The study shows that the extent of each region varies under different clearance heights. The development of the mean flow and turbulence characteristics associated with varying clearance heights are compared to illustrate boundary effects in these regions. In the impingement region, the measured transverse flow fields provide new insights on the lateral motions induced by the impingement of the swirling jet. In the wall jet region, observations reveal that the jet behaves like a typical three-dimensional wall jet and its axial velocity profiles show good agreement with the classical wall jet similarity function.

  6. Nano-Electrochemistry and Nano-Electrografting with an Original Combined AFM-SECM

    Directory of Open Access Journals (Sweden)

    Ammar Ben Brahim

    2013-05-01

    Full Text Available This study demonstrates the advantages of the combination between atomic force microscopy and scanning electrochemical microscopy. The combined technique can perform nano-electrochemical measurements onto agarose surface and nano-electrografting of non-conducting polymers onto conducting surfaces. This work was achieved by manufacturing an original Atomic Force Microscopy-Scanning ElectroChemical Microscopy (AFM-SECM electrode. The capabilities of the AFM-SECM-electrode were tested with the nano-electrografting of vinylic monomers initiated by aryl diazonium salts. Nano-electrochemical and technical processes were thoroughly described, so as to allow experiments reproducing. A plausible explanation of chemical and electrochemical mechanisms, leading to the nano-grafting process, was reported. This combined technique represents the first step towards improved nano-processes for the nano-electrografting.

  7. Nano-Electrochemistry and Nano-Electrografting with an Original Combined AFM-SECM

    Science.gov (United States)

    Ghorbal, Achraf; Grisotto, Federico; Charlier, Julienne; Palacin, Serge; Goyer, Cédric; Demaille, Christophe; Ben Brahim, Ammar

    2013-01-01

    This study demonstrates the advantages of the combination between atomic force microscopy and scanning electrochemical microscopy. The combined technique can perform nano-electrochemical measurements onto agarose surface and nano-electrografting of non-conducting polymers onto conducting surfaces. This work was achieved by manufacturing an original Atomic Force Microscopy-Scanning ElectroChemical Microscopy (AFM-SECM) electrode. The capabilities of the AFM-SECM-electrode were tested with the nano-electrografting of vinylic monomers initiated by aryl diazonium salts. Nano-electrochemical and technical processes were thoroughly described, so as to allow experiments reproducing. A plausible explanation of chemical and electrochemical mechanisms, leading to the nano-grafting process, was reported. This combined technique represents the first step towards improved nano-processes for the nano-electrografting. PMID:28348337

  8. From one to many: dynamic assembly and collective behavior of self-propelled colloidal motors.

    Science.gov (United States)

    Wang, Wei; Duan, Wentao; Ahmed, Suzanne; Sen, Ayusman; Mallouk, Thomas E

    2015-07-21

    The assembly of complex structures from simpler, individual units is a hallmark of biology. Examples include the pairing of DNA strands, the assembly of protein chains into quaternary structures, the formation of tissues and organs from cells, and the self-organization of bacterial colonies, flocks of birds, and human beings in cities. While the individual behaviors of biomolecules, bacteria, birds, and humans are governed by relatively simple rules, groups assembled from many individuals exhibit complex collective behaviors and functions that do not exist in the absence of the hierarchically organized structure. Self-assembly is a familiar concept to chemists who study the formation and properties of monolayers, crystals, and supramolecular structures. In chemical self-assembly, disorder evolves to order as the system approaches equilibrium. In contrast, living assemblies are typically characterized by two additional features: (1) the system constantly dissipates energy and is not at thermodynamic equilibrium; (2) the structure is dynamic and can transform or disassemble in response to stimuli or changing conditions. To distinguish them from equilibrium self-assembled structures, living (or nonliving) assemblies of objects with these characteristics are referred to as active matter. In this Account, we focus on the powered assembly and collective behavior of self-propelled colloids. These nano- and microparticles, also called nano- and micromotors or microswimmers, autonomously convert energy available in the environment (in the form of chemical, electromagnetic, acoustic, or thermal energy) into mechanical motion. Collections of these colloids are a form of synthetic active matter. Because of the analogy to living swimmers of similar size such as bacteria, the dynamic interactions and collective behavior of self-propelled colloids are interesting in the context of understanding biological active matter and in the development of new applications. The progression

  9. Cryogenic Propellant Storage and Transfer

    Data.gov (United States)

    National Aeronautics and Space Administration — Space Flight Demonstration development has been canceled in favor of a ground test bed development for of passive/active cryogenic propellant storage, transfer, and...

  10. Deconsolidation and combustion performance of thermally consolidated propellants deterred by multi-layers coating

    Directory of Open Access Journals (Sweden)

    Zheng-gang Xiao

    2014-06-01

    Full Text Available Both heating and solvent-spray methods are used to consolidate the standard grains of double-base oblate sphere propellants plasticized with triethyleneglycol dinitrate (TEGDN (TEGDN propellants to high density propellants. The obtained consolidated propellants are deterred and coated with the slow burning multi-layer coating. The maximum compaction density of deterred and coated consolidated propellants can reach up to 1.39 g/cm3. Their mechanic, deconsolidation and combustion performances are tested by the materials test machine, interrupted burning set-up and closed vessel, respectively. The static compression strength of consolidated propellants deterred by multi-layer coating increases significantly to 18 MPa, indicating that they can be applied in most circumstances of charge service. And the samples are easy to deconsolidate in the interrupted burning test. Furthermore, the closed bomb burning curves of the samples indicate a two-stage combustion phenomenon under the condition of certain thickness of coated multi-layers. After the outer deterred multi-layer coating of consolidated samples is finished burning, the inner consolidated propellants continue to burn and breakup into aggregates and grains. The high burning progressivity can be carefully obtained by the smart control of deconsolidation process and duration of consolidated propellants. The preliminary results of consolidated propellants show that a rapid deconsolidation process at higher deconsolidation pressure is presented in the dynamic vivacity curves of closed bomb test. Higher density and higher macro progressivity of consolidated propellants can be obtained by the techniques in this paper.

  11. Space Transportation Infrastructure Supported By Propellant Depots

    Science.gov (United States)

    Smitherman, David; Woodcock, Gordon

    2012-01-01

    A space transportation infrastructure is described that utilizes propellant depot servicing platforms to support all foreseeable missions in the Earth-Moon vicinity and deep space out to Mars. The infrastructure utilizes current expendable launch vehicle (ELV) systems such as the Delta IV Heavy, Atlas V, and Falcon 9, for all crew, cargo, and propellant launches to orbit. Propellant launches are made to Low-Earth-Orbit (LEO) Depot and an Earth-Moon Lagrange Point 1 (L1) Depot to support a new reusable in-space transportation vehicles. The LEO Depot supports missions to Geosynchronous Earth Orbit (GEO) for satellite servicing and to L1 for L1 Depot missions. The L1 Depot supports Lunar, Earth-Sun L2 (ESL2), Asteroid and Mars Missions. New vehicle design concepts are presented that can be launched on current 5 meter diameter ELV systems. These new reusable vehicle concepts include a Crew Transfer Vehicle (CTV) for crew transportation between the LEO Depot, L1 Depot and missions beyond L1; a new reusable lunar lander for crew transportation between the L1 Depot and the lunar surface; and Mars orbital Depot are based on International Space Station (ISS) heritage hardware. Data provided includes the number of launches required for each mission utilizing current ELV systems (Delta IV Heavy or equivalent) and the approximate vehicle masses and propellant requirements. Also included is a discussion on affordability with ideas on technologies that could reduce the number of launches required and thoughts on how this infrastructure include competitive bidding for ELV flights and propellant services, developments of new reusable in-space vehicles and development of a multiuse infrastructure that can support many government and commercial missions simultaneously.

  12. Measuring scientific research in emerging nano-energy field

    Science.gov (United States)

    Guan, Jiancheng; Liu, Na

    2014-04-01

    The purpose of this paper is to comprehensively explore scientific research profiles in the field of emerging nano-energy during 1991-2012 based on bibliometrics and social network analysis. We investigate the growth pattern of research output, and then carry out across countries/regions comparisons on research performances. Furthermore, we examine scientific collaboration across countries/regions by analyzing collaborative intensity and networks in 3- to 4-year intervals. Results indicate with an impressively exponential growth pattern of nano-energy articles, the world share of scientific "giants," such as the USA, Germany, England, France and Japan, display decreasing research trends, especially in the USA. Emerging economies, including China, South Korea and India, exhibit a rise in terms of the world share, illustrating strong development momentum of these countries in nano-energy research. Strikingly, China displays a remarkable rise in scientific influence rivaling Germany, Japan, France, and England in the last few years. Finally, the scientific collaborative network in nano-energy research has expanded steadily. Although the USA and several major European countries play significantly roles on scientific collaboration, China and South Korea exert great influence on scientific collaboration in recent years. The findings imply that emerging economies can earn competitive advantages in some emerging fields by properly engaging a catch-up strategy.

  13. 76 FR 25534 - Airworthiness Directives; Hamilton Sundstrand Propellers Model 247F Propellers

    Science.gov (United States)

    2011-05-05

    ... 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, the... through FR2279 inclusive, FR 2398, FR2449 to FR2958 inclusive, FR20010710 to FR20010722 inclusive, and FR20010723RT to FR20020127RT inclusive, installed. Propeller blades reworked to Hamilton Sundstrand Service...

  14. Innovative Swirl Injector for LOX and Hydrocarbon Propellants, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Gases trapped in the propellant feed lines of space-based rocket engines due to cryogenic propellant boil-off or pressurant ingestion can result in poor combustion...

  15. Ecological assessment of nano-enabled supercapacitors for automotive applications

    Science.gov (United States)

    Weil, M.; Dura, H.; Shimon, B.; Baumann, M.; Zimmermann, B.; Ziemann, S.; Lei, C.; Markoulidis, F.; Lekakou, T.; Decker, M.

    2012-09-01

    New materials on nano scale have the potential to overcome existing technical barriers and are one of the most promising key technologies to enable the decoupling of economic growth and resource consumption. Developing these innovative materials for industrial applications means facing a complex quality profile, which includes among others technical, economic, and ecological aspects. So far the two latter aspects are not sufficiently included in technology development, especially from a life cycle point of view. Supercapacitors are considered a promising option for electric energy storage in hybrid and full electric cars. In comparison with presently used lithium based electro chemical storage systems supercapacitors possess a high specific power, but a relatively low specific energy. Therefore, the goal of ongoing research is to develop a new generation of supercapacitors with high specific power and high specific energy. To reach this goal particularly nano materials are developed and tested on cell level. In the presented study the ecological implications (regarding known environmental effects) of carbon based nano materials are analysed using Life Cycle Assessment (LCA). Major attention is paid to efficiency gains of nano particle production due to scaling up of such processes from laboratory to industrial production scales. Furthermore, a developed approach will be displayed, how to assess the environmental impact of nano materials on an automotive system level over the whole life cycle.

  16. Ecological assessment of nano-enabled supercapacitors for automotive applications

    International Nuclear Information System (INIS)

    Weil, M; Dura, H; Shimon, B; Baumann, M; Zimmermann, B; Ziemann, S; Decker, M; Lei, C; Markoulidis, F; Lekakou, T

    2012-01-01

    New materials on nano scale have the potential to overcome existing technical barriers and are one of the most promising key technologies to enable the decoupling of economic growth and resource consumption. Developing these innovative materials for industrial applications means facing a complex quality profile, which includes among others technical, economic, and ecological aspects. So far the two latter aspects are not sufficiently included in technology development, especially from a life cycle point of view. Supercapacitors are considered a promising option for electric energy storage in hybrid and full electric cars. In comparison with presently used lithium based electro chemical storage systems supercapacitors possess a high specific power, but a relatively low specific energy. Therefore, the goal of ongoing research is to develop a new generation of supercapacitors with high specific power and high specific energy. To reach this goal particularly nano materials are developed and tested on cell level. In the presented study the ecological implications (regarding known environmental effects) of carbon based nano materials are analysed using Life Cycle Assessment (LCA). Major attention is paid to efficiency gains of nano particle production due to scaling up of such processes from laboratory to industrial production scales. Furthermore, a developed approach will be displayed, how to assess the environmental impact of nano materials on an automotive system level over the whole life cycle.

  17. Magnetite nano-islands on Graphene

    Science.gov (United States)

    Anderson, Nathaniel; Zhang, Qiang; Rosenberg, Richard; Vaknin, David

    X-ray magnetic circular dichroism (XMCD) of ex-situ iron nano-islands grown on graphene reveals that iron oxidation spontaneously leads to the formation of magnetite nano-particles - i.e, the formation of the inverse spinel Fe3O4. Fe islands have been grown with two different heights (20 and 75 MLs) on epitaxial graphene and we have determined their magnetic behavior both as function of temperature and applied external field. Our XAS and XMCD at an applied magnetic field of B = 5 T show that the thin film (20 MLs) is totally converted to magnetite whereas the thicker film (75 MLs) exhibits magnetite properties but also those of pure metal iron. For both samples, temperature dependence of the XMCD shows clear transitions at ~120 K consistent with the Verwey transition of bulk magnetite. XMCD at low temperatures shows a weak hysteresis and provide the average spin and angular-momentum moments, the dipolar term, and the total moment . In addition, manipulation and comparison of the XMCD data from both samples allows us to extract information about the pure iron nano-islands from the thicker sample. Ames Laboratory is supported by the U.S. DOE, BES, MSE Contract No. DE-AC02-07CH11358. APS is supported by U.S. DOE Contract No. DE-AC02-06CH11357.

  18. Neural Network Predictions of the 4-Quadrant Wageningen Propeller Series

    National Research Council Canada - National Science Library

    Roddy, Robert F; Hess, David E; Faller, Will

    2006-01-01

    .... This report describes the development of feedforward neural network (FFNN) predictions of four-quadrant thrust and torque behavior for the Wageningen B-Screw Series of propellers and for two Wageningen ducted propeller series...

  19. Study of the pitting effects during the pre-ignition plasma–propellant interaction process

    International Nuclear Information System (INIS)

    Hang, Yuhua; Li, Xingwen; Wu, Jian; Jia, Shenli; Zhao, Weiyu; Murphy, Anthony B

    2016-01-01

    The propellant ignition mechanism has become a central issue in the electrothermal chemical (ETC) launch technology, and the pre-ignition plasma–propellant interactions are critical in determining the ignition characteristics. In this work, both an open-air ablation test and an interrupted burning test are conducted for three different propellants. A fused silica window, which is transparent in all relevant wavelengths, is utilized to investigate the role of the plasma radiation. Surface pitting of the propellants after interaction with the plasma is analyzed using a scanning electron microscope (SEM). The effect of pits on the plasma ignition is then studied and a possible formation mechanism of pits is proposed. The input heat flux and the surface temperature of the propellants are obtained by solving a pre-ignition plasma–propellant interaction model. The results shed light on the pre-ignition plasma ignition mechanisms and will assist in the development of propellants for an ETC launcher. (paper)

  20. Aerodynamic interaction effects of tip-mounted propellers installed on the horizontal tailplane

    NARCIS (Netherlands)

    van Arnhem, N.; Sinnige, T.; Stokkermans, T.C.A.; Eitelberg, G.; Veldhuis, L.L.M.

    2018-01-01

    This paper addresses the effects of propeller installation on the aerodynamic performance of a tailplane featuring tip-mounted propellers. A model of a low aspect ratio tailplane equipped with an elevator and a tip-mounted propeller was installed in a low-speed wind-tunnel. Measurements were

  1. Diagnostics of Gun Barrel Propellants

    National Research Council Canada - National Science Library

    Lederman, S

    1983-01-01

    A preliminary investigation of the applicability of the spontaneous Raman diagnostic technique to the determination of the temperature of the propellant gases in the vicinity of the muzzle of a 2Omm...

  2. Feasibility Study on Cutting HTPB Propellants with Abrasive Water Jet

    Science.gov (United States)

    Jiang, Dayong; Bai, Yun

    2018-01-01

    Abrasive water jet is used to carry out the experiment research on cutting HTPB propellants with three components, which will provide technical support for the engineering treatment of waste rocket motor. Based on the reliability theory and related scientific research results, the safety and efficiency of cutting sensitive HTPB propellants by abrasive water jet were experimentally studied. The results show that the safety reliability is not less than 99.52% at 90% confidence level, so the safety is adequately ensured. The cooling and anti-friction effect of high-speed water jet is the decisive factor to suppress the detonation of HTPB propellant. Compared with pure water jet, cutting efficiency was increased by 5% - 87%. The study shows that abrasive water jets meet the practical use for cutting HTPB propellants.

  3. New Horizons for Lipoprotein ReceptorsCommunication by β-propellers

    DEFF Research Database (Denmark)

    Andersen, Olav Michael; Dagil, Robert; Kragelund, Birthe B

    2013-01-01

    , this dogma has transformed with the observation that β-propellers of some LRs actively engage in complex formation too. Based on an in-depth decomposition of current structures and sequences, we suggest that exploitation of the β-propellers as binding targets depends on receptor subgroups. In particular, we...

  4. Propeller flaps for lower-limb trauma | Rogers | South African ...

    African Journals Online (AJOL)

    The propeller flap has become a versatile and important component in our reconstructive algorithm following complex lower limb trauma. First described by Hyakusoku in 1991, it has since been adapted and modified by Hallock and Teo. This article outlines our experience specifically with perforator pedicled propeller flaps ...

  5. A fractional calculus perspective of distributed propeller design

    Science.gov (United States)

    Tenreiro Machado, J.; Galhano, Alexandra M.

    2018-02-01

    A new generation of aircraft with distributed propellers leads to operational performances superior to those exhibited by standard designs. Computational simulations and experimental tests show a reduction of fuel consumption and noise. This paper proposes an analogy between aerodynamics and electrical circuits. The model reveals properties similar to those of fractional-order systems and gives a deeper insight into the dynamics of multi-propeller coupling.

  6. Remote nano-optical beam focusing lens by illusion optics

    Science.gov (United States)

    Margousi, David; Shoorian, Hamed Reza

    2014-08-01

    In this paper, as a new application of illusion optics, a nano-optical plasmonic focusing lens structure is proposed to manipulate the light remotely by employing illusion optics theory. Plasmonic nano-optic lenses that enable super-focusing beyond the diffraction limit have been proposed as an alternative to the conventional dielectric-based refractive lenses. In the presence of an illusion device, the electromagnetic plane-waves can penetrate into a metal layer and a clear focus appears. When the illusion device is removed, waves are blocked to transmit through the metal wall. In comparison with conventional methods, our proposed method avoids any physical changes or damages in the original structure. The proposed structure can be realized by isotropic layered materials, using effective medium theory. The special feature of the proposed structure and the device concepts introduced in this work gives it an opportunity to be used as a flexible element in ultrahigh nano-scale integrated circuits for miniaturization and tuning purposes.

  7. Evaluation of Shear Bond Strength of Orthodontic Brackets Bonded with Nano-Filled Composites

    OpenAIRE

    Chalipa, Javad; Akhondi, Mohammad Sadegh Ahmad; Arab, Sepideh; Kharrazifard, Mohammad Javad; Ahmadyar, Maryam

    2013-01-01

    Objectives: The purpose of this study was to evaluate the shear bond strength (SBS) of orthodontic brackets bonded with two types of nano-composites in comparison to a conventional orthodontic composite. Materials and Methods: Sixty extracted human first premolars were randomly divided into 3 groups each containing 20 teeth. In group I, a conventional orthodontic composite (Transbond XT) was used to bond the brackets, while two nano-composites (Filtek TM Supreme XT and AELITE Aesthetic Enamel...

  8. A numerical study of scale effects on performance of a tractor type podded propeller

    Directory of Open Access Journals (Sweden)

    Choi Jung-Kyu

    2014-06-01

    Full Text Available In this study, the scale effect on the performance of the podded propeller of tractor type is investigated. Turbulent flow computations are carried out for Reynolds numbers increasing progressively from model scale to full scale using the CFD analysis. The result of the flow calculation for model scale Reynolds numbers agrees well with that of the experiment of a large cavitation tunnel. The existing numerical analysis indicates that the performance of the podded propeller blades is mainly influenced by the advance coefficient and relatively little by the Reynolds number. However, the drag of pod housing with propeller in operation is different from that of pod housing without propeller due to the acceleration and swirl of propeller slipstream which is altered by propeller loading as well as the pressure recovery and friction according to Reynolds number, which suggests that the pod housing drag under the condition of propeller in operation is the key factor of the scale effect on the performance between model and full scale podded propellers. The so called ‘drag ratio’, which is the ratio of pod housing drag to total thrust of podded propeller, increases as the advance coefficient increases due to accelerated flow in the slipstream of the podded propeller. However, the increasing rate of the drag ratio reduces continuously as the Reynolds number increases from model to full scale progressively. The contribution of hydrodynamic forces, which acts on the parts composed of the pod housing with propeller operating in various loading conditions, to the thrust and the torque of the total propeller unit are presented for a range of Reynolds numbers from model to full scales.

  9. Joint High Speed Sealift (JHSS) Baseline Shaft & Strut (BSS) Model 5653-3: Series 2, Propeller Disk LDV Wake Survey; and Series 3, Stock Propeller Powering and Stern Flap Evaluation Experiments

    National Research Council Canada - National Science Library

    Cusanelli, Dominic S; Chesnakas, Christopher J

    2007-01-01

    ...) and Stock Propeller Powering and Stern Flap Evaluation tests (Series 3. In order to assist in the design of a propeller for the BSS hull, the nominal wakes in the inboard and outboard starboard propeller planes were measured using LDV...

  10. Utilizing Solar Power Technologies for On-Orbit Propellant Production

    Science.gov (United States)

    Fikes, John C.; Howell, Joe T.; Henley, Mark W.

    2006-01-01

    The cost of access to space beyond low Earth orbit may be reduced if vehicles can refuel in orbit. The cost of access to low Earth orbit may also be reduced by launching oxygen and hydrogen propellants in the form of water. To achieve this reduction in costs of access to low Earth orbit and beyond, a propellant depot is considered that electrolyzes water in orbit, then condenses and stores cryogenic oxygen and hydrogen. Power requirements for such a depot require Solar Power Satellite technologies. A propellant depot utilizing solar power technologies is discussed in this paper. The depot will be deployed in a 400 km circular equatorial orbit. It receives tanks of water launched into a lower orbit from Earth, converts the water to liquid hydrogen and oxygen, and stores up to 500 metric tons of cryogenic propellants. This requires a power system that is comparable to a large Solar Power Satellite capable of several 100 kW of energy. Power is supplied by a pair of solar arrays mounted perpendicular to the orbital plane, which rotates once per orbit to track the Sun. The majority of the power is used to run the electrolysis system. Thermal control is maintained by body-mounted radiators; these also provide some shielding against orbital debris. The propellant stored in the depot can support transportation from low Earth orbit to geostationary Earth orbit, the Moon, LaGrange points, Mars, etc. Emphasis is placed on the Water-Ice to Cryogen propellant production facility. A very high power system is required for cracking (electrolyzing) the water and condensing and refrigerating the resulting oxygen and hydrogen. For a propellant production rate of 500 metric tons (1,100,000 pounds) per year, an average electrical power supply of 100 s of kW is required. To make the most efficient use of space solar power, electrolysis is performed only during the portion of the orbit that the Depot is in sunlight, so roughly twice this power level is needed for operations in sunlight

  11. Small transport aircraft technology propeller study

    Science.gov (United States)

    Black, B. M.; Magliozzi, B.; Rohrbach, C.

    1983-01-01

    A study to define potential benefits of advanced technology propeller for 1985-1990 STAT commuter airplanes was completed. Two baselines, a Convair, 30 passenger, 0.47 Mach number airplane and a Lockheed, 50 passenger, 0.70 Mach number airplane, were selected from NASA-Ames sponsored airframe contracts. Parametric performance, noise level, weight and cost trends for propellers with varying number of blades, activity factor, camber and diameter incorporating blade sweep, tip proplets, advanced composite materials, advanced airfoils, advanced prevision synchrophasing and counter-rotation are presented. The resulting DOC, fuel burned, empty weight and acquisition cost benefits are presented for resizings of the two baseline airplanes. Six-bladed propeller having advanced composite blades, advanced airfoils, tip proplets and advanced prevision synchrophasers provided the maximum DOC improvements for both airplanes. DOC and fuel burned were reduced by 8.3% and 17.0% respectively for the Convair airplane and by 24.9% and 41.2% respectively for the Lockheed airplane. The larger reductions arose from a baseline definition with very heavy fuselage acoustic treatment. An alternate baseline, with a cabin noise 13dB in excess of the objective, was also studied.

  12. GISAXS modelling of helium-induced nano-bubble formation in tungsten and comparison with TEM

    Science.gov (United States)

    Thompson, Matt; Sakamoto, Ryuichi; Bernard, Elodie; Kirby, Nigel; Kluth, Patrick; Riley, Daniel; Corr, Cormac

    2016-05-01

    Grazing-incidence small angle x-ray scattering (GISAXS) is a powerful non-destructive technique for the measurement of nano-bubble formation in tungsten under helium plasma exposure. Here, we present a comparative study between transmission electron microscopy (TEM) and GISAXS measurements of nano-bubble formation in tungsten exposed to helium plasma in the Large Helical Device (LHD) fusion experiment. Both techniques are in excellent agreement, suggesting that nano-bubbles range from spheroidal to ellipsoidal, displaying exponential diameter distributions with mean diameters μ=0.68 ± 0.04 nm and μ=0.6 ± 0.1 nm measured by TEM and GISAXS respectively. Depth distributions were also computed, with calculated exponential depth distributions with mean depths of 8.4 ± 0.5 nm and 9.1 ± 0.4 nm for TEM and GISAXS. In GISAXS modelling, spheroidal particles were fitted with an aspect ratio ε=0.7 ± 0.1. The GISAXS model used is described in detail.

  13. Comparison of tungsten nano-tendrils grown in Alcator C-Mod and linear plasma devices

    International Nuclear Information System (INIS)

    Wright, G.M.; Brunner, D.; Baldwin, M.J.; Bystrov, K.; Doerner, R.P.; Labombard, B.; Lipschultz, B.; De Temmerman, G.; Terry, J.L.; Whyte, D.G.; Woller, K.B.

    2013-01-01

    Growth of tungsten nano-tendrils (“fuzz”) has been observed for the first time in the divertor region of a high-power density tokamak experiment. After 14 consecutive helium L-mode discharges in Alcator C-Mod, the tip of a tungsten Langmuir probe at the outer strike point was fully covered with a layer of nano-tendrils. The depth of the W fuzz layer (600 ± 150 nm) is consistent with an empirical growth formula from the PISCES experiment. Re-creating the C-Mod exposures as closely as possible in Pilot-PSI experiment can produce nearly-identical nano-tendril morphology and layer thickness at surface temperatures that agree with uncertainties with the C-Mod W probe temperature data. Helium concentrations in W fuzz layers are measured at 1–4 at.%, which is lower than expected for the observed sub-surface voids to be filled with several GPa of helium pressure. This possibly indicates that the void formation is not pressure driven

  14. Stable Poly(methacrylic acid Brush Decorated Silica Nano-Particles by ARGET ATRP for Bioconjugation

    Directory of Open Access Journals (Sweden)

    Marcello Iacono

    2015-08-01

    Full Text Available The synthesis of polymer brush decorated silica nano-particles is demonstrated by activator regeneration by electron transfer atom transfer radical polymerization (ARGET ATRP grafting of poly(tert-butyl methacrylate. ATRP initiator decorated silica nano-particles were obtained using a novel trimethylsiloxane derivatised ATRP initiator obtained by click chemistry. Comparison of de-grafted polymers with polymer obtained from a sacrificial initiator demonstrated good agreement up to 55% monomer conversion. Subsequent mild deprotection of the tert-butyl ester groups using phosphoric acid yielded highly colloidal and pH stable hydrophilic nano-particles comprising approximately 50% methacrylic acid groups. The successful bio-conjugation was achieved by immobilization of Horseradish Peroxidase to the polymer brush decorated nano-particles and the enzyme activity demonstrated in a conversion of o-phenylene diamine dihydrochloride assay.

  15. 75 FR 62333 - Airworthiness Directives; Hamilton Sundstrand Propellers Model 247F Propellers

    Science.gov (United States)

    2010-10-08

    ...., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory... that the 247F propeller blades, P/N 817370-1, S/Ns FR2449 to FR2958 inclusive, FR20010710 to FR20010722 inclusive, and FR20010723RT to FR20020127RT inclusive, manufactured since January 1999, might also have...

  16. Tests of Nacelle-Propeller Combinations in Various Positions with Reference to Wings V : Clark Y Biplane Cellule - NACA Cowled Nacelle - Tractor Propeller

    Science.gov (United States)

    Valentine, E Floyd

    1935-01-01

    This report is the fifth of a series giving the results obtained from wind tunnel tests on the interference drag and propulsive efficiency of nacelle-propeller-wing combinations. This report gives results of tests of an NACA cowled air-cooled engine nacelle with tractor propeller located in 12 positions with reference to a Clark Y biplane cellule.

  17. Recent Advances and Applications in Cryogenic Propellant Densification Technology

    Science.gov (United States)

    Tomsik, Thomas M.

    2000-01-01

    This purpose of this paper is to review several historical cryogenic test programs that were conducted at the NASA Glenn Research Center (GRC), Cleveland, Ohio over the past fifty years. More recently these technology programs were intended to study new and improved denser forms of liquid hydrogen (LH2) and liquid oxygen (LO2) cryogenic rocket fuels. Of particular interest are subcooled cryogenic propellants. This is due to the fact that they have a significantly higher density (eg. triple-point hydrogen, slush etc.), a lower vapor pressure and improved cooling capacity over the normal boiling point cryogen. This paper, which is intended to be a historical technology overview, will trace the past and recent development and testing of small and large-scale propellant densification production systems. Densifier units in the current GRC fuels program, were designed and are capable of processing subcooled LH2 and L02 propellant at the X33 Reusable Launch Vehicle (RLV) scale. One final objective of this technical briefing is to discuss some of the potential benefits and application which propellant densification technology may offer the industrial cryogenics production and end-user community. Density enhancements to cryogenic propellants (LH2, LO2, CH4) in rocket propulsion and aerospace application have provided the opportunity to either increase performance of existing launch vehicles or to reduce the overall size, mass and cost of a new vehicle system.

  18. Unsteady Aerodynamic Investigation of the Propeller-Wing Interaction for a Rocket Launched Unmanned Air Vehicle

    Directory of Open Access Journals (Sweden)

    G. Q. Zhang

    2013-01-01

    Full Text Available The aerodynamic characteristics of propeller-wing interaction for the rocket launched UAV have been investigated numerically by means of sliding mesh technology. The corresponding forces and moments have been collected for axial wing placements ranging from 0.056 to 0.5D and varied rotating speeds. The slipstream generated by the rotating propeller has little effects on the lift characteristics of the whole UAV. The drag can be seen to remain unchanged as the wing's location moves progressively closer to the propeller until 0.056D away from the propeller, where a nearly 20% increase occurred sharply. The propeller position has a negligible effect on the overall thrust and torque of the propeller. The efficiency affected by the installation angle of the propeller blade has also been analyzed. Based on the pressure cloud and streamlines, the vortices generated by propeller, propeller-wing interaction, and wing tip have also been captured and analyzed.

  19. Nano-bio-sensing

    CERN Document Server

    Carrara, Sandro

    2011-01-01

    This book examines state-of-the-art applications of nano-bio-sensing. It brings together researchers from nano-electronics and bio-technology, providing multidisciplinary content from nano-structures fabrication to bio-sensing applications.

  20. Studies on Effective Elastic Properties of CNT/Nano-Clay Reinforced Polymer Hybrid Composite

    Science.gov (United States)

    Thakur, Arvind Kumar; Kumar, Puneet; Srinivas, J.

    2016-02-01

    This paper presents a computational approach to predict elastic propertiesof hybrid nanocomposite material prepared by adding nano-clayplatelets to conventional CNT-reinforced epoxy system. In comparison to polymers alone/single-fiber reinforced polymers, if an additional fiber is added to the composite structure, it was found a drastic improvement in resultant properties. In this regard, effective elastic moduli of a hybrid nano composite are determined by using finite element (FE) model with square representative volume element (RVE). Continuum mechanics based homogenization of the nano-filler reinforced composite is considered for evaluating the volumetric average of the stresses and the strains under different periodic boundary conditions.A three phase Halpin-Tsai approach is selected to obtain the analytical result based on micromechanical modeling. The effect of the volume fractions of CNTs and nano-clay platelets on the mechanical behavior is studied. Two different RVEs of nano-clay platelets were used to investigate the influence of nano-filler geometry on composite properties. The combination of high aspect ratio of CNTs and larger surface area of clay platelets contribute to the stiffening effect of the hybrid samples. Results of analysis are validated with Halpin-Tsai empirical formulae.

  1. Characterization of Hall effect thruster propellant distributors with flame visualization

    Science.gov (United States)

    Langendorf, S.; Walker, M. L. R.

    2013-01-01

    A novel method for the characterization and qualification of Hall effect thruster propellant distributors is presented. A quantitative measurement of the azimuthal number density uniformity, a metric which impacts propellant utilization, is obtained from photographs of a premixed flame anchored on the exit plane of the propellant distributor. The technique is demonstrated for three propellant distributors using a propane-air mixture at reservoir pressure of 40 psi (gauge) (377 kPa) exhausting to atmosphere, with volumetric flow rates ranging from 15-145 cfh (7.2-68 l/min) with equivalence ratios from 1.2 to 2.1. The visualization is compared with in-vacuum pressure measurements 1 mm downstream of the distributor exit plane (chamber pressure held below 2.7 × 10-5 Torr-Xe at all flow rates). Both methods indicate a non-uniformity in line with the propellant inlet, supporting the validity of the technique of flow visualization with flame luminosity for propellant distributor characterization. The technique is applied to a propellant distributor with a manufacturing defect in a known location and is able to identify the defect and characterize its impact. The technique is also applied to a distributor with numerous small orifices at the exit plane and is able to resolve the resulting non-uniformity. Luminosity data are collected with a spatial resolution of 48.2-76.1 μm (pixel width). The azimuthal uniformity is characterized in the form of standard deviation of azimuthal luminosities, normalized by the mean azimuthal luminosity. The distributors investigated achieve standard deviations of 0.346 ± 0.0212, 0.108 ± 0.0178, and 0.708 ± 0.0230 mean-normalized luminosity units respectively, where a value of 0 corresponds to perfect uniformity and a value of 1 represents a standard deviation equivalent to the mean.

