869 research outputs found

    Rocket Propulsion Engineering Company Small Launch Vehicle

    Get PDF
    Rocket Propulsion Engineering (RPe) is developing the first in a family of two low-cost, two stage, small rocket vehicles suitable for target, suborbital, and small-sat orbital applications. The first of these two launch vehicles, the Prospect LV-1 will have an orbital payload of 300-400 lb. The larger vehicle, the Prospect LV-2, uses about 80% of the components and technology of the LV-1 and will orbit payloads of 1500-1700 lb. Two engines are being developed. A first stage 30,000 lbf class engine (R1-30L) and a second stage engine of approximately 2400 lbf (R1-2H). The engine designs are essentially identical except for size. Propellants are hydrogen peroxide/kerosene. The engines are ablatively cooled with additional film cooling. Chamber pressure is approximately 715 PSIA. Both engines use centrifugal turbopumps driven by an open cycle, bipropellant gas generator. Medium-technology pump-fed rockets have significant advantages over pressure fed alternatives, provided the pump technology remains simple. Among these advantages are: smaller, lighter, more efficient engines; less propellant use; and simpler and smaller ground-handling equipment. Most importantly, propellant tank structure is lighter and much simpler to engineer and manufacture, and high-pressure helium tankage is greatly reduced. RPe therefore decided to put the engineering effort into developing the turbopump rather than pressure-fed vehicle structures. To be practical and cost effective, the turbopump must be simple by modern rocket engine standards. To this end, RPe has been pursuing a very modular, scalable pump design, utilizing as few components as possible – all components being readily available through standard commercial supply and manufacturing processes. The result is a very simple, very low-cost pump design that significantly enhances the overall vehicle design and greatly reduces vehicle structural weight and propellant requirements. Vehicle structure employs weight-saving features such as the use of a common propellant tank bulkhead and the extensive use of modern composites. Storable, ambient temperature propellants eliminate many of the material, embrittlement, and strain-related design problems that typically accompany cryogenic vehicles. The engines for these vehicles, especially the smaller R1-2H, should also be attractive candidates for use as the main propulsion engines on orbital transfer upper stages and as storable spacecraft engines

    DNA-Ormocer based biocomposite for fabrication of photonic structures

    No full text
    We report microfabrication of high quality photonicstructures such as two-dimensional photonic crystals and beam splitters from a high DNA load, photosensitive Ormocer nanocomposite. This nanocomposite combines the high dye loading capacity of DNA with the photopatternability and hardness of the Ormocer. The fabrication is performed with the two-photon lithography method. Detailed studies of the deoxyribonucleic acid distribution in the fabricatedstructures are conducted with Raman microscopy. We also demonstrate that the deoxyribonucleic acid based nanocomposite films cast on glass substrates are of high enough quality to support amplified spontaneous emission from dyes intercalated in the deoxyribonucleic acid

    High power and ultra-low-noise photodetector for squeezed-light enhanced gravitational wave detectors

    Get PDF
    Current laser-interferometric gravitational wave detectors employ a self-homodyne readout scheme where a comparatively large light power (5–50 mW) is detected per photosensitive element. For best sensitivity to gravitational waves, signal levels as low as the quantum shot noise have to be measured as accurately as possible. The electronic noise of the detection circuit can produce a relevant limit to this accuracy, in particular when squeezed states of light are used to reduce the quantum noise. We present a new electronic circuit design reducing the electronic noise of the photodetection circuit in the audio band. In the application of this circuit at the gravitational-wave detector GEO 600 the shot-noise to electronic noise ratio was permanently improved by a factor of more than 4 above 1 kHz, while the dynamic range was improved by a factor of 7. The noise equivalent photocurrent of the implemented photodetector and circuit is about 5 µA/ √\ud Hz above 1 kHz with a maximum detectable photocurrent of 20 mA. With the new circuit, the observed squeezing level in GEO 600 increased by 0.2 dB. The new circuit also creates headroom for higher laser power and more squeezing to be observed in the future in GEO 600 and is applicable to other optics experiments

    DNA Based Electrolyte/Separator for Lithium Battery Application

    Get PDF
    In this study, we demonstrated the use of DNA-CTMA (DC) in combination with PolyVinylidene Fluoride (PVDF) as a host matrix or separator for Lithium based electrolyte to form solid polymer/gel like electrolyte for potential application in Li-ion batteries. The addition of DC provided a better thermal stability of the composite electrolyte as shown by the thermos-gravimetric analysis (TGA). The AC conductivity measurements suggest that the addition of DC to the gel electrolyte had no effect on the overall ionic conductivity of the composite. The obtained films are flexible with high mechanical stretch-ability as compared to the gel type electrolytes only

    Deoxyribonucleic acid-based photochromic material for fast dynamic holography

    No full text
    The authors report on a biopolymeric material made of deoxyribonucleic acid (DNA) complexed with the cationic surfactant cetyltrimethyl-ammonium (CTMA) and doped with the photochromic disperse red 1 dye (DR1) for dynamic holographic recording. The molar ratio of the DNA-CTMA to the dye is about 5:1. They have found that the photochromic properties of DR1 in the DNA-CTMA matrix are favorably modified in speed of response with respect to conventional polymeric matrices. Dynamic holographic gratings which were inscribed in DR1:DNA-CTMA films are characterized by switching times within a 1–10ms range. An excellent reversibility of the recording process is reported.The authors acknowledge the Australian Research Council Discovery Project No. DP0556942, the Materials and Manufacturing Directorate Air Force Office of Scientific Research, the AOARD Grant No. 05-4010, and the Polish Ministry of Science and Higher Education Grant No. N50713231/3302 for financial support

    First demonstration of 6 dB quantum noise reduction in a kilometer scale gravitational wave observatory

    Get PDF
    Photon shot noise, arising from the quantum-mechanical nature of the light, currently limits the sensitivity of all the gravitational wave observatories at frequencies above one kilohertz. We report a successful application of squeezed vacuum states of light at the GEO\,600 observatory and demonstrate for the first time a reduction of quantum noise up to 6.03±0.026.03 \pm 0.02 dB in a kilometer-scale interferometer. This is equivalent at high frequencies to increasing the laser power circulating in the interferometer by a factor of four. Achieving this milestone, a key goal for the upgrades of the advanced detectors, required a better understanding of the noise sources and losses, and implementation of robust control schemes to mitigate their contributions. In particular, we address the optical losses from beam propagation, phase noise from the squeezing ellipse, and backscattered light from the squeezed light source. The expertise gained from this work carried out at GEO 600 provides insight towards the implementation of 10 dB of squeezing envisioned for third-generation gravitational wave detectors

    An Experiment for Observing Quantum Gravity Phenomena using Twin Table-Top 3D Interferometers

    Get PDF
    Theories of quantum gravity based on the holographic principle predict the existence of quantum fluctuations of distance measurements that accumulate and exhibit correlations over macroscopic distances. This paper models an expected signal due to this phenomenology, and details the design and estimated sensitivity of co-located twin table-top 3D interferometers being built to measure or constrain it. The experiment is estimated to be sensitive to displacements ∼10−19 m/Hz\sim10^{-19}\,\rm{m}/\sqrt{\rm{Hz}} in a frequency band between 1 and 250 MHz, surpassing previous experiments and enabling the possible observation of quantum gravity phenomena. The experiment will also be sensitive to MHz gravitational waves and various dark matter candidates.Comment: Accepted for publication in Classical and Quantum Gravit
    • …
    corecore