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Sample records for optical storage puzzle

  1. Manchester's Magiscope: An Interesting Optics Puzzle

    NASA Astrophysics Data System (ADS)

    Lancor, Rachael; Lancor, Brian

    2017-02-01

    The Magiscope was an attraction at Manchester's department store in Madison, WI, in 1939 that allowed children to peek into Santa's workshop (as shown in Fig. 1). The "magiscope" was a telescope-like device that gave children the illusion they were looking at a distant Santa, when in fact they were looking at a fabricated workshop on an upper level of the department store. In this article, we describe how we used the puzzle of the magiscope as a final assessment for our optics unit in an introductory physics course.

  2. Wideband optical storage

    NASA Technical Reports Server (NTRS)

    Heard, H. G.

    1979-01-01

    This paper has five purposes. First, to focus upon the key relationships that bound the technology choices for large, archival, digital storage devices; second, to identify the motivations for selecting the optical technology for a petabit-exabit level storage system (10 to the 15th to 10 to the 18th bits); third, to present a generic example and a specific implementation of a terabit-level optical storage device; fourth, to characterize the global design space constraints that will allow one to build a technology-limited optical store; and fifth, to sketch the outline of the BYTERON concept, a wideband 10 to the 16th to 10 to the 17th bit optical store concept and contrast its performance to that of an optical store that is in operation today

  3. Holographic Optical Data Storage

    NASA Technical Reports Server (NTRS)

    Timucin, Dogan A.; Downie, John D.; Norvig, Peter (Technical Monitor)

    2000-01-01

    Although the basic idea may be traced back to the earlier X-ray diffraction studies of Sir W. L. Bragg, the holographic method as we know it was invented by D. Gabor in 1948 as a two-step lensless imaging technique to enhance the resolution of electron microscopy, for which he received the 1971 Nobel Prize in physics. The distinctive feature of holography is the recording of the object phase variations that carry the depth information, which is lost in conventional photography where only the intensity (= squared amplitude) distribution of an object is captured. Since all photosensitive media necessarily respond to the intensity incident upon them, an ingenious way had to be found to convert object phase into intensity variations, and Gabor achieved this by introducing a coherent reference wave along with the object wave during exposure. Gabor's in-line recording scheme, however, required the object in question to be largely transmissive, and could provide only marginal image quality due to unwanted terms simultaneously reconstructed along with the desired wavefront. Further handicapped by the lack of a strong coherent light source, optical holography thus seemed fated to remain just another scientific curiosity, until the field was revolutionized in the early 1960s by some major breakthroughs: the proposition and demonstration of the laser principle, the introduction of off-axis holography, and the invention of volume holography. Consequently, the remainder of that decade saw an exponential growth in research on theory, practice, and applications of holography. Today, holography not only boasts a wide variety of scientific and technical applications (e.g., holographic interferometry for strain, vibration, and flow analysis, microscopy and high-resolution imagery, imaging through distorting media, optical interconnects, holographic optical elements, optical neural networks, three-dimensional displays, data storage, etc.), but has become a prominent am advertising

  4. ICI optical data storage tape

    NASA Technical Reports Server (NTRS)

    Mclean, Robert A.; Duffy, Joseph F.

    1991-01-01

    Optical data storage tape is now a commercial reality. The world's first successful development of a digital optical tape system is complete. This is based on the Creo 1003 optical tape recorder with ICI 1012 write-once optical tape media. Several other optical tape drive development programs are underway, including one using the IBM 3480 style cartridge at LaserTape Systems. In order to understand the significance and potential of this step change in recording technology, it is useful to review the historical progress of optical storage. This has been slow to encroach on magnetic storage, and has not made any serious dent on the world's mountains of paper and microfilm. Some of the reasons for this are the long time needed for applications developers, systems integrators, and end users to take advantage of the potential storage capacity; access time and data transfer rate have traditionally been too slow for high-performance applications; and optical disk media has been expensive compared with magnetic tape. ICI's strategy in response to these concerns was to concentrate its efforts on flexible optical media; in particular optical tape. The manufacturing achievements, media characteristics, and media lifetime of optical media are discussed.