  2. An Integrated Hydrofoil and Propeller Design Tool for the Windows Environment

    OpenAIRE

    Beckett, David R.

    1996-01-01

    CIVINS (Civilian Institutions) Thesis document Includes supplementary material Approved for public release ; distribution is unlimited An investigation of the feasibility and desirability of the employment of personal computers in hydrofoil and propeller design was performed. The feasibility and desirability of the employment of personal computers in hydrofoil and propeller design was demonstrated by the seamless linking of the MIT Propulsor Lifting Line Code and the MIT Propeller Bl...

  3. A Cis-Lunar Propellant Infrastructure for Flexible Path Exploration and Space Commerce

    Science.gov (United States)

    Oeftering, Richard C.

    2012-01-01

    This paper describes a space infrastructure concept that exploits lunar water for propellant production and delivers it to users in cis-lunar space. The goal is to provide responsive economical space transportation to destinations beyond low Earth orbit (LEO) and enable in-space commerce. This is a game changing concept that could fundamentally affect future space operations, provide greater access to space beyond LEO, and broaden participation in space exploration. The challenge is to minimize infrastructure development cost while achieving a low operational cost. This study discusses the evolutionary development of the infrastructure from a very modest robotic operation to one that is capable of supporting human operations. The cis-lunar infrastructure involves a mix of technologies including cryogenic propellant production, reusable lunar landers, propellant tankers, orbital transfer vehicles, aerobraking technologies, and electric propulsion. This cislunar propellant infrastructure replaces Earth-launched propellants for missions beyond LEO. It enables users to reach destinations with smaller launchers or effectively multiplies the user s existing payload capacity. Users can exploit the expanded capacity to launch logistics material that can then be traded with the infrastructure for propellants. This mutually beneficial trade between the cis-lunar infrastructure and propellant users forms the basis of in-space commerce.

  4. On the selection of optimized carbon nano tube synthesis method using analytic hierarchy process

    International Nuclear Information System (INIS)

    Besharati, M. K.; Afaghi Khatibi, A.; Akbari, M.

    2008-01-01

    Evidence from the early and late industrializes shows that technology, as the commercial application of scientific knowledge, has been a major driver of industrial and economic development. International technology transfer is now being recognized as having played an important role in the development of the most successful late industrializes of the second half of the twentieth Century. Our society stands to be significantly influenced by carbon nano tubes, shaped by nano tube applications in every aspect, just as silicon-based technology still shapes society today. Nano tubes can be formed in various structures using several different processing methods. In this paper, the synthesis methods used to produce nano tubes in industrial or laboratory scales are discussed and a comparison is made. A technical feasibility study is conducted by using the multi criteria decision-making model, namely Analytic Hierarchy Process. The article ends with a discussion of selecting the best method of Technology Transferring of Carbon Nano tubes to Iran

  5. Lateral-directional aerodynamic characteristics of light, twin-engine, propeller driven airplanes

    Science.gov (United States)

    Wolowicz, C. H.; Yancey, R. B.

    1972-01-01

    Analytical procedures and design data for predicting the lateral-directional static and dynamic stability and control characteristics of light, twin engine, propeller driven airplanes for propeller-off and power-on conditions are reported. Although the consideration of power effects is limited to twin engine airplanes, the propeller-off considerations are applicable to single engine airplanes as well. The procedures are applied to a twin engine, propeller driven, semi-low-wing airplane in the clean configuration through the linear lift range. The calculated derivative characteristics are compared with wind tunnel and flight data. Included in the calculated characteristics are the spiral mode, roll mode, and Dutch roll mode over the speed range of the airplane.

  6. Experimental investigation of atomization characteristics of swirling spray by ADN gelled propellant

    Science.gov (United States)

    Guan, Hao-Sen; Li, Guo-Xiu; Zhang, Nai-Yuan

    2018-03-01

    Due to the current global energy shortage and increasingly serious environmental issues, green propellants are attracting more attention. In particular, the ammonium dinitramide (ADN)-based monopropellant thruster is gaining world-wide attention as a green, non-polluting and high specific impulse propellant. Gel propellants combine the advantages of liquid and solid propellants, and are becoming popular in the field of spaceflight. In this paper, a swirling atomization experimental study was carried out using an ADN aqueous gel propellant under different injection pressures. A high-speed camera and a Malvern laser particle size analyzer were used to study the spray process. The flow coefficient, cone angle of swirl atomizing spray, breakup length of spray membrane, and droplet size distribution were analyzed. Furthermore, the effects of different injection pressures on the swirling atomization characteristics were studied.

  7. Pre-Swirl Stator and Propeller Design for Varying Operating Conditions

    DEFF Research Database (Denmark)

    Saettone, Simone; Regener, Pelle Bo; Andersen, Poul

    2016-01-01

    blades ahead of the propeller.This paper describes the hydrodynamic design of apre-swirl stator with radially variable pitch, paired with aconventional propeller. The aim is to achieve the highest possible effciency in various operating conditions, and to avoid effciency penalties in off-design operation.......To investigate the propeller and stator designs and configurations in different operating conditions, the computationally inexpensive vortex-lattice method is used a sa first step to optimize the geometry in an initial parameter study. Then the flow over hull, stator and propelleris simulated in a CFD...

  8. Prevention of Dealloying in Manganese Aluminium Bronze Propeller: Part II

    Directory of Open Access Journals (Sweden)

    Napachat Tareelap

    2014-03-01

    Full Text Available Due to the failure of manganese aluminium bronze (MAB propeller caused by dealloying corrosion as described in Part I [1], this work aims to study the prevention of dealloying corrosion using aluminium and zinc sacrificial anodes. The results indicated that both of the sacrificial anodes could prevent the propeller from dealloying. Moreover, the dealloying in seawater was less than that found in brackish water. It was possible that hydroxide ions, from cathodic reaction, reacted with calcium in seawater to form calcium carbonate film protecting the propeller from corrosion.

  9. Environmental silicate nano-biocomposites

    CERN Document Server

    Pollet, Eric

    2012-01-01

    Environmental Silicate Nano-Biocomposites focuses on nano-biocomposites, which are obtained by the association of silicates such as bioclays with biopolymers. By highlighting recent developments and findings, green and biodegradable nano-composites from both renewable and biodegradable polymers are explored. This includes coverage of potential markets such as packaging, agricultures, leisure and the fast food industry. The knowledge and experience of more than twenty international experts in diverse fields, from chemical and biochemical engineering to applications, is brought together in four different sections covering: Biodegradable polymers and Silicates, Clay/Polyesters Nano-biocomposites, Clay/Agropolymers Nano-biocomposites, and Applications and biodegradation of Nano-biocomposites. By exploring the relationships between the biopolymer structures, the processes, and the final properties Environmental Silicate Nano-Biocomposites explains how to design nano-materials to develop new, valuable, environmenta...

  10. Propellant and Purge System Contamination "2007: A Summer of Fun"

    Science.gov (United States)

    Galloway, Randy

    2010-01-01

    This slide presentation reviews the propellant and purge system contamination that occurred during the summer of 2007 at Stennis Space Center. During this period Multiple propellant/pressurant system contamination events prompted a thorough investigation, the results of which are reviewed.

  11. Concept and performance study of turbocharged solid propellant ramjet

    Science.gov (United States)

    Li, Jiang; Liu, Kai; Liu, Yang; Liu, Shichang

    2018-06-01

    This study proposes a turbocharged solid propellant ramjet (TSPR) propulsion system that integrates a turbocharged system consisting of a solid propellant (SP) air turbo rocket (ATR) and the fuel-rich gas generator of a solid propellant ramjet (SPR). First, a suitable propellant scheme was determined for the TSPR. A solid hydrocarbon propellant is used to generate gas for driving the turbine, and a boron-based fuel-rich propellant is used to provide fuel-rich gas to the afterburner. An appropriate TSPR structure was also determined. The TSPR's thermodynamic cycle was analysed to prove its theoretical feasibility. The results showed that the TSPR's specific cycle power was larger than those of SP-ATR and SPR and thermal efficiency was slightly less than that of SP-ATR. Overall, TSPR showed optimal performance in a wide flight envelope. The specific impulses and specific thrusts of TSPR, SP-ATR, and SPR in the flight envelope were calculated and compared. TSPR's flight envelope roughly overlapped that of SP-ATR, its specific impulse was larger than that of SP-ATR, and its specific thrust was larger than those of SP-ATR and SPR. Attempts to improve the TSPR off-design performance prompted our proposal of a control plan for off-design codes in which both the turbocharger corrected speed and combustor excess gas coefficient are kept constant. An off-design performance model was established by analysing the TSPR working process. We concluded that TSPR with a constant corrected speed had wider flight envelope, higher thrust, and higher specific impulse than TSPR with a constant physical speed determined by calculating the performance of off-design TSPR codes under different control plans. The results of this study can provide a reference for further studies on TSPRs.

  12. Modeling and Fault Simulation of Propellant Filling System

    International Nuclear Information System (INIS)

    Jiang Yunchun; Liu Weidong; Hou Xiaobo

    2012-01-01

    Propellant filling system is one of the key ground plants in launching site of rocket that use liquid propellant. There is an urgent demand for ensuring and improving its reliability and safety, and there is no doubt that Failure Mode Effect Analysis (FMEA) is a good approach to meet it. Driven by the request to get more fault information for FMEA, and because of the high expense of propellant filling, in this paper, the working process of the propellant filling system in fault condition was studied by simulating based on AMESim. Firstly, based on analyzing its structure and function, the filling system was modular decomposed, and the mathematic models of every module were given, based on which the whole filling system was modeled in AMESim. Secondly, a general method of fault injecting into dynamic system was proposed, and as an example, two typical faults - leakage and blockage - were injected into the model of filling system, based on which one can get two fault models in AMESim. After that, fault simulation was processed and the dynamic characteristics of several key parameters were analyzed under fault conditions. The results show that the model can simulate effectively the two faults, and can be used to provide guidance for the filling system maintain and amelioration.

  13. Weight savings in aerospace vehicles through propellant scavenging

    Science.gov (United States)

    Schneider, Steven J.; Reed, Brian D.

    1988-01-01

    Vehicle payload benefits of scavenging hydrogen and oxygen propellants are addressed. The approach used is to select a vehicle and a mission and then select a scavenging system for detailed weight analysis. The Shuttle 2 vehicle on a Space Station rendezvous mission was chosen for study. The propellant scavenging system scavenges liquid hydrogen and liquid oxygen from the launch propulsion tankage during orbital maneuvers and stores them in well insulated liquid accumulators for use in a cryogenic auxiliary propulsion system. The fraction of auxiliary propulsion propellant which may be scavenged for propulsive purposes is estimated to be 45.1 percent. The auxiliary propulsion subsystem dry mass, including the proposed scavenging system, an additional 20 percent for secondary structure, an additional 5 percent for electrical service, a 10 percent weight growth margin, and 15.4 percent propellant reserves and residuals is estimated to be 6331 kg. This study shows that the fraction of the on-orbit vehicle mass required by the auxiliary propulsion system of this Shuttle 2 vehicle using this technology is estimated to be 12.0 percent compared to 19.9 percent for a vehicle with an earth-storable bipropellant system. This results in a vehicle with the capability of delivering an additional 7820 kg to the Space Station.

  14. Weight savings in aerospace vehicles through propellant scavenging

    Science.gov (United States)

    Schneider, Steven J.; Reed, Brian D.

    1988-05-01

    Vehicle payload benefits of scavenging hydrogen and oxygen propellants are addressed. The approach used is to select a vehicle and a mission and then select a scavenging system for detailed weight analysis. The Shuttle 2 vehicle on a Space Station rendezvous mission was chosen for study. The propellant scavenging system scavenges liquid hydrogen and liquid oxygen from the launch propulsion tankage during orbital maneuvers and stores them in well insulated liquid accumulators for use in a cryogenic auxiliary propulsion system. The fraction of auxiliary propulsion propellant which may be scavenged for propulsive purposes is estimated to be 45.1 percent. The auxiliary propulsion subsystem dry mass, including the proposed scavenging system, an additional 20 percent for secondary structure, an additional 5 percent for electrical service, a 10 percent weight growth margin, and 15.4 percent propellant reserves and residuals is estimated to be 6331 kg. This study shows that the fraction of the on-orbit vehicle mass required by the auxiliary propulsion system of this Shuttle 2 vehicle using this technology is estimated to be 12.0 percent compared to 19.9 percent for a vehicle with an earth-storable bipropellant system. This results in a vehicle with the capability of delivering an additional 7820 kg to the Space Station.

  15. The Effect of Slipstream Obstructions on Air Propellers

    Science.gov (United States)

    Lesley, E P; Woods, B M

    1924-01-01

    The screw propeller on airplanes is usually placed near other objects, and hence its performance may be modified by them. Results of tests on propellers free from slip stream obstructions, both fore and aft, are therefore subject to correction, for the effect of such obstructions and the purpose of the investigation was to determine the effect upon the thrust and torque coefficients and efficiency, for previously tested air propellers, of obstructions placed in the slip stream, it being realized that such previous tests had been conducted under somewhat ideal conditions that are impracticable of realization in flight. Simple geometrical forms were used for the initial investigation. Such forms offered the advantage of easy, exact reproduction at another time or in other laboratories, and it was believed that the effects of obstructions usually encountered might be deduced or surmise from those chosen.

  16. Liquid Hydrogen Propellant Tank Sub-Surface Pressurization with Gaseous Helium

    Science.gov (United States)

    Stephens, J. R.; Cartagena, W.

    2015-01-01

    A series of tests were conducted to evaluate the performance of a propellant tank pressurization system with the pressurant diffuser intentionally submerged beneath the surface of the liquid. Propellant tanks and pressurization systems are typically designed with the diffuser positioned to apply pressurant gas directly into the tank ullage space when the liquid propellant is settled. Space vehicles, and potentially propellant depots, may need to conduct tank pressurization operations in micro-gravity environments where the exact location of the liquid relative to the diffuser is not well understood. If the diffuser is positioned to supply pressurant gas directly to the tank ullage space when the propellant is settled, then it may become partially or completely submerged when the liquid becomes unsettled in a microgravity environment. In such case, the pressurization system performance will be adversely affected requiring additional pressurant mass and longer pressurization times. This series of tests compares and evaluates pressurization system performance using the conventional method of supplying pressurant gas directly to the propellant tank ullage, and then supplying pressurant gas beneath the liquid surface. The pressurization tests were conducted on the Engineering Development Unit (EDU) located at Test Stand 300 at NASA Marshall Space Flight Center (MSFC). EDU is a ground based Cryogenic Fluid Management (CFM) test article supported by Glenn Research Center (GRC) and MSFC. A 150 ft3 propellant tank was filled with liquid hydrogen (LH2). The pressurization system used regulated ambient helium (GHe) as a pressurant, a variable position valve to maintain flow rate, and two identical independent pressurant diffusers. The ullage diffuser was located in the forward end of the tank and was completely exposed to the tank ullage. The submerged diffuser was located in the aft end of the tank and was completely submerged when the tank liquid level was 10% or greater

  17. Current state of the art of HNF based composite propellants

    NARCIS (Netherlands)

    Ciucci, A.; Frota, O.; Welland, W.H.M.; Heijden, A.E.D.M. van der; Leeming, B.; Bellerby, J.M.; Brotzu, A.

    2004-01-01

    The main activities currently performed for the development of HNF-based propellants are presented. The objectives and approach adopted are described. The results obtained on the HNF decomposition mechanism and on the re- and co-crystallisation of HNF with potential propellant ingredients are

  18. Producing propellants from water in lunar soil using solar lasers

    Science.gov (United States)

    de Morais Mendonca Teles, Antonio

    The exploration of the Solar System is directly related to the efficiency of engines designed to explore it, and consequently, to the propulsion techniques, materials and propellants for those engines. With the present day propulsion techniques it is necessary great quantities of propellants to impulse a manned spacecraft to Mars and beyond in the Solar System, which makes these operations financially very expensive because of the costs involved in launching it from planet Earth, due to its high gravity field strength. To solve this problem, it is needed a planetary place with smaller gravity field strength, near to the Earth and with great quantities of substances at the surface necessary for the in-situ production of propellants for spacecrafts. The only place available is Earth's natural satellite the Moon. So, here in this paper, I propose the creation of a Lunar Propellant Manufacturer. It is a robot-spacecraft which can be launched from Earth using an Energia Rocket, and to land on the Moon in an area (principally near to the north pole where it was discovered water molecules ice recently) with great quantities of oxygen and hydrogen (propellants) in the silicate soil, previously observed and mapped by spacecrafts in lunar orbit, for the extraction of those molecules from the soil and the in-situ production of the necessary propellants. The Lunar Propellant Manufacturer (LPM) spacecraft consists of: 1) a landing system with four legs (extendable) and rovers -when the spacecraft touches down, the legs retract in order that two apparatuses, analogue to tractor's wheeled belts parallel sided and below the spacecraft, can touch firmly the ground -it will be necessary for the displacement of the spacecraft to new areas with richer propellants content, when the early place has already exhausted in propellants; 2) a digging machine -a long, resistant extendable arm with an excavator hand, in the outer part of the spacecraft -it will extend itself to the ground

  19. Evaluation of the sonosensitizing properties of nano-graphene oxide in comparison with iron oxide and gold nanoparticles

    Science.gov (United States)

    Beik, Jaber; Abed, Ziaeddin; Shakeri-Zadeh, Ali; Nourbakhsh, Mitra; Shiran, Mohammad Bagher

    2016-07-01

    In cancer hyperthermia, ultrasound is considered as an appropriate source of energy to achieve desired therapeutic levels of heating. It is assumed that such a heating is targeted to cancer cells by using nanoparticles as sonosensitization agents. Here, we report the sonosensitizing effects of Nano-Graphene Oxide (NGO) and compare them with gold nanoparticles (AuNPs), Iron Oxide nanoparticles (IONPs). Experiments were conducted to explore the effects of nanoparticle type and concentration, as well as ultrasound power, on transient heating up of the solutions exposed by 1 MHz ultrasound. Nanoparticles concentration was selected from 0.25 to 2.5 mg/ml and the solutions were exposed by ultrasound powers from 1 to 8 W. Real time temperature monitoring was done by a thermocouple and obtained data was analyzed. Temperature profiles of various nanoparticle solutions showed the higher heating rates, in comparison to water. Heating rise was strongly depended on nanoparticles concentration and ultrasound power. AuNPs showed a superior efficiency in heat generation enhancement in comparison to IONPs and NGO. Our result supports the idea of sonosensitizing capabilities of AuNPs, IONPs, and NGO. Targeted hyperthermia may be achievable by preferential loading of tumor with nanoparticles and subsequent ultrasound irradiation.

  20. Propeller Test Facilities Â

    Data.gov (United States)

    Federal Laboratory Consortium — Description: Three electrically driven whirl test stands are used to determine propeller (or other rotating device) performance at various rotational speeds. These...

  1. Mass production of polymer nano-wires filled with metal nano-particles.

    Science.gov (United States)

    Lomadze, Nino; Kopyshev, Alexey; Bargheer, Matias; Wollgarten, Markus; Santer, Svetlana

    2017-08-17

    Despite the ongoing progress in nanotechnology and its applications, the development of strategies for connecting nano-scale systems to micro- or macroscale elements is hampered by the lack of structural components that have both, nano- and macroscale dimensions. The production of nano-scale wires with macroscale length is one of the most interesting challenges here. There are a lot of strategies to fabricate long nanoscopic stripes made of metals, polymers or ceramics but none is suitable for mass production of ordered and dense arrangements of wires at large numbers. In this paper, we report on a technique for producing arrays of ordered, flexible and free-standing polymer nano-wires filled with different types of nano-particles. The process utilizes the strong response of photosensitive polymer brushes to irradiation with UV-interference patterns, resulting in a substantial mass redistribution of the polymer material along with local rupturing of polymer chains. The chains can wind up in wires of nano-scale thickness and a length of up to several centimeters. When dispersing nano-particles within the film, the final arrangement is similar to a core-shell geometry with mainly nano-particles found in the core region and the polymer forming a dielectric jacket.

  2. High-Lift Propeller System Configuration Selection for NASA's SCEPTOR Distributed Electric Propulsion Flight Demonstrator

    Science.gov (United States)

    Patterson, Michael D.; Derlaga, Joseph M.; Borer, Nicholas K.

    2016-01-01

    Although the primary function of propellers is typically to produce thrust, aircraft equipped with distributed electric propulsion (DEP) may utilize propellers whose main purpose is to act as a form of high-lift device. These \\high-lift propellers" can be placed upstream of wing such that, when the higher-velocity ow in the propellers' slipstreams interacts with the wing, the lift is increased. This technique is a main design feature of a new NASA advanced design project called Scalable Convergent Electric Propulsion Technology Operations Research (SCEPTOR). The goal of the SCEPTOR project is design, build, and y a DEP aircraft to demonstrate that such an aircraft can be much more ecient than conventional designs. This paper provides details into the high-lift propeller system con guration selection for the SCEPTOR ight demonstrator. The methods used in the high-lift propeller system conceptual design and the tradeo s considered in selecting the number of propellers are discussed.

  3. Nano-scaled hydroxyapatite/silk fibroin sheets support osteogenic differentiation of rat bone marrow mesenchymal cells

    International Nuclear Information System (INIS)

    Tanaka, Toshimitsu; Hirose, Motohiro; Kotobuki, Noriko; Ohgushi, Hajime; Furuzono, Tsutomu; Sato, Junichi

    2007-01-01

    A novel biomaterial that was composed of nano-scaled sintered hydroxyapatite (HAp) and silk fibroin (SF) was fabricated. We cultured rat marrow mesenchymal cells (MMCs) on this biomaterial (nano-HAp/SF sheet), on bare SF sheets, and on tissue culture polystyrene (TCPS) dishes as controls, then evaluated cell adhesion, proliferation, and differentiation of the MMCs. After 1 h of culture, a large number of viable cells were observed on the nano-HAp/SF sheets in comparison to the controls. In addition, after 3 h of culture, the morphology of the cells on the nano-HAp/SF sheets was quite different from that on the SF sheets. MMCs extrude their cytoplasmic processes to nano-HAp particles and are well attached to the sheets. After 14 days of culture, under osteogenic conditions, the alkaline phosphatase (ALP) activity and bone-specific osteocalcin secretion of the cells on nano-HAp/SF sheets were higher than were those on the controls. These results indicated that the surface of the nano-HAp/SF sheets is covered with appropriate HAp crystal for MMC adhesion/proliferation and that the sheets effectively support the osteogenic differentiation of MMCs. Therefore, the nano-HAp/SF sheet is an effective biomaterial that is applicable in bone reconstruction surgery

  4. Plasmonic graded nano-disks as nano-optical conveyor belt.

    Science.gov (United States)

    Kang, Zhiwen; Lu, Haifei; Chen, Jiajie; Chen, Kun; Xu, Fang; Ho, Ho-Pui

    2014-08-11

    We propose a plasmonic system consisting of nano-disks (NDs) with graded diameters for the realization of nano-optical conveyor belt. The system contains a couple of NDs with individual elements coded with different resonant wavelengths. By sequentially switching the wavelength and polarization of the excitation source, optically trapped target nano-particle can be transferred from one ND to another. The feasibility of such function is verified based on the three-dimensional finite-difference time-domain technique and the Maxwell stress tensor method. Our design may provide an alternative way to construct nano-optical conveyor belt with which target molecules can be delivered between trapping sites, thus enabling many on-chip optofluidic applications.

  5. Report on surveys in fiscal 2000 on the surveys and researches in relation to nano-technology; 2000 nendo nano technology ni kakawaru chosa kenkyu hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    In order to view over the situation surrounding the nano-technology as a whole, surveys and discussions were given by means of questionnaire and open discussion meetings. In the questionnaire, the answer that the products utilizing nano-scale structure have already been, or scheduled to be put on sale has exceeded half of the total answers. Experts view that the nano-technology is infiltrating steadily into the actual society. In view of the applicable fields, and in the opening discussion meetings, drastic innovation was expected in the industrial technologies in the future not too far away as a dream world, by using the 'nano-technology' that utilizes a principle completely different from the principles that have been practically used. In order to achieve that goal, a recognition was made clear that the braeakthrough in other fields is important, and the field crossing fusion such as coordination with academia, and exchanges between different businesses and different fields is important. In the comparison of competitive edges of Japan, America and Europe, Japan was recognized to possess sufficient competitive power, but the sense of crisis is felt toward the latent technological power of America of the future. (NEDO)

  6. Report on surveys in fiscal 2000 on the surveys and researches in relation to nano-technology; 2000 nendo nano technology ni kakawaru chosa kenkyu hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    In order to view over the situation surrounding the nano-technology as a whole, surveys and discussions were given by means of questionnaire and open discussion meetings. In the questionnaire, the answer that the products utilizing nano-scale structure have already been, or scheduled to be put on sale has exceeded half of the total answers. Experts view that the nano-technology is infiltrating steadily into the actual society. In view of the applicable fields, and in the opening discussion meetings, drastic innovation was expected in the industrial technologies in the future not too far away as a dream world, by using the 'nano-technology' that utilizes a principle completely different from the principles that have been practically used. In order to achieve that goal, a recognition was made clear that the braeakthrough in other fields is important, and the field crossing fusion such as coordination with academia, and exchanges between different businesses and different fields is important. In the comparison of competitive edges of Japan, America and Europe, Japan was recognized to possess sufficient competitive power, but the sense of crisis is felt toward the latent technological power of America of the future. (NEDO)

  7. Analysis of swirl recovery vanes for increased propulsive efficiency in tractor propeller aircraft

    NARCIS (Netherlands)

    Veldhuis, L.L.M.; Stokkermans, T.C.A.; Sinnige, T.; Eitelberg, G.

    2016-01-01

    In this paper we address a preliminary assessment of the performance effects of swirl recovery vanes (SRVs) in a installed and uninstalled tractor propeller arrangement. A numerical analysis was performed on a propeller and a propeller-wing configuration after the SRVs were optimized first in a

  8. Burning Characteristics of Ammonium-Nitrate-Based Composite Propellants with a Hydroxyl-Terminated Polybutadiene/Polytetrahydrofuran Blend Binder

    Directory of Open Access Journals (Sweden)

    Makoto Kohga

    2012-01-01

    Full Text Available Ammonium-nitrate-(AN- based composite propellants prepared with a hydroxyl-terminated polybutadiene (HTPB/polytetrahydrofuran (PTHF blend binder have unique thermal decomposition characteristics. In this study, the burning characteristics of AN/HTPB/PTHF propellants are investigated. The specific impulse and adiabatic flame temperature of an AN-based propellant theoretically increases with an increase in the proportion of PTHF in the HTPB/PTHF blend. With an AN/HTPB propellant, a solid residue is left on the burning surface of the propellant, and the shape of this residue is similar to that of the propellant. On the other hand, an AN/HTPB/PTHF propellant does not leave a solid residue. The burning rates of the AN/HTPB/PTHF propellant are not markedly different from those of the AN/HTPB propellant because some of the liquefied HTPB/PTHF binder cover the burning surface and impede decomposition and combustion. The burning rates of an AN/HTPB/PTHF propellant with a burning catalyst are higher than those of an AN/HTPB propellant supplemented with a catalyst. The beneficial effect of the blend binder on the burning characteristics is clarified upon the addition of a catalyst. The catalyst suppresses the negative influence of the liquefied binder that covers the burning surface. Thus, HTPB/PTHF blend binders are useful in improving the performance of AN-based propellants.

  9. The Effect of Nano Loading and Ultrasonic Compounding of EVA/LDPE/Nano-magnesium Hydroxide on Mechanical Properties and Distribution of Nano Particles

    Science.gov (United States)

    Azman, I. A.; Salleh, R. M.; Alauddin, S. M.; Shueb, M. I.

    2018-05-01

    Blends of Ethylene Vinyl Acetate (EVA) and Low-Density Polyethylene (LDPE) are promising composite which have good mechanical properties to environmental stress cracking. However, they lack fire resistant properties, which limits it usage in wire and cable industry. In order to improve flame retardancy ability, a range of nano-magnesium hydroxide (nano-MH) loading which is from 0 phr to maximum of 20 phr with ultrasonic extrusion 0-100 kHz frequencies have been introduced. Ultrasonic extrusion was used to improve the distribution of nano-MH. It was found that, 10 phr of nano loading with 100 kHz ultrasonic assisted has greater tensile strength compared to the nanocomposite without ultrasonication. Further increase of nano MH loading, will decrease the tensile properties. Better elongation at break was observed at10 phr nano-MH with the frequency of 50 kHz. The sample of 20 phr of nanoMH assisted with 50 kHz ultrasonic exhibits good flexural properties while 10 phr of nano-MH without the ultrasonic assisted demonstrates good in izod impact properties. From the evaluation of mechanical properties studied, it was found that 10 phr of nano-MH has shown the best performance among all the samples tested for EVA/LDPE/nano-MH composites. Transmission Electron Microscopy (TEM) has been conducted on 10 phr sample with different frequencies in order to observe the distribution of nano-MH particles. The sample with 100 kHz frequency shows more uniform dispersion of nano-MH in EVA/LDPE composites. This investigation indicates that the ultrasonic technology can enhance the mechanical properties studied as well as the dispersion of nano particles in the composite.

  10. On the combustion mechanisms of ZrH2 in double-base propellant.

    Science.gov (United States)

    Yang, Yanjing; Zhao, Fengqi; Yuan, Zhifeng; Wang, Ying; An, Ting; Chen, Xueli; Xuan, Chunlei; Zhang, Jiankan

    2017-12-13

    Metal hydrides are regarded as a series of promising hydrogen-supplying fuel for solid rocket propellants. Their effects on the energetic and combustion performances of propellants are closely related to their reaction mechanisms. Here we report a first attempt to determine the reaction mechanism of ZrH 2 , a high-density metal hydride, in the combustion of a double-base propellant to evaluate its potential as a fuel. ZrH 2 is determined to possess good resistance to oxidation by nitrocellulose and nitroglycerine. Thus its combustion starts with dehydrogenation to generate H 2 and metallic Zr. Subsequently, the newly formed Zr and H 2 participate in the combustion and, especially, Zr melts and then combusts on the burning surface which favors the heat feedback to the propellant. This phenomenon is completely different from the combustion behavior of the traditional fuel Al, where the Al particles are ejected off the burning surface of the propellant to get into the luminous flame zone to burn. The findings in this work validate the potential of ZrH 2 as a hydrogen-supplying fuel for double-base propellants.

  11. Cryogenic Propellant Feed System Analytical Tool Development

    Science.gov (United States)

    Lusby, Brian S.; Miranda, Bruno M.; Collins, Jacob A.

    2011-01-01

    The Propulsion Systems Branch at NASA s Lyndon B. Johnson Space Center (JSC) has developed a parametric analytical tool to address the need to rapidly predict heat leak into propellant distribution lines based on insulation type, installation technique, line supports, penetrations, and instrumentation. The Propellant Feed System Analytical Tool (PFSAT) will also determine the optimum orifice diameter for an optional thermodynamic vent system (TVS) to counteract heat leak into the feed line and ensure temperature constraints at the end of the feed line are met. PFSAT was developed primarily using Fortran 90 code because of its number crunching power and the capability to directly access real fluid property subroutines in the Reference Fluid Thermodynamic and Transport Properties (REFPROP) Database developed by NIST. A Microsoft Excel front end user interface was implemented to provide convenient portability of PFSAT among a wide variety of potential users and its ability to utilize a user-friendly graphical user interface (GUI) developed in Visual Basic for Applications (VBA). The focus of PFSAT is on-orbit reaction control systems and orbital maneuvering systems, but it may be used to predict heat leak into ground-based transfer lines as well. PFSAT is expected to be used for rapid initial design of cryogenic propellant distribution lines and thermodynamic vent systems. Once validated, PFSAT will support concept trades for a variety of cryogenic fluid transfer systems on spacecraft, including planetary landers, transfer vehicles, and propellant depots, as well as surface-based transfer systems. The details of the development of PFSAT, its user interface, and the program structure will be presented.

  12. Towards a renewal of the propeller in aeronautics

    Science.gov (United States)

    Berger, D.; Jacquet, P.

    1985-01-01

    The reasons for reconsidering the propeller for aircraft propulsion, the areas of application, and necessary developments are considered. Rising fuel costs and an increasing theoretical and experimental data base for turboprop engines have demonstrated that significant cost savings can be realized by the use of propellers. Propellers are well-suited to powering aircraft traveling at speeds up to Mach 0.65. Work is progressing on the development of a 150 seat aircraft which has a cruise speed of Mach 0.8, powered by a turboprop attached to an engine of 15,000 shp. Aeroelasticity analyses ae necessary in order to characterize the behavior of thin profile propfan blades, particularly to predict the oscillations through the entire functional range. High-power reducers must be developed, and the level of cabin noise must be controlled to less than 90 dB. Commercial applications are predicted for turboprops in specific instances.

  13. Non-intrusive aerodynamic loads analysis of an aircraft propeller blade

    Energy Technology Data Exchange (ETDEWEB)

    Ragni, D.; Oudheusden, B.W. van; Scarano, F. [Delft University of Technology, Faculty of Aerospace Engineering, Delft (Netherlands)

    2011-08-15

    The flow field in a cross-sectional plane of a scaled Beaver DHC aircraft propeller has been measured by means of a stereoscopic PIV setup. Phase-locked measurements are obtained in a rotational frequency range from 18,900 to 21,000 rpm, at a relative Mach number of 0.6 at 3/4 propeller radius. The use of an adapted formulation of the momentum equation in differential form for rotating frame of references, integrated with isentropic relations as boundary conditions, allowed to compute the pressure field around the blade and the surface pressure distribution directly from the velocity data in the compressible regime. The procedure, extended to the computation of the aerodynamic lift and drag coefficients by a momentum contour integral approach, proved to be able to couple the aerodynamical loads to the flow field on the moving propeller blade, comparing favorably with a numerical simulation of the entire scaled model. Results are presented for two propeller rotation speeds and three different yawing angles. (orig.)

  14. Non-intrusive aerodynamic loads analysis of an aircraft propeller blade

    Science.gov (United States)

    Ragni, D.; van Oudheusden, B. W.; Scarano, F.

    2011-08-01

    The flow field in a cross-sectional plane of a scaled Beaver DHC aircraft propeller has been measured by means of a stereoscopic PIV setup. Phase-locked measurements are obtained in a rotational frequency range from 18,900 to 21,000 rpm, at a relative Mach number of 0.6 at ¾ propeller radius. The use of an adapted formulation of the momentum equation in differential form for rotating frame of references, integrated with isentropic relations as boundary conditions, allowed to compute the pressure field around the blade and the surface pressure distribution directly from the velocity data in the compressible regime. The procedure, extended to the computation of the aerodynamic lift and drag coefficients by a momentum contour integral approach, proved to be able to couple the aerodynamical loads to the flow field on the moving propeller blade, comparing favorably with a numerical simulation of the entire scaled model. Results are presented for two propeller rotation speeds and three different yawing angles.

  15. Cancer Nano medicine

    International Nuclear Information System (INIS)

    Li, H.; Pike, M.M.; Luo, X.; Liu, L.H.

    2013-01-01

    Bioengineered nano materials have inspired revolutionary imaging and drug delivery methods whose clinical application in cancer research has resulted in powerful medical devices for early diagnosis, treatment, and prevention of cancer. Recent advances in super imaging agents have resulted in improved resolution and sensitivity. For instance, fluorescent quantum dots with wavelength-tunable emissions, plasmon-resonant gold nano structures with shape-controlled near-infrared absorptions, and MRI-active iron oxide nanoparticles are well-established molecular imaging probes for noninvasive cancer imaging. Nano materials are also considered to be the most effective vectors that can break through transport bio barriers and deliver a constant dose of multiple therapeutic agents to tumors and intracellular endocytic compartments for cancer gene therapy, immunotherapy, or chemotherapy. Furthermore, nano wire- or nano tube-based electronic devices demonstrate extraordinary sensitivity capable of detection at the single molecule or protein level. It is anticipated that developing nano technology-driven imaging, sensing, and therapeutic systems will dramatically advance cancer research and clinical treatments.

  16. Proof-of-concept automation of propellant processing

    Science.gov (United States)

    Ramohalli, Kumar; Schallhorn, P. A.

    1989-01-01

    For space-based propellant production, automation of the process is needed. Currently, all phases of terrestrial production have some form of human interaction. A mixer was acquired to help perform the tasks of automation. A heating system to be used with the mixer was designed, built, and installed. Tests performed on the heating system verify design criteria. An IBM PS/2 personal computer was acquired for the future automation work. It is hoped that some the mixing process itself will be automated. This is a concept demonstration task; proving that propellant production can be automated reliably.

  17. The nanorod approach: GaN NanoLEDs for solid state lighting

    Energy Technology Data Exchange (ETDEWEB)

    Waag, Andreas; Wang, Xue; Fuendling, Soenke; Ledig, Johannes; Erenburg, Milena; Neumann, Richard; Al Suleiman, Mohamed; Merzsch, Stephan; Wei, Jiandong; Li, Shunfeng; Wehmann, Hergo H. [Institut fuer Halbleitertechnik, TU Braunschweig, Hans-Sommer-Strasse 66, 38106 Braunschweig (Germany); Bergbauer, Werner; Strassburg, Martin [OSRAM Opto Semiconductors GmbH, Leibnizstr. 4, 93055 Regensburg (Germany); Trampert, Achim; Jahn, Uwe; Riechert, Henning [Paul-Drude-Institut fuer Festkoerperelektronik, Hausvogteiplatz 5-7, 10117 Berlin (Germany)

    2011-07-15

    Vertically aligned GaN nanorods have recently obtained substantial interest as a new approach to solid state lighting. In comparison to conventional planar LEDs, 3D NanoLEDs are expected to offer substantial advantageous: very low defect density, quasi free-standing, no strain due to mismatch of thermal expansion coefficients, no substrate bending even when grown on large area silicon. Core-shell strategies are another very interesting aspect. The active LED surface per wafer could be increased by more than one order of magnitude. However, most of these advantages have not yet been proven in real devices, which would include a quantitative comparison of light emission. Related to the 3D character, there are also technological risks. In the following we will discuss the main developments which have paved the way up to this point, including a detailed discussion of possible benefits and risks connected with the NanoLED approach (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. Preparation, Characterization, and Modeling of Carbon Nano fiber/Epoxy Nano composites

    International Nuclear Information System (INIS)

    Sun, L.H.; Yang, Z.G.; Ounaies, Z.; Whalen, C.A.; Gao, X.L.

    2011-01-01

    There is a lack of systematic investigations on both mechanical and electrical properties of carbon nano fiber (CNF)-reinforced epoxy matrix nano composites. In this paper, an in-depth study of both static and dynamic mechanical behaviors and electrical properties of CNF/epoxy nano composites with various contents of CNFs is provided. A modified Halpin-Tsai equation is used to evaluate the Young's modulus and storage modulus of the nano composites. The values of Young's modulus predicted using this method account for the effect of the CNF agglomeration and fit well with those obtained experimentally. The results show that the highest tensile strength is found in the epoxy nano composite with a 1.0 wt % CNFs. The alternate-current (AC) electrical properties of the CNF/epoxy nano composites exhibit a typical insulator-conductor transition. The conductivity increases by four orders of magnitude with the addition of 0.1 wt % (0.058 vol %) CNFs and by ten orders of magnitude for nano composites with CNF volume fractions higher than 1.0 wt % (0.578 vol %). The percolation threshold (i.e., the critical CNF volume fraction) is found to be at 0.057 vol %.

  19. Characteristic Evaluation of a Shrouded Propeller Mechanism for a Magnetic Actuated Microrobot

    Directory of Open Access Journals (Sweden)

    Qiang Fu

    2015-09-01

    Full Text Available Medical microrobots have been widely used in clinical applications, particularly the spiral type locomotion mechanism, which was recently considered one of the main self-propelling mechanisms for the next medical microrobot to perform tasks such as capsule endoscopy and drug delivery. However, limits in clinical applications still exist. The spiral action of the microrobot while being used for diagnosis may lead to pain or even damage to the intestinal wall due to the exposed mechanisms. Therefore, a new locomotive mechanism, named the shrouded propeller mechanism, was proposed to achieve a high level of medical safety as well as effective propulsive performance in our study. The shrouded propeller mechanism consists of a bare spiral propeller and a non-rotating nozzle. To obtain a high effective propulsive performance, two types of screw grooves with different shapes including the cylindrical screw groove and the rectangular screw groove with different parameters were analyzed using the shrouded model. Two types of magnetic actuated microrobots with different driving modes, the electromagnetic (three-pole rotor actuated microrobot and the permanent magnet (O-ring type magnet actuated microrobot were designed to evaluate the performance of the electromagnetic actuation system. Based on experimental results, the propulsive force of the proposed magnetic actuated microrobot with a shrouded propeller was larger than the magnetic actuated microrobot with a bare spiral propeller under the same parameters. Additionally, the shrouded propeller mechanism as an actuator can be used for other medical microrobots for flexible locomotion.

  20. Hydro-Elastic Tailoring and Optimization of a Composite Marine Propeller

    DEFF Research Database (Denmark)

    Blasques, José Pedro Albergaria Amaral; Berggreen, Christian; Andersen, Poul

    2008-01-01

    The following paper deals with the design and optimization of a flexible composite marine propeller. The blade shape is obtained from an existing high skew metal propeller. The aim is to tailor the laminate to control the elastic couplings and therefore the deformed shape of the blade. The develo...

  1. Alternate Propellant Thermal Rocket, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The Alternate Propellant Thermal Rocket (APTR) is a novel concept for propulsion of space exploration or orbit transfer vehicles. APTR propulsion is provided by...

  2. CFD Analysis of Scale Effects on Conventional and Tip-Modified Propellers

    DEFF Research Database (Denmark)

    Shin, Keun Woo; Andersen, Poul

    2017-01-01

    Full-scale propeller performance is traditionally predictedby scaling model-scale test results, but the traditionalscaling methods do not take into account hydrodynamicdistinctions of tip-modified propellers in full-scaleperformance. An open-water CFD analysis is made onscale effects of tip...... the transition model shows that laminar and transitionalflow modeling is crucial in model-scale computations.Grid-independent solutions at model and full scale areachieved by grid verification studies. The CFD analysis of scale effects shows that theefficiency gain of the tip-modified propeller is increasedat...

  3. Design and numerical investigation of swirl recovery vanes for the Fokker 29 propeller

    Directory of Open Access Journals (Sweden)

    Wang Yangang

    2014-10-01

    Full Text Available Swirl recovery vanes (SRVs are a set of stationary vanes located downstream from a propeller, which may recover some of the residual swirl from the propeller, hoping for an improvement in both thrust and efficiency. The SRV concept design for a scaled version representing the Fokker 29 propeller is performed in this paper, which may give rise to a promotion in propulsive performance of this traditional propeller. Firstly the numerical strategy is validated from two aspects of global quantities and the local flow field of the propeller compared with experimental data, and then the exit flow together with the development of propeller wake is analyzed in detail. Three kinds of SRV are designed with multiple circular airfoils. The numerical results show that the swirl behind the propeller is recovered significantly with Model V3, which is characterized by the highest solidity along spanwise, for various working conditions, and the combination of rotor and vane produced 5.76% extra thrust at the design point. However, a lower efficiency is observed asking for a better vane design and the choice of a working point. The vane position is studied which shows that there is an optimum range for higher thrust and efficiency.

  4. Comparison of Different Numerical Methods for Quality Factor Calculation of Nano and Micro Photonic Cavities

    DEFF Research Database (Denmark)

    Taghizadeh, Alireza; Mørk, Jesper; Chung, Il-Sug

    2014-01-01

    Four different numerical methods for calculating the quality factor and resonance wavelength of a nano or micro photonic cavity are compared. Good agreement was found for a wide range of quality factors. Advantages and limitations of the different methods are discussed.......Four different numerical methods for calculating the quality factor and resonance wavelength of a nano or micro photonic cavity are compared. Good agreement was found for a wide range of quality factors. Advantages and limitations of the different methods are discussed....

  5. NanoAODs

    CERN Document Server

    Husova, Lucia Anna

    2017-01-01

    The scientist on LHC experiment analyse a huge amount of data every day on the Grid. Thus new methods are requested, how to make the analysis more efficient. The NanoAOD is a derived dataset from AOD, where only information necessary for the analysis is stored. Thus the analysis can be more than two times faster, because of the smaller file size, which can be read faster on the Grid. The main goal of this summer student project was to help other users to start using NanoAODs by rewriting their user tasks. Two example users tasks were converted to NanoAODs and tested with the local train test. A speed up of 3.5 was reached. The results of the analysis tasks are identical independent if they use AODs or NanoAODs.

  6. Burning characteristics of ammonium nitrate-based composite propellants supplemented with ammonium dichromate

    Energy Technology Data Exchange (ETDEWEB)

    Kohga, Makoto; Nishino, Saeko [Department of Applied Chemistry, National Defense Academy, Yokosuka, Kanagawa 239-8686 (Japan)

    2009-08-15

    Ammonium nitrate (AN)-based composite propellants have attracted much attention, primarily because of the clean burning nature of AN as an oxidizer. However, such propellants have some disadvantages such as poor ignition and low burning rate. Ammonium dichromate (ADC) is used as a burning catalyst for AN-based propellants; however, the effect of ADC on the burning characteristics has yet to be sufficiently delineated. The burning characteristics of AN/ADC propellants prepared with various contents of AN and ADC have been investigated in this study. The theoretical performance of an AN-based propellant is improved by the addition of ADC. The increase in the burning rate is enhanced and the pressure deflagration limit (PDL) becomes lower with increasing amount of ADC added. The increasing ratio of the burning rate with respect to the amount of ADC is independent of the AN content and the combustion pressure. The optimal amount of ADC for improving the burning characteristics has been determined. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  7. Study on Combustion Characteristics and Propelling Projectile Motion Process of Bulk-Loaded Liquid Propellant

    Science.gov (United States)

    Xue, Xiaochun; Yu, Yonggang; Mang, Shanshan

    2017-07-01

    Data are presented showing that the problem of gas-liquid interaction instability is an important subject in the combustion and the propellant projectile motion process of a bulk-loaded liquid propellant gun (BLPG). The instabilities themselves arise from the sources, including fluid motion, to form a combustion gas cavity called Taylor cavity, fluid turbulence and breakup caused by liquid motion relative to the combustion chamber walls, and liquid surface breakup arising from a velocity mismatch on the gas-liquid interface. Typically, small disturbances that arise early in the BLPG combustion interior ballistic cycle can become amplified in the absence of burn rate limiting characteristics. Herein, significant attention has been given to developing and emphasizing the need for better combustion repeatability in the BLPG. Based on this goal, the concept of using different geometries of the combustion chamber is introduced and the concept of using a stepped-wall structure on the combustion chamber itself as a useful means of exerting boundary control on the combustion evolution to thus restrain the combustion instability has been verified experimentally in this work. Moreover, based on this background, the numerical simulation is devoted to a special combustion issue under transient high-pressure and high-temperature conditions, namely, studying the combustion mechanism in a stepped-wall combustion chamber with full monopropellant on one end that is stationary and the other end can move at high speed. The numerical results also show that the burning surface of the liquid propellant can be defined geometrically and combustion is well behaved as ignition and combustion progressivity are in a suitable range during each stage in this combustion chamber with a stepped-wall structure.

  8. Different Structures of PVA Nano fibrous Membrane for Sound Absorption Application

    International Nuclear Information System (INIS)

    Mohrova, J.; Kalinova, K.

    2012-01-01

    The thin nano fibrous layer has different properties in the field of sound absorption in comparison with porous fibrous material which works on a principle of friction of air particles in contact with walls of pores. In case of the thin nano fibrous layer, which represents a sound absorber here, the energy of sonic waves is absorbed by the principle of membrane resonance. The structure of the membrane can play an important role in the process of converting the sonic energy to a different energy type. The vibration system acts differently depending on the presence of smooth fibers in the structure, amount of partly merged fibers, or structure of polymer foil as extreme. Polyvinyl alcohol (PVA) was used as a polymer because of its good water solubility. It is possible to influence the structure of nano fibrous layer during the production process thanks to this property of polyvinyl alcohol.

  9. A Design Tool for Matching UAV Propeller and Power Plant Performance

    Science.gov (United States)

    Mangio, Arion L.

    A large body of knowledge is available for matching propellers to engines for large propeller driven aircraft. Small UAV's and model airplanes operate at much lower Reynolds numbers and use fixed pitch propellers so the information for large aircraft is not directly applicable. A design tool is needed that takes into account Reynolds number effects, allows for gear reduction, and the selection of a propeller optimized for the airframe. The tool developed in this thesis does this using propeller performance data generated from vortex theory or wind tunnel experiments and combines that data with an engine power curve. The thrust, steady state power, RPM, and tip Mach number vs. velocity curves are generated. The Reynolds number vs. non dimensional radial station at an operating point is also found. The tool is then used to design a geared power plant for the SAE Aero Design competition. To measure the power plant performance, a purpose built engine test stand was built. The characteristics of the engine test stand are also presented. The engine test stand was then used to characterize the geared power plant. The power plant uses a 26x16 propeller, 100/13 gear ratio, and an LRP 0.30 cubic inch engine turning at 28,000 RPM and producing 2.2 HP. Lastly, the measured power plant performance is presented. An important result is that 17 lbf of static thrust is produced.

  10. Launch Vehicle Performance for Bipropellant Propulsion Using Atomic Propellants With Oxygen

    Science.gov (United States)

    Palaszewski, Bryan

    2000-01-01

    Atomic propellants for bipropellant launch vehicles using atomic boron, carbon, and hydrogen were analyzed. The gross liftoff weights (GLOW) and dry masses of the vehicles were estimated, and the 'best' design points for atomic propellants were identified. Engine performance was estimated for a wide range of oxidizer to fuel (O/F) ratios, atom loadings in the solid hydrogen particles, and amounts of helium carrier fluid. Rocket vehicle GLOW was minimized by operating at an O/F ratio of 1.0 to 3.0 for the atomic boron and carbon cases. For the atomic hydrogen cases, a minimum GLOW occurred when using the fuel as a monopropellant (O/F = 0.0). The atomic vehicle dry masses are also presented, and these data exhibit minimum values at the same or similar O/F ratios as those for the vehicle GLOW. A technology assessment of atomic propellants has shown that atomic boron and carbon rocket analyses are considered to be much more near term options than the atomic hydrogen rockets. The technology for storing atomic boron and carbon has shown significant progress, while atomic hydrogen is not able to be stored at the high densities needed for effective propulsion. The GLOW and dry mass data can be used to estimate the cost of future vehicles and their atomic propellant production facilities. The lower the propellant's mass, the lower the overall investment for the specially manufactured atomic propellants.

  11. Plasma ignition of LOVA propellants

    NARCIS (Netherlands)

    Driel, C.A. van; Boluijt, A.G.; Schilt, A.

    2010-01-01

    Ignition experiments were performed using a gun simulator which is equipped with a burst disk. This equipment facilitates the application of propellant loading densities which are comparable to those applied in regular ammunitions. For this study the gun simulator was equipped with a plasma jet

  12. Rocket Solid Propellant Alternative Based on Ammonium Dinitramide

    Directory of Open Access Journals (Sweden)

    Grigore CICAN

    2017-03-01

    Full Text Available Due to the continuous run for a green environment the current article proposes a new type of solid propellant based on the fairly new synthesized oxidizer, ammonium dinitramide (ADN. Apart of having a higher specific impulse than the worldwide renowned oxidizer, ammonium perchlorate, ADN has the advantage, of leaving behind only nitrogen, oxygen and water after decomposing at high temperatures and therefore totally avoiding the formation of hydrogen chloride fumes. Based on the oxidizer to fuel ratios of the current formulations of the major rocket solid booster (e.g. Space Shuttle’s SRB, Ariane 5’s SRB which comprises mass variations of ammonium perchlorate oxidizer (70-75%, atomized aluminum powder (10-18% and polybutadiene binder (12-20% a new solid propellant was formulated. As previously stated, the new propellant formula and its variations use ADN as oxidizer and erythritol tetranitrate as fuel, keeping the same polybutadiene as binder.

  13. Bifurcations of propellant burning rate at oscillatory pressure

    Energy Technology Data Exchange (ETDEWEB)

    Novozhilov, Boris V. [N. N. Semenov Institute of Chemical Physics, Russian Academy of Science, 4 Kosygina St., Moscow 119991 (Russian Federation)

    2006-06-15

    A new phenomenon, the disparity between pressure and propellant burning rate frequencies, has revealed in numerical studies of propellant burning rate response to oscillatory pressure. As is clear from the linear approximation, under small pressure amplitudes, h, pressure and propellant burning rate oscillations occur with equal period T (T-solution). In the paper, however, it is shown that at a certain critical value of the parameter h the system in hand undergoes a bifurcation so that the T-solution converts to oscillations with period 2T (2T-solution). When the bifurcation parameter h increases, the subsequent behavior of the system becomes complicated. It is obtained a sequence of period doubling to 4T-solution and 8T-solution. Beyond a certain value of the bifurcation parameter h an apparently fully chaotic solution is found. These effects undoubtedly should be taken into account in studies of oscillatory processes in combustion chambers. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  14. Potential low cost, safe, high efficiency propellant for future space program

    Science.gov (United States)

    Zhou, D.

    2005-03-01

    Mixtures of nanometer or micrometer sized carbon powder suspended in hydrogen and methane/hydrogen mixtures are proposed as candidates for low cost, high efficiency propellants for future space programs. While liquid hydrogen has low weight and high heat of combustion per unit mass, because of the low mass density the heat of combustion per unit volume is low, and the liquid hydrogen storage container must be large. The proposed propellants can produce higher gross heat combustion with small volume with trade off of some weight increase. Liquid hydrogen can serve as the fluid component of the propellant in the mixtures and thus used by current rocket engine designs. For example, for the same volume a mixture of 5% methane and 95% hydrogen, can lead to an increase in the gross heat of combustion by about 10% and an increase in the Isp (specific impulse) by 21% compared to a pure liquid hydrogen propellant. At liquid hydrogen temperatures of 20.3 K, methane will be in solid state, and must be formed as fine granules (or slush) to satisfy the requirement of liquid propellant engines.

  15. Rheokinetic Analysis of Hydroxy Terminated Polybutadiene Based Solid Propellant Slurry

    Directory of Open Access Journals (Sweden)

    Abhay K Mahanta

    2010-01-01

    Full Text Available The cure kinetics of propellant slurry based on hydroxy-terminated polybutadiene (HTPB and toluene diisocyanate (TDI polyurethane reaction has been studied by viscosity build up method. The viscosity (ɳ–time (t plots conform to the exponential function ɳ = aebt, where a & b are empirical constants. The rate constants (k for viscosity build up at various shear rate (rpm, evaluated from the slope of dɳ/dt versus ɳ plots at different temperatures, were found to vary from 0.0032 to 0.0052 min-1. It was observed that the increasing shear rate did not have significant effect on the reaction rate constants for viscosity build up of the propellant slurry. The activation energy (Eɳ, calculated from the Arrhenius plots, was found to be 13.17±1.78 kJ mole-1, whereas the activation enthalpy (∆Hɳ* and entropy (∆Sɳ* of the propellant slurry, calculated from Eyring relationship, were found to be 10.48±1.78 kJ mole-1 and –258.51± 5.38 J mole-1K-1, respectively. The reaction quenching temperature of the propellant slurry was found to be -9 ° C, based upon the experimental data. This opens up an avenue for a “freeze-and-store”, then “warm-up and cast”, mode of manufacturing of very large solid rocket propellant grains.

  16. Wind tunnel tests of stratospheric airship counter rotating propellers

    Directory of Open Access Journals (Sweden)

    Yaxi Chen

    2015-01-01

    Full Text Available Aerodynamic performance of the high-altitude propeller, especially the counter rotation effects, is experimentally studied. Influences of different configurations on a stratospheric airship, included 2-blade counter-rotating propeller (CRP, dual 2-blade single rotation propellers (SRPs and 4-blade SRP, are also indicated. This research indicates that the effect of counter rotation can greatly improve the efficiency. It shows that the CRP configuration results in a higher efficiency than the dual 2-blade SRPs configuration or 4-blade SRP configuration under the same advance ratio, and the CRP configuration also gains the highest efficiency whether under the situation of providing the same trust or absorbing the same power. It concludes that, for a stratospheric airship, the CRP configuration is better than the multiple SRPs configuration or a multi-blade SRP one.

  17. Hydrothermal preparation and physicochemical studies of new copper nano-complexes for antitumor application

    Science.gov (United States)

    Saif, M.; El-Shafiy, Hoda F.; Mashaly, Mahmoud M.; Eid, Mohamed F.; Nabeel, A. I.; Fouad, R.

    2018-03-01

    Two novel nano-complexes [(Cu)2(L) (NO3)2(OH2)] (CuH) and [Cu(HL) (OH2)2(NO3)] (CuCTH)were synthesized by hydrothermal method at 200 °C for 48 h in absence and presence of surfactant (CTAB), respectively. Introducing surfactant (CTAB) leads to changing stoichiometric metal/ligand ratio from binuclear (CuH) to mononuclear (CuCTH) nano-complexes. CuH shows irregular nano-flake shape while CuCTH have separately uniform nano-spherical morphology. Thermal analysis revealed that CuCTH is thermally stable in comparison with CuH Nano-complex. CuCTH absorption peak shifted to shorter wavelength (blue shift) and sharpness of the peak also decreased in presence of CTAB. The role of CTAB in the crystal growth is discussed. CuH and CuCTH nano-complexes were tested for their in vitro cytotoxicity against Ehrlich Ascites Carcinoma cell line (E.A.C.). Both nano-complexes effectively inhibited E.A.C. growth with IC50value of 37 and 25 μM for CuH and CuCTH, respectively. The high antitumor activity of CuCTH was attributed to several factors such as spherical morphology, smaller size, chemical structure, and geometry. The LD50 for high cytotoxic CuCTH nano-complex on mice was found to be 100 mg/kg with strong abscess in abdomen side effect. To overcome this side effect, different molar ratio of CuCTH and previously prepared ZnNano-complexes were tested for their in vitrocytotoxicity and in vivo toxicity. Obtained results show that the 2:8 M ratio between CuCTH and Zn nano-complexes gives very low toxicity without any side effects. Also, geometric optimization and conformational analysis were performed using semi-empirical PM3 method. Energy gap (ΔE), dipole moment, and structure activity relationship were performed and discussed.

  18. Evaluation of nano-specific toxicity of zinc oxide, copper oxide, and silver nanoparticles through toxic ratio

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Weicheng; Liu, Xiawei; Bao, Shaopan; Xiao, Bangding; Fang, Tao, E-mail: fangt@ihb.ac.cn [Chinese Academy of Sciences, Institute of Hydrobiology (China)

    2016-12-15

    For safety and environmental risk assessments of nanomaterials (NMs) and to provide essential toxicity data, nano-specific toxicities, or excess toxicities, of ZnO, CuO, and Ag nanoparticles (NPs) (20, 20, and 30 nm, respectively) to Escherichia coli and Saccharomyces cerevisiae in short-term (6 h) and long-term (48 h) bioassays were quantified based on a toxic ratio. ZnO NPs exhibited no nano-specific toxicities, reflecting similar toxicities as ZnO bulk particles (BPs) (as well as zinc salt). However, CuO and Ag NPs yielded distinctly nano-specific toxicities when compared with their BPs. According to their nano-specific toxicities, the capability of these NPs in eliciting hazardous effects on humans and the environment was as follows: CuO > Ag > ZnO NPs. Moreover, long-term bioassays were more sensitive to nano-specific toxicity than short-term bioassays. Overall, nano-specific toxicity is a meaningful measurement to evaluate the environmental risk of NPs. The log T{sub e}{sup particle} value is a useful parameter for quantifying NP nano-specific toxicity and enabling comparisons of international toxicological data. Furthermore, this value could be used to determine the environmental risk of NPs.

  19. Solid State MEMS Thrusters Using Electrically Controlled Extinguishable Solid Propellant, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — ET Materials, LLC developed the first ever electrically controlled extinguishable solid propellant (ECESP). The original propellant developed under Air Force SBIR...

  20. Electrochemically synthesized Si nano wire arrays and thermoelectric nano structures

    International Nuclear Information System (INIS)

    Khuan, N.I.; Ying, K.K.; Nur Ubaidah Saidin; Foo, C.T.

    2012-01-01

    Thermoelectric nano structures hold great promise for capturing and directly converting into electricity some vast amount of low-grade waste heats now being lost to the environment (for example from nuclear power plant, fossil fuel burning, automotive and household appliances). In this study, large-area vertically-aligned silicon nano wire (SiNW) arrays were synthesized in an aqueous solution containing AgNO 3 and HF on p-type Si (100) substrate by self-selective electroless etching process. The etching conditions were systematically varied in order to achieve different stages of nano wire formation. Diameters of the SiNWs obtained varied from approximately 50 to 200 nm and their lengths ranged from several to a few tens of μm. Te/ Bi 2 Te 3 -Si thermoelectric core-shell nano structures were subsequently obtained via galvanic displacement of SiNWs in acidic HF electrolytes containing HTeO 2 + and Bi 3+ / HTeO 2 + ions. The reactions were basically a nano-electrochemical process due to the difference in redox potentials between the materials. the surface-modified SiNWs of core-shell structures had roughened surface morphologies and therefore, higher surface-t-bulk ratios compared to unmodified SiNWs. They have potential applications in sensors, photovoltaic and thermoelectric nano devices. Growth study on the SiNWs and core-shell nano structures produced is presented using various microscopy, diffraction and probe-based techniques for microstructural, morphological and chemical characterizations. (Author)

  1. Synthesis of Calcite Nano Particles from Natural Limestone assisted with Ultrasonic Technique

    Science.gov (United States)

    Handayani, M.; Sulistiyono, E.; Firdiyono, F.; Fajariani, E. N.

    2018-03-01

    This article represents a precipitation method assisted with ultrasonic process to synthesize precipitated calcium carbonate nano particles from natural limestone. The synthesis of nanoparticles material of precipitated calcium carbonate from commercial calcium carbonate was done for comparison. The process was performed using ultrasonic waves at optimum condition, that is, at temperature of 80oC for 10 minutes with various amplitudes. Synthesized precipitated calcium carbonate nanoparticles were characterized using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Particle Size Analyzer (PSA). The result of PSA measurements showed that precipitated calcium carbonate nano particles was obtained with the average size of 109 nm.

  2. Formulation and properties of ADN/GAP propellants

    Energy Technology Data Exchange (ETDEWEB)

    Menke, Klaus; Heintz, Thomas; Schweikert, Wenka; Keicher, Thomas; Krause, Horst [Fraunhofer-Institut fuer Chemische Technologie ICT, Pfinztal (Germany)

    2009-06-15

    In this contribution two ways are described, how it is possible to achieve perfectly cured and processible propellants with prilled ADN, low amounts of HMX 5{mu}m mps and a binder system based on GAP diole and GAP triole oligomers with and without TMETN as a nitrate ester plasticizer. It was shown how it will be possible to suppress the strongly gas forming reaction between ADN and reactive isocyanates by a mixture of stabilizers. In this way it was possible to create minimum smoke ADN/HMX/GAP/TMETN propellants cured with the triisocyanate N100. In the second part an unconventional binder system based on the 1.3 dipolar cycloaddition reaction of azido groups with acetylene compounds forming 1,2,3-triazole heterocyclic rings has been applied for ADN/GAP and AP/GAP propellants. Together with small parts of HMX formulations with ADN/HMX/GAP and the corresponding AP/HMX/GAP exhibit high thermodynamic performance, are easily processible, and cure successfully at 60 C. Their basic properties consisting of burning behavior and mechanical properties, at ambient temperature, chemical stability, and sensitivity have been investigated and are compared to each other. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  3. In-Space Manufacture of Storable Propellants

    Data.gov (United States)

    National Aeronautics and Space Administration — Many deep-space, missions, especially those that return material or crews to near-Earth space, are severely limited by the need to carry propellants and heat shields...

  4. Combinatorial Nano-Bio Interfaces.

    Science.gov (United States)

    Cai, Pingqiang; Zhang, Xiaoqian; Wang, Ming; Wu, Yun-Long; Chen, Xiaodong

    2018-06-08

    Nano-bio interfaces are emerging from the convergence of engineered nanomaterials and biological entities. Despite rapid growth, clinical translation of biomedical nanomaterials is heavily compromised by the lack of comprehensive understanding of biophysicochemical interactions at nano-bio interfaces. In the past decade, a few investigations have adopted a combinatorial approach toward decoding nano-bio interfaces. Combinatorial nano-bio interfaces comprise the design of nanocombinatorial libraries and high-throughput bioevaluation. In this Perspective, we address challenges in combinatorial nano-bio interfaces and call for multiparametric nanocombinatorics (composition, morphology, mechanics, surface chemistry), multiscale bioevaluation (biomolecules, organelles, cells, tissues/organs), and the recruitment of computational modeling and artificial intelligence. Leveraging combinatorial nano-bio interfaces will shed light on precision nanomedicine and its potential applications.

  5. Nano-scale Materials and Nano-technology Processes in Environmental Protection

    International Nuclear Information System (INIS)

    Vissokov, Gh; Tzvetkoff, T.

    2003-01-01

    A number of environmental and energy technologies have benefited substantially from nano-scale technology: reduced waste and improved energy efficiency; environmentally friendly composite structures; waste remediation; energy conversion. In this report examples of current achievements and paradigm shifts are presented: from discovery to application; a nano structured materials; nanoparticles in the environment (plasma chemical preparation); nano-porous polymers and their applications in water purification; photo catalytic fluid purification; hierarchical self-assembled nano-structures for adsorption of heavy metals, etc. Several themes should be considered priorities in developing nano-scale processes related to environmental management: 1. To develop understanding and control of relevant processes, including protein precipitation and crystallisation, desorption of pollutants, stability of colloidal dispersion, micelle aggregation, microbe mobility, formation and mobility of nanoparticles, and tissue-nanoparticle interaction. Emphasis should be given to processes at phase boundaries (solid-liquid, solid-gas, liquid-gas) that involve mineral and organic soil components, aerosols, biomolecules (cells, microbes), bio tissues, derived components such as bio films and membranes, and anthropogenic additions (e.g. trace and heavy metals); 2. To carry out interdisciplinary research that initiates Noel approaches and adopts new methods for characterising surfaces and modelling complex systems to problems at interfaces and other nano-structures in the natural environment, including those involving biological or living systems. New technological advances such as optical traps, laser tweezers, and synchrotrons are extending examination of molecular and nano-scale processes to the single-molecule or single-cell level; 3. To integrate understanding of the roles of molecular and nano-scale phenomena and behaviour at the meso- and/or macro-scale over a period of time

  6. Experimental set-up and results of the process of co-extruded perforated gun propellants

    NARCIS (Netherlands)

    Zebregs, M.; Driel, C.A. van

    2009-01-01

    Enhancement of gun performance can be obtained by increasing the propellant loading density or the energy content of the propellant. Serious consequences of these options are difficulties with regard to ignition and to gun barrel wear. Application of co-layered propellants is a good alternative,

  7. A Comparative Study of Conventional and Tip-Fin Propeller Performance

    DEFF Research Database (Denmark)

    Andersen, Poul

    1997-01-01

    During more than a decade several attempts have been made to obtain higher propeller efficiencies by radically modifying the geometry in the tip region of the blade. In the tip-fin propeller a tip fin or winglet is attached to the blade tip and integrated into the blade in such a way that the bla...