  5. Nanomaterials for optical data storage

    NASA Astrophysics Data System (ADS)

    Gu, Min; Zhang, Qiming; Lamon, Simone

    2016-12-01

    The growing amount of data that is generated every year creates an urgent need for new and improved data storage methods. Nanomaterials, which have unique mechanical, electronic and optical properties owing to the strong confinement of electrons, photons and phonons at the nanoscale, are enabling the development of disruptive methods for optical data storage with ultra-high capacity, ultra-long lifetime and ultra-low energy consumption. In this Review, we survey recent advancements in nanomaterials technology towards the next generation of optical data storage systems, focusing on metallic nanoparticles, graphene and graphene oxide, semiconductor quantum dots and rare-earth-doped nanocrystals. We conclude by discussing the use of nanomaterials in data storage systems that do not rely on optical mechanisms and by surveying the future prospects for the field.

  6. Optical Storage Performance Modeling and Evaluation.

    ERIC Educational Resources Information Center

    Behera, Bailochan; Singh, Harpreet

    1990-01-01

    Evaluates different types of storage media for long-term archival storage of large amounts of data. Existing storage media are reviewed, including optical disks, optical tape, magnetic storage, and microfilm; three models are proposed based on document storage requirements; performance analysis is considered; and cost effectiveness is discussed.…

  7. Optical storage device

    NASA Technical Reports Server (NTRS)

    Welch, Sharon S.

    1991-01-01

    A new holographic image storage device which uses four-wave mixing in two photorefractive crystals is described. Photorefractive crystals promise information storage densities on the order of 10(exp 9) to 10(exp 12) bits per cubic centimeter at real-time rates. Several studies in recent years have investigated the use of photorefractive crystals for storing holographic image information. However, all of the previous studies have focused on techniques for storing information in a single crystal. The disadvantage of using a single crystal is that the read process is destructive. Researchers have developed techniques for fixing the information in a crystal so that it may be read many times. However, when fixed, the information cannot be readily erased and overwritten with new information. It two photorefractive crystals are used, holographic image information may be stored dynamically. That is, the stored image information may be read out more than once, and it may be easily erased and overwritten with new image information.

  8. Optical Storage Technology Subgroup (FIMUG)

    DTIC Science & Technology

    1990-04-01

    PROCUREMENT INSTRUMENT IDEyTiFiCAT,ON NUMBER ORGANIZATION (If applicable) US Army Corps of Engineers I 8c. ADDRESS (Citv. State, and ZIP Code) I0 SOURCE OF... Engineering , and Automation) are considered in relation to the current level of optical technology, and options for the US Army Corps of Engi- neers are... Engineer - ing, and Automation are provided in the report. Conclusions General conclusions are as follow: a. The use of optical storage technologies can

  9. Advanced optical disk storage technology

    NASA Technical Reports Server (NTRS)

    Haritatos, Fred N.

    1996-01-01

    There is a growing need within the Air Force for more and better data storage solutions. Rome Laboratory, the Air Force's Center of Excellence for C3I technology, has sponsored the development of a number of operational prototypes to deal with this growing problem. This paper will briefly summarize the various prototype developments with examples of full mil-spec and best commercial practice. These prototypes have successfully operated under severe space, airborne and tactical field environments. From a technical perspective these prototypes have included rewritable optical media ranging from a 5.25-inch diameter format up to the 14-inch diameter disk format. Implementations include an airborne sensor recorder, a deployable optical jukebox and a parallel array of optical disk drives. They include stand-alone peripheral devices to centralized, hierarchical storage management systems for distributed data processing applications.

  10. Optical Storage Developments--Write-Once Media.

    ERIC Educational Resources Information Center

    Edwards, Ian C.

    1987-01-01

    Discusses the user benefits of write-once optical storage devices; describes typical applications in archival storage, one-off complex instruction sets, and information storage and retrieval systems; and identifies current trends toward standardization of equipment. (CLB)

  11. Optical storage in lithium niobate

    NASA Technical Reports Server (NTRS)

    Alphonse, G. A.

    1976-01-01

    Holographic storage and retrieval using photorefractive media (electro-optic ferroelectric materials), particularly iron-doped lithium niobate with its enhanced sensitivity, are discussed. Refractive index changes induced by exposure to light render the materials useful for read-write memories and read-write memory simulation. Resolution, dark storage time, write and erase times, reversibility, and noise levels of the materials are examined. The laser source, deflection system, hololens, page composer, and detector array of the holographic memory system are described. High SNR and two orders of magnitude improvement in speed are reported over earlier experimental prototypes, but the system is still too slow to meet practical needs.

  12. Optical storage in quantized media

    NASA Astrophysics Data System (ADS)

    Djotyan, G. P.; Sandor, N.; Bakos, J. S.; Sörlei, Zs.