  8. A stochastic pocket model for aluminum agglomeration in solid propellants

    Energy Technology Data Exchange (ETDEWEB)

    Gallier, Stany [SNPE Materiaux Energetiques, Vert le Petit (France)

    2009-04-15

    A new model is derived to estimate the size and fraction of aluminum agglomerates at the surface of a burning propellant. The basic idea relies on well-known pocket models in which aluminum is supposed to aggregate and melt within pocket volumes imposed by largest oxidizer particles. The proposed model essentially relaxes simple assumptions of previous pocket models on propellant structure by accounting for an actual microstructure obtained by packing. The use of statistical tools from stochastic geometry enables to determine a statistical pocket size volume and hence agglomerate diameter and agglomeration fraction. Application to several AP/Al propellants gives encouraging results that are shown to be superior to former pocket models. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  9. Spot Size Limited Carbon Propellant Characterization for Efficient High Isp Laser Propulsion

    International Nuclear Information System (INIS)

    Uchida, Shigeaki; Shimada, Yoshinori; Hashimoto, Kazuhisa; Yamaura, Michiteru; Birou, Tomoya; Yoshida, Minoru

    2005-01-01

    Laser propulsion has very unique advantage of producing exhausting gas (ions) of very high velocity. Specific impulse from laser plasma could easily exceed 10,000 seconds that reduce the current propellant consumption rate on space born thrusters significantly. For efficient propellant usage, it is desirable that the exhaust plasma has rather narrow velocity distribution of fast ions. In order to accomplish the requirements, thermal conduction and neutral particle losses at and vicinity of the laser heated region have to be eliminated. A concept of spot size limited propellant shape has been proposed and tested in terms of the effects of the loss reduction. Ion and neutral particle measurements from laser plasmas produced on the above mentioned carbon targets are used to characterize the performance of the propellant

  10. ON NANO Λg-CLOSED SETS

    OpenAIRE

    Rajasekaran, Ilangovan; Nethaji, Ochanan

    2017-01-01

    Abstaract−In this paper, we introduce nano ∧g-closed sets in nano topological spaces. Some properties of nano ∧g-closed sets and nano ∧g-open sets are weaker forms of nano closed sets and nano open sets

  11. Transferring metallic nano-island on hydrogen passivated silicon surface for nano-electronics

    International Nuclear Information System (INIS)

    Deng, J; Troadec, C; Joachim, C

    2009-01-01

    In a planar configuration, precise positioning of ultra-flat metallic nano-islands on semiconductor surface opens a way to construct nanostructures for atomic scale interconnects. Regular triangular Au nano-islands have been grown on atomically flat MoS 2 substrates and manipulated by STM to form nanometer gap metal-pads connector for single molecule electronics study. The direct assembly of regular shaped metal nano-islands on H-Si(100) is not achievable. Here we present how to transfer Au triangle nano-islands from MoS 2 onto H-Si(100) in a clean manner. In this experiment, clean MoS 2 substrates are patterned as array of MoS 2 pillars with height of 8 μm. The Au triangle nano-islands are grown on top of the pillars. Successful printing transfer of these Au nano-islands from the MoS 2 pillars to the H-Si(100) is demonstrated.

  12. CFD Fuel Slosh Modeling of Fluid-Structure Interaction in Spacecraft Propellant Tanks with Diaphragms

    Science.gov (United States)

    Sances, Dillon J.; Gangadharan, Sathya N.; Sudermann, James E.; Marsell, Brandon

    2010-01-01

    Liquid sloshing within spacecraft propellant tanks causes rapid energy dissipation at resonant modes, which can result in attitude destabilization of the vehicle. Identifying resonant slosh modes currently requires experimental testing and mechanical pendulum analogs to characterize the slosh dynamics. Computational Fluid Dynamics (CFD) techniques have recently been validated as an effective tool for simulating fuel slosh within free-surface propellant tanks. Propellant tanks often incorporate an internal flexible diaphragm to separate ullage and propellant which increases modeling complexity. A coupled fluid-structure CFD model is required to capture the damping effects of a flexible diaphragm on the propellant. ANSYS multidisciplinary engineering software employs a coupled solver for analyzing two-way Fluid Structure Interaction (FSI) cases such as the diaphragm propellant tank system. Slosh models generated by ANSYS software are validated by experimental lateral slosh test results. Accurate data correlation would produce an innovative technique for modeling fuel slosh within diaphragm tanks and provide an accurate and efficient tool for identifying resonant modes and the slosh dynamic response.

  13. The steady performance prediction of propeller-rudder-bulb system based on potential iterative method

    International Nuclear Information System (INIS)

    Liu, Y B; Su, Y M; Ju, L; Huang, S L

    2012-01-01

    A new numerical method was developed for predicting the steady hydrodynamic performance of propeller-rudder-bulb system. In the calculation, the rudder and bulb was taken into account as a whole, the potential based surface panel method was applied both to propeller and rudder-bulb system. The interaction between propeller and rudder-bulb was taken into account by velocity potential iteration in which the influence of propeller rotation was considered by the average influence coefficient. In the influence coefficient computation, the singular value should be found and deleted. Numerical results showed that the method presented is effective for predicting the steady hydrodynamic performance of propeller-rudder system and propeller-rudder-bulb system. Comparing with the induced velocity iterative method, the method presented can save programming and calculation time. Changing dimensions, the principal parameter—bulb size that affect energy-saving effect was studied, the results show that the bulb on rudder have a optimal size at the design advance coefficient.

  14. Editorial Emerging Multifunctional Nano structures

    International Nuclear Information System (INIS)

    Fan, H.; Lu, Y.; Ramanath, G.; Pomposo, J.A.

    2009-01-01

    The interest in emerging nano structures is growing exponentially since they are promising building blocks for advanced multifunctional nano composites. In recent years, an evolution from the controlled synthesis of individual monodisperse nanoparticles to the tailored preparation of hybrid spherical and also unsymmetrical multiparticle nano structures is clearly observed. As a matter of fact, the field of nano structures built around a nano species such as inside, outside, and next to a nanoparticle is becoming a new evolving area of research and development with potential applications in improved drug delivery systems, innovative magnetic devices, biosensors, and highly efficient catalysts, among several others Emerging nano structures with improved magnetic, conducting and smart characteristics are currently based on the design, synthesis, characterization and modeling of multifunctional nano object-based materials. In fact, core-shell nanoparticles and other related complex nano architectures covering a broad spectrum of materials (from metal and metal oxide to fused carbon, synthetic polymer, and bio polymer structures) to nano structure morphologies (spherical, cylindrical, star-like, etc.) are becoming the main building blocks for next generation of drug delivery systems, advanced sensors and biosensors, or improved nano composites. The five papers presented in this special issue examine the preparation and characterization of emerging multifunctional materials, covering from hybrid asymmetric structures to engineering nano composites.

  15. Synthesis and characterization of nano hydroxyapatite using reverse micro emulsions as nano reactors

    International Nuclear Information System (INIS)

    Amin, S.; Siddique, T.

    2015-01-01

    In the present work reverse micro emulsion has been employed as nano reactors to synthesize nano crystalline Hydroxyapatite (HA). Two precursors; calcium and phosphate with different counter ions of each were used for the synthesis of HA at two different temperatures. To maintain the emulsified nano reactor, cyclohexane, TX-100 and 1-butanol including phosphate precursor was the continuous phase while aqueous Ca precursor solution was taken as the dispersed phase. Nano crystalline particles thus produced were evaluated on the basis of synthesis route, counter ions and temperature. It has been shown that emulsified nano reactors control the morphology, particle size and minimize phase transformation of HA. Characterizations of nano powder of HA are carried out using x-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FTIR), and scanning electron microscopy (SEM). HA crystallite size was found to be in the range of 20-25 nm whereas the morphology of nano particles changed from spheres to rods. (author)

  16. Analysis of Aerodynamic Load of LSU-03 (LAPAN Surveillance UAV-03) Propeller

    Science.gov (United States)

    Rahmadi Nuranto, Awang; Jamaludin Fitroh, Ahmad; Syamsudin, Hendri

    2018-04-01

    The existing propeller of the LSU-03 aircraft is made of wood. To improve structural strength and obtain better mechanical properties, the propeller will be redesigned usingcomposite materials. It is necessary to simulate and analyze the design load. This research paper explainsthe simulation and analysis of aerodynamic load prior to structural design phase of composite propeller. Aerodynamic load calculations are performed using both the Blade Element Theory(BET) and the Computational Fluid Dynamic (CFD)simulation. The result of both methods show a close agreement, the different thrust forces is only 1.2 and 4.1% for two type mesh. Thus the distribution of aerodynamic loads along the surface of the propeller blades of the 3-D CFD simulation results are considered valid and ready to design the composite structure. TheCFD results is directly imported to the structure model using the Direct Import CFD / One-Way Fluid Structure Interaction (FSI) method. Design load of propeller is chosen at the flight condition at speed of 20 km/h at 7000 rpm.

  17. On the Stress Analysis of the Kappel Propeller using Finite Elements

    DEFF Research Database (Denmark)

    Atkinson, P.; Andersen, Poul

    2003-01-01

    The Kappel propeller design concept promotes the inclusion of a "forward facing" blade tip winglet with the objective that propeller efficiency may be improved. Design development has enabled a series of finite element investigations in order to establish how the inclusion of an unconventional bl...

  18. Fabrication and characteristics of magnetic field sensors based on nano-polysilicon thin-film transistors

    International Nuclear Information System (INIS)

    Zhao Xiaofeng; Wen Dianzhong; Zhuang Cuicui; Cao Jingya; Wang Zhiqiang

    2013-01-01

    A magnetic field sensor based on nano-polysilicon thin films transistors (TFTs) with Hall probes is proposed. The magnetic field sensors are fabricated on 〈100〉 orientation high resistivity (ρ > 500 Ω·cm) silicon substrates by using CMOS technology, which adopt nano-polysilicon thin films with thicknesses of 90 nm and heterojunction interfaces between the nano-polysilicon thin films and the high resistivity silicon substrates as the sensing layers. The experimental results show that when V DS = 5.0 V, the magnetic sensitivities of magnetic field sensors based on nano-polysilicon TFTs with length—width ratios of 160 μm/80 μm, 320 μm/80 μm and 480 μm/80 μm are 78 mV/T, 55 mV/T and 34 mV/T, respectively. Under the same conditions, the magnetic sensitivity of the obtained magnetic field sensor is significantly improved in comparison with a Hall magnetic field sensor adopting silicon as the sensing layers. (semiconductor technology)

  19. Nano devices and sensors

    CERN Document Server

    Liaw, Shien-Kuei; Chung, Yung-Hui

    2016-01-01

    This volume on semiconductor devices focuses on such topics as nano-imprinting, lithography, nanowire charge-trapping, thermo-stability in nanowires, nano-electrodes, and voltage and materials used for fabricating and improving electrical characteristics of nano-materials.

  20. Application of emission CT on nano-robot radiation imaging tracing and isotope sign in nano-robot

    International Nuclear Information System (INIS)

    Wang Xuewu; Cheng Jianping; Kang Kejun

    2000-01-01

    Nano-technology has been a scientific and technical frontier with major trends foreseen in several disciplines. Nano-robot is the most remarkable imagination of the application of nano-technology. And it should be concerned of tracing technology along with nano-robot. The character of nano-robot is deeply analyzed, the development status of emission CT is integrated, and the application of emission CT on nano-robot radiation imaging tracing is discussed. The isotope sign of nano-robot is especially calculated and analyzed

  1. Fabrication of high-aspect-ratio nano structures using a nano x-ray shadow mask

    International Nuclear Information System (INIS)

    Kim, Yong Chul; Lee, Seung S

    2008-01-01

    This paper describes a novel method for the fabrication of high-aspect-ratio nano structures (HAR-nano structures) using a nano x-ray shadow mask and deep x-ray lithography (DXRL). The nano x-ray shadow mask is fabricated by depositing an x-ray absorber layer (Au, 3 µm) onto the back side of a nano shadow mask. The nano shadow mask is produced with nano-sized apertures whose dimensions are reduced to several tens of nanometers by the accumulation of low-stress silicon nitride (Si x N y ) using the LPCVD process on the shadow mask. A shadow mask containing apertures with a size of 1 µm is fabricated on a bulk micromachined Si x N y membrane. The thickness of an absorber layer must be in the range of several tens of micrometers in order to obtain a contrast of more than 100 for the conventional DXRL process at the Pohang Light Source (PLS). However, a 3 µm thick absorber layer can provide a sufficient contrast if the modified DXRL of the central beam-stop method is used, which blocks high-energy x-rays. A nano shadow mask with 30 nm sized apertures is fabricated and a nano x-ray shadow mask with 250 nm sized apertures is fabricated by depositing a 3 µm thick absorber layer on a nano shadow mask with 500 nm sized apertures. HAR-nano structures (circles with a diameter of 420 nm and lines with a width of 274 nm) with aspect ratios of over 10:1 on a 3.2 µm SU-8 are successfully fabricated by using the nano x-ray shadow mask and the central beam-stop method

  2. Low cost chemical oxygen demand sensor based on electrodeposited nano-copper film

    Directory of Open Access Journals (Sweden)

    Hamdy H. Hassan

    2018-02-01

    Full Text Available A commercially available copper electrical cable and pure Cu disk were used as substrates for the electrodeposition of copper nanoparticles (nano-Cu. The surface morphology of the prepared nano-Cu/Cu electrodes was investigated by scanning electron microscope (SEM and energy dispersive X-ray spectrometer (EDX. The bare copper substrates and the nano-copper modified electrodes were utilized and optimized for electrochemical assay of chemical oxygen demand (COD using glycine as a standard. A comparison was made among the four electrodes (i.e., bare and nano-Cu coated copper cable and pure copper disk as potential COD sensors. The oxidation behavior of glycine was investigated on the surface of the prepared sensors using linear sweep voltammetry (LSV. The results indicate significant enhancement of the electrochemical oxidation of glycine by the deposited nano-Cu. The effects of different deposition parameters, such as Cu2+ concentration, deposition potential, deposition time, pH, and scan rate on the response of the prepared sensors were investigated. Under optimized conditions, the optimal nano-Cu based COD sensor exhibited a linear range of 2–595 mg/L, lower limit of detection (LOD as low as 1.07 mg/L (S/N = 3. The developed method exhibited high tolerance level to Cl− ion where 1.0 M Cl− exhibited minimal influence. The sensor was utilized for the detection of COD in different real water samples. The results obtained were validated using the standard dichromate method.

  3. Neural Network Predictions of the 4-Quadrant Wageningen Propeller Series (CD-ROM)

    National Research Council Canada - National Science Library

    Roddy, Robert F; Hess, David E; Faller, Will

    2006-01-01

    .... This report describes the development of feedforward neural network (FFNN) predictions of four-quadrant thrust and torque behavior for the Wageningen B-Screw Series of propellers and for two Wageningen ducted propeller series...

  4. Nonsteady Combustion Mechanisms of Advanced Solid Propellants

    National Research Council Canada - National Science Library

    Branch, Melvyn

    1997-01-01

    .... The individual tasks which we are studying will pursue solid propellant decomposition under unsteady conditions, nonsteady aspects of gas phase flame structure measurements, numerical modeling...

  5. Rocket propellants with reduced smoke and high burning rates

    Energy Technology Data Exchange (ETDEWEB)

    Menke, K.; Eisele, S. [Fraunhofer-Institut fuer Chemische Technologie (ICT), Pfinztal-Berghausen (Germany)

    1997-07-01

    Rocket propellants with reduced smoke and high burning rates recommend themselves for use in a rocket motor for high accelerating tactical missiles. They serve for an improved camouflage on the battle field and may enable guidance control due to the higher transmission of their rocket plume compared to traditional aluminized composite propellants. In this contribution the material based ranges of performance and properties of three non aluminized rocket propellants will be introduced and compared to each other. The selected formulations based on AP/HTPB; AP/PU/TMETN and AP/HMX/GAP/TMETN have roughly the same specific impulse of I{sub SP}=2430 Ns/kg at 70:1 expansion ratio. The burning rates in the pressure range from 10-18 MPa vary from to 26-33 mm/s for the AP/HTPB propellant, 52-68 mm/s for the formulation based on AP/PU/TMETN and 28-39 mm/s for the propellant based on AP/HMX/GAP. With 58% and 20% AP-contents the propellants with nitrate ester plasticizers create a much smaller secondary signature than the AP/HTPB representative containing 85% AP. Their disadvantage, however, is the connection of high performance to a high level of energetic plasticizer. For this reason, the very fast burning propellant based on AP/PU/TMETN is endowed with a low elastic modulus and is limited to a grain configuration which isn`t exposed too much to the fast and turbulent airstream. The mechanical properties of the AP/HMX/GAP-propellant are as good or better as those of the AP/HTPB propellant. The first one exhibits the same performance and burn rates as the composite representative but produces only one fifth of HCl exhaust. For this reason it is recommended for missile applications, which must have high accelerating power together with a significantly reduced plume signature and smoke production. (orig.) [Deutsch] Rauchreduzierte Festtreibstoffe mit hohen Abbrandgeschwindigkeiten bieten sich fuer den Antrieb hochbeschleunigender taktischer Flugkoerper an, da sie gegenueber

  6. Chirality Relay in 2,2'-Substituted 1,1'-Binaphthyl: Access to Propeller Chirality of the Tricoordinate Boron Center.

    Science.gov (United States)

    Wang, Chen; Sun, Zuo-Bang; Xu, Qing-Wen; Zhao, Cui-Hua

    2016-11-14

    It is a challenging issue to achieve propeller chirality for triarylboranes owing to the low transition barrier between the P and M forms of the boron center. Herein, we report a new strategy to achieve propeller chirality of triarylboranes. It was found that the chirality relay from axially chiral 1,1'-binaphthyl to propeller chirality of the trivalent boron center can be realized when a Me 2 N and a Mes 2 B group (Mes=mesityl) are introduced at the 2,2'-positions of the 1,1'-binaphthyl skeleton (BN-BNaph) owing to the strong π-π interaction between the Me 2 N-bonded naphthyl ring and the phenyl ring of one adjacent Mes group, which not only exerts great steric hindrance on the rotation of the two Mes groups but also gives unequal stability to the two configurations of the boron center for a given configuration of the binaphthyl moiety. The stereostructures of the boron center were fully characterized through 1 H NMR spectroscopy, X-ray crystal analyses, and theoretical calculations. Detailed comparisons with the analog BN-Ph-BNaph, in which the Mes 2 B group is separated from 1,1'-binaphthyl by a para-phenylene spacer, confirmed the essential role of π-π interaction for the successful chirality relay in BN-BNaph. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Nano-metal Oxides: Exposure and Engineering Control Assessment

    OpenAIRE

    Garcia, Alberto; Sparks, Christopher; Martinez, Kenneth; Topmiller, Jennifer L.; Eastlake, Adrienne; Geraci, Charles L.

    2017-01-01

    This paper discusses the evaluation of a facility that produces high quality engineered nanomaterials. These ENMs consist of various metals including iron, nickel, silver, manganese, and palladium. Although occupational exposure levels are not available for these metals, studies have indicated that it may be prudent to keep exposures to the nano-scale metal as low as possible. Previous In vitro studies indicated that in comparison with a material’s larger (parent) counterpart, nanomaterials c...

  8. In-Situ tensile testing of propellants in SEM: influence of temperature

    NARCIS (Netherlands)

    Di Benedetto, G.L.; Ramshorst, M.C.J.; Duvalois, W.; Hooijmeijer, P.; Heijden, A. van der

    2017-01-01

    A tensile module system placed within a Scanning Electron Microscope (SEM) was utilized to conduct insitu tensile testing of propellant samples. The tensile module system allows for real-time in-situ SEM analysis of the samples to determine the failure mechanism of the propellant material under

  9. Development of a novel hydroxyl ammonium nitrate based liquid propellant for air-independent propulsion

    Science.gov (United States)

    Fontaine, Joseph Henry

    The focus of this dissertation is the development of an Unmanned Undersea Vehicle (UUV) liquid propellant employing Hydroxyl Ammonium Nitrate (HAN) as the oxidizer. Hydroxyl Ammonium Nitrate is a highly acidic aqueous based liquid oxidizer. Therefore, in order to achieve efficient combustion of a propellant using this oxidizer, the fuel must be highly water soluble and compatible with the oxidizer to prevent a premature ignition prior to being heated within the combustion chamber. An extensive search of the fuel to be used with this oxidizer was conducted. Propylene glycol was chosen as the fuel for this propellant, and the propellant given the name RF-402. The propellant development process will first evaluate the propellants thermal stability and kinetic parameters using a Differential Scanning Calorimeter (DSC). The purpose of the thermal stability analysis is to determine the temperature at which the propellant decomposition begins for the future safe handling of the propellant and the optimization of the combustion chamber. Additionally, the thermogram results will provide information regarding any undesirable endotherms prior to the decomposition and whether or not the decomposition process is a multi-step process. The Arrhenius type kinetic parameters will be determined using the ASTM method for thermally unstable materials. The activation energy and pre-exponential factor of the propellant will be determined by evaluating the decomposition peak temperature over a temperature scan rate ranging from 1°C per minute to 10°C per minute. The kinetic parameters of the propellant will be compared to those of 81 wt% HAN to determine if the HAN decomposition is controlling the overall decomposition of the propellant RF-402. The lifetime of individual droplets will be analyzed using both experimental and theoretical techniques. The theoretical technique will involve modeling the lifetime of an individual droplet in a combustion chamber like operating environment

  10. Triphenylamine - a 'new' stabilizer for nitrocellulose based propellants. Pt. 1: chemical stability studies

    Energy Technology Data Exchange (ETDEWEB)

    Wilker, Stephan; Heeb, Gerhard [WIWEB ASt Heimerzheim, Grosses Cent, 53913 Swisttal (Germany); Vogelsanger, Beat [Nitrochemie Wimmis AG, Niesenstr. 44, 3752 Wimmis (Switzerland); Petrzilek, Jan; Skladal, Jan [Explosia a.s. - Research Institute of Industrial Chemistry (VUPCH), 532 17 Pardubice (Czech Republic)

    2007-04-15

    Triphenylamine (TPA) was used for the first time in France in 1937 as a stabilizer for propellants. The stability of those samples was described as 'good'. Around 1950 an American group produced TPA stabilized propellants and investigated the decomposition mechanism. Apart from one single experiment in the 1970s no further attempts were made to take TPA as a stabilizer for propellants. With the background of an increasingly critical discussion about nitrosamines in propellants and their declaration of being carcinogenic, TPA revealed a renaissance since the year 2000. To achieve the goal of nitrosamine free propellants several TPA stabilized propellants were produced. Their processability, stability and ballistic properties were investigated. This publication summarizes the most important results of stability tests on more than 30 different TPA stabilized propellants including the decomposition mechanism, the synthesis of the consecutive products and their stabilizing properties. In addition, the internal compatibility of TPA with the most important propellant ingredients is discussed and its relative decomposition rate is compared with that of other stabilizers. In summary TPA is a suitable stabilizer for propellants. It has nevertheless two disadvantages. It is relatively rapidly consumed in double base formulations (which makes it difficult to pass the criteria of AOP-48, Ed. 2) and the stabilizing activity of the two major consecutive products 4-NO{sub 2}-TPA and especially 4,4{sup '}-di-NO{sub 2}-TPA is low. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  11. Integral performance optimum design for multistage solid propellant rocket motors

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hongtao (Shaanxi Power Machinery Institute (China))

    1989-04-01

    A mathematical model for integral performance optimization of multistage solid propellant rocket motors is presented. A calculation on a three-stage, volume-fixed, solid propellant rocket motor is used as an example. It is shown that the velocity at burnout of intermediate-range or long-range ballistic missile calculated using this model is four percent greater than that using the usual empirical method.

  12. Working-cycle processes in solid-propellant rocket engines (Handbook). Rabochie protsessy v raketnykh dvigateliakh tverdogo topliva /Spravochnik/

    Energy Technology Data Exchange (ETDEWEB)

    Shishkov, A.A.; Panin, S.D.; Rumiantsev, B.V.

    1989-01-01

    Physical and mathematical models of processes taking place in solid-propellant rocket engines and gas generators are presented in a systematic manner. The discussion covers the main types of solid propellants, the general design and principal components of solid-propellant rocket engines, the combustion of a solid-propellant charge, thermodynamic calculation of combustion and outflow processes, and analysis of gasdynamic processes in solid-propellant rocket engines. 40 refs.

  13. Lifetime prediction of EC, DPA, akardite II and MNA stabilized triple base propellants, comparison of heat generation rate and stabilizer consumption

    NARCIS (Netherlands)

    Boers, M.N.; Klerk, W.P.C. de

    2005-01-01

    A lifetime prediction study is carried out on four triple base propellant compositions by artificial ageing. The ageing effects are studied with High Performance Liquid Chromatography (HPLC) and Heat Flow Calorimetry (HFC) in order to find the most effective stabilizer and to evaluate the advantages

  14. Nano-dot and nano-pit fabrication on a GaAs substrate by a pulse applied AFM

    International Nuclear Information System (INIS)

    Kim, H C; Yu, J S; Ryu, S H

    2012-01-01

    The nano-patterning characteristics of GaAs is investigated using a pulse applied atomic force microscope (AFM). Very short range voltage pulses of micro to nano-seconds’ duration are applied to a conductive diamond-coated silicon (Si) tip in contact mode, to regulate the created feature size. The effects of pulse conditions such as pulse voltage, duration, frequency, offset voltage, anodization time, and applied tip pressure on nano-dot generation are characterized, based on the experiments. An interesting phenomenon, nano-pit creation instead of nano-dot creation, is observed when the applied pulse duration is less than 100 μs. Pulse frequency and offset voltage are also involved in nano-pit generation. The electrical spark discharge between the tip and the GaAs's surface is the most probable cause of the nano-pit creation and its generation mechanism is explained by considering the relevant pulse parameters. Nano-pits over 15 nm in depth are acquired on the GaAs substrate by adjusting the pulse conditions. This research facilitates the fabrication of more complex nano-structures on semiconductor materials since nano-dots and nano-pits could be easily made without any additional post-processes. (paper)

  15. Effect of tin oxide nano particles and heat treatment on decay resistance and physical properties of beech wood (Fagus orientalis

    Directory of Open Access Journals (Sweden)

    Maryam Ghorbani

    2014-11-01

    Full Text Available This research was conducted to investigate the effect of Tin oxide nanoparticles and heat treatment on decay resistance and physical properties of beech wood. Biological and physical test samples were prepared according to EN-113 and ASTM-D4446-05 standards respectively. Samples were classified into 4 groups: control, impregnation with Tin oxide nanoparticles, heat treatment and nano-heat treatment. Impregnation with Tin oxide nano at 5000ppm concentration was carried out in the cylinder according to Bethell method. Then, samples were heated at 140, 160 and 185˚C for 2 and 4 hours. According to results, decay resistance improved with increasing time and temperature of heat treatment. Least weight loss showed 46.39% reduction in nano-heat samples treated at 180˚C for 4 hours in comparison with control at highest weight loss. Nano-heat treated samples demonstrated the maximum amount of water absorption without significant difference with control and nanoparticles treated samples. Increase in heat treatment temperature reduced water absorption so that it is revealed 47.8% reduction in heat treated samples at 180°C for 4h after 24h immersion in water. In nano-heat treated samples at 180˚C for 2h was measured least volume swelling. Volume swelling in nano-treated samples decreased 8.7 and 22.76% after 2 and 24 h immersion in comparison with the control samples respectively.

  16. Development of nano SiO2 incorporated nano zinc phosphate coatings on mild steel

    International Nuclear Information System (INIS)

    Tamilselvi, M.; Kamaraj, P.; Arthanareeswari, M.; Devikala, S.; Selvi, J. Arockia

    2015-01-01

    Highlights: • Nano SiO 2 incorporated nano zinc phosphate coating on mild steel was developed. • Coatings showed enhanced corrosion resistance. • The nano SiO 2 is adsorbed on mild steel surface and become nucleation sites. • The nano SiO 2 accelerates the phosphating process. - Abstract: This paper reports the development of nano SiO 2 incorporated nano zinc phosphate coatings on mild steel at low temperature for achieving better corrosion protection. A new formulation of phosphating bath at low temperature with nano SiO 2 was attempted to explore the possibilities of development of nano zinc phosphate coatings on mild steel with improved corrosion resistance. The coatings developed were studied by Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDX), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Electrochemical measurements. Significant variation in the coating weight, morphology and corrosion resistance was observed as nano SiO 2 concentrations varied from 0.5–4 g/L. The results showed that, the nano SiO 2 in the phosphating solution changed the initial potential of the interface between mild steel substrate and phosphating solution and reduce the activation energy of the phosphating process, increase the nucleation sites and yielded zinc phosphate coatings of higher coating weight, greater surface coverage and enhanced corrosion resistance. Better corrosion resistance was observed for coatings derived from phosphating bath containing 1.5 g/L nano SiO 2 . The new formulation reported in the present study was free from Ni or Mn salts and had very low concentration of sodium nitrite (0.4 g/L) as accelerator

  17. To be nano or not to be nano?

    Science.gov (United States)

    Joachim, Christian

    2005-02-01

    Nanomaterials, nanostructures, nanostructured materials, nanoimprint, nanobiotechnology, nanophysics, nanochemistry, radical nanotechnology, nanosciences, nanooptics, nanoelectronics, nanorobotics, nanosoldiers, nanomedecine, nanoeconomy, nanobusiness, nanolawyer, nanoethics to name a few of the nanos. We need a clear definition of all these burgeoning fields for the sake of the grant attribution, for the sake of research program definition, and to avoid everyone being lost in so many nanos.

  18. Atmospheric surveillance self-propelling device

    International Nuclear Information System (INIS)

    Cartoux, Gerard.

    1980-11-01

    The atmospheric surveillance self-propelling device of the Saclay Nuclear Research Center can, by its conception (autonomy, rapid put into service, multiplicity of sampling and measurements), be used for all kind of measuring campains: pollution radioactive or not, routine or accidental situation, technical and logistic support and as a coordination or investigation vehicle [fr

  19. Propelling arboriculture into the future

    Science.gov (United States)

    E. Gregory McPherson

    2011-01-01

    Research is the engine that propels arboriculture and urban forestry into the future. New knowledge, technologies, and tools provide arborists with improved tree care practices that result in healthier urban forests. The ISA Science and Research Committee (SRC) is composed of 13 professionals and researchers who are dedicated to elevating the importance of research...

  20. The nano-materials, at the heart of the nano galaxy; Les nano-materiaux, au coeur de la galaxie nano

    Energy Technology Data Exchange (ETDEWEB)

    Le Marois, G. [Direction Generale de l' Industrie, des Technologies de l' Information et des Postes, 75 - Paris (France); Carlac, D. [Societe Developpement et Conseil, 51 - Reims (France)

    2004-02-01

    The researches on nano-materials are continuously increasing in most of industrialized countries. Between 1998 and 2003, the corresponding investment has been multiplied by six in Europe, eight in Usa and in Japan, to reach 3 milliards of euros in the world. Based on the nano-technologies development, these materials would represent the main part of the market at short and middle dated. Many examples of utilization are presented. (A.L.B.)

  1. Aluminum Templates of Different Sizes with Micro-, Nano- and Micro/Nano-Structures for Cell Culture

    Directory of Open Access Journals (Sweden)

    Ming-Liang Yen

    2017-10-01

    Full Text Available This study investigates the results of cell cultures on aluminum (Al templates with flat-structures, micro-structures, nano-structures and micro/nano-structures. An Al template with flat-structure was obtained by electrolytic polishing; an Al template with micro-structure was obtained by micro-powder blasting; an Al template with nano-structure was obtained by aluminum anodization; and an Al template with micro/nano-structure was obtained by micro-powder blasting and then anodization. Osteoblast-like cells were cultured on aluminum templates with various structures. The microculture tetrazolium test assay was utilized to assess the adhesion, elongation, and proliferation behaviors of cultured osteoblast-like cells on aluminum templates with flat-structures, micro-structures, nano-structures, and micro/nano-structures. The results showed that the surface characterization of micro/nano-structure of aluminum templates had superhydrophilic property, and these also revealed that an aluminum template with micro/nano-structure could provide the most suitable growth situation for cell culture.

  2. JANNAF 28th Propellant Development and Characterization Subcommittee and 17th Safety and Environmental Protection Subcommittee Joint Meeting. Volume 1

    Science.gov (United States)

    Cocchiaro, James E. (Editor); Mulder, Edwin J. (Editor); Gomez-Knight, Sylvia J. (Editor)

    1999-01-01

    This volume contains 37 unclassified/unlimited-distribution technical papers that were presented at the JANNAF 28th Propellant Development & Characterization Subcommittee (PDCS) and 17th Safety & Environmental Protection Subcommittee (S&EPS) Joint Meeting, held 26-30 April 1999 at the Town & Country Hotel and the Naval Submarine Base, San Diego, California. Volume II contains 29 unclassified/limited-distribution papers that were presented at the 28th PDCS and 17th S&EPS Joint Meeting. Volume III contains a classified paper that was presented at the 28th PDCS Meeting on 27 April 1999. Topics covered in PDCS sessions include: solid propellant rheology; solid propellant surveillance and aging; propellant process engineering; new solid propellant ingredients and formulation development; reduced toxicity liquid propellants; characterization of hypergolic propellants; and solid propellant chemical analysis methods. Topics covered in S&EPS sessions include: space launch range safety; liquid propellant hazards; vapor detection methods for toxic propellant vapors and other hazardous gases; toxicity of propellants, ingredients, and propellant combustion products; personal protective equipment for toxic liquid propellants; and demilitarization/treatment of energetic material wastes.

  3. Cavitating Propeller Performance in Inclined Shaft Conditions with OpenFOAM: PPTC 2015 Test Case

    Science.gov (United States)

    Gaggero, Stefano; Villa, Diego

    2018-05-01

    In this paper, we present our analysis of the non-cavitating and cavitating unsteady performances of the Potsdam Propeller Test Case (PPTC) in oblique flow. For our calculations, we used the Reynolds-averaged Navier-Stokes equation (RANSE) solver from the open-source OpenFOAM libraries. We selected the homogeneous mixture approach to solve for multiphase flow with phase change, using the volume of fluid (VoF) approach to solve the multiphase flow and modeling the mass transfer between vapor and water with the Schnerr-Sauer model. Comparing the model results with the experimental measurements collected during the Second Workshop on Cavitation and Propeller Performance - SMP'15 enabled our assessment of the reliability of the open-source calculations. Comparisons with the numerical data collected during the workshop enabled further analysis of the reliability of different flow solvers from which we produced an overview of recommended guidelines (mesh arrangements and solver setups) for accurate numerical prediction even in off-design conditions. Lastly, we propose a number of calculations using the boundary element method developed at the University of Genoa for assessing the reliability of this dated but still widely adopted approach for design and optimization in the preliminary stages of very demanding test cases.

  4. Effects of incorporation of nano-fluorapatite or nano-fluorohydroxyapatite on a resin-modified glass ionomer cement.

    Science.gov (United States)

    Lin, Jun; Zhu, Jiajun; Gu, Xiaoxia; Wen, Wenjian; Li, Qingshan; Fischer-Brandies, Helge; Wang, Huiming; Mehl, Christian

    2011-03-01

    This study aimed to investigate the fluoride release properties and the effect on bond strength of two experimental adhesive cements. Synthesized particles of nano-fluorapatite (nano-FA) or nano-fluorohydroxyapatite (nano-FHA) were incorporated into a resin-modified glass ionomer cement (Fuji Ortho LC) and characterized using X-ray diffraction and scanning electron microscopy. Blocks with six different concentrations of nano-FA or nano-FHA were manufactured and their fluoride release properties evaluated by ultraviolet spectrophotometry. The unaltered glass ionomer cement Fuji Ortho LC (GC, control) and the two experimental cements with the highest fluoride release capacities (nano-FA+Fuji Ortho LC (GFA) and nano-FHA+Fuji Ortho LC (GFHA)) were used to bond composite blocks and orthodontic brackets to human enamel. After 24 h water storage all specimens were debonded, measuring the micro-tensile bond strength (μTBS) and the shear bond strength (SBS), respectively. The optimal concentration of added nano-FA and nano-FHA for maximum fluoride release was 25 wt.%, which nearly tripled fluoride release after 70 days compared with the control group. GC exhibited a significantly higher SBS than GFHA/GFA, with GFHA and GFA not differing significantly (P>0.05). The μTBS of GC and GFA were significantly higher than that of GFHA (P≤0.05). The results seem to indicate that the fluoride release properties of Fuji Ortho LC are improved by incorporating nano-FA or nano-FHA, simultaneously maintaining a clinically sufficient bond strength when nano-FA was added. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  5. Comparison of the tribology performance of nano-diesel soot and graphite particles as lubricant additives

    International Nuclear Information System (INIS)

    Zhang, Zu-chuan; Cai, Zhen-bing; Peng, Jin-fang; Zhu, Min-hao

    2016-01-01

    The tribology behavior of exhaust diesel soot as a lubricant additive was investigated and then compared with that of a selection of commercial nano-graphite particles. Specifically, 0.01 wt% particles were dispersed in PAO4 oil with 1 wt% sorbitan monooleate (Span 80) as a dispersing agent, and wear tests based on the ball against plate mode were conducted at various temperatures. Different analytical techniques (e.g. transmission electron, scanning electron and infrared microscopy; energy dispersive x-ray and Raman spectroscopy; and charge measurement) were employed to characterize the chemistry and morphology of the additives and their tribology performance. The oil containing only 0.01 wt% diesel soot clearly improved wear resistance over 60 °C. In particular, at 100 °C the wear rate decreased by approximately 90% compared to the function of base oil. In the same test conditions, diesel soot exhibited better anti-wear performance than nano-graphite at high temperatures. The potential measure showed that the nano-graphite had positive charge and the diesel soot had negative charge. Electrochemical action may play an important role in the lubricant mechanisms of diesel soot and graphite as oil additives. (paper)

  6. Selective and lithography-independent fabrication of 20 nm nano-gap electrodes and nano-channels for nanoelectrofluidics applications

    International Nuclear Information System (INIS)

    Zhang, J Y; Wang, X F; Wang, X D; Fan, Z C; Li, Y; Ji, An; Yang, F H

    2010-01-01

    A new method has been developed to selectively fabricate nano-gap electrodes and nano-channels by conventional lithography. Based on a sacrificial spacer process, we have successfully obtained sub-100-nm nano-gap electrodes and nano-channels and further reduced the dimensions to 20 nm by shrinking the sacrificial spacer size. Our method shows good selectivity between nano-gap electrodes and nano-channels due to different sacrificial spacer etch conditions. There is no length limit for the nano-gap electrode and the nano-channel. The method reported in this paper also allows for wafer scale fabrication, high throughput, low cost, and good compatibility with modern semiconductor technology.

  7. Nano materials for Energy and Environmental Applications

    International Nuclear Information System (INIS)

    Srinivasan, S.; Kannan, A.M.; Kothurkar, N.; Khalil, Y.; Kuravi, S.

    2015-01-01

    Nano materials enabled technologies have been seamlessly integrated into applications such as aviation and space, chemical industry, optics, solar hydrogen, fuel cell, batteries, sensors, power generation, aeronautic industry, building/construction industry, automotive engineering, consumer electronics, thermoelectric devices, pharmaceuticals, and cosmetic industry. Clean energy and environmental applications often demand the development of novel nano materials that can provide shortest reaction pathways for the enhancement of reaction kinetics. Understanding the physicochemical, structural, microstructural, surface, and interface properties of nano materials is vital for achieving the required efficiency, cycle life, and sustain ability in various technological applications. Nano materials with specific size and shape such as nano tubes, nano fibers/nano wires, nano cones, nano composites, nano rods, nano islands, nanoparticles, nanospheres, and nano shells to provide unique properties can be synthesized by tuning the process conditions.

  8. Model-based Diagnostics for Propellant Loading Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — The loading of spacecraft propellants is a complex, risky operation. Therefore, diagnostic solutions are neces- sary to quickly identify when a fault occurs, so that...

  9. Nano

    DEFF Research Database (Denmark)

    Nørgaard, Bent; Engel, Lars Romann

    2007-01-01

    Gennem de sidste par år har et lille ord med et meget stort potentiale gentagende trængt sig på i den offentlige bevidsthed, det er ordet "nano". Nanovidenskab og nanoteknologi er lige nu to af de "hotteste" forskningsområder og betragtes af mange som porten til en helt ny verden af muligheder....... Muligheder, vi endnu ikke kender konsekvenserne af. Center for Kunst og Videnskabs forestilling NANO giver dig chancen for at blive bekendt med verdens mindste byggesten og idégrundlaget for nanoforskningen. Vi har skabt et rum, som på mange måder minder om et laboratorium. Rummet er forsynet med storskærme......, kolber, væsker og nanopartikler. Her vil du f.eks. opleve, hvordan forskere tilfører guld helt nye egenskaber. Forestillingen veksler mellem kemiske arbejdsdemonstrationer, stemningsskabende musik og livlig debat på storskærme mellem eksperter. NANO opfordrer publikum til at tage stilling til forskningen...

  10. The therapeutic effect of nano-encapsulated and nano-emulsion forms of carvacrol on experimental liver fibrosis.

    Science.gov (United States)

    Hussein, Jihan; El-Banna, Mona; Mahmoud, Khaled F; Morsy, Safaa; Abdel Latif, Yasmin; Medhat, Dalia; Refaat, Eman; Farrag, Abdel Razik; El-Daly, Sherien M

    2017-06-01

    The present study aimed to compare the therapeutic efficiency of nano-encapsulated and nano-emulsion carvacrol administration on liver injury in thioacetamide (TAA) treated rats. To fulfill our target, we used sixty male albino rats classified into six groups as follow: control, nano-encapsulated carvacrol, nano-emulsion carvacrol, thioacetamide, treated nano-encapsulated carvacrol and treated nano-emulsion carvacrol groups. Blood samples were collected from all groups and the separated serum was used for analysis of the following biochemical parameters; aspartate aminotransferase (AST), alanine aminotransferase (ALT), S100 B protein, alpha fetoprotein (AFP) and caspase-3. The levels of malondialdehyde (MDA), reduced glutathione (GSH), nitric oxide (NO), monocyte chemoattractant protein-1(MCP-1) and hydroxyproline content were all evaluated in liver tissue homogenate. Histopathological examinations for liver tissues were also performed. Thioacetamide induced hepatic damage in rats as revealed by the significant increase in the levels of serum ALT, AST and produced oxidative stress as displayed by the significant elevation in the levels of hepatic MDA and NO concomitant with a significant decrease in GSH. In addition, thioacetamide significantly increased serum S100B protein, alpha fetoprotein and caspase-3 along with hepatic MCP-1 and hydroxyproline; these results were confirmed by the histopathological investigation. In contrast, nano-encapsulated and nano-emulsion carvacrol were able to ameliorate these negative changes in the thioacetamide injected rats. However, the effect of the nano-encapsulated form of carvacrol was more prominent than the nano-emulsion form. Nano-encapsulated and nano-emulsion carvacrol can ameliorate thioacetamide induced liver injury. These results could be attributed to the potential anti-inflammatory, antioxidant, and anti-apoptotic activities of carvacrol in addition to the effectiveness of the encapsulation technique that can protect

  11. On the mechanism of energy transfer in the plasma-propellant interaction

    Energy Technology Data Exchange (ETDEWEB)

    Porwitzky, Andrew J.; Keidar, Michael; Boyd, Iain D. [University of Michigan, Department of Aerospace Engineering, Ann Arbor, Michigan 48109-2140 (United States)

    2007-10-15

    A coupled plasma sheath/ablation model is developed for electrothermal chemical gun applications. By combining a commonly employed collisional sheath model with a previous ablation model, the convective heat flux as a function of time to the propellant bed is determined for two potential electrothermal chemical gun propellants, XM39 and JA2. It is found that the convective heat flux varies smoothly from a nearly collisionless to a fully collisional regime over the short duration of the plasma pulse. The possibility of determining an accurate estimate of the amount of heat flux to the propellant bed due to radiation from the bulk plasma presents itself. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  12. A Fabrication Technique for Nano-gap Electrodes by Atomic Force Microscopy Nano lithography

    International Nuclear Information System (INIS)

    Jalal Rouhi; Shahrom Mahmud; Hutagalung, S.D.; Kakooei, S.

    2011-01-01

    A simple technique is introduced for fabrication of nano-gap electrodes by using nano-oxidation atomic force microscopy (AFM) lithography with a Cr/ Pt coated silicon tip. AFM local anodic oxidation was performed on silicon-on-insulator (SOI) surfaces by optimization of desired conditions to control process in contact mode. Silicon electrodes with gaps of sub 31 nm were fabricated by nano-oxidation method. This technique which is simple, controllable, inexpensive and fast is capable of fabricating nano-gap structures. The current-voltage measurements (I-V) of the electrodes demonstrated very good insulating characteristics. The results show that silicon electrodes have a great potential for fabrication of single molecule transistors (SMT), single electron transistors (SET) and the other nano electronic devices. (author)

  13. Investigation of the Aerodynamic Performance of a DG808s UAS in Propeller Slipstream Using Computational Fluid Dynamics

    Science.gov (United States)

    Chandra, Yatish

    Unmanned Aerial Systems (UASs) are relatively affordable and immediately available compared to commercial aircraft. Hence, their aerodynamics and design accuracies are often based on extrapolating from design standards and procedures widely used in the aerospace industry for commercial aircraft with most often, acceptable results. Engineering level software such as Advanced Aircraft Analysis (AAA) use general aviation aircraft data and later extrapolate them onto UASs for aerodynamic and flight dynamics modeling but are limited by their platform repository and relatively high Reynolds number evaluations. UASs however, are aircraft which fly at comparatively low speeds and low Reynolds number with close proximities between the components wherein such standards may not hold good. This thesis focuses on evaluating the accuracy and impact of such industry standards on the aerodynamics and flight dynamics of UASs. A DG808s UAS is chosen for the study which was previously modeled using the AAA software at The University of Kansas by the Flight Systems Team. Using the STAR-CCM+ code, performance data were compared and assessed with AAA. Aerodynamic simulations were carried out for two different configurations viz., aircraft with and without propeller slipstream effects. Data obtained for the non-powered simulations were found to be in good agreement with the AAA model. For the powered flight however, discrepancies between the AAA model and CFD data were observed with large values for the vertical tail side-force coefficient. A comparison with the system identification data from the flight tests was made to confirm and validate this vertical tail behavior with the help of rudder deflection inputs. A relationship between the propeller RPM and the aerodynamic model was established by simulating two different propeller speeds. Based on the STAR-CCM+ data and the resulting comparisons with AAA, updates necessary to the UAS aerodynamic and flight dynamics models currently used

  14. Comparison between nano-diamond and carbon nanotube doping effects on critical current density and flux pinning in MgB2

    International Nuclear Information System (INIS)

    Cheng, C H; Yang, Y; Munroe, P; Zhao, Y

    2007-01-01

    Doping effects of nano-diamond and carbon nanotubes (CNTs) on critical current density of bulk MgB 2 have been studied. CNTs are found prone to be doped into the MgB 2 lattice whereas nano-diamond tends to form second-phase inclusions in the MgB 2 matrix, leading to a more significant improvement of J c (H) by doping by nano-diamond than by CNTs in MgB 2 . TEM reveals tightly packed MgB 2 nanograins (50-100 nm) with a dense distribution of diamond nanoparticles (10-20 nm) inside MgB 2 grains in nano-diamond-doped samples. Such a unique microstructure leads to a flux pinning behaviour different from that in CNTs-doped MgB 2

  15. Self-Propelled Micromotors for Cleaning Polluted Water

    Science.gov (United States)

    2013-01-01

    We describe the use of catalytically self-propelled microjets (dubbed micromotors) for degrading organic pollutants in water via the Fenton oxidation process. The tubular micromotors are composed of rolled-up functional nanomembranes consisting of Fe/Pt bilayers. The micromotors contain double functionality within their architecture, i.e., the inner Pt for the self-propulsion and the outer Fe for the in situ generation of ferrous ions boosting the remediation of contaminated water.The degradation of organic pollutants takes place in the presence of hydrogen peroxide, which acts as a reagent for the Fenton reaction and as main fuel to propel the micromotors. Factors influencing the efficiency of the Fenton oxidation process, including thickness of the Fe layer, pH, and concentration of hydrogen peroxide, are investigated. The ability of these catalytically self-propelled micromotors to improve intermixing in liquids results in the removal of organic pollutants ca. 12 times faster than when the Fenton oxidation process is carried out without catalytically active micromotors. The enhanced reaction–diffusion provided by micromotors has been theoretically modeled. The synergy between the internal and external functionalities of the micromotors, without the need of further functionalization, results into an enhanced degradation of nonbiodegradable and dangerous organic pollutants at small-scale environments and holds considerable promise for the remediation of contaminated water. PMID:24180623

  16. Experiences in supporting the structured collection of cancer nanotechnology data using caNanoLab

    Science.gov (United States)

    Gaheen, Sharon; Lijowski, Michal; Heiskanen, Mervi; Klemm, Juli

    2015-01-01

    Summary The cancer Nanotechnology Laboratory (caNanoLab) data portal is an online nanomaterial database that allows users to submit and retrieve information on well-characterized nanomaterials, including composition, in vitro and in vivo experimental characterizations, experimental protocols, and related publications. Initiated in 2006, caNanoLab serves as an established resource with an infrastructure supporting the structured collection of nanotechnology data to address the needs of the cancer biomedical and nanotechnology communities. The portal contains over 1,000 curated nanomaterial data records that are publicly accessible for review, comparison, and re-use, with the ultimate goal of accelerating the translation of nanotechnology-based cancer therapeutics, diagnostics, and imaging agents to the clinic. In this paper, we will discuss challenges associated with developing a nanomaterial database and recognized needs for nanotechnology data curation and sharing in the biomedical research community. We will also describe the latest version of caNanoLab, caNanoLab 2.0, which includes enhancements and new features to improve usability such as personalized views of data and enhanced search and navigation. PMID:26425409

  17. Ceramic compositions based on nano forsterite/nano magnesium aluminate spinel powders

    International Nuclear Information System (INIS)

    Khattab, R.M.; Wahsh, M.M.S.; Khalil, N.M.

    2015-01-01

    According to the wide applications in the field of chemical and engineering industries, forsterite (Mg_2SiO_4)/spinel (MgAl_2O_4) ceramic compositions were the matter of interest of several research works during the last three decades. This work aims at preparation and characterization of improved ceramic bodies based on forsterite and spinel nano powders through controlling the forsterite and spinel contents in the prepared mixes. These prepared ceramic compositions have been investigated through measuring the densification parameters, cold crushing strength as well as volume resistively. Nano spinel was added from 0 to 30 mass% on expense of nano forsterite matrix and fired at 1550 °C for 2 h. The phase composition of the fired samples was examined using x-ray diffraction (XRD) technique. The microstructure of some selected samples was shown using scanning electron microscope (SEM). A pronounced improvement in the sintering, mechanical properties and volume resistively were achieved with increasing of nano spinel addition up to 15 mass%. This is due to the improvement in the matrix of the prepared forsterite/spinel bodies as a result of well distribution of spinel in the forsterite matrix as depicted by SEM analysis. - Highlights: • Ceramic compositions based on nano forsterite/nano-MgAl_2O_4 spinel were synthesized. • CCS was improved (333.78 MPa) through 15 mass% of nano-MgAl_2O_4 spinel addition. • Volume resistivity was enhanced to 203*10"1"3 Ohm cm with 15 mass% of spinel addition. • Beyond 15 mass% spinel, CCS and volume resistivity were decreased.

  18. Propellant Preparation Laboratory Complex (Area1-21)

    Data.gov (United States)

    Federal Laboratory Consortium — Description: Area 1-21 is an explosion resistant complex of nine cells built into the side of a granite ridge. Three solid propellant cutting cells are housed in the...

  19. Fuels and Space Propellants for Reusable Launch Vehicles: A Small Business Innovation Research Topic and Its Commercial Vision

    Science.gov (United States)

    Palaszewski, Bryan A.

    1997-01-01

    Under its Small Business Innovation Research (SBIR) program (and with NASA Headquarters support), the NASA Lewis Research Center has initiated a topic entitled "Fuels and Space Propellants for Reusable Launch Vehicles." The aim of this project would be to assist in demonstrating and then commercializing new rocket propellants that are safer and more environmentally sound and that make space operations easier. Soon it will be possible to commercialize many new propellants and their related component technologies because of the large investments being made throughout the Government in rocket propellants and the technologies for using them. This article discusses the commercial vision for these fuels and propellants, the potential for these propellants to reduce space access costs, the options for commercial development, and the benefits to nonaerospace industries. This SBIR topic is designed to foster the development of propellants that provide improved safety, less environmental impact, higher density, higher I(sub sp), and simpler vehicle operations. In the development of aeronautics and space technology, there have been limits to vehicle performance imposed by traditionally used propellants and fuels. Increases in performance are possible with either increased propellant specific impulse, increased density, or both. Flight system safety will also be increased by the use of denser, more viscous propellants and fuels.

  20. Designing Small Propellers for Optimum Efficiency and Low Noise Footprint

    Science.gov (United States)

    2015-06-26

    each one. The GUI contains input boxes for all of the necessary data in order to run QMIL, QPROP, NAFNoise, and to produce Visual Basic ( VBA ) code... VBA macros that will automatically place reference planes for each airfoil section and insert the splined airfoils to their respective reference...Figure 24. Solid propeller exa mple. Figure 25. Hub and spoke propeller design. Figure 26. Alumninum hub design. accessed on May 12, 2015. DC, August

  1. Orbital Dynamics of Low-Earth Orbit Laser-Propelled Space Vehicles

    International Nuclear Information System (INIS)

    Yamakawa, Hiroshi; Funaki, Ikkoh; Komurasaki, Kimiya

    2008-01-01

    Trajectories applicable to laser-propelled space vehicles with a laser station in low-Earth orbit are investigated. Laser vehicles are initially located in the vicinity of the Earth-orbiting laser station in low-earth orbit at an altitude of several hundreds kilometers, and are accelerated by laser beaming from the laser station. The laser-propelled vehicles start from low-earth orbit and finally escape from the Earth gravity well, enabling interplanetary trajectories and planetary exploration

  2. 3D pressure imaging of an aircraft propeller blade-tip flow by phase-locked stereoscopic PIV

    Energy Technology Data Exchange (ETDEWEB)

    Ragni, D.; Oudheusden, B.W. van; Scarano, F. [Delft University of Technology, Faculty of Aerospace Engineering, Delft (Netherlands)

    2012-02-15

    The flow field at the tip region of a scaled DHC Beaver aircraft propeller, running at transonic speed, has been investigated by means of a multi-plane stereoscopic particle image velocimetry setup. Velocity fields, phase-locked with the blade rotational motion, are acquired across several planes perpendicular to the blade axis and merged to form a 3D measurement volume. Transonic conditions have been reached at the tip region, with a revolution frequency of 19,800 rpm and a relative free-stream Mach number of 0.73 at the tip. The pressure field and the surface pressure distribution are inferred from the 3D velocity data through integration of the momentum Navier-Stokes equation in differential form, allowing for the simultaneous flow visualization and the aerodynamic loads computation, with respect to a reference frame moving with the blade. The momentum and pressure data are further integrated by means of a contour-approach to yield the aerodynamic sectional force components as well as the blade torsional moment. A steady Reynolds averaged Navier-Stokes numerical simulation of the entire propeller model has been used for comparison to the measurement data. (orig.)

  3. 3D pressure imaging of an aircraft propeller blade-tip flow by phase-locked stereoscopic PIV

    Science.gov (United States)

    Ragni, D.; van Oudheusden, B. W.; Scarano, F.

    2012-02-01

    The flow field at the tip region of a scaled DHC Beaver aircraft propeller, running at transonic speed, has been investigated by means of a multi-plane stereoscopic particle image velocimetry setup. Velocity fields, phase-locked with the blade rotational motion, are acquired across several planes perpendicular to the blade axis and merged to form a 3D measurement volume. Transonic conditions have been reached at the tip region, with a revolution frequency of 19,800 rpm and a relative free-stream Mach number of 0.73 at the tip. The pressure field and the surface pressure distribution are inferred from the 3D velocity data through integration of the momentum Navier-Stokes equation in differential form, allowing for the simultaneous flow visualization and the aerodynamic loads computation, with respect to a reference frame moving with the blade. The momentum and pressure data are further integrated by means of a contour-approach to yield the aerodynamic sectional force components as well as the blade torsional moment. A steady Reynolds averaged Navier-Stokes numerical simulation of the entire propeller model has been used for comparison to the measurement data.

  4. Nonlinear output feedback control of underwater vehicle propellers using feedback form estimated axial flow velocity

    DEFF Research Database (Denmark)

    Fossen, T. I.; Blanke, Mogens

    2000-01-01

    Accurate propeller shaft speed controllers can be designed by using nonlinear control theory and feedback from the axial water velocity in the propeller disc. In this paper, an output feedback controller is derived, reconstructing the axial flow velocity from vehicle speed measurements, using...... a three-state model of propeller shaft speed, forward (surge) speed of the vehicle, and the axial flow velocity. Lyapunov stability theory is used to prove that a nonlinear observer combined with an output feedback integral controller provide exponential stability. The output feedback controller...... compensates for variations in thrust due to time variations in advance speed. This is a major problem when applying conventional vehicle-propeller control systems, The proposed controller is simulated for an underwater vehicle equipped with a single propeller. The simulations demonstrate that the axial water...

  5. CZT nanoRAIDER_VFG Factsheet

    Energy Technology Data Exchange (ETDEWEB)

    James, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Bolotnikov, A. E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Cui, Yonggang [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-01-15

    Brookhaven National Laboratory (BNL) is working with FLIR System Inc., the manufacturer of the nanoRAIDER, to design a handheld device based on a position-sensitive virtual Frisch-grid (VFG) Cadmium-Zinc-Telluride (CdZnTe or CZT) detector array (with 1% or better energy resolution). The new device called nanoRAIDER VFG will be an improvement to the current nanoRAIDER, which is a compact gamma-ray detection instrument manufactured by FLIR Systems Inc. that employs relatively lower-performing CZT hemispheric detectors (i.e., 3%-FWHM CZT detectors). The nanoRAIDER will significantly improve the accuracy while maintaining similar efficiency, as compared to the nanoRAIDER, for in-field analysis of nuclear materials and detection of undeclared activities during inspections conducted by the International Atomic Energy Agency (IAEA). Since the nanoRAIDER is currently used by the IAEA as part of its Complementary Access toolkit, a relatively quick acceptance of the nanoRAIDER VFG for safeguards is anticipated. The nanoRAIDER VFG will help address several items listed in the IAEA’s Long-Term R&D Plan that could enhance the abilities to detect undeclared nuclear material and activities.

  6. Linear stability analysis in a solid-propellant rocket motor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K.M.; Kang, K.T.; Yoon, J.K. [Agency for Defense Development, Taejon (Korea, Republic of)

    1995-10-01

    Combustion instability in solid-propellant rocket motors depends on the balance between acoustic energy gains and losses of the system. The objective of this paper is to demonstrate the capability of the program which predicts the standard longitudinal stability using acoustic modes based on linear stability analysis and T-burner test results of propellants. Commercial ANSYS 5.0A program can be used to calculate the acoustic characteristic of a rocket motor. The linear stability prediction was compared with the static firing test results of rocket motors. (author). 11 refs., 17 figs.

  7. Development of surrogate models for the prediction of the flow around an aircraft propeller

    Science.gov (United States)

    Salpigidou, Christina; Misirlis, Dimitris; Vlahostergios, Zinon; Yakinthos, Kyros

    2018-05-01

    In the present work, the derivation of two surrogate models (SMs) for modelling the flow around a propeller for small aircrafts is presented. Both methodologies use derived functions based on computations with the detailed propeller geometry. The computations were performed using k-ω shear stress transport for modelling turbulence. In the SMs, the modelling of the propeller was performed in a computational domain of disk-like geometry, where source terms were introduced in the momentum equations. In the first SM, the source terms were polynomial functions of swirl and thrust, mainly related to the propeller radius. In the second SM, regression analysis was used to correlate the source terms with the velocity distribution through the propeller. The proposed SMs achieved faster convergence, in relation to the detail model, by providing also results closer to the available operational data. The regression-based model was the most accurate and required less computational time for convergence.

  8. 1D Nano materials 2012

    International Nuclear Information System (INIS)

    Yanqiu Zhu, Y.; Ma, R.; Whitby, R.; Acquah, S.

    2013-01-01

    We witnessed an initial hyped period and enthusiasm on carbon nano tubes in the 1990s later went through a significant expansion into nano tubes of other materials (metal di chalcogenides, boron nitride, etc.) as well as various nano wires and nano rods. While much of the hype might have gone, the research on one-dimensional (1D) nano materials has matured as one of the most active research areas within the nano science and nano technology community, flourishing with ample, exciting, and new research opportunities. Just like any other research frontier, researchers working in the 1D nano materials field are constantly striving to develop new fundamental science as well as potential applications. It remains a common belief that versatility and tunability of 1D nano materials would challenge many new rising tasks coming from our resource and energy demanding modern society. The traditional semiconductor industry has produced so many devices and systems from transistors, sensors, lasers, and LEDs to more sophisticated solar panels, which are now part of our daily lives. By down sizing the core components or parts to 1D form, one might wonder how fundamentally the dimensionality and morphology would impact the device performance, this is, as always, requiring us to fully understand the structure-property relationship in 1D nano materials. It may be equally crucial in connecting discovery-driven fundamental science to market-driven technology industry concerning potentially relevant findings derived from these novel materials. The importance of a platform that allows active researchers in this field to present their new development in a timely and efficient manner is therefore self-evident. Following the success of two early special issues devoted to 1D nano materials, this is the third one in a row organized by the same group of guest editors, attesting that such a platform has been well received by the readers

  9. 6. international conference on Nano-technology in Carbon: from synthesis to applications of nano-structured carbon and related materials

    International Nuclear Information System (INIS)

    2004-01-01

    This is the sixth international conference sponsored this year by the French Carbon Group (GFEC), the European Research Group on Nano-tubes GDRE 'Nano-E', in collaboration with the British Carbon Group and the 'Institut des Materiaux Jean Rouxel' (local organizer). The aim of this conference is to promote carbon science in the nano-scale as, for example, nano-structured carbons, nano-tubes, nano-wires, fullerenes, etc. This conference is designed to introduce those with an interest in materials to current research in nano-technology and to bring together research scientists working in various disciplines in the broad area of nano-structured carbons, nano-tubes and fullerene-related nano-structures. Elemental carbon is the simplest exemplar of this nano-technology based on covalent bonding, however other systems (for example containing hetero-atoms) are becoming important from a research point of view, and provide alternative nano-materials with unique properties opening a broad field of applications. Nano-technology requires an understanding of these materials on a structural and textural point of view and this will be the central theme. This year the conference will feature sessions on: S1. Control and synthesis of nano-materials 1.1 Nano-structured carbons: pyrolysis of polymers, activation, templates,... 1.2 Nano-tubes: Catalytic method, HiPCO, graphite vaporization, electrolysis,... 1.3 Fullerenes S2. Chemistry of carbon nano-materials 2.1 Purification of carbon nano-tubes 2.2 Functionalization - Self-assembling S3. Structural characterization S4. Theory and modelling S5. Relationship between structure and properties S6. Applications Water and air purification, Gas and energy storage, Composite materials, Field emission, Nano-electronics, Biotechnology,... S7. Environmental impact. Only one paper concerning carbon under irradiation has been added to the INIS database. (authors)

  10. Propellant Feed System for Swirl-Coaxial Injection

    Science.gov (United States)

    Reynolds, David Christopher (Inventor)

    2015-01-01

    A propellant feed system for swirl-coaxial injection of a liquid propellant includes a reservoir having a bottom plate and at least one tube originating in the bottom plate and extending therefrom. The tube has rectangular slits defined in and distributed tangentially and evenly about a portion of the tube that is disposed in the bottom plate. Drain holes are provided in the bottom plate and tunnels are defined in the bottom plate. Each tunnel fluidly couples one of the drain holes to a corresponding one of the rectangular slits. Each tunnel includes (i) a bend of at least 90.degree., and (ii) a straight portion leading to its corresponding rectangular slit wherein the straight portion is at least five times as long as a hydraulic diameter of the corresponding rectangular slit.

  11. On shear rheology of gel propellants

    Energy Technology Data Exchange (ETDEWEB)

    Rahimi, Shai; Peretz, Arie [RAFAEL, MANOR Propulsion and Explosive Systems Division, Haifa (Israel); Natan, Benveniste [Faculty of Aerospace Engineering, Technion - Israel Institute of Technology, Haifa (Israel)

    2007-04-15

    Selected fuel, oxidizer and simulant gels were prepared and rheologically characterized using a rotational rheometer. For fuel gelation both organic and inorganic gellants were utilized, whereas oxidizers and simulants were gelled with addition of silica and polysaccharides, respectively. The generalized Herschel-Bulkley constitutive model was found to most adequately represent the gels studied. Hydrazine-based fuels, gelled with polysaccharides, were characterized as shear-thinning pseudoplastic fluids with low shear yield stress, whereas inhibited red-fuming nitric acid (IRFNA) and hydrogen peroxide oxidizers, gelled with silica, were characterized as yield thixotropic fluids with significant shear yield stress. Creep tests were conducted on two rheological types of gels with different gellant content and the results were fitted by Burgers-Kelvin viscoelastic constitutive model. The effect of temperature on the rheological properties of gel propellant simulants was also investigated. A general rheological classification of gel propellants and simulants is proposed. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  12. Kinematic matrix theory and universalities in self-propellers and active swimmers.

    Science.gov (United States)

    Nourhani, Amir; Lammert, Paul E; Borhan, Ali; Crespi, Vincent H

    2014-06-01

    We describe an efficient and parsimonious matrix-based theory for studying the ensemble behavior of self-propellers and active swimmers, such as nanomotors or motile bacteria, that are typically studied by differential-equation-based Langevin or Fokker-Planck formalisms. The kinematic effects for elementary processes of motion are incorporated into a matrix, called the "kinematrix," from which we immediately obtain correlators and the mean and variance of angular and position variables (and thus effective diffusivity) by simple matrix algebra. The kinematrix formalism enables us recast the behaviors of a diverse range of self-propellers into a unified form, revealing universalities in their ensemble behavior in terms of new emergent time scales. Active fluctuations and hydrodynamic interactions can be expressed as an additive composition of separate self-propellers.

  13. Fundamental Issues of Nano-fluid Behavior

    International Nuclear Information System (INIS)

    Williams, Wesley C.

    2006-01-01

    This paper will elucidate some of the behaviors of nano-fluids other than the abnormal conductivity enhancement, which are of importance to the experimental and engineering use of nano-fluids. Nano-fluid is the common name of any sol colloid involving nano-scale (less than 100 nm) sized particles dispersed within a base fluid. It has been shown previously that the dispersion of nano-particulate metallic oxides into water can increase thermal conductivity up to 30-40% over that of the base fluid and anomalously more than the mere weighed average of the colloid. There is a great potential for the use of nano-fluids as a way to enhance fluid/thermal energy transfer systems. Due to the recentness of nano-fluid science, there are still many issues which have not been fully investigated. This paper should act as a primer for the basic understanding of nano-fluid behavior. Particle size and colloid stability are of key importance to the functionality of nano-fluids. The pH and concentration/loading of nano-fluids can alter the size of the nano-particles and also the stability of the fluids. It will be shown through experiment and colloid theory the importance of these parameters. Furthermore, most of the existing literature uses volume percentage as the measure of particle loading, which can often be misleading. There will be discussion of this and other misleading ideas in nano-fluid science. (author)

  14. Electrodeposition of nickel nano wire arrays

    International Nuclear Information System (INIS)

    Nur Ubaidah Saidin; Kok Kuan Ying; Ng Inn Khuan; Nurazila Mat Zali; Siti Salwa Zainal Abidin

    2010-01-01

    Synthesis, characterization and assembly of one-dimensional nickel nano wires prepared by template directed electrodeposition are discussed in this paper. Parallel arrays of high aspect ratio nickel nano wires were electrodeposited using electrolytes with different cations and pH. The nano wires were characterized using X-ray diffractometry and scanning electron microscopy. It was found that the orientations of the electro deposited Ni nano wires were governed by the deposition current and the electrolyte conditions. Free standing nickel nano wires can be obtained by dissolving the template. Due to the magnetic nature of the nano wires, magnetic alignment was employed to assemble and position the free standing nano wires in the device structure. (author)

  15. Numerical Analysis of the Unsteady Propeller Performance in the Ship Wake Modified By Different Wake Improvement Devices

    Directory of Open Access Journals (Sweden)

    Bugalski Tomasz

    2014-10-01

    Full Text Available The paper presents the summary of results of the numerical analysis of the unsteady propeller performance in the non-uniform ship wake modified by the different wake improvement devices. This analysis is performed using the lifting surface program DUNCAN for unsteady propeller analysis. Te object of the analysis is a 7000 ton chemical tanker, for which four different types of the wake improvement devices have been designed: two vortex generators, a pre-swirl stator, and a boundary layer alignment device. These produced five different cases of the ship wake structure: the original hull and hull equipped alternatively with four wake improvement devices. Two different propellers were analyzed in these five wake fields, one being the original reference propeller P0 and the other - a specially designed, optimized propeller P3. Te analyzed parameters were the pictures of unsteady cavitation on propeller blades, harmonics of pressure pulses generated by the cavitating propellers in the selected points and the fluctuating bearing forces on the propeller shaft. Some of the calculated cavitation phenomena were confronted with the experimental. Te objective of the calculations was to demonstrate the differences in the calculated unsteady propeller performance resulting from the application of different wake improvement devices. Te analysis and discussion of the results, together with the appropriate conclusions, are included in the paper.