    2011-07-01

    The schemes of storing of images in quantum states of atoms being used nowadays are based on electromagnetically induced transparency. The images are stored in the collective atomic coherence with the storage time limited by different relaxation processes in the system with the transverse relaxation being the most detrimental among them. In this communication, we present a method of coherent writing of optical information (a transverse image) into the populations instead of the coherences of the metastable atomic states. The method is based on an action of a sequence of frequency chirped laser pulses on an atom with lambda-structure of working levels. Such storage results in drastic increase of the storage time. The reading out of the stored information is performed by measuring the population of one of the metastable atomic states.

  13. Multiwavelength optical storage of diarylethene PMMA films

    NASA Astrophysics Data System (ADS)

    Guo, Haobo; Zhang, Fushi; Sun, Fan; Pu, Shouzhi; Zhou, Xinhong

    2003-04-01

    Current applied optical storage technologies are all based on the heat effect of the recording laser, i.e., heat-mode optical storage. In the present work, photon-mode optical storage using photochromic diarylethene materials was investigated. Two diarylethene molecules dispersed into PMMA together was used as storage material. The recording layer was spin-coated on a glass substrate with Al reflective layer. Two laser beams of 532 nm and 650 nm were used in recording and readout by simultaneously writing and reading, and the reading lasers detected signals with high S/N ratio. Multi-wavelength storage was realized with the diarylethene PMMA film.

  14. Puzzling Mechanisms

    ERIC Educational Resources Information Center

    van Deventer, M. Oskar

    2009-01-01

    The basis of a good mechanical puzzle is often a puzzling mechanism. This article will introduce some new puzzling mechanisms, like two knots that engage like gears, a chain whose links can be interchanged, and flat gears that do not come apart. It illustrates how puzzling mechanisms can be transformed into real mechanical puzzles, e.g., by…

  15. Laser beam modeling in optical storage systems

    NASA Technical Reports Server (NTRS)

    Treptau, J. P.; Milster, T. D.; Flagello, D. G.

    1991-01-01

    A computer model has been developed that simulates light propagating through an optical data storage system. A model of a laser beam that originates at a laser diode, propagates through an optical system, interacts with a optical disk, reflects back from the optical disk into the system, and propagates to data and servo detectors is discussed.

  16. ICI optical data storage tape: An archival mass storage media

    NASA Technical Reports Server (NTRS)

    Ruddick, Andrew J.

    1993-01-01

    At the 1991 Conference on Mass Storage Systems and Technologies, ICI Imagedata presented a paper which introduced ICI Optical Data Storage Tape. This paper placed specific emphasis on the media characteristics and initial data was presented which illustrated the archival stability of the media. More exhaustive analysis that was carried out on the chemical stability of the media is covered. Equally important, it also addresses archive management issues associated with, for example, the benefits of reduced rewind requirements to accommodate tape relaxation effects that result from careful tribology control in ICI Optical Tape media. ICI Optical Tape media was designed to meet the most demanding requirements of archival mass storage. It is envisaged that the volumetric data capacity, long term stability and low maintenance characteristics demonstrated will have major benefits in increasing reliability and reducing the costs associated with archival storage of large data volumes.

  17. The Open Approach to Optical Storage.

    ERIC Educational Resources Information Center

    Noordenbos, Meino G.

    1987-01-01

    Discusses the need for user oriented optical storage systems to deal with information storage in offices, and describes the Megadoc system. The features described include hardware configurations, microcomputer applications, the ability to read microfilm or microfiche documents, equipment standards, and current systems software. (CLB)

  18. Optical data storage and metallization of polymers

    NASA Technical Reports Server (NTRS)

    Roland, C. M.; Sonnenschein, M. F.

    1991-01-01

    The utilization of polymers as media for optical data storage offers many potential benefits and consequently has been widely explored. New developments in thermal imaging are described, wherein high resolution lithography is accomplished without thermal smearing. The emphasis was on the use of poly(ethylene terephthalate) film, which simultaneously serves as both the substrate and the data storage medium. Both physical and chemical changes can be induced by the application of heat and, thereby, serve as a mechanism for high resolution optical data storage in polymers. The extension of the technique to obtain high resolution selective metallization of poly(ethylene terephthalate) is also described.

  19. Optical Storage and Retrieval of Library Material.

    ERIC Educational Resources Information Center

    Folen, Doris R.; Stackpole, Laurie E.