  16. Formation of Au nano-patterns on various substrates using simplified nano-transfer printing method

    Science.gov (United States)

    Kim, Jong-Woo; Yang, Ki-Yeon; Hong, Sung-Hoon; Lee, Heon

    2008-06-01

    For future device applications, fabrication of the metal nano-patterns on various substrates, such as Si wafer, non-planar glass lens and flexible plastic films become important. Among various nano-patterning technologies, nano-transfer print method is one of the simplest techniques to fabricate metal nano-patterns. In nano-transfer printing process, thin Au layer is deposited on flexible PDMS mold, containing surface protrusion patterns, and the Au layer is transferred from PDMS mold to various substrates due to the difference of bonding strength of Au layer to PDMS mold and to the substrate. For effective transfer of Au layer, self-assembled monolayer, which has strong bonding to Au, is deposited on the substrate as a glue layer. In this study, complicated SAM layer coating process was replaced to simple UV/ozone treatment, which can activates the surface and form the -OH radicals. Using simple UV/ozone treatments on both Au and substrate, Au nano-pattern can be successfully transferred to as large as 6 in. diameter Si wafer, without SAM coating process. High fidelity transfer of Au nano-patterns to non-planar glass lens and flexible PET film was also demonstrated.

  17. Effect of Chamber Pressurization Rate on Combustion and Propagation of Solid Propellant Cracks

    Science.gov (United States)

    Yuan, Wei-Lan; Wei, Shen; Yuan, Shu-Shen

    2002-01-01

    area of the propellant grain satisfies the designed value. But cracks in propellant grain can be generated during manufacture, storage, handing and so on. The cracks can provide additional surface area for combustion. The additional combustion may significantly deviate the performance of the rocket motor from the designed conditions, even lead to explosive catastrophe. Therefore a thorough study on the combustion, propagation and fracture of solid propellant cracks must be conducted. This paper takes an isolated propellant crack as the object and studies the effect of chamber pressurization rate on the combustion, propagation and fracture of the crack by experiment and theoretical calculation. deformable, the burning inside a solid propellant crack is a coupling of solid mechanics and combustion dynamics. In this paper, a theoretical model describing the combustion, propagation and fracture of the crack was formulated and solved numerically. The interaction of structural deformation and combustion process was included in the theoretical model. The conservation equations for compressible fluid flow, the equation of state for perfect gas, the heat conducting equation for the solid-phase, constitutive equation for propellant, J-integral fracture criterion and so on are used in the model. The convective burning inside the crack and the propagation and fracture of the crack were numerically studied by solving the set of nonlinear, inhomogeneous gas-phase governing equations and solid-phase equations. On the other hand, the combustion experiments for propellant specimens with a precut crack were conducted by RTR system. Predicted results are in good agreement with experimental data, which validates the reasonableness of the theoretical model. Both theoretical and experimental results indicate that the chamber pressurization rate has strong effects on the convective burning in the crack, crack fracture initiation and fracture pattern.

  18. NANO-SIZED PIGMENT APPLICATIONS IN İZNİK TILES

    Directory of Open Access Journals (Sweden)

    Esin GÜNAY

    2012-12-01

    Full Text Available Traditional İznik tiles are known as “unproducable” due to its high quartz content. İznik tiles contain four different layers as “body, engobe (slip, decors and glaze” and each one has some different starting materials. Recent studies have showed that the production techniques and the particle size of pigments are important parameters in development of colours. TUBITAK MRC and İznik Foundation carried out an experimental work to improve and understand the effects of nanotechnology application to İznik tiles. High quartz content was kept as it is and pigments were applied in decorationas nano-sized pigments.İznik tiles were produced and comparison was carried out between traditional and modern İznik tiles in colour and brightness. Characterization techniques were used in order to understand andcompare the results and also the effects of nano-sized pigments to İznik tiles.

  19. Studies on composite solid propellant with tri-modal ammonium perchlorate containing an ultrafine fraction

    Directory of Open Access Journals (Sweden)

    K.V. Suresh Babu

    2017-08-01

    Full Text Available Composite solid propellant is prepared using tri-modal Ammonium perchlorate (AP containing coarse, fine and ultrafine fractions of AP with average particle size (APS 340, 40 and 5 μm respectively, in various compositions and their rheological, mechanical and burn rate characteristics are evaluated. The optimum combination of AP coarse to fine to ultrafine weight fraction was obtained by testing of series of propellant samples by varying the AP fractions at fixed solid loading. The concentration of aluminium was maintained constant throughout the experiments for ballistics requirement. The propellant formulation prepared using AP with coarse to fine to ultrafine ratio of 67:24:9 has lowest viscosity for the propellant paste and highest tensile strength due to dense packing as supported by the literature. A minimum modulus value was also observed at 9 wt. % of ultrafine AP concentration indicates the maximum solids packing density at this ratio of AP fractions. The burn rate is evaluated at different pressures to obtain pressure exponent. Incorporation of ultrafine fraction of AP in propellant increased burn rate without adversely affecting the pressure exponent. Higher solid loading propellants are prepared by increased AP concentration from 67 to 71 wt. % using AP with coarse to fine to ultrafine ratio of 67:24:9. Higher solid content up to 89 wt. % was achieved and hence increased solid motor performance. The unloading viscosity showed a trend with increased AP content and the propellant couldn't able to cast beyond 71 wt. % of AP. Mechanical properties were also studied and from the experiments noticed that % elongation decreased with increased AP content from 67 to 71 wt.%, whereas tensile strength and modulus increased. Burn rate increased with increased AP content and observed that pressure exponent also increased and it is high for the propellant containing with 71 wt.% of AP due to increased oxidiser to fuel ratio. Catalysed

  20. Influence of different propellant systems on ablation of EPDM insulators in overload state

    Science.gov (United States)

    Guan, Yiwen; Li, Jiang; Liu, Yang; Xu, Tuanwei

    2018-04-01

    This study examines the propellants used in full-scale solid rocket motors (SRM) and investigates how insulator ablation is affected by two propellant formulations (A and B) during flight overload conditions. An experimental study, theoretical analysis, and numerical simulations were performed to discover the intrinsic causes of insulator ablation rates from the perspective of lab-scaled ground-firing tests, the decoupling of thermochemical ablation, and particle erosion. In addition, the difference in propellant composition, and the insulator charring layer microstructure were analyzed. Results reveal that the degree of insulator ablation is positively correlated with the propellant burn rate, particle velocity, and aggregate concentrations during the condensed phase. A lower ratio of energetic additive material in the AP oxidizer of the propellant is promising for the reduction in particle size and increase in the burn rate and pressure index. However, the overall higher velocity of a two-phase flow causes severe erosion of the insulation material. While the higher ratio of energetic additive to the AP oxidizer imparts a smaller ablation rate to the insulator (under lab-scale test conditions), the slag deposition problem in the combustion chamber may cause catastrophic consequences for future large full-scale SRM flight experiments.

  1. Using PDV to Understand Damage in Rocket Motor Propellants

    Science.gov (United States)

    Tear, Gareth; Chapman, David; Ottley, Phillip; Proud, William; Gould, Peter; Cullis, Ian

    2017-06-01

    There is a continuing requirement to design and manufacture insensitive munition (IM) rocket motors for in-service use under a wide range of conditions, particularly due to shock initiation and detonation of damaged propellant spalled across the central bore of the rocket motor (XDT). High speed photography has been crucial in determining this behaviour, however attempts to model the dynamic behaviour are limited by the lack of precision particle and wave velocity data with which to validate against. In this work Photonic Doppler Velocimetery (PDV) has been combined with high speed video to give accurate point velocity and timing measurements of the rear surface of a propellant block impacted by a fragment travelling upto 1.4 km s-1. By combining traditional high speed video with PDV through a dichroic mirror, the point of velocity measurement within the debris cloud has been determined. This demonstrates a new capability to characterise the damage behaviour of a double base rocket motor propellant and hence validate the damage and fragmentation algorithms used in the numerical simulations.

  2. A research on polyether glycol replaced APCP rocket propellant

    Science.gov (United States)

    Lou, Tianyou; Bao, Chun Jia; Wang, Yiyang

    2017-08-01

    Ammonium perchlorate composite propellant (APCP) is a modern solid rocket propellant used in rocket vehicles. It differs from many traditional solid rocket propellants by the nature of how it is processed. APCP is cast into shape, as opposed to powder pressing it with black powder. This provides manufacturing regularity and repeatability, which are necessary requirements for use in the aerospace industry. For traditional APCP, ingredients normally used are ammonium peroxide, aluminum, Hydroxyl-terminated polybutadiene(HTPB), curing agency and other additives, the greatest disadvantage is that the fuel is too expensive. According to the price we collected in our country, a single kilogram of this fuel will cost 200 Yuan, which is about 35 dollars, for a fan who may use tons of the fuel in a single year, it definitely is a great deal of money. For this reason, we invented a new kind of APCP fuel. Changing adhesive agency from cross-linked htpb to cross linked polyether glycol gives a similar specific thrust, density and mechanical property while costs a lower price.

  3. Low-Cost Propellant Launch From a Tethered Balloon

    Science.gov (United States)

    Wilcox, Brian

    2006-01-01

    A document presents a concept for relatively inexpensive delivery of propellant to a large fuel depot in low orbit around the Earth, for use in rockets destined for higher orbits, the Moon, and for remote planets. The propellant is expected to be at least 85 percent of the mass needed in low Earth orbit to support the NASA Exploration Vision. The concept calls for the use of many small ( 10 ton) spin-stabilized, multistage, solid-fuel rockets to each deliver 250 kg of propellant. Each rocket would be winched up to a balloon tethered above most of the atmospheric mass (optimal altitude 26 2 km). There, the rocket would be aimed slightly above the horizon, spun, dropped, and fired at a time chosen so that the rocket would arrive in orbit near the depot. Small thrusters on the payload (powered, for example, by boil-off gases from cryogenic propellants that make up the payload) would precess the spinning rocket, using data from a low-cost inertial sensor to correct for small aerodynamic and solid rocket nozzle misalignment torques on the spinning rocket; would manage the angle of attack and the final orbit insertion burn; and would be fired on command from the depot in response to observations of the trajectory of the payload so as to make small corrections to bring the payload into a rendezvous orbit and despin it for capture by the depot. The system is low-cost because the small rockets can be mass-produced using the same techniques as those to produce automobiles and low-cost munitions, and one or more can be launched from a U.S. territory on the equator (Baker or Jarvis Islands in the mid-Pacific) to the fuel depot on each orbit (every 90 minutes, e.g., any multiple of 6,000 per year).

  4. AC dielectrophoresis alignment of single-walled carbon nano tubes (SWNTS) and palladium nano wires for hydrogen gas sensor

    International Nuclear Information System (INIS)

    Nur Ubaidah Saidin; Nur Ubaidah Saidin; Ying, K.K.; KKhuan, N.I.; Mohammad Hafizuddin Jumali

    2013-01-01

    Full-text: Using AC electric field, nano wires or nano tubes can be aligned, chained or accelerated in a direction parallel to the applied field, oriented or concentrated onto designated locations as well as dispersed in controlled manner under high efficiencies. In this work, systematic study on the alignment of nano wires/ nano tubes across the 3 μm-gaps between pairs of micro fabricated gold electrodes was carried out using AC dielectrophoresis technique. Densities and alignment of the nano wires/ nano tubes across the gaps of the electrodes were controlled by the applied AC field strengths and frequencies on the electrodes. Good alignments of SWNTs and Pd nano wires were achieved at an applied frequency of 5 MHz and a field strength as high as 25 V pp for Pd nano wires compared to only 2 V pp for SWNTs. The aligned nano wires/ nano tubes will be functioned as sensor elements for hydrogen gas sensing. (author)

  5. 14 CFR 21.6 - Manufacture of new aircraft, aircraft engines, and propellers.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Manufacture of new aircraft, aircraft... Manufacture of new aircraft, aircraft engines, and propellers. (a) Except as specified in paragraphs (b) and (c) of this section, no person may manufacture a new aircraft, aircraft engine, or propeller based on...

  6. Nonlinear super-resolution nano-optics and applications

    CERN Document Server

    Wei, Jingsong

    2015-01-01

    This book covers many advances in the subjects of nano-optics and nano photonics. The author describes the principle and technical schematics of common methods for breaking through the optical diffraction limit and focuses on realizing optical super-resolution with nonlinear effects of thin film materials. The applications of nonlinear optical super-resolution effects in nano-data storage, nanolithography, and nano-imaging are also presented. This book is useful to graduate students majoring in optics and nano science and also serves as a reference book for academic researchers, engineers, technical professionals in the fields of super-resolution optics and laser techniques, nano-optics and nano photonics, nano-data storage, nano imaging, micro/nanofabrication and nanolithography and nonlinear optics.

  7. Nano-ceramics and its molding technologies

    International Nuclear Information System (INIS)

    Liu Jian; Xu Yunshu

    2007-01-01

    Nano-ceramics and its related knowledge were introduced. Fabrication of nano-ceramic powder, as well as the molding and sintering technologies of nano-ceramics were reviewed. Features of the present molding technologies were analyzed. The applications of nano-ceramics were prospected. (authors)

  8. Phosphorylated nano-diamond/ Polyimide Nanocomposites

    International Nuclear Information System (INIS)

    Beyler-Çiǧil, Asli; Çakmakçi, Emrah; Kahraman, Memet Vezir

    2014-01-01

    In this study, a novel route to synthesize polyimide (PI)/phosphorylated nanodiamond films with improved thermal and mechanical properties was developed. Surface phosphorylation of nano-diamond was performed in dichloromethane. Phosphorylation dramatically enhanced the thermal stability of nano-diamond. Poly(amic acid) (PAA), which is the precursor of PI, was successfully synthesized with 3,3',4,4'-Benzophenonetetracarboxylic dianhydride (BTDA) and 4,4'-oxydianiline (4,4'-ODA) in the solution of N,N- dimethylformamide (DMF). Pure BTDA-ODA polyimide films and phosphorylated nanodiamond containing BTDA-ODA PI films were prepared. The PAA displayed good compatibility with phosphorylated nano-diamond. The morphology of the polyimide (PI)/phosphorylated nano-diamond was characterized by scanning electron microscopy (SEM). Chemical structure of polyimide and polyimide (PI)/phosphorylated nano-diamond was characterized by FTIR. SEM and FTIR results showed that the phosphorylated nano-diamond was successfully prepared. Thermal properties of the polyimide (PI)/phosphorylated nanodiamond was characterized by thermogravimetric analysis (TGA). TGA results showed that the thermal stability of (PI)/phosphorylated nano-diamond film was increased

  9. Sea trials of wave propulsion of a yacht using a flexible fin propeller

    Energy Technology Data Exchange (ETDEWEB)

    McGregor, R.C.; Thomson, G.R. [Glasgow Univ. (United Kingdom). Dept. of Mechanical Engineering

    1997-02-01

    Evidence has been accumulating from theoretical and model test studies over several years that propellers that could be designated as ``oscillating foil`` are potentially more energy efficient than conventional screw propellers. There has been demonstrations that, in the controlled conditions of a laboratory, the flexible fin propeller can convert wave energy into an auxiliary means of forward propulsion. Two questions which are immediately raised are ``is the effect realisable in a real seaway?`` and ``what is the mechanism of energy transfer?``. This paper provides clear evidence of a positive answer to the first question. (author)

  10. Strength of Screw Propellers

    Science.gov (United States)

    1975-07-07

    ship because of increese of propeller efficiency and saving on the high cost of difficult to obtain materials (bronze, brass, stainless steel). The...indAjate that. x :axmuin stresses in the blade cross section are the cor-,prc-.,; ivFe norm-al strcs3es at point G. The maximom tensile stres-ses cis a...and stern part of the ship. Because of purely technical difficulties and also because of the relatively high cost of preparations for such tests, only

  11. Nano surface generation of grinding process using carbon nano tubes

    Indian Academy of Sciences (India)

    Nano surface finish has become an important parameter in the semiconductor, optical, electrical and mechanical industries. The materials used in these industries are classified as difficult to machine materials such as ceramics, glasses and silicon wafers. Machining of these materials up to nano accuracy is a great ...

  12. Pharmaceutical Applications of Polymeric Nano materials

    International Nuclear Information System (INIS)

    Wu, L.; Sun, L.

    2011-01-01

    With significant attention focused on nano science and nano technology in recent years, nano materials have been used in a wide variety of applications such as automotive, environmental, energy, catalysis, biomedical, drug delivery, and polymeric industries. Among those fields, the application of nano materials with pharmaceutical science is an emerging and rapidly growing field and has drawn increasing attention recently. Research and development in this field is mainly focused on several aspects such as the discoveries of novel functional nano materials, exploration on nanoparticles with controlled and targeted drug delivery characteristics, and investigation of bio functionalized and diagnostic nano materials. In this special issue, we have invited a few papers related to recent advances in pharmaceutical application of polymeric nano materials

  13. Vent System Analysis for the Cryogenic Propellant Storage Transfer Ground Test Article

    Science.gov (United States)

    Hedayat, A

    2013-01-01

    To test and validate key capabilities and technologies required for future exploration elements such as large cryogenic propulsion stages and propellant depots, NASA is leading the efforts to develop and design the Cryogenic Propellant Storage and Transfer (CPST) Cryogenic Fluid Management (CFM) payload. The primary objectives of CPST payload are to demonstrate: 1) in-space storage of cryogenic propellants for long duration applications; and 2) in-space transfer of cryogenic propellants. The Ground Test Article (GTA) is a technology development version of the CPST payload. The GTA consists of flight-sized and flight-like storage and transfer tanks, liquid acquisition devices, transfer, and pressurization systems with all of the CPST functionality. The GTA is designed to perform integrated passive and active thermal storage and transfer performance testing with liquid hydrogen (LH2) in a vacuum environment. The GTA storage tank is designed to store liquid hydrogen and the transfer tank is designed to be 5% of the storage tank volume. The LH2 transfer subsystem is designed to transfer propellant from one tank to the other utilizing pressure or a pump. The LH2 vent subsystem is designed to prevent over-pressurization of the storage and transfer tanks. An in-house general-purpose computer program was utilized to model and simulate the vent subsystem operation. The modeling, analysis, and the results will be presented in the final paper.

  14. Molecular Treatment of Nano-Kaolinite Generations.

    Science.gov (United States)

    Táborosi, Attila; Szilagyi, Robert K; Zsirka, Balázs; Fónagy, Orsolya; Horváth, Erzsébet; Kristóf, János

    2018-06-18

    A procedure is developed for defining a compositionally and structurally realistic, atomic-scale description of exfoliated clay nanoparticles from the kaolinite family of phylloaluminosilicates. By use of coordination chemical principles, chemical environments within a nanoparticle can be separated into inner, outer, and peripheral spheres. The edges of the molecular models of nanoparticles were protonated in a validated manner to achieve charge neutrality. Structural optimizations using semiempirical methods (NDDO Hamiltonians and DFTB formalism) and ab initio density functionals with a saturated basis set revealed previously overlooked molecular origins of morphological changes as a result of exfoliation. While the use of semiempirical methods is desirable for the treatment of nanoparticles composed of tens of thousands of atoms, the structural accuracy is rather modest in comparison to DFT methods. We report a comparative survey of our infrared data for untreated crystalline and various exfoliated states of kaolinite and halloysite. Given the limited availability of experimental techniques for providing direct structural information about nano-kaolinite, the vibrational spectra can be considered as an essential tool for validating structural models. The comparison of experimental and calculated stretching and bending frequencies further justified the use of the preferred level of theory. Overall, an optimal molecular model of the defect-free, ideal nano-kaolinite can be composed with respect to stationary structure and curvature of the potential energy surface using the PW91/SVP level of theory with empirical dispersion correction (PW91+D) and polarizable continuum solvation model (PCM) without the need for a scaled quantum chemical force field. This validated theoretical approach is essential in order to follow the formation of exfoliated clays and their surface reactivity that is experimentally unattainable.

  15. Indoor Surveillance Security Robot with a Self-Propelled Patrolling Vehicle

    Directory of Open Access Journals (Sweden)

    Hou-Tsan Lee

    2011-01-01

    Full Text Available Self-propelled patrolling vehicles can patrol periodically in the designed area to ensure the safety like men do. The proposed vehicle cannot only save manpower, but also ensure the performance without mistakes caused by man. It is different from the traditional patrolling system which is limited by the manpower and the fixed camera positions. To improve such situation, this paper proposes a self-propelled patrolling vehicle which can move automatically to a wider range and record the monitored image by IPCAM within a predefined patrolling route. Besides, the user can use the mobile device or website to connect to the vehicle at anytime and anywhere and control it to move to the position to get the indoor image user wants. The position of self-propelled vehicles can be detected by the RFID reader as a feedback and be shown on the PC screen and smart phone. The recorded images can be also transmitted back to the server via WiFi system for face tracking and discriminating analysis. On the other hand, the self-propelled vehicle patrolling routes can be modified by the Android smart-phone remote-control module. When some defined events occur, the build-in MSN module will notice users by sending messages to PC and smart phone. Experimental results are given in the paper to validate its performance.

  16. Properties of the chalcogenide–carbon nano tubes and graphene composite materials

    International Nuclear Information System (INIS)

    Singh, Abhay Kumar; Kim, JunHo; Park, Jong Tae; Sangunni, K.S.

    2015-01-01

    Highlights: • Chalcogenides. • Melt quenched. • Composite materials. • Multi walled carbon nano tubes. • Bilayer graphene. - Abstract: Composite can deliver more than the individual elemental property of the material. Specifically chalcogenide- multi walled carbon nano tubes and chalcogenide- bilayer graphene composite materials could be interesting for the investigation, which have been less covered by the investigators. We describe micro structural properties of Se 55 Te 25 Ge 20, Se 55 Te 25 Ge 20 + 0.025% multi walled carbon nano tubes and Se 55 Te 25 Ge 20 + 0.025% bilayer graphene materials. This gives realization of the alloying constituents inclusion/or diffusion inside the multi walled carbon nano tubes and bilayer graphene under the homogeneous parent alloy configuration. Raman spectroscopy, X-ray photoelectron spectroscopy, UV/Visible spectroscopy and Fourier transmission infrared spectroscopy have also been carried out under the discussion. A considerable core energy levels peak shifts have been noticed for the composite materials by the X-ray photoelectron spectroscopy. The optical energy band gaps are measured to be varied in between 1.2 and 1.3 eV. In comparison to parent (Se 55 Te 25 Ge 20 ) alloy a higher infrared transmission has been observed for the composite materials. Subsequently, variation in physical properties has been explained on the basis of bond formation in solids

  17. Electrostatic force microscopy and electrical isolation of etched few-layer graphene nano-domains

    Energy Technology Data Exchange (ETDEWEB)

    Hunley, D. Patrick; Sundararajan, Abhishek; Boland, Mathias J.; Strachan, Douglas R., E-mail: doug.strachan@uky.edu [Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506 (United States)

    2014-12-15

    Nanostructured bi-layer graphene samples formed through catalytic etching are investigated with electrostatic force microscopy. The measurements and supporting computations show a variation in the microscopy signal for different nano-domains that are indicative of changes in capacitive coupling related to their small sizes. Abrupt capacitance variations detected across etch tracks indicates that the nano-domains have strong electrical isolation between them. Comparison of the measurements to a resistor-capacitor model indicates that the resistance between two bi-layer graphene regions separated by an approximately 10 nm wide etch track is greater than about 1×10{sup 12} Ω with a corresponding gap resistivity greater than about 3×10{sup 14} Ω⋅nm. This extremely large gap resistivity suggests that catalytic etch tracks within few-layer graphene samples are sufficient for providing electrical isolation between separate nano-domains that could permit their use in constructing atomically thin nanogap electrodes, interconnects, and nanoribbons.

  18. Electrostatic force microscopy and electrical isolation of etched few-layer graphene nano-domains

    International Nuclear Information System (INIS)

    Hunley, D. Patrick; Sundararajan, Abhishek; Boland, Mathias J.; Strachan, Douglas R.

    2014-01-01

    Nanostructured bi-layer graphene samples formed through catalytic etching are investigated with electrostatic force microscopy. The measurements and supporting computations show a variation in the microscopy signal for different nano-domains that are indicative of changes in capacitive coupling related to their small sizes. Abrupt capacitance variations detected across etch tracks indicates that the nano-domains have strong electrical isolation between them. Comparison of the measurements to a resistor-capacitor model indicates that the resistance between two bi-layer graphene regions separated by an approximately 10 nm wide etch track is greater than about 1×10 12  Ω with a corresponding gap resistivity greater than about 3×10 14  Ω⋅nm. This extremely large gap resistivity suggests that catalytic etch tracks within few-layer graphene samples are sufficient for providing electrical isolation between separate nano-domains that could permit their use in constructing atomically thin nanogap electrodes, interconnects, and nanoribbons

  19. High Power Flex-Propellant Arcjet Performance

    Science.gov (United States)

    Litchford, Ron J.

    2011-01-01

    A MW-class electrothermal arcjet based on a water-cooled, wall-stabilized, constricted arc discharge configuration was subjected to extensive performance testing using hydrogen and simulated ammonia propellants with the deliberate aim of advancing technology readiness level for potential space propulsion applications. The breadboard design incorporates alternating conductor/insulator wafers to form a discharge barrel enclosure with a 2.5-cm internal bore diameter and an overall length of approximately 1 meter. Swirling propellant flow is introduced into the barrel, and a DC arc discharge mode is established between a backplate tungsten cathode button and a downstream ringanode/ spin-coil assembly. The arc-heated propellant then enters a short mixing plenum and is accelerated through a converging-diverging graphite nozzle. This innovative design configuration differs substantially from conventional arcjet thrusters, in which the throat functions as constrictor and the expansion nozzle serves as the anode, and permits the attainment of an equilibrium sonic throat (EST) condition. During the test program, applied electrical input power was varied between 0.5-1 MW with hydrogen and simulated ammonia flow rates in the range of 4-12 g/s and 15-35 g/s, respectively. The ranges of investigated specific input energy therefore fell between 50-250 MJ/kg for hydrogen and 10-60 MJ/kg for ammonia. In both cases, observed arc efficiencies were between 40-60 percent as determined via a simple heat balance method based on electrical input power and coolant water calorimeter measurements. These experimental results were found to be in excellent agreement with theoretical chemical equilibrium predictions, thereby validating the EST assumption and enabling the utilization of standard TDK nozzle expansion analyses to reliably infer baseline thruster performance characteristics. Inferred specific impulse performance accounting for recombination kinetics during the expansion process

  20. Gas Gun Model and Comparison to Experimental Performance of Pipe Guns Operating with Light Propellant Gases and Large Cryogenic Pellets

    Energy Technology Data Exchange (ETDEWEB)

    Reed, J. R. [University of Tennessee, Knoxville (UTK); Carmichael, J. R. [Fermi National Accelerator Laboratory (FNAL); Gebhart, T. E. [University of Florida, Gainesville; Combs, Stephen Kirk [ORNL; Baylor, Larry R. [ORNL; Rasmussen, David A. [ORNL; Meitner, Steven J. [ORNL; Lyttle, Mark S. [ORNL

    2017-10-01

    Injection of multiple large (~10 to 30 mm diameter) shattered pellets into ITER plasmas is presently part of the scheme planned to mitigate the deleterious effects of disruptions on the vessel components. To help in the design and optimize performance of the pellet injectors for this application, a model referred to as “the gas gun simulator” has been developed and benchmarked against experimental data. The computer code simulator is a Java program that models the gas-dynamics characteristics of a single-stage gas gun. Following a stepwise approach, the code utilizes a variety of input parameters to incrementally simulate and analyze the dynamics of the gun as the projectile is launched down the barrel. Using input data, the model can calculate gun performance based on physical characteristics, such as propellant-gas and fast-valve properties, barrel geometry, and pellet mass. Although the model is fundamentally generic, the present version is configured to accommodate cryogenic pellets composed of H2, D2, Ne, Ar, and mixtures of them and light propellant gases (H2, D2, and He). The pellets are solidified in situ in pipe guns that consist of stainless steel tubes and fast-acting valves that provide the propellant gas for pellet acceleration (to speeds ~200 to 700 m/s). The pellet speed is the key parameter in determining the response time of a shattered pellet system to a plasma disruption event. The calculated speeds from the code simulations of experiments were typically in excellent agreement with the measured values. With the gas gun simulator validated for many test shots and over a wide range of physical and operating parameters, it is a valuable tool for optimization of the injector design, including the fast valve design (orifice size and volume) for any operating pressure (~40 bar expected for the ITER application) and barrel length for any pellet size (mass, diameter, and length). Key design parameters and proposed values for the pellet injectors for

  1. EFFECT OF GEOMETRIC CONFIGURATIONS ON HYDRODYNAMIC PERFORMANCE ASSESSMENT OF A MARINE PROPELLER

    Directory of Open Access Journals (Sweden)

    Samir. E. Belhenniche

    2016-12-01

    Full Text Available The present paper deals with the effect of the geometric characteristics on the propeller hydrodynamic performances. Several propeller configurations are created by changing number of blades, expanded area and pitch ratios. The Reynolds-Averaged Navier-Stokes (RANS equations are solved using the commercial code FLUENT 6.3.26. The standard

  2. A computational tool for the rapid design and prototyping of propellers for underwater vehicles

    OpenAIRE

    D'Epagnier, Kathryn Port.

    2007-01-01

    An open source, MATLAB (trademarked)-based propeller design code MPVL was improved to include rapid prototyping capabilities as well as other upgrades as part of this effort. The resulting code, OpenPVL is described in this thesis. In addition, results from the development code BasicPVL are presented. An intermediate code, BasicPVL, was created by the author while OpenPVL was under development, and it provides guidance for initial propeller designs and propeller efficiency analysis. OpenPVL i...

  3. Nano structures for Medical Diagnostics Md

    International Nuclear Information System (INIS)

    Bellah, M.; Iqbal, S.M.; Bellah, M.; Iqbal, S.M.; Christensen, S.M.; Iqbal, S.M.; Iqbal, S.M.

    2012-01-01

    Nano technology is the art of manipulating materials on atomic or molecular scales especially to build nano scale structures and devices. The field is expanding quickly, and a lot of work is ongoing in the design, characterization, synthesis, and application of materials, structures, devices, and systems by controlling shape and size at nanometer scale. In the last few years, much work has been focused on the use of nano structures toward problems of biology and medicine. In this paper, we focus on the application of various nano structures and nano devices in clinical diagnostics and detection of important biological molecules. The discussion starts by introducing some basic techniques of micro-/nano scale fabrication that have enabled reproducible production of nano structures. The prospects, benefits, and limitations of using these novel techniques in the fields of bio detection and medical diagnostics are then discussed. Finally, the challenges of mass production and acceptance of nano technology by the medical community are considered.

  4. An investigation on thermal decomposition of DNTF-CMDB propellants

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Wei; Wang, Jiangning; Ren, Xiaoning; Zhang, Laying; Zhou, Yanshui [Xi' an Modern Chemistry Research Institute, Xi' an 710065 (China)

    2007-12-15

    The thermal decomposition of DNTF-CMDB propellants was investigated by pressure differential scanning calorimetry (PDSC) and thermogravimetry (TG). The results show that there is only one decomposition peak on DSC curves, because the decomposition peak of DNTF cannot be separated from that of the NC/NG binder. The decomposition of DNTF can be obviously accelerated by the decomposition products of the NC/NG binder. The kinetic parameters of thermal decompositions for four DNTF-CMDB propellants at 6 MPa were obtained by the Kissinger method. It is found that the reaction rate decreases with increasing content of DNTF. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  5. Torsional vibration of crankshaft in an engine propeller nonlinear dynamical system

    Science.gov (United States)

    Zhang, X.; Yu, S. D.

    2009-01-01

    Theoretical and experimental studies on torsional vibration of an aircraft engine-propeller system are presented in this paper. Two system models—a rigid body model and a flexible body model, are developed for predicting torsional vibrations of the crankshaft under different engine powers and propeller pitch settings. In the flexible body model, the distributed torsional flexibility and mass moment of inertia of the crankshaft are considered using the finite element method. The nonlinear autonomous equations of motion for the engine-propeller dynamical system are established using the augmented Lagrange equations, and solved using the Runge-Kutta method after a degrees of freedom reduction scheme is applied. Experiments are carried out on a three-cylinder four-stroke engine. Both theoretical and experimental studies reveal that the crankshaft flexibility has significant influence on the system dynamical behavior.

  6. Research on Radar Micro-Doppler Feature Parameter Estimation of Propeller Aircraft

    Science.gov (United States)

    He, Zhihua; Tao, Feixiang; Duan, Jia; Luo, Jingsheng

    2018-01-01

    The micro-motion modulation effect of the rotated propellers to radar echo can be a steady feature for aircraft target recognition. Thus, micro-Doppler feature parameter estimation is a key to accurate target recognition. In this paper, the radar echo of rotated propellers is modelled and simulated. Based on which, the distribution characteristics of the micro-motion modulation energy in time, frequency and time-frequency domain are analyzed. The micro-motion modulation energy produced by the scattering points of rotating propellers is accumulated using the Inverse-Radon (I-Radon) transform, which can be used to accomplish the estimation of micro-modulation parameter. Finally, it is proved that the proposed parameter estimation method is effective with measured data. The micro-motion parameters of aircraft can be used as the features of radar target recognition.

  7. Cryogenic Propellant Storage and Transfer Engineering Development Unit Hydrogen Tank

    Science.gov (United States)

    Werkheiser, Arthur

    2015-01-01

    The Cryogenic Propellant Storage and Transfer (CPST) project has been a long-running program in the Space Technology Mission Directorate to enhance the knowledge and technology related to handling cryogenic propellants, specifically liquid hydrogen. This particular effort, the CPST engineering development unit (EDU), was a proof of manufacturability effort in support of a flight article. The EDU was built to find and overcome issues related to manufacturability and collect data to anchor the thermal models for use on the flight design.

  8. Lifetime prediction of EC, DPA, Akardite II and MNA stabilized triple base propellants, comparison of heat generation rate and stabilizer consumption

    Energy Technology Data Exchange (ETDEWEB)

    Boers, Marco N.; Klerk, Willem (Wim) P.C. de [TNO Defence, Security and Safety, P. O. Box 45, 2280 AA Rijswijk ZH (Netherlands)

    2005-10-01

    A lifetime prediction study is carried out on four triple base propellant compositions by artificial ageing. The ageing effects are studied with High Performance Liquid Chromatography (HPLC) and Heat Flow Calorimetry (HFC) in order to find the most effective stabilizer and to evaluate the advantages and disadvantages of both methods. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  9. Fabrication of Graded Porous and Skin-Core Structure RDX-Based Propellants via Supercritical CO2 Concentration Profile

    Science.gov (United States)

    Yang, Weitao; Li, Yuxiang; Ying, Sanjiu

    2015-04-01

    A fabrication process to produce graded porous and skin-core structure propellants via supercritical CO2 concentration profile is reported in this article. It utilizes a partial gas saturation technique to obtain nonequilibrium gas concentration profiles in propellants. Once foamed, the propellant obtains a graded porous or skin-pore structure. This fabrication method was studied with RDX(Hexogen)-based propellant under an SC-CO2 saturation condition. The principle was analyzed and the one-dimensional diffusion model was employed to estimate the gas diffusion coefficient and to predict the gas concentration profiles inside the propellant. Scanning electron microscopy images were used to analyze the effects of partial saturation on the inner structure. The results also suggested that the sorption time and desorption time played an important role in gas profile generation and controlled the inner structure of propellants.

  10. Manipulation and functionalization of nano-tubes: application to boron nitride nano-tubes

    International Nuclear Information System (INIS)

    Maguer, A.

    2007-01-01

    This PhD work is divided into two parts dealing with boron nitride (BNNT) and carbon nano-tubes. The first part is about synthesis, purification and chemical functionalization of BNNT. Single-walled BNNT are synthesized by LASER ablation of a hBN target. Improving the synthesis parameters first allowed us to limit the byproducts (hBN, boric acid). A specific purification process was then developed in order to enrich the samples in nano-tubes. Purified samples were then used to develop two new chemical functionalization methods. They both involve chemical molecules that present a high affinity towards the BN network. The use of long chain-substituted quinuclidines and borazines actually allowed the solubilization of BNNT in organic media. Purification and functionalization were developed for single-walled BNNT and were successfully applied to multi-walled BNNT. Sensibility of boron to thermic neutrons finally gave birth to a study about covalent functionalization possibilities of the network. The second part of the PhD work deals with separation of carbon nano-tubes depending on their properties. Microwave irradiation of carbon nano-tubes first allowed the enrichment of initially polydisperse samples in large diameter nano-tubes. A second strategy involving selective interaction between one type of tubes and fullerene micelles was finally envisaged to selectively solubilize carbon nano-tubes with specific electronic properties. (author) [fr

  11. High Impulse Nanoparticulate-Based Gel Propellants, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposed Small Business Innovative Research (SBIR) Phase I addresses the development of advanced gel propellants and determination of their suitability for...

  12. Effect of TMAH Etching Duration on the Formation of Silicon Nano wire Transistor Patterned by AFM Nano lithography

    International Nuclear Information System (INIS)

    Hutagalung, S.D.; Lew, K.C.

    2012-01-01

    Atomic force microscopy (AFM) lithography was applied to produce nano scale pattern for silicon nano wire transistor fabrication. This technique takes advantage of imaging facility of AFM and the ability of probe movement controlling over the sample surface to create nano patterns. A conductive AFM tip was used to grow the silicon oxide nano patterns on silicon on insulator (SOI) wafer. The applied tip-sample voltage and writing speed were well controlled in order to form pre-designed silicon oxide nano wire transistor structures. The effect of tetra methyl ammonium hydroxide (TMAH) etching duration on the oxide covered silicon nano wire transistor structure has been investigated. A completed silicon nano wire transistor was obtained by removing the oxide layer via hydrofluoric acid etching process. The fabricated silicon nano wire transistor consists of a silicon nano wire that acts as a channel with source and drain pads. A lateral gate pad with a nano wire head was fabricated very close to the channel in the formation of transistor structures. (author)

  13. CONSTRUCTION SELF-PROPELLED PNEUMOPUNCHERS WITH LOCKING MECHANISM

    Directory of Open Access Journals (Sweden)

    V. K. Perederey

    2016-01-01

    Full Text Available The paper reveals one of possible methods for higher productivity and reliability of building self-propelled pneumopunchers which are intended for making holes in soil while using trenchless method and constructing various engineering communications under car, tram and rail lines, airport runways. A new design of building pneumopuncher with increased productivity due to higher speed for hole formation in soil and its reliability has been presented in the paper. A formula for determination of displacement increment for a new pneumopuncher in comparison with the conventional one has been obtained in the paper. The paper describes a design and operation principal of the building self-propelled pneumopuncher which is equipped with a locking mechanism with the purpose to neutralize action of soil elastic forces and reactive repulsive force. The locking mechanism keeps the pneumopuncher in the hole. The pneumopuncher consists of a body with anvil, movable hammer, a manifold which is set in axial deepening of the hammer, a nut and a locking mechanism. Improvement of operational pneumopuncher reliability is attained due to the fact that the locking mechanism is made in the form of two coaxially positioned inner and outer cups having a common basis. A piston is installed in the middle of the inner cup, a spring is fixed over the piston and a rod with a breaking shoe is positioned at the end. Height of the inner cup is less the outer cup height and there is an annular cavity between them which is connected with a chamber. The chamber is formed by the piston, the inner cup and the manifold. The annular cavity through an opening in the inner cup wall, two sylphons, a channel in the nut end and an opening in the vertical wall of the manifold are connected with a chamber of operating stroke. The sylphons are placed between the outer cup and the nut, between the nut and the manifold. Differential equations for movement of pneumopuncher in soil have been

  14. Conceptual study of on orbit production of cryogenic propellants by water electrolysis

    Science.gov (United States)

    Moran, Matthew E.

    1991-01-01

    The feasibility is assessed of producing cryogenic propellants on orbit by water electrolysis in support of NASA's proposed Space Exploration Initiative (SEI) missions. Using this method, water launched into low earth orbit (LEO) would be split into gaseous hydrogen and oxygen by electrolysis in an orbiting propellant processor spacecraft. The resulting gases would then be liquified and stored in cryogenic tanks. Supplying liquid hydrogen and oxygen fuel to space vehicles by this technique has some possible advantages over conventional methods. The potential benefits are derived from the characteristics of water as a payload, and include reduced ground handling and launch risk, denser packaging, and reduced tankage and piping requirements. A conceptual design of a water processor was generated based on related previous studies, and contemporary or near term technologies required. Extensive development efforts would be required to adapt the various subsystems needed for the propellant processor for use in space. Based on the cumulative results, propellant production by on orbit water electrolysis for support of SEI missions is not recommended.

  15. Flow measurement around a model ship with propeller and rudder

    Energy Technology Data Exchange (ETDEWEB)

    Van, S H; Yoon, H S; Lee, Y Y; Park, I R [Korea Research Institute of Ships and Ocean Engineering, KORDI, Marine Transportation Systems Laboratory, Daejeon (Korea); Kim, W J [Mokpo National University, Department of Naval Architecture and Marine Engineering, Jeonnam (Korea)

    2006-04-15

    For the design of hull forms with better resistance and propulsive performance, it is essential to understand flow characteristics, such as wave and wake development, around a ship. Experimental data detailing the local flow characteristics are invaluable for the validation of the physical and numerical modeling of computational fluid dynamics (CFD) codes, which are recently gaining attention as efficient tools for hull form evaluation. This paper describes velocity and wave profiles measured in the towing tank for the KRISO 138,000 m{sup 3} LNG carrier model with propeller and rudder. The effects of propeller and rudder on the wake and wave profiles in the stern region are clearly identified. The results contained in this paper can provide an opportunity to explore integrated flow phenomena around a model ship in the self-propelled condition, and can be added to the International Towing Tank Conference benchmark data for CFD validation as the previous KCS and KVLCC cases. (orig.)

  16. Flow measurement around a model ship with propeller and rudder

    Science.gov (United States)

    van, S. H.; Kim, W. J.; Yoon, H. S.; Lee, Y. Y.; Park, I. R.

    2006-04-01

    For the design of hull forms with better resistance and propulsive performance, it is essential to understand flow characteristics, such as wave and wake development, around a ship. Experimental data detailing the local flow characteristics are invaluable for the validation of the physical and numerical modeling of computational fluid dynamics (CFD) codes, which are recently gaining attention as efficient tools for hull form evaluation. This paper describes velocity and wave profiles measured in the towing tank for the KRISO 138,000 m3 LNG carrier model with propeller and rudder. The effects of propeller and rudder on the wake and wave profiles in the stern region are clearly identified. The results contained in this paper can provide an opportunity to explore integrated flow phenomena around a model ship in the self-propelled condition, and can be added to the International Towing Tank Conference benchmark data for CFD validation as the previous KCS and KVLCC cases.

  17. Direct comparison between X-ray nanotomography and scanning electron microscopy for the microstructure characterization of a solid oxide fuel cell anode

    International Nuclear Information System (INIS)

    Quey, R.; Suhonen, H.; Laurencin, J.; Cloetens, P.; Bleuet, P.

    2013-01-01

    X-ray computed nanotomography (nano-CT) and scanning electron microscopy (SEM) have been applied to characterize the microstructure of a Solid Oxide Fuel Cell (SOFC) anode. A direct comparison between the results of both methods is conducted on the same region of the microstructure to assess the spatial resolution of the nano-CT microstructure, SEM being taken as a reference. A registration procedure is proposed to find out the position of the SEM image within the nano-CT volume. It involves a second SEM observation, which is taken along an orthogonal direction and gives an estimate reference SEM image position, which is then refined by an automated optimization procedure. This enables an unbiased comparison between the cell porosity morphologies provided by both methods. In the present experiment, nano-CT is shown to underestimate the number of pores smaller than 1 μm and overestimate the size of the pores larger than 1.5 μm. - Highlights: ► X-ray computed nanotomography (nano-CT) and SEM are used to characterize an SOFC anode. ► A methodology is proposed to compare the nano-CT and SEM data on the same region. ► The spatial resolution of the nano-CT data is assessed from that comparison

  18. Radio-Frequency Tank Eigenmode Sensor for Propellant Quantity Gauging

    Science.gov (United States)

    Zimmerli, Gregory A.; Buchanan, David A.; Follo, Jeffrey C.; Vaden, Karl R.; Wagner, James D.; Asipauskas, Marius; Herlacher, Michael D.

    2010-01-01

    Although there are several methods for determining liquid level in a tank, there are no proven methods to quickly gauge the amount of propellant in a tank while it is in low gravity or under low-settling thrust conditions where propellant sloshing is an issue. Having the ability to quickly and accurately gauge propellant tanks in low-gravity is an enabling technology that would allow a spacecraft crew or mission control to always know the amount of propellant onboard, thus increasing the chances for a successful mission. The Radio Frequency Mass Gauge (RFMG) technique measures the electromagnetic eigenmodes, or natural resonant frequencies, of a tank containing a dielectric fluid. The essential hardware components consist of an RF network analyzer that measures the reflected power from an antenna probe mounted internal to the tank. At a resonant frequency, there is a drop in the reflected power, and these inverted peaks in the reflected power spectrum are identified as the tank eigenmode frequencies using a peak-detection software algorithm. This information is passed to a pattern-matching algorithm, which compares the measured eigenmode frequencies with a database of simulated eigenmode frequencies at various fill levels. A best match between the simulated and measured frequency values occurs at some fill level, which is then reported as the gauged fill level. The database of simulated eigenmode frequencies is created by using RF simulation software to calculate the tank eigenmodes at various fill levels. The input to the simulations consists of a fairly high-fidelity tank model with proper dimensions and including internal tank hardware, the dielectric properties of the fluid, and a defined liquid/vapor interface. Because of small discrepancies between the model and actual hardware, the measured empty tank spectra and simulations are used to create a set of correction factors for each mode (typically in the range of 0.999 1.001), which effectively accounts for

  19. Design Procedure of 4-Bladed Propeller

    African Journals Online (AJOL)

    PROF. O. E. OSUAGWU

    2013-09-01

    Sep 1, 2013 ... West African Journal of Industrial and Academic Research Vol.8 No.1 September 2013 ..... Number of blades. 5. Taylor's wake friction (w). The speed of ship (Vs), the number of propeller revolution (n), the blade number (Z) and the blade area ratio.... .... moment of inertia of a blade, the approximate.

  20. Nano Fertilizers

    Directory of Open Access Journals (Sweden)

    Hatice DAĞHAN

    2017-06-01

    Full Text Available Agricultural land is decreasing day by day due to erosion, environmental pollution, unconscious irrigation and fertilization. On the other hand, it is necessary to increase agricultural production in order to meet the needs of the developing industry as well as the nutritional needs of the growing population. In the recent years, nano fertilizers have begun to be produced to obtain the highest amount and quality of production from the unit area. Previous research shows that nano fertilizers cause an increase in the use efficiency of plant nutrients, reduce soil toxicity, minimize the potential adverse effects of excessive chemical fertilizer use, and reduce fertilizer application frequency. Nano fertilizers are important in agriculture to increase crop yield and nutrient use efficiency, and to reduce excessive use ofchemical fertilizers. The most important properties of these fertilizers are that they contain one or more of macro and micronutrients, they can be applied frequently in small amounts and are environmentally friendly. However, when applied at high doses, they exhibit decreasing effects on plant growth and crop yields, similar to chemical fertilizers. In this review, the definition, importan ce, and classification of nano fertilizers, their application in plant production, advantages and disadvantages and the results obtained in this field were discussed.

  1. Multi-Segment Direct Inject nano-ESI-LTQ-FT-ICR-MS/MS For Protein Identification

    Directory of Open Access Journals (Sweden)

    Neal Rachel E

    2011-07-01

    Full Text Available Abstract Reversed phase high performance liquid chromatography (HPLC interfaced to electrospray tandem mass spectrometry (MS/MS is commonly used for the identification of peptides from proteolytically cleaved proteins embedded in a polyacrylamide gel matrix as well as for metabolomics screening. HPLC separations are time consuming (30-60 min average, costly (columns and mobile phase reagents, and carry the risk of column carry over between samples. The use of a chip-based nano-ESI platform (Advion NanoMate based on replaceable nano-tips for sample introduction eliminates sample cross-contamination, provides unchanging sample matrix, and enhances spray stability with attendant increases in reproducibility. Recent papers have established direct infusion nano-ESI-MS/MS utilizing the NanoMate for protein identification of gel spots based on full range MS scans with data dependent MS/MS. In a full range scan, discontinuous ion suppression due to sample matrix can impair identification of putative mass features of interest in both the proteomic and metabolomic workflows. In the current study, an extension of an established direct inject nano-ESI-MS/MS method is described that utilizes the mass filtering capability of an ion-trap for ion packet separation into four narrow mass ranges (50 amu overlap with segment specific dynamic data dependent peak inclusion for MS/MS fragmentation (total acquisition time of 3 minutes. Comparison of this method with a more traditional nanoLC-MS/MS based protocol utilizing solvent/sample stream splitting to achieve nanoflow demonstrated comparable results for protein identification from polyacrylamide gel matrices. The advantages of this method include full automation, lack of cross-contamination, low cost, and high throughput.

  2. Morphology of Poly lactide/Polycaprolactone (PLA/PCL) Nano composite by Scanning Electron Microscopy (SEM)

    International Nuclear Information System (INIS)

    Siti Zulaiha Hairaldin; Wan Md Zin Wan Yunus; Norazowa Ibrahim

    2011-01-01

    In this study, Octadecylamine Modified Montmorillonites (ODAMMT) were used to prepare Poly lactide/ Polycaprolactone (PLA/ PCL) nano composites. PLA and PCL mix in 90:10 ratios, using an internal mixer by melt blending technique. The other sample was blend with Natrium Montmorillonite (NaMMT) and Octadecylamine Modified Montmorillonite (ODA-MMT) to produce PLA/ PCL-NaMMT and PLA/ PCL ODAMMT. To characterize the polymer nano composites, X-ray diffraction (XRD), FTIR and SEM analysis were conducted. Comparison of morphology were made up between PLA/ PCL, PLA/ PCL with presence of 7 % of Na-MMT and 7 % ODA-MMT respectively based on SEM micrograph by calculate the number-average diameter. (author)

  3. Carbon nanotubes: from nano test tube to nano-reactor.

    Science.gov (United States)

    Khlobystov, Andrei N

    2011-12-27

    Confinement of molecules and atoms inside carbon nanotubes provides a powerful strategy for studying structures and chemical properties of individual molecules at the nanoscale. In this issue of ACS Nano, Allen et al. explore the nanotube as a template leading to the formation of unusual supramolecular and covalent structures. The potential of carbon nanotubes as reactors for synthesis on the nano- and macroscales is discussed in light of recent studies.

  4. Antileishmanial Activity of Lavandula angustifolia and Rosmarinus Officinalis Essential Oils and Nano-emulsions on Leishmania major (MRHO/IR/75/ER

    Directory of Open Access Journals (Sweden)

    Azar SHOKRI

    2017-12-01

    Full Text Available AbstractBackground: The aim of present study was to evaluate antileishmanial effects of Lavandula angustifolia (L. angustifolia and Rosmarinus officinalis (R. officinalis medicinal plants essential oils and nano-emulsions on Leishmania major (L. major. Methods: The present study was performed in Leishmaniasis Reference Lab at Mazandaran University of Medical Sciences, Iran during 2016-2017. The IC50 values were calculated in both the promastigote and amastigote stages in J774 macrophage in comparison with meglumine antimoniate (MA as positive control. In addition, cytotoxicity effects of essential oils and nano-emulsions prepared from both plants against macrophages were evaluated.Results: Both essential oil and nano-emulsion of Lavander and Rosemary showed anti-leishmania activity on promastigote with IC50=0.11 μl/mL, IC50=0.26 μl/mL, and IC50=0.08 μl/mL respectively. Moreover, during amastigote assay, Lavander and Rosemary essential oils and nano-emulsion were effective at least in concentration of 0.12 μl/mL and 0.06 µl/mL (P=0.0001 respectively, on mean infected macrophages (MIR and amastigotes in macrophages (P=0.0001. Additionally, cytotoxicity assay against macrophage revealed no toxicity on the host cells at IC50 concentrations.Conclusion: The nano-emulsions of both plants were more effective than essential oil in both MIR and amastigote. However, in comparison with MA, the Lavander essential oil is more effective in reducing MIR. Rosemary nano-emulsion reduced MIR significantly more than MA in concentration of 0.25 μl/mL (P<0.001. Further investigations are recommended to evaluate the effect of these medicinal plants in murine models.

  5. An Additively Manufactured Torch Igniter for Liquid Propellants

    Data.gov (United States)

    National Aeronautics and Space Administration — Consistent and reliable rocket engine ignition has yet to be proven through an additively manufactured torch igniter for liquid propellants. The coupling of additive...

  6. Liquid oxygen (LO2) propellant conditioning concept testing

    Science.gov (United States)

    Perry, Gretchen L. E.; Orth, Michael S.; Mehta, Gopal K.

    1993-01-01

    Testing of a simplified LO2 propellant conditioning concept for future expendable launch vehicles is discussed. Four different concepts are being investigated: no-bleed, low-bleed, use of a recirculation line, and He bubbling. A full-scale test article, which is a facsimile of a propellant feed duct with an attached section to simulate heat input from an LO2 turbopump, is to be tested at the Cold Flow Facility of the Marshall Space Flight Center West Test Area. Work to date includes: design and fabrication of the test article, design of the test facility and initial fabrication, development of a test matrix and test procedures, initial predictions of test output, and heat leak calibration and heat exchanger tests on the test articles.

  7. Nano-cellulose biopolymer based nano-biofilm biomaterial using plant biomass: An innovative plant biomaterial dataset

    Directory of Open Access Journals (Sweden)

    A.B.M. Sharif hossain

    2018-04-01

    Full Text Available The nano-cellulose derived nano-biofilm keeps a magnificent role in medical, biomedical, bioengineering and pharmaceutical industries. Plant biomaterial is naturally organic and biodegradable. This study has been highlighted as one of the strategy introducing biomass based nano-bioplastic (nanobiofilm to solve dependency on petroleum and environment pollution because of non-degradable plastic. The data study was carried out to investigate the nano-biopolymer (nanocellulose based nano-biofilm data from corn leaf biomass coming after bioprocess technology without chemicals. Corn leaf biomass was used to produce biodegradable nano-bioplastic for medical and biomedical and other industrial uses. Data on water absorption, odor, pH, cellulose content, shape and firmness, color coating and tensile strength test have been exhibited under standardization of ASTM (American standard for testing and materials. Moreover, the chemical elements of nanobiofilm like K+, CO3−−, Cl−, Na+ showed standard data using the EN (166. Keywords: Nanocellulose, Nanobiofilm, Nanobioplastic, Biodegradable, Corn leaf

  8. Self-sensing and thermal energy experimental characterization of multifunctional cement-matrix composites with carbon nano-inclusions

    Science.gov (United States)

    D'Alessandro, A.; Pisello, A. L.; Sambuco, Sara; Ubertini, F.; Asdrubali, F.; Materazzi, A. L.; Cotana, F.

    2016-04-01

    The recent progress of Nanotechnology allowed the development of new smart materials in several fields of engineering. In particular, innovative construction materials with multifunctional enhanced properties can be produced. The paper presents an experimental characterization on cement-matrix pastes doped with Carbon Nanotubes, Carbon Nano-fibers, Carbon Black and Graphene Nano-platelets. Both electro-mechanical and thermo-physical investigations have been carried out. The conductive nano-inclusions provide the cementitious matrix with piezo-resistive properties allowing the detection of external strain and stress changes. Thereby, traditional building materials, such as concrete and cementitious materials in general, would be capable of self-monitoring the state of deformation they are subject to, giving rise to diffuse sensing systems of structural integrity. Besides supplying self-sensing abilities, carbon nano-fillers may change mechanical, physical and thermal properties of cementitious composites. The experimental tests of the research have been mainly concentrated on the thermal conductivity and the optical properties of the different nano-modified materials, in order to make a critical comparison between them. The aim of the work is the characterization of an innovative multifunctional composite capable of combining self-monitoring properties with proper mechanical and thermal-energy efficiency characteristics. The potential applications of these nano-modified materials cover a wide range of possibilities, such as structural elements, floors, geothermal piles, radiant systems and more.

  9. Nano-structural characteristics and optical properties of silver chiral nano-flower sculptured thin films

    International Nuclear Information System (INIS)

    Savaloni, Hadi; Haydari-Nasab, Fatemh; Malmir, Mariam

    2011-01-01

    Silver chiral nano-flowers with 3-, 4- and 5-fold symmetry were produced using oblique angle deposition method in conjunction with the rotation of sample holder with different speeds at different sectors of each revolution corresponding to symmetry order of the acquired nano-flower. Atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM), were employed to obtain morphology and nano-structure of the films. Optical characteristics of silver chiral nano-flower thin films were obtained using single beam spectrophotometer with both s- and p-polarization incident light at 30 o and 70 o incidence angles and at different azimuthal angles (φ). Optical spectra showed both TM (TDM (transverse dipole mode) and TQM (transverse quadruple mode)) and LM (longitudinal mode) Plasmon resonance peaks. For 3- and 4-fold symmetry chiral nano-flowers the s-polarization extinction spectra obtained at different azimuthal angles did not show significant change in the Plasmon peak position while 5-fold symmetry chiral nano-flower showed a completely different behavior, which may be the result of increased surface anisotropy, so when the φ angle is changed the s-polarization response from the surface can change more significantly than that for lower symmetries. In general, for 3-, 4- and 5-fold symmetry chiral nano-flowers a sharp peak at lower wavelengths ( o incidence angle.

  10. Evaluation for probabilistic distributions of fatigue life of marine propeller materials by using a Monte Carlo simulation

    International Nuclear Information System (INIS)

    Yoon, Han Yong; Zhang, Jian Wei

    2008-01-01

    Engineering materials have been studied and developed remarkably for a long time. But, few reports about marine propeller materials are presented. Recently, some researchers have studied the material strength of marine propellers. However, studies on parametric sensitivity and probabilistic distribution of fatigue life of propeller materials have not been made yet. In this study, a method to predict the probabilistic distributions of fatigue life of propeller materials is presented, and the influence of several parameters on the life distribution is discussed

  11. Studies on Decomposition and Combustion Mechanism of Solid Fuel Rich Propellants

    Science.gov (United States)

    2010-08-30

    thrust to cruise at supersonic speed. This was followed by the test of large diameter ramjet called burner test vehicle (BTV). Advanced low volume...propellant surface. Vernekar et al (43) found that in pressed AP-Al pellets , maximum burn rate is obtained at intermediate metal content. Jain et al...conjunction with high pressure window strand burner . They found that the propellant combustion was irregular and regression rate varied from 0.3 to 3

  12. Vertical-axis turbine/propeller for ship propulsion

    Energy Technology Data Exchange (ETDEWEB)

    Barkla, H.M.

    1984-01-01

    There are so many variables in the design and operating conditions of a vertical-axis turbine/propeller for the propulsion of a ship by wind that a preliminary study is offered, based on two simplified models. Study of a linear motion of blades in air and water shows optimum conditions for blade-speed and blade-incidence. Analysis of the second, cyclical model is simplified by the assumption of constant angles of incidence. While the logical superiority of the vertical-axis system, with its low transmission loss, may not alone give it the advantage over all other systems in upwind and downwind sailing, there are indications that in the beam wind it is in a class of its own; the Voith-Schneider-Type propeller then produces a thrust with a major component to windward, so that the combined unit leaves little or no athwartships force.

  13. Aligned Layers of Silver Nano-Fibers

    Directory of Open Access Journals (Sweden)

    Andrii B. Golovin

    2012-02-01

    Full Text Available We describe a new dichroic polarizers made by ordering silver nano-fibers to aligned layers. The aligned layers consist of nano-fibers and self-assembled molecular aggregates of lyotropic liquid crystals. Unidirectional alignment of the layers is achieved by means of mechanical shearing. Aligned layers of silver nano-fibers are partially transparent to a linearly polarized electromagnetic radiation. The unidirectional alignment and density of the silver nano-fibers determine degree of polarization of transmitted light. The aligned layers of silver nano-fibers might be used in optics, microwave applications, and organic electronics.

  14. Self-aligned periodic Ni nano dots embedded in nano-oxide layer

    International Nuclear Information System (INIS)

    Doi, M.; Izumi, M.; Kawasaki, S.; Miyake, K.; Sahashi, M.

    2007-01-01

    The Ni nano constriction dots embedded in the Ta-nano-oxide layer (NOL) was prepared by the ion beam sputtering (IBS) method. After the various conditions of the oxidations, the structural analyses of the NOL were performed by RHEED, AES and in situ STM/AFM observations. From the current image of the conductive AFM for NOL, the periodically aligned metallic dots with the size around 5-10 nm were successfully observed. The mechanism of the formation of the self-organized aligned Ni nano constriction dots is discussed from the standpoint of the grain size, the crystal orientation, the preferred oxidation of Ta at the diffused interface

  15. Comparison on the interaction of Al3+/nano-Al13 with calf thymus DNA /salmon sperm DNA

    Science.gov (United States)

    Ma, Fei; Ma, Yue; Du, Changwen; Yang, Xiaodi; Shen, Renfang

    2015-11-01

    The conformation change, binding mode and binding site between Al3+/nano-Al13 and calf thymus DNA/salmon sperm DNA were investigated by UV-vis absorption, FTIR spectra, Raman spectroscopy and CD spectra, as well as melting curves measurement. The UV-vis spectra and circular dichroism spectra results suggested that the phosphate group structure was changed when Al3+ interacted with DNA, while the double-helix was distorted when nano-Al13 interacted with DNA. The FTIR and Raman spectroscopy revealed that the binding sites were Al3+ … PO2, Al3+ … N7/guanine PO2 … Al13 … N7-C8/guanine with calf thymus DNA, and Al3+ … N3-O2/cytosine, Al3+ … N7-C8/guanine, PO2 … Al13 … N7-C8/guanine, PO2 … Al13 … N1/adenine with salmon sperm DNA, respectively. The electrostatic binding was existed between Al3+ and DNA, and the electrostatic binding and complexing were found between nano-Al13 and DNA.

  16. Low cost manned Mars mission based on indigenous propellant production

    Science.gov (United States)

    Bruckner, A. P.; Cinnamon, M.; Hamling, S.; Mahn, K.; Phillips, J.; Westmark, V.

    1993-01-01

    The paper describes a low-cost approach to the manned exploration of Mars (which involves an unmanned mission followed two years later by a manned mission) based on near-term technologies and in situ propellant production. Particular attention is given to the basic mission architecture and its major components, including the orbital analysis, the unmanned segment, the Earth Return Vehicle, the aerobrake design, life sciences, guidance, communications, power, propellant production, the surface rovers, and Mars science. Also discussed are the cost per mission over an assumed 8-yr initiative.

  17. Review on Nano SeleniumProduced by Bacteria

    Directory of Open Access Journals (Sweden)

    LI Ji-xiang

    2014-12-01

    Full Text Available Selenium (Se is a kind of essential trace element for people and animal, while ionic state of selenium is toxic with high concentrations and will cause the selenium pollution. Nano-selenium is stable, nontoxic with higher biological activity. Application of bacteria reducing selenite or selenate to biological nano-selenium has great potential in selenium pollution control and nano-selenium production. This review summarizes the research progress of the red elemental nano-selenium reduced by bacteria including characteristics and application of nano-selenium, effects of carbon and nitrogen source, oxygen, temperature and pH in bacteria nano-selenium production, and molecular mechanisms of nano-selenium reduced by bacteria.

  18. Evaluation of shear bond strength of orthodontic brackets bonded with nano-filled composites.

    Science.gov (United States)

    Chalipa, Javad; Akhondi, Mohammad Sadegh Ahmad; Arab, Sepideh; Kharrazifard, Mohammad Javad; Ahmadyar, Maryam

    2013-09-01

    The purpose of this study was to evaluate the shear bond strength (SBS) of orthodontic brackets bonded with two types of nano-composites in comparison to a conventional orthodontic composite. Sixty extracted human first premolars were randomly divided into 3 groups each containing 20 teeth. In group I, a conventional orthodontic composite (Transbond XT) was used to bond the brackets, while two nano-composites (Filtek TM Supreme XT and AELITE Aesthetic Enamel) were used in groups II and III respectively. The teeth were stored in distilled water at 37°C for 24 hours, thermocycled in distilled water and debonded with a universal testing machine at a crosshead speed of 1 mm/min. The adhesive remnant index (ARI) was also evaluated using a stereomicroscope. AELITE Aesthetic Enamel nano-composite revealed a SBS value of 8.44±2.09 MPa, which was higher than Transbond XT (6.91±2.13) and Filtek TM Supreme XT (6.04±2.01). Statistical analysis revealed a significant difference between groups II and III (P 0.05). Evaluation of ARI showed that Transbond XT left fewer adhesive remains on teeth after debonding. Results of this study indicate that the aforementioned nano-composites can be successfully used for bonding orthodontic brackets.

  19. Application of transient burning rate model of solid propellant in electrothermal-chemical launch simulation

    Directory of Open Access Journals (Sweden)

    Yan-jie Ni

    2016-04-01

    Full Text Available A 30 mm electrothermal-chemical (ETC gun experimental system is employed to research the burning rate characteristics of 4/7 high-nitrogen solid propellant. Enhanced gas generation rates (EGGR of propellants during and after electrical discharges are verified in the experiments. A modified 0D internal ballistic model is established to simulate the ETC launch. According to the measured pressure and electrical parameters, a transient burning rate law including the influence of EGGR coefficient by electric power and pressure gradient (dp/dt is added into the model. The EGGR coefficient of 4/7 high-nitrogen solid propellant is equal to 0.005 MW−1. Both simulated breech pressure and projectile muzzle velocity accord with the experimental results well. Compared with Woodley's modified burning rate law, the breech pressure curves acquired by the transient burning rate law are more consistent with test results. Based on the parameters calculated in the model, the relationship among propellant burning rate, pressure gradient (dp/dt and electric power is analyzed. Depending on the transient burning rate law and experimental data, the burning of solid propellant under the condition of plasma is described more accurately.

  20. Repair of bone defect by nano-modified white mineral trioxide aggregates in rabbit: A histopathological study.

    Science.gov (United States)

    Saghiri, Mohammad-Ali; Orangi, Jafar; Tanideh, Nader; Asatourian, Armen; Janghorban, Kamal; Garcia-Godoy, Franklin; Sheibani, Nader

    2015-09-01

    Many researchers have tried to enhance materials functions in different aspects of science using nano-modification method, and in many cases the results have been encouraging. To evaluate the histopathological responses of the micro-/nano-size cement-type biomaterials derived from calcium silicate-based composition with addition of nano tricalcium aluminate (3CaO.Al2O3) on bone healing response. Ninety mature male rabbits were anesthetized and a bone defect was created in the right mandible. The rabbits were divided into three groups, which were in turn subdivided into five subgroups with six animals each based on the defect filled by: white mineral trioxide aggregate (WMTA), Nano-WMTA, WMTA without 3CaO.Al2O3, Nano-WMTA with 2% Nano-3CaO.Al2O3, and empty as control. Twenty, forty and sixty days postoperatively the animals were sacrificed and the right mandibles were removed for histopathological evaluations. Kruskal-Wallis test with post-hoc comparisons based on the LSMeans procedure was used for data analysis. All the experimental materials provoked a moderate to severe inflammatory reaction, which significantly differed from the control group (pbone formation and bone regeneration data showed significant differences between groups at 40- and 60- day intervals in all groups. Absence of 3CaO.Al2O3 leads to more inflammation and foreign body reaction than other groups in all time intervals. Both powder nano-modification and addition of 2% Nano-3CaO.Al2O3 to calcium silicate-based cement enhanced the favorable tissue response and osteogenesis properties of WMTA based materials.

  1. Metal Oxide Nano structures: Synthesis, Properties, and Applications

    International Nuclear Information System (INIS)

    Xu, L. H.; Patil, D. S.; Yang, J.; Xiao, J.

    2015-01-01

    In recent years, nano structured materials have attracted wide attention due to their fascinating optical and electrical properties, which make these materials potentially suitable for applications in electronics, optics, photonics, and sensors. Some metal oxides show a wide variety of morphologies such as nano wires, nano rods, nano tubes, nano rings, and nano belts. Synthesis and investigation of these metal-oxide nano structures are beneficial not only for understanding the fundamental phenomena in low dimensional systems, but also for developing new-generation nano devices with high performance.

  2. Nano-JASMINE Data Analysis and Publication

    Science.gov (United States)

    Yamada, Y.; Hara, T.; Yoshioka, S.; Kobayashi, Y.; Gouda, N.; Miyashita, H.; Hatsutori, Y.; Lammers, U.; Michalik, D.

    2012-09-01

    The core data reduction for the Nano-JASMINE mission is planned to be done with Gaia's Astrometric Global Iterative Solution (AGIS). A collaboration between the Gaia AGIS and Nano-JASMINE teams on the Nano-JASMINE data reduction started in 2007. The Nano-JASMINE team writes codes to generate AGIS input, and this is called Initial Data Treament (IDT). Identification of observed stars and their observed field of view, getting color index, are different from those of Gaia because Nano-JASMINE is ultra small satellite. For converting centroiding results on detector to the celestial sphere, orbit and attitude data of the satellite are used. In Nano-JASMINE, orbit information is derived from on board GPS data and attitude is processed from on-board star sensor data and on-ground Kalman filtering. We also show the Nano-JASMINE goals, status of the data publications and utilizations, and introduce the next Japanese space astrometric mission.