    1993-01-01

    Describes the newly installed optical disk storage system at the Naval Research Laboratory's Research Library and Technical Information Center. Planning and design of the system, the conversion of 140,000 reports to optical disk, the information retrieval process, and future plans are covered. (Contains nine references.) (KRN)

  20. Liquid crystals for holographic optical data storage.

    PubMed

    Matharu, Avtar S; Jeeva, Shehzad; Ramanujam, P S

    2007-12-01

    A tutorial review is presented to inform and inspire the reader to develop and integrate strong scientific links between liquid crystals and holographic data storage, from a materials scientist's viewpoint. The principle of holographic data storage as a means of providing a solution to the information storage demands of the 21st century is detailed. Holography is a small subset of the much larger field of optical data storage and similarly, the diversity of materials used for optical data storage is enormous. The theory of polarisation holography which produces holograms of constant intensity, is discussed. Polymeric liquid crystals play an important role in the development of materials for holographic storage and photoresponsive materials based on azobenzene are targeted for discussion due to their ease of photo-reversion between trans- and cis-states. Although the final polymer may not be liquid crystalline, irradiation can induce ordered domains. The mesogens act in a co-operative manner, enhancing refractive indices and birefringences. Surface relief gratings are discussed as a consequence of holographic storage. Cholesteric polymers comprising azobenzene are briefly highlighted. Irradiation causing cis-trans-isomerisation can be used to control helix pitch. A brief mention of liquid crystals is also made since these materials may be of future interest since they are optically transparent and amenable to photo-induced anisotropy.

  1. Holographic Optical Storage Using Photorefractive Polymers

    NASA Technical Reports Server (NTRS)

    Hayden, L. Michael; Strutz, Shane J.; Harris, Kristi; Ayachitula, Rajani

    2000-01-01

    The task for this report is to perform the basic research and develop a prototype benchtop holographic optical storage system based on photochromic and/or photorefractive polymers so that both permanent and erasable images may be stored and retrieved in the same mixed polymer medium. The task consist of: assembly and setup of the benchtop holographic storage system, including lasers, optics, and other ancillary equipment in a laboratory setting; and research and development of a suitable polymer matrix that will allow practical storage and retrieval of digital data. This will necessitate molecular design of the matrices involved and subsequent physics test to verify the characteristics of the matrices provide practical storage and retrieval.

  2. Biomolecular optical data storage and data encryption.

    PubMed

    Fischer, Thorsten; Neebe, Martin; Juchem, Thorsten; Hampp, Norbert A

    2003-03-01

    The use of bacteriorhodopsin (BR) as an active layer in write-once-read-many optical storage is presented. This novel feature of BR materials may be used on a wide variety of substrates, among them transparent substrates but also paper and plastics. The physical basis of the recording process is polarization-sensitive two-photon absorption. As an example for this new BR application, an identification card equipped with an optical recording strip is presented, which has a capacity of about 1 MB of data. The recording density currently used is 125 kB/cm2, which is far from the optical limits but allows operation with cheap terminals using plastic optics. In the examples given, data are stored in blocks of 10 kB each. A special optical encryption procedure allows the stored data to be protected from unauthorized reading. The molecular basis of this property is again the polarization-sensitive recording mechanism. The unique combination of optical storage, photochromism, and traceability of the BR material is combined on the single-molecule level. BR introduces a new quality of storage capability for applications with increased security and anticounterfeiting requirements.

  3. Optical storage media data integrity studies

    NASA Astrophysics Data System (ADS)

    Podio, Fernando L.

    1994-03-01

    Optical disk-based information systems are being used in private industry and many Federal Government agencies for on-line and long-term storage of large quantities of data. The storage devices that are part of these systems are designed with powerful, but not unlimited, media error correction capacities. The integrity of data stored on optical disks does not only depend on the life expectancy specifications for the medium. Different factors, including handling and storage conditions, may result in an increase of medium errors in size and frequency. Monitoring the potential data degradation is crucial, especially for long term applications. Efforts are being made by the Association for Information and Image Management Technical Committee C21, Storage Devices and Applications, to specify methods for monitoring and reporting to the user medium errors detected by the storage device while writing, reading or verifying the data stored in that medium. The Computer Systems Laboratory (CSL) of the National Institute of Standard and Technology (NIST) has a leadership role in the development of these standard techniques. In addition, CSL is researching other data integrity issues, including the investigation of error-resilient compression algorithms. NIST has conducted care and handling experiments on optical disk media with the objective of identifying possible causes of degradation. NIST work in data integrity and related standards activities is described.

  4. Optical storage media data integrity studies

    NASA Technical Reports Server (NTRS)

    Podio, Fernando L.

    1994-01-01

    Optical disk-based information systems are being used in private industry and many Federal Government agencies for on-line and long-term storage of large quantities of data. The storage devices that are part of these systems are designed with powerful, but not unlimited, media error correction capacities. The integrity of data stored on optical disks does not only depend on the life expectancy specifications for the medium. Different factors, including handling and storage conditions, may result in an increase of medium errors in size and frequency. Monitoring the potential data degradation is crucial, especially for long term applications. Efforts are being made by the Association for Information and Image Management Technical Committee C21, Storage Devices and Applications, to specify methods for monitoring and reporting to the user medium errors detected by the storage device while writing, reading or verifying the data stored in that medium. The Computer Systems Laboratory (CSL) of the National Institute of Standard and Technology (NIST) has a leadership role in the development of these standard techniques. In addition, CSL is researching other data integrity issues, including the investigation of error-resilient compression algorithms. NIST has conducted care and handling experiments on optical disk media with the objective of identifying possible causes of degradation. NIST work in data integrity and related standards activities is described.

  5. Optical Imaging versus Paper Records Storage.

    ERIC Educational Resources Information Center

    Baldygo, Robert

    1999-01-01

    States that the maintenance and storage of paper documents has many inherent weaknesses, including hidden costs and attached risks. Asserts that document imaging is a viable, up-to-date technology that could eliminate many of these costs and risks. Describes the system benefits, scope, requirements, and costs and the legality of optically stored…

  6. Photonic nanojet-enabled optical data storage.

    PubMed

    Kong, Soon-Cheol; Sahakian, Alan; Taflove, Allen; Backman, Vadim

    2008-09-01

    We show that our recently reported microwave photonic jet technique for detection of deeply subwavelength pits in a metal substrate can be extended to optical wavelengths for purposes of high-density data storage. Three-dimensional finite-difference time-domain computational solutions of Maxwell's equations are used to optimize the photonic nanojet and pit configuration to account for the Drude dispersion of an aluminum substrate in the spectral range near lambda= 400 nm. Our results show that nanojet-illuminated pits having lateral dimensions of only 50 nm x 80 nm yield a contrast ratio 27 dB greater than previously reported using a lens system for pits of similar area. Such pits are much smaller than BluRay features. The high detection contrast afforded by the photonic nanojet could potentially yield significant increases in data density and throughput relative to current commercial optical data-storage systems while retaining the basic geometry of the storage medium.

  7. Challenges and opportunities for optical storage

    NASA Astrophysics Data System (ADS)

    Chen, Di

    2005-09-01

    Optical technique for data storage was driven from the challenges to achieve data storage performance required by the user. The first attempt to address the recording density improvement over HDD using magneto-optic technology started over thirty years ago. Subsequent efforts to develop 15", 12" and 5 and 1/4" WORM disc drives met with limited success. Advances in semiconductor lasers, lithography, and auto focusing and tracking techniques finally allow the development of the Compact Disc to answer the call for improvement in audio recording technology and data distribution in mid to late 1980. Recordable and erasable technology then followed with the introduction of CD-R, CD-RW and MO drives and media. By early 1990, advances in high density recording with the use of shorter wavelength lasers, larger n.a. lenses, improved lithographic and data compression techniques, allows the development of 4.7 GB DVD drives and discs to answer the challenge for recording 2-hour high quality movies on a CD size disc. Recordable and erasable DVD became available in 2000, and Dual Layer DVD was introduced last year . With the advent of HDTV and movie in recent years, Storage of 25 GB data in a DVD disc is needed. Blue-ray and HD-DVD are the leading technologies to answer this challenge. Looking to the future, optical storage areal density of one to two orders of magnitude improvement will be required to compete with HDD which is now reaching 133 Gb/in2 . In addition, high data transfer rate of 1Gb/s, data security, copy protection, ease of use, cost and standards issues sums up the monumental challenges facing the optical recording industry in the years to come. Some of the leading technologies, such as multi-layer, new encoding schemes, volume recording, near-field optics, micro-optics, domain expansion, UV laser, holographic storage, could provide the answers. Meeting these challenges, optical storage could become the dominant recording technology to satisfy the data storage

  8. Puzzles & Problems.

    ERIC Educational Resources Information Center

    Murphy, Pat, Ed.