  3. Frontiers in nano-therapeutics

    CERN Document Server

    Tasnim, Nishat; Sai Krishna, Katla; Kalagara, Sudhakar; Narayan, Mahesh; Noveron, Juan C; Joddar, Binata

    2017-01-01

    This brief highlights recent research advances in the area of nano-therapeutics. Nanotechnology holds immense potential for application in a wide range of biological and engineering applications such as molecular sensors for disease diagnosis, therapeutic agents for the treatment of diseases, a vehicle for delivering therapeutics and imaging agents for theranostic applications, both in-vitro and in-vivo. The brief is grouped into the following sections namely, A) Discrete Nanosystems ; B) Anisotropic Nanoparticles; C) Nano-films/coated/layered and D) Nano-composites.

  4. Investigation on hydrodynamic performance of a marine propeller in oblique flow by RANS computations

    Directory of Open Access Journals (Sweden)

    Jianxi Yao

    2015-01-01

    Full Text Available This paper presents a numerical study on investigating on hydrodynamic characteristics of a marine propeller in oblique flow. The study is achieved by RANS simulations on an open source platform - OpenFOAM. A sliding grid approach is applied to compute the rotating motion of the propeller. Total force and moment acting on blades, as well as average force distributions in one revolution on propeller disk, are obtained for 70 cases of com- binations of advance ratios and oblique angles. The computed results are compared with available experimental data and discussed.

  5. Porous Nano-Si/Carbon Derived from Zeolitic Imidazolate Frameworks@Nano-Si as Anode Materials for Lithium-Ion Batteries

    International Nuclear Information System (INIS)

    Song, Yonghai; Zuo, Li; Chen, Shouhui; Wu, Jiafeng; Hou, Haoqing; Wang, Li

    2015-01-01

    Graphical abstract: Display Omitted -- Highlights: •The porous cage-like carbon/Si nanocomposites were synthesized based on nano-Si@ZIF-8-templatedmethod. •The nano-Si was uniformly embedded in porous amorphous carbon matrices. •The porous dodecahedral carbon framework effectively accommodates the volume variation of Si during the discharge/charge process. •The Si/C nanocomposites exhibit superior reversible capacity of 1168 mA h g −1 after 100 cycles. -- Abstract: Novel porous cage-like carbon (C)/nano-Si nanocomposites as anode materials for lithium-ion batteries (LIBs) was prepared based on nano-Si@zeolitic imidazolate frameworks (ZIF-8)-templated method. In this strategy, p-aminobenzoic acid was initially grafted onto nano-Si to form benzoic acid-functionalized nano-Si, and then nano-Si@ZIF-8 was constructed by alternately growing Zn(NO 3 ) 2 ·6H 2 O and 2-methylimidazolate on benzoic acid-functionalized nano-Si under ultrasound. The novel porous cage-like nano-Si/C nanocomposites were fabricated by pyrolyzing the resulted nano-Si@ZIF-8 and washing with HCl to remove off ZnO. Scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, Raman spectra and N 2 adsorption/desorption isotherms were employed to characterize the porous cage-like nano-Si/C nanocomposites. The resulted nano-Si/C nanocomposites as anode materials for LIBs showed a high reversible capacity of ∼1168 mA h g −1 at 100 mA g −1 after 100 cycles, which was higher than many previously reported Si/C nanocomposites. The porous nanostructure, high specific surface area and good electrical conductivity of the cage-like nano-Si/C nanocomposites contributed together to the good performance for LIBs. It might open up a new way for application of silicon materials

  6. Combustion diagnosis for analysis of solid propellant rocket abort hazards: Role of spectroscopy

    Science.gov (United States)

    Gill, W.; Cruz-Cabrera, A. A.; Donaldson, A. B.; Lim, J.; Sivathanu, Y.; Bystrom, E.; Haug, A.; Sharp, L.; Surmick, D. M.

    2014-11-01

    Solid rocket propellant plume temperatures have been measured using spectroscopic methods as part of an ongoing effort to specify the thermal-chemical-physical environment in and around a burning fragment of an exploded solid rocket at atmospheric pressures. Such specification is needed for launch safety studies where hazardous payloads become involved with large fragments of burning propellant. The propellant burns in an off-design condition producing a hot gas flame loaded with burning metal droplets. Each component of the flame (soot, droplets and gas) has a characteristic temperature, and it is only through the use of spectroscopy that their temperature can be independently identified.

  7. Combustion diagnosis for analysis of solid propellant rocket abort hazards: Role of spectroscopy

    International Nuclear Information System (INIS)

    Gill, W; Cruz-Cabrera, A A; Bystrom, E; Donaldson, A B; Haug, A; Sharp, L; Lim, J; Sivathanu, Y; Surmick, D M

    2014-01-01

    Solid rocket propellant plume temperatures have been measured using spectroscopic methods as part of an ongoing effort to specify the thermal-chemical-physical environment in and around a burning fragment of an exploded solid rocket at atmospheric pressures. Such specification is needed for launch safety studies where hazardous payloads become involved with large fragments of burning propellant. The propellant burns in an off-design condition producing a hot gas flame loaded with burning metal droplets. Each component of the flame (soot, droplets and gas) has a characteristic temperature, and it is only through the use of spectroscopy that their temperature can be independently identified

  8. PIV-based load determination in aircraft propellers

    NARCIS (Netherlands)

    Ragni, D.

    2012-01-01

    The thesis describes the application of particle image velocimetry (PIV) to study the aerodynamic loads of airfoils and aircraft propellers. The experimental work focuses on the development of a measurement procedure to infer the pressure of the flow field from the velocity distribution obtained by

  9. Applications of Nano palm oil fuel ash and Nano fly ash in concrete

    Science.gov (United States)

    Hamada, Hussein M.; Jokhio, Gul Ahmed; Mat Yahaya, Fadzil; Humada, Ali M.

    2018-04-01

    This paper discusses the applications of Nano waste materials including palm oil fuel ash and fly ash in the concrete production. The implementation of nanotechnology has been instrumental in the development of significant interest among the stakeholders to improve the mechanical and chemical properties of materials involved in the production of concrete. Although many researchers have shown the potential of nanomaterials to increase strength and durability of concrete and improve its physical and chemical properties, there is still a knowledge gap regarding the preparation of Nano waste materials from agricultural waste to use as cement replacement instead of non-renewable materials. Therefore, it should be focused on to study Nano- waste materials to benefit from these characteristics during preparation of concrete mixtures. Therefore, this paper highlights the potential of waste materials in the Nano size to partially replace cement in concrete and achieve the same or better result than the traditional concrete. This paper recommends to conduct further experimental works to improve the concrete material properties by investigating the properties of waste materials in Nano size.

  10. Numerical analysis of the effect of plasma flow control on enhancing the aerodynamic characteristics of stratospheric screw propeller

    International Nuclear Information System (INIS)

    Cheng Yufeng; Nie Wansheng

    2012-01-01

    Based on the body force aerodynamic actuation mechanism of dielectric barrier discharge (DBD) plasma, the effect of plasma flow control on enhancing the aerodynamic characteristics of ten blade elements equably along the stratospheric screw propeller blade was numerical studied. Then the effect of plasma flow control enhancing the aerodynamic characteristics of stratospheric screw propeller was compared that by the blade element theory method. The results show that the flow separate phenomena will easily happen in the root region and top end region of screw propeller, and the blade elements in the root region of screw propeller may work on the negative attack angle condition. DBD plasma flow control can entirely restrain the faintish flow separate phenomena in middle region of screw propeller. Although DBD plasma flow control can not entirely restrain the badly flow separate phenomena in top end region of screw propeller, it also can enhance the aerodynamic characteristics of blade elements in these regions in same degree. But effect of DBD plasma flow control on enhancing the aerodynamic characteristics of the blade elements working on the negative attack angle condition is ineffectively. It can be concluded that DBD plasma flow control can enhance the aerodynamic characteristics of stratospheric screw propeller, the thrust of the whole propeller and the propeller efficiency in the case of plasma on will increases by a factor of 28.27% and 12.3% respectively compared with that in the case of plasma off studied. (authors)

  11. Probabilistic environmental risk assessment of five nanomaterials (nano-TiO2, nano-Ag, nano-ZnO, CNT, and fullerenes).

    Science.gov (United States)

    Coll, Claudia; Notter, Dominic; Gottschalk, Fadri; Sun, Tianyin; Som, Claudia; Nowack, Bernd

    2016-01-01

    The environmental risks of five engineered nanomaterials (nano-TiO2, nano-Ag, nano-ZnO, CNT, and fullerenes) were quantified in water, soils, and sediments using probabilistic Species Sensitivity Distributions (pSSDs) and probabilistic predicted environmental concentrations (PECs). For water and soil, enough ecotoxicological endpoints were found for a full risk characterization (between 17 and 73 data points per nanomaterial for water and between 4 and 20 for soil) whereas for sediments, the data availability was not sufficient. Predicted No Effect Concentrations (PNECs) were obtained from the pSSD and used to calculate risk characterization ratios (PEC/PNEC). For most materials and environmental compartments, exposure and effect concentrations were separated by several orders of magnitude. Nano-ZnO in freshwaters and nano-TiO2 in soils were the combinations where the risk characterization ratio was closest to one, meaning that these are compartment/ENM combinations to be studied in more depth with the highest priority. The probabilistic risk quantification allows us to consider the large variability of observed effects in different ecotoxicological studies and the uncertainty in modeled exposure concentrations. The risk characterization results presented in this work allows for a more focused investigation of environmental risks of nanomaterials by consideration of material/compartment combinations where the highest probability for effects with predicted environmental concentrations is likely.

  12. NanoChemistry Group at DTU uses NanoSight's NTA System for Nanoparticle Characterization

    DEFF Research Database (Denmark)

    2011-01-01

    (Nanowerk News) NanoSight, leading manufacturers of unique nanoparticle characterization technology, describes how the Nano Chemistry group at DTU Copenhagen is utilizing nanoparticle tracking analysis, NTA, in its research and teaching programs....

  13. Rapid fabrication of an ordered nano-dot array by the combination of nano-plastic forming and annealing methods

    International Nuclear Information System (INIS)

    Yoshino, Masahiko; Ohsawa, Hiroki; Yamanaka, Akinori

    2011-01-01

    In this paper, a new fabrication method for an ordered nano-dot array is developed. Combination of coating, nano-plastic forming and annealing processes is studied to produce uniformly sized and ordered gold nano-dot array on a quartz glass substrate. The experimental results reveal that patterning of a groove grid on the gold-coated substrate with NPF is effective to obtain the ordered gold nano-dot array. In the proposed fabrication process, the size of the gold nano-dot can be controlled by adjusting the groove grid size. A minimum gold nano-dot array fabricated on a quartz-glass substrate was 93 nm in diameter and 100 nm in pitch. Furthermore, the mechanism of nano-dot array generation by the presented process is investigated. Using a theoretical model it is revealed that the proposed method is capable of fabrication of smaller nano-dots than 10 nm by controlling process conditions adequately.

  14. The effect of brushing with nano calcium carbonate and calcium carbonate toothpaste on the surface roughness of nano-ionomer

    Science.gov (United States)

    Anisja, D. H.; Indrani, D. J.; Herda, E.

    2017-08-01

    Nanotechnology developments in dentistry have resulted in the development of nano-ionomer, a new restorative material. The surface roughness of restorative materials can increase bacteria adhesion and lead to poor oral hygiene. Abrasive agents in toothpaste can alter tooth and restorative material surfaces. The aim of this study is to identify the effect of brushing with nano calcium carbonate, and calcium carbonate toothpaste on surface roughness of nano-ionomer. Eighteen nano-ionomer specimens were brushed with Aquabidest (doubledistilled water), nano calcium carbonate and calcium carbonate toothpaste. Brushing lasted 30 minutes, and the roughness value (Ra) was measured after each 10 minute segment using a surface roughness tester. The data was analyzed using repeated ANOVA and one-way ANOVA test. The value of nano-ionomer surface roughness increased significantly (p<0.05) after 20 minutes of brushing with the nano calcium carbonate toothpaste. Brushing with calcium carbonate toothpaste leaves nano-ionomer surfaces more rugged than brushing with nano calcium carbonate toothpaste.

  15. Accelerated aging of AP/HTPB propellants and the influence of various environmental aging conditions

    NARCIS (Netherlands)

    Keizers, H.L.J.

    1995-01-01

    Preliminary resuits on accelerated aging of lab-scale produced AP/HTPB propellant and propellants from dissectioned rocket motors are discussed, including aging logic, storage conditions, test techniques and resuits on mechanical, ballistic and safety testing. The mam aging effect observed was

  16. Nano dots and nano crystals detectors applications and questions

    International Nuclear Information System (INIS)

    Paltiel, Y.; Shusterman, S.; Naaman, R.; Aqua, T.; Banin, U.; Aharoni, A.

    2006-01-01

    Full Text: Nano technology is in the center of attention in the last decade. In our work we are using nano dots, nano crystals and quantum wells to study and fabricate infrared devices. In this study we aim to develop an accurate narrow band infrared sensor that will use quantum mechanics at room temperature. The sensor is based on a FET like structure, in which the current is very sensitive to potential changes on its surface. We have shown that this configuration provides flexibility and variability in operation bandgap and response. However, the relations between the quantum and the macroscopic world are not trivial and the coupling between worlds influences the transport, noise, and optical measurements. In this talk we will show some of the infrared devices we are studying, and try to present the rich physics and relations that combine between the two worlds

  17. Novel plasmon nano-lasers

    NARCIS (Netherlands)

    Hill, M.T.; Marell, M.J.H.

    2010-01-01

    We will discuss some of the latest developments in metallic and plasmonic nano-lasers. Furthermore we will present our latest results on further miniaturization of electrically pumped plasmonic nano-lasers and also DFB Plasmon mode devices.

  18. Preparation and characterization of bipolar membranes modified by photocatalyst nano-ZnO and nano-CeO2

    International Nuclear Information System (INIS)

    Zhou Tingjin; Hu Yanyu; Chen Riyao; Zheng Xi; Chen Xiao; Chen Zhen; Zhong Jieqiong

    2012-01-01

    Nano-ZnO-CeO 2 coupled semiconductor was added into the chitosan (CS) anion exchange membrane layer to prepare the PVA-CMC/nano-ZnO-CeO 2 -CS (here, PVA: polyvinyl alcohol; CMC: carboxymethyl cellulose) bipolar membrane (BPM), and the prepared BPM was characterized by SEM, J-V characteristics, electronic universal testing machine, contact angle measurement and so on. Experimental results showed that nano-ZnO-CeO 2 exhibited better photocatalytic property for water splitting at the interlayer of BPM than nano-ZnO or nano-CeO 2 , which could greatly reduce the membrane impedance of the BPM. Under the irradiation of high-pressure mercury lamps, the cell voltage of PVA-CMC/nano-ZnO-CeO 2 -CS BPM decreased by 0.7 V at the current density of 60 mA/cm 2 , and the cell voltages of PVA-CMC/nano-ZnO-CS BPM and PVA-CMC/nano-CeO 2 -CS BPM were only reduced by 0.3 V and 0.5 V, respectively. Furthermore, the hydrophilicity, and mechanical properties of the modified BPM were increased.

  19. Counter-rotating type tidal stream power unit boarded on pillar (performances and flow conditions of tandem propellers)

    Science.gov (United States)

    Usui, Yuta; Kanemoto, Toshiaki; Hiraki, Koju

    2013-12-01

    The authors have invented the unique counter-rotating type tidal stream power unit composed of the tandem propellers and the double rotational armature type peculiar generator without the traditional stator. The front and the rear propellers counter-drive the inner and the outer armatures of the peculiar generator, respectively. The unit has the fruitful advantages that not only the output is sufficiently higher without supplementary equipment such as a gearbox, but also the rotational moment hardly act on the pillar because the rotational torque of both propellers/armatures are counter-balanced in the unit. This paper discusses experimentally the performances of the power unit and the effects of the propeller rotation on the sea surface. The axial force acting on the pillar increases naturally with the increase of not only the stream velocity but also the drag of the tandem propellers. Besides, the force vertical to the stream also acts on the pillar, which is induced from the Karman vortex street and the dominant frequencies appear owing to the front and the rear propeller rotations. The propeller rotating in close to the sea surface brings the abnormal wave and the amplitude increases as the stream velocity is faster and/or the drag is stronger.

  20. Applications and Nano toxicity of Carbon Nano tubes and Graphene in Biomedicine Caitlin Fisher

    International Nuclear Information System (INIS)

    Rider, A.E.; Han, Z.J.; Kumar, S.; Levchenko, L.; Ostrikov, K.K.

    2012-01-01

    Owing to their unique mechanical, electrical, optical, and thermal properties, carbon nano structures including carbon nano tubes and graphenes show great promise for advancing the fields of biology and medicine. Many reports have demonstrated the promise of these carbon nano structures and their hybrid structures (composites with polymers, ceramics, and metal nanoparticles, etc.) for a variety of biomedical areas ranging from bio sensing, drug delivery, and diagnostics, to cancer treatment, tissue engineering, and bio terrorism prevention. However, the issue of the safety and toxicity of these carbon nano structures, which is vital to their use as diagnostic and therapeutic tools in biomedical fields, has not been completely resolved. This paper aims to provide a summary of the features of carbon nano tube and graphene-based materials and current research progress in biomedical applications. We also highlight the current opinions within the scientific community on the toxicity and safety of these carbon structures

  1. Spray and Combustion of Gelled Hypergolic Propellants

    Science.gov (United States)

    2014-10-20

    moisture absorption on the fumed silica surface correlates directly to the ambient humidity , and can reach 12% by weight at an atmospheric humidity of...propellant interface, the liquid at the interface can be heated to the homogeneous vapor nucleation temperature rather than the boiling point. At this

  2. 30 CFR 56.4230 - Self-propelled equipment.

    Science.gov (United States)

    2010-07-01

    ....4230 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Fire Prevention and Control Firefighting Equipment § 56.4230 Self-propelled equipment. (a)(1) Whenever a fire or its effects...

  3. The Degradation of Mechanical Properties in Halloysite Nano clay-Polyester Nano composites Exposed in Seawater Environment

    International Nuclear Information System (INIS)

    Saharudin, M.S.; Saharudin, M. Sh.; Wei, J.; Shyha, I.; Inam, F.

    2016-01-01

    Polyester based polymers are extensively used in aggressive marine environments; however, inadequate data is available on the effects of the seawater on the polyester based nano composites mechanical properties. This paper reports the effect of seawater absorption on the mechanical properties degradation of halloysite nano clay-polyester nano composites. Results confirmed that the addition of halloysite nano clay into polyester matrix was found to increase seawater uptake and reduce mechanical properties compared to monolithic polyester. The maximum decreases in microhardness, tensile and flexural properties, and impact toughness were observed in case of 1 wt% nano clay. The microhardness decreased from 107 HV to 41.7 HV (61% decrease). Young s modulus decreased from 0.6 GPa to 0.4 GPa (33% decrease). The flexural modulus decreased from 0.6 GPa to 0.34 GPa (43% decrease). The impact toughness dropped from 0.71 kJ/m"2 to 0.48 kJ/m"2 (32% decrease). Interestingly, the fracture toughnessκ_1C increased with the addition of halloysite nano clay due to the plasticization effect of the resin matrix. SEM images revealed the significant reduction in mechanical properties in case of 1 wt% reinforcement which is attributed to the degradation of the nano clay-matrix interface influenced by seawater absorption and agglomeration of halloysite nano clay.

  4. Applications of Nano-optics.

    Science.gov (United States)

    Zhou, Changhe; Fainman, Yeshaiahu; Sheng, Yunlong

    2011-11-01

    As nanoscale fabrication techniques advance, nano-optics continues to offer enabling solutions to numerous practical applications for information optics. This Applied Optics feature issue focuses on the Application of Nano-optics. © 2011 Optical Society of America

  5. Nano materials for Medical and Dental Applications

    International Nuclear Information System (INIS)

    Yub Kwon, T.; Oh, D.S.; Narayanan, R.

    2015-01-01

    Welcome to this special issue. Nano science and nano technology concepts are applicable across all fields of science and a more widespread application of nano materials and nano technologies is imminent or already occurring in many areas, including health care. Today is scientists take those cutting-edge technologies and concepts and apply them to medicine and dentistry. They are finding a wide variety of ways to make medical and dental materials at the nano scale to take advantage of their enhanced physical and biological properties.The purpose of this special issue is to publish high-quality research papers as well as review articles addressing recent advances in the field of nano materials for medical and dental applications. A particular interest is given to papers exploring or discussing nano materials and nano technologies related to delivery system, bonding substitutes, and surface modification techniques applicable in these areas. For this special issue, several investigators were invited to contribute original research findings that can stimulate continuing efforts to understand the cutting-edge applications of nano materials in medicine and dentistry.

  6. Self-regulation in self-propelled nematic fluids.

    Science.gov (United States)

    Baskaran, A; Marchetti, M C

    2012-09-01

    We consider the hydrodynamic theory of an active fluid of self-propelled particles with nematic aligning interactions. This class of materials has polar symmetry at the microscopic level, but forms macrostates of nematic symmetry. We highlight three key features of the dynamics. First, as in polar active fluids, the control parameter for the order-disorder transition, namely the density, is dynamically convected by the order parameter via active currents. The resulting dynamical self-regulation of the order parameter is a generic property of active fluids and destabilizes the uniform nematic state near the mean-field transition. Secondly, curvature-driven currents render the system unstable deep in the nematic state, as found previously. Finally, and unique to self-propelled nematics, nematic order induces local polar order that in turn leads to the growth of density fluctuations. We propose this as a possible mechanism for the smectic order of polar clusters seen in numerical simulations.

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

    Directory of Open Access Journals (Sweden)

    Thelma Manning

    2014-06-01

    Full Text Available 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 charges. CAN 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 NC. The formulation, development and small-scale characterization testing of several CAN-based propellants were done. The formulations, using insensitive energetic solid fillers and high-nitrogen modifiers in place of nitramine were completed. The small scale characterization testing, such as closed bomb testing, small scale sensitivity, thermal stability, and chemical compatibility were done. The mechanical response of the propellants under high-rate uni-axial compression at, hot, cold, and ambient temperatures were also completed. Critical diameter testing, hot fragment conductive ignition (HFCI tests were done to evaluate the propellants' responses to thermal and shock stimuli. Utilizing the propellant chemical composition, theoretical predictions of erosivity were completed. All 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 the 105 mm M67 artillery charge configurations. The test results completed in the small and large scale testing are discussed.

  8. A novel approach to nano topology via neutrosophic sets

    OpenAIRE

    M. Lellis Thivagar; Saeid Jafari; V. Sutha Devi; V. Antonysamy

    2018-01-01

    The main objective of this study is to introduce a new hybrid intelligent structure called Neutrosophic nano topology. Fuzzy nano topology and intuitionistic nano topology can also be deduced from the neutrosophic nano topology. Based on the neutrosophic nano approximations we have classified neutrosophic nano topology. Some properties like neutrosophic nano interior and neutrosophic nano closure are derived.

  9. Mass transfer in nano-fluids: A review

    International Nuclear Information System (INIS)

    Ashrafmansouri, Seyedeh-Saba; Esfahany, Mohsen Nasr

    2014-01-01

    Growing attention has been recently paid to nano-fluids because of their potential for augmenting transfer processes - i.e., heat and mass transfer. Conflicting results have been reported in the literature on mass transfer in nano-fluids. The aim of this paper is to summarize the literature on mass transfer in nano-fluids stating the conflicts and possible reasons. Literature on mass transfer in nano-fluids has been reviewed in two sections. The first section concentrates on surveying mass diffusivity in nano-fluids while the second section focuses on convective mass transfer in nano-fluids. In each section, published articles, type of nano-fluids used, size and concentration range of nanoparticles, measurement methods, maximum observed enhancement, and suggested mass transport mechanisms are summarized. (authors)

  10. Spin-accumulation effect in magnetic nano-bridge

    International Nuclear Information System (INIS)

    Khvalkovskii, A.V.; Zvezdin, A.A.; Zvezdin, K.A.; Pullini, D.; Perlo, P.

    2004-01-01

    Large values of magnetoresistance experimentally observed in magnetic nano-contacts and nano-wires are explained in terms of spin accumulation. The investigation of the spin-accumulation effect in magnetic nano-contacts (Phys. Rev. Lett. 82 (1999) 2923) and nano-bridges (JETP Lett. 75 (10) (2002) 613), which are considered to be very promising for various spintronic applications, is presented. The two-dimensional spin-diffusion problem in a magnetic nano-bridge is solved. Dependences of the specific resistance of the domain wall and of the distribution of non-equilibrium spin density on the nano-bridge geometry and the material parameters are obtained

  11. Fabrication of Propeller-Shaped Supra-amphiphile for Construction of Enzyme-Responsive Fluorescent Vesicles.

    Science.gov (United States)

    Li, Jie; Liu, Kaerdun; Han, Yuchun; Tang, Ben Zhong; Huang, Jianbin; Yan, Yun

    2016-10-04

    Propeller-shaped molecules have been recognized to display fantastic AIE (aggregation induced emission), but they can hardly self-assemble into nanostructures. Herein, we for the first time report that ionic complexation between a water-soluble tetrapheneyl derivative and an enzyme substrate in aqueous media produces a propeller-shaped supra-amphiphile that self-assembles into enzyme responsive fluorescent vesicles. The supra-amphiphile was fabricated upon complexation between a water-soluble propeller-shaped AIE luminogen TPE-BPA and myristoylcholine chloride (MChCl) in aqueous media. MChCl filled in the intramolecular voids of propeller-shaped TPE-BPA upon supra-amphiphile formation, which endows the supra-amphiphile superior self-assembling ability to the component molecules thus leading to the formation of fluorescent vesicles. Because MChCl is the substrate of cholinesterases, the vesicles dissemble in the presence of cholinesterases, and the fluorescent intensity can be correlated to the level of enzymes. The resulting fluorescent vesicles may be used to recognize the site of Alzheimer's disease, to encapsulate the enzyme inhibitor, and to release the inhibitor at the disease site.

  12. Nano catalysis: Academic Discipline and Industrial Realities

    International Nuclear Information System (INIS)

    Olveira, S.; Forster, S.P.; Seeger, S.

    2014-01-01

    Nano technology plays a central role in both academic research and industrial applications. Nano enabled products are not only found in consumer markets, but also importantly in business to business markets (B2B). One of the oldest application areas of nano technology is nano catalysis—an excellent example for such a B2 B market. Several existing reviews illustrate the scientific developments in the field of nano catalysis. The goal of the present review is to provide an up-to-date picture of academic research and to extend this picture by an industrial and economic perspective. We therefore conducted an extensive search on several scientific databases and we further analyzed more than 1,500 nano catalysis-related patents and numerous market studies. We found that scientists today are able to prepare nano catalysts with superior characteristics regarding activity, selectivity, durability, and recoverability, which will contribute to solve current environmental, social, and industrial problems. In industry, the potential of nano catalysis is recognized, clearly reflected by the increasing number of nano catalysis-related patents and products on the market. The current nano catalysis research in academic and industrial laboratories will therefore enable a wealth of future applications in the industry

  13. Editorial Nano structures for Medicine and Pharmaceuticals

    International Nuclear Information System (INIS)

    Xing-Jie, L.; Kumar, A.; Donglu, S.; Daxiang, C.

    2012-01-01

    The rapid developments in nano structured materials and nano technology will have profound impact in many areas of biomedical applications including delivery of drugs and biomolecules, tissue engineering, detection of bio markers, cancer diagnosis, cancer therapy, and imaging. This field is expanding quickly, and a lot of work is ongoing in the design, characterization, synthesis, and application of materials, for controlling shape and size at nanometer scale to develop highly advanced materials for biomedical application and even to design better pharmaceutical products. In recent years, novel nano structure with multi functionalities has been focused on the use of nano structures toward solving problems of biology and medicine. The main scope of this special issue is to demonstrate the latest achievement of nano technology and its application in nano medicine particularly in new approaches for drug delivery such as targeted drug delivery system, nano structure for drug storage, nano materials for tissue engineering, medical diagnosis and treatment, and generation of new kinds of materials from biological sources. Therefore, many critical issues in nano structured materials, particularly their applications in biomedicine, must be addressed before clinical applications. This special issue devotes several review and research articles encompassing various aspects of nano materials for medicine and pharmaceuticals.

  14. The nano-science of C60 molecule

    International Nuclear Information System (INIS)

    Rafii-Tabar, H.

    2002-01-01

    Over the past few years, nano-science and its associated nano-technology have emerged into prominence in research institutions across the world. They have brought about new scientific and engineering paradigms, allowing for the manipulation of single atoms and molecules, designing and fabricating new materials, atom-by-atom, and devices that operate on significantly reduced time and length scales. One important area of research in nano-science and nano technology is carbon-based physics in the form of fullerene physics. The C 6 0 molecule, and other cage-like fullerenes, together with carbon nano tubes provide objects that can be combined to generate three-dimensional functional structures for use in the anticipated nano-technology of future. The unique properties of C 6 0 can also be exploited in designing nano-phase thin films with applications in nano-scope device technology and processes such as nano-lithography. This requires a deep understanding of the highly complex process of adsorption of this molecule on a variety of substrates. We review the field of nano-scale nucleation and growth of C 6 0 molecules on some of the technologically important substrates. In addition to experimental results, the results of a set of highly accurate computational simulations are also reported

  15. Observations of tip vortex cavitation inception from a model marine propeller

    Science.gov (United States)

    Lodha, R. K.; Arakeri, V. H.

    1984-01-01

    Cavitation inception characteristics of a model marine propeller having three blades, developed area ratio of 0.34 and at three different pitch to diameter ratios of 0.62, 0.83 and 1.0 are reported. The dominant type of cavitation observed at inception was the tip vortex type. The measured magnitude of inception index is found to agree well with a proposed correlation due to Strasberg. Performance calculations of the propeller based on combined vortex and blade element theory are also presented.

  16. Study the scratch resistance of UV-cured epoxy acrylate in the presence of nano alumina particles via nano indentation

    International Nuclear Information System (INIS)

    Bastani, S.; Ebrahimi, M.; Kardar, P.

    2007-01-01

    In this research, an epoxy acrylate resin was synthesized, then the synthesized resin was used along with different multifunctional acrylate monomers and with a photoinitiator in different formulations and cured with UV radiation. The experiments were designed based on mixture method by using Design-Expert software. To investigate the effect of nano particles on the some of physical and mechanical properties of the UV cured resins, the suspension of nano alumina in TPGDA, was used in formulations. The hardness of prepared films was evaluated by using konig hardness tester and nano indentater. The scratch resistance and gloss of the films were also determined. The results showed that the visibility of scratch decreased when the nano particles were used. It seems that the self-healing property of the film improved in the presence of nano particles. The hardness of the samples with nano particles was found to be less than that the samples of without any nano particles. It was observed that the gloss of the films with the nano particles, almost was the same as the film without nano particles. (Author)

  17. Rational design and dynamics of self-propelled colloidal bead chains: from rotators to flagella

    NARCIS (Netherlands)

    Vutukuri, Hanumantha Rao|info:eu-repo/dai/nl/304838926; Bet, Bram|info:eu-repo/dai/nl/370530667; van Roij, Rene|info:eu-repo/dai/nl/152978984; Dijkstra, Marjolein|info:eu-repo/dai/nl/123538807; Huck, Wilhelm T S

    2017-01-01

    The quest for designing new self-propelled colloids is fuelled by the demand for simple experimental models to study the collective behaviour of their more complex natural counterparts. Most synthetic self-propelled particles move by converting the input energy into translational motion. In this

  18. Active matter in silico : phase behaviour of attractive, repulsive and anisotropic self-propelled particles

    NARCIS (Netherlands)

    Prymidis, V.

    2017-01-01

    In this thesis we study emergent statistical properties of many-particle systems of self-propelled particles using computer simulations. Ensembles of self-propelled particles belong to the class of physical systems labeled active matter, a term that refers to systems whose individual components are

  19. Research on a Micro-Nano Si/SiGe/Si Double Heterojunction Electro-Optic Modulation Structure

    Directory of Open Access Journals (Sweden)

    Song Feng

    2018-01-01

    Full Text Available The electro-optic modulator is a very important device in silicon photonics, which is responsible for the conversion of optical signals and electrical signals. For the electro-optic modulator, the carrier density of waveguide region is one of the key parameters. The traditional method of increasing carrier density is to increase the external modulation voltage, but this way will increase the modulation loss and also is not conducive to photonics integration. This paper presents a micro-nano Si/SiGe/Si double heterojunction electro-optic modulation structure. Based on the band theory of single heterojunction, the barrier heights are quantitatively calculated, and the carrier concentrations of heterojunction barrier are analyzed. The band and carrier injection characteristics of the double heterostructure structure are simulated, respectively, and the correctness of the theoretical analysis is demonstrated. The micro-nano Si/SiGe/Si double heterojunction electro-optic modulation is designed and tested, and comparison of testing results between the micro-nano Si/SiGe/Si double heterojunction micro-ring electro-optic modulation and the micro-nano Silicon-On-Insulator (SOI micro-ring electro-optic modulation, Free Spectrum Range, 3 dB Bandwidth, Q value, extinction ratio, and other parameters of the micro-nano Si/SiGe/Si double heterojunction micro-ring electro-optic modulation are better than others, and the modulation voltage and the modulation loss are lower.

  20. Nano Surface Engineering in the 21st Century

    Institute of Scientific and Technical Information of China (English)

    Xu Bin-shi; Wang Hai-dou; Dong Shi-yun; Shi Pei-jing; Xu Yi

    2004-01-01

    Nano surface engineering is the new development of surface engineering, and is the typical representation that the advanced nano technology improves the traditional surface engineering. The connotation of nano surface engineering is profound. The initial stage of nano surface engineering is realized at present day. The key technologies of nano surface engineering are the support to the equipment remanufacturing. Today the relatively mature key technologies are: nano thermal spraying technology, nano electric-brush plating technology, nano self-repairing anti-friction technology and metal surface nanocrystallization, etc. Many scientific issues have been continuously discovered. Meanwhile they have been applied in the practice more and more, and have archived the excellent remanufacturing effect.