    1993-01-01

    "Exploring" is a magazine of science, art, and human perception, produced by Exploratorium in collaboration with other participating museums. This issue focuses on puzzles and problem solving. Brain teasers, puzzles, and the strategies for solving them are included. Features include: (1) "Homework Assignment #3" (Paul Doherty);…

  9. Fiendishly puzzling

    NASA Astrophysics Data System (ADS)

    2016-12-01

    The UK's Government Communications Headquarters (GCHQ) has, over the last few years, published puzzles that keen members of the public could solve to get noticed by the organization's recruitment team. The GCHQ Puzzle Book is a chunky compendium whose readers are introduced to the whole back catalogue.

  10. Optical Pickup Feeding Velocity Profile Design of Optical Disk Storage

    NASA Astrophysics Data System (ADS)

    Park, Juhn Ho; Seo, Heui-Sik; Lee, Jung Joon; Min, Byunghoon; Son, Heuigi

    2001-03-01

    Residual vibrations and jerks of a pickup body caused by the flexibility of an optical pickup feeding system in optical disk storage may degrade the quality of reading and writing, and increase the track access time. In this study, a feeding velocity profile that suppresses the residual vibrations and jerks is calculated and applied to a stepping-motor-driven feeding system. The calculated feeding velocity profile shows good results compared to the conventional feeding velocity profile of trapezoidal shape.

  11. Lockean Puzzles

    ERIC Educational Resources Information Center

    Milligan, Tony

    2007-01-01

    In analytic moral philosophy it is standard to use unrealistic puzzles to set up moral dilemmas of a sort that I will call Lockean Puzzles. This paper will try to pinpoint just what is and what is not problematic about their use as a teaching tool or component part of philosophical arguments. I will try to flesh out the claim that what may be lost…

  12. Balloon borne optical disk mass storage system

    NASA Technical Reports Server (NTRS)

    Vanek, M. D.; Jennings, D. A.

    1991-01-01

    An on-board data recording system for balloon-borne interferometer using a vacuum operable, ruggedized WORM optical drive is presented. This system, as presently under development, provides 320 Mbytes of data storage (or approximately 11 hrs at the 64 kbits/sec telemetry rate of the experiment). It has the capability of recording the unmodified telemetry bit system as transmitted or doing some preprocessing of the data onboard. The system is compact and requires less than 28 watts of battery power to operate.

  13. Multi-wavelength optical storage of diarylethene PMMA film

    NASA Astrophysics Data System (ADS)

    Guo, Haobo; Zhang, Fushi; Wu, Guo-shi; Sun, Fan; Pu, Shouzhi; Mai, Xuesong; Qi, Guosheng

    2003-05-01

    Current commercial optical storage technologies are all based on the heat effect of the recording laser, i.e., heat-mode optical storage. In the present work, photon-mode optical storage using photochromic diarylethene materials was investigated. Two diarylethene derivatives were dispersed into PMMA solution, and spin-coated on a glass substrate with Al reflective layer as the recording layer. Two laser beams of 532 and 650 nm were used in recording and readout simultaneously, and signals with high S/ N ratio were detected. Multi-wavelength optical storage was realized with the diarylethene PMMA film.

  14. Special Reports: Optical Disks: Mass Storage of Information.

    ERIC Educational Resources Information Center

    McLeod, Jonah

    1984-01-01

    Examines trends in the mass storage of information using optical disks, focusing on applications and various types of systems. Includes a list of optical disk drive products with manufacturer, product, capacity, and access time. (JN)

  15. X-ray versus Optical Variations in the Seyfert 1 Nucleus NGC 3516: A Puzzling Disconnectedness

    NASA Technical Reports Server (NTRS)

    Maoz, Dan; Markowitz, Alex; Edelson, Rick; Nandra, Kirpal; White, Nicholas E. (Technical Monitor)

    2002-01-01

    We present optical broadband (B and R) observations of the Seyfert 1 nucleus NGC 3516, obtained at Wise Observatory from March 1997 to March 2002, contemporaneously with X-ray 2-10 keV measurements with RXTE. With these data we increase the temporal baseline of this dataset to 5 years, more than triple to the coverage we have previously presented for this object. Analysis of the new data does not confirm the 100-day lag of X-ray behind optical variations, tentatively reported in our previous work. Indeed, excluding the first year's data, which drive the previous result, there is no significant correlation at any Lag between the X-ray and optical bands. We also find no correlation at any lag between optical flux and various X-ray hardness ratios. We conclude that the close relation observed between the bands during the first year of our program was either a fluke, or perhaps the result of the exceptionally bright state of NGC 3516 in 1997, to which it has yet to return. Reviewing the results of published joint X-ray and UV/optical Seyfert monitoring programs, we speculate that there are at least two components or mechanisms contributing to the X-ray continuum emission up to 10 key: a soft component that is correlated with UV/optical variations on timescales approx. greater than 1 day, and whose presence can be detected when the source is observed at low enough energies (approx. 1 keV), is unabsorbed, or is in a sufficiently bright phase; and a hard component whose variations are uncorrelated with the UV/optical.

  16. Pilot Project for Spaceborne Massive Optical Storage Devices

    NASA Technical Reports Server (NTRS)

    Chen, Y. J.

    1996-01-01

    A space bound storage device has many special requirements. In addition to large storage capacity, fas read/ write time, and high reliability, it also needs to have small volume, light weight, low power consumption, radiation hardening, ability to operate in extreme temperature ranges, etc. Holographic optical recording technology, which has been making major advancements in recent years, is an extremely promising candidate. The goal of this pilot project is to demonstrate a laboratory bench-top holographic optical recording storage system (HORSS) based on nonlinear polymer films 1 and/or other advanced photo-refractive materials. This system will be used as a research vehicle to study relevant optical properties of novel holographic optical materials, to explore massive optical storage technologies based on the photo-refractive effect and to evaluate the feasibility of developing a massive storage system, based on holographic optical recording technology, for a space bound experiment in the near future.

  17. Optical signatures of molecular dissymmetry: Combining theory with experiments to address stereochemical puzzles

    PubMed Central

    Mukhopadhyay, Parag; Wipf, Peter; Beratan, David N.

    2009-01-01

    Conspectus Modern chemistry emerged from the quest to describe the three-dimensional structure of molecules: van’t Hoff’s tetravalent carbon placed symmetry and dissymmetry at the heart of chemistry. In this Account, we explore how modern theory, synthesis, and spectroscopy can be used in concert to elucidate the symmetry and dissymmetry of molecules and their assemblies. Chiroptical spectroscopy—including optical rotatory dispersion (ORD), electronic circular dichroism (ECD), vibrational circular dichroism (VCD), and Raman optical activity (ROA)—measures the response of dissymmetric structures to electromagnetic radiation. This response can in turn reveal the arrangement of atoms in space, but deciphering the molecular information encoded in chiroptical spectra requires an effective theoretical approach. Although important correlations between ECD and molecular stereochemistry have existed for some time, a battery of accurate new theoretical methods that link a much wider range of chiroptical spectroscopies to structure have emerged over the last decade. The promise of this field is considerable: theory and spectroscopy can assist in assigning the relative and absolute configurations of complex products, in revealing the structure of non-covalent aggregates, in defining metrics for molecular diversity based upon polarization response, and in designing chirally imprinted nanomaterials. The physical organic chemistry of chirality is fascinating in its own right: defining atomic and group contributions to optical rotation (OR) is now possible. Although the common expectation is that chiroptical response is determined solely by a chiral solute’s electronic structure in a given environment, chiral imprinting effects on the surrounding medium and molecular assembly can, in fact, dominate the chiroptical signatures. The theoretical interpretation of chiroptical markers is challenging because the optical properties are subtle, which results from the strong

  18. Optical signatures of molecular dissymmetry: combining theory with experiments to address stereochemical puzzles.

    PubMed

    Mukhopadhyay, Parag; Wipf, Peter; Beratan, David N

    2009-06-16

    Modern chemistry emerged from the quest to describe the three-dimensional structure of molecules: van't Hoff's tetravalent carbon placed symmetry and dissymmetry at the heart of chemistry. In this Account, we explore how modern theory, synthesis, and spectroscopy can be used in concert to elucidate the symmetry and dissymmetry of molecules and their assemblies. Chiroptical spectroscopy, including optical rotatory dispersion (ORD), electronic circular dichroism (ECD), vibrational circular dichroism (VCD), and Raman optical activity (ROA), measures the response of dissymmetric structures to electromagnetic radiation. This response can in turn reveal the arrangement of atoms in space, but deciphering the molecular information encoded in chiroptical spectra requires an effective theoretical approach. Although important correlations between ECD and molecular stereochemistry have existed for some time, a battery of accurate new theoretical methods that link a much wider range of chiroptical spectroscopies to structure have emerged over the past decade. The promise of this field is considerable: theory and spectroscopy can assist in assigning the relative and absolute configurations of complex products, revealing the structure of noncovalent aggregates, defining metrics for molecular diversity based on polarization response, and designing chirally imprinted nanomaterials. The physical organic chemistry of chirality is fascinating in its own right: defining atomic and group contributions to optical rotation (OR) is now possible. Although the common expectation is that chiroptical response is determined solely by a chiral solute's electronic structure in a given environment, chiral imprinting effects on the surrounding medium and molecular assembly can, in fact, dominate the chiroptical signatures. The theoretical interpretation of chiroptical markers is challenging because the optical properties are subtle, resulting from the strong electric dipole and the weaker electric

  19. Multi-wavelength multi-level optical storage

    NASA Astrophysics Data System (ADS)

    Wullert, John R., II

    Current digital information storage technologies offer rapid access and seemingly ever-increasing capacities. New storage techniques that improve the data rate of high-density storage technologies are attractive, particularly for cost-sensitive services such as video on demand. Wavelength multiplexing of optical information storage has the potential to increase storage capacity, density and data rate. This dissertation addresses the design, simulation and fabrication of a multi-wavelength, multi-level optical storage structure that has the potential to increase the capacity, density and data rate of optical storage. Multi-wavelength, multi-layer optical storage is a technique for storing data in many separate layers in a medium, where each layer responds to a unique optical wavelength. This approach builds on the strengths of current optical storage technologies and addresses some of their limitations. Multiple layers of storage increase the high storage density possible with optical techniques and the parallelism of wavelength multiplexing improves the relatively low data rate. Multi-wavelength, multi-level optical storage has been investigated theoretically and experimentally. The experimental results provide the first demonstration of optical storage using three wavelengths to read three separate layers of information. These read-only optical memories were based on dielectric mirrors of silicon dioxide, magnesium oxide and aluminum oxide. The layers were designed to be read with semiconductor lasers of 635, 780 and 980 nanometers. The prototype devices exhibited open margins between the on and off states for all eight combinations of the presence and absence of the three mirrors. Theoretical simulations were employed to assess the dynamic operation of multi-wavelength storage devices. Through systematic simulations, variations in the thickness and refractive index of the layers in the structure were identified as the primary noise mechanism and a critical

  20. Optical system storage design with diffractive optical elements

    NASA Technical Reports Server (NTRS)

    Kostuk, Raymond K.; Haggans, Charles W.

    1993-01-01

    Optical data storage systems are gaining widespread acceptance due to their high areal density and the ability to remove the high capacity hard disk from the system. In magneto-optical read-write systems, a small rotation of the polarization state in the return signal from the MO media is the signal which must be sensed. A typical arrangement used for detecting these signals and correcting for errors in tracking and focusing on the disk is illustrated. The components required to achieve these functions are listed. The assembly and alignment of this complex system has a direct impact on cost, and also affects the size, weight, and corresponding data access rates. As a result, integrating these optical components and improving packaging techniques is an active area of research and development. Most designs of binary optic elements have been concerned with optimizing grating efficiency. However, rigorous coupled wave models for vector field diffraction from grating surfaces can be extended to determine the phase and polarization state of the diffracted field, and the design of polarization components. A typical grating geometry and the phase and polarization angles associated with the incident and diffracted fields are shown. In our current stage of work, we are examining system configurations which cascade several polarization functions on a single substrate. In this design, the beam returning from the MO disk illuminates a cascaded grating element which first couples light into the substrate, then introduces a quarter wave retardation, then a polarization rotation, and finally separates s- and p-polarized fields through a polarization beam splitter. The input coupler and polarization beam splitter are formed in volume gratings, and the two intermediate elements are zero-order elements.

  1. Research Studies on Advanced Optical Module/Head Designs for Optical Data Storage

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Preprints are presented from the recent 1992 Optical Data Storage meeting in San Jose. The papers are divided into the following topical areas: Magneto-optical media (Modeling/design and fabrication/characterization/testing); Optical heads (holographic optical elements); and Optical heads (integrated optics). Some representative titles are as follow: Diffraction analysis and evaluation of several focus and track error detection schemes for magneto-optical disk systems; Proposal for massively parallel data storage system; Transfer function characteristics of super resolving systems; Modeling and measurement of a micro-optic beam deflector; Oxidation processes in magneto-optic and related materials; and A modal analysis of lamellar diffraction gratings in conical mountings.

  2. Experimental study of optical storage characteristics of photochromic material: pyrrylfulgide

    NASA Astrophysics Data System (ADS)

    Lei, Ming; Yao, Baoli; Chen, Yi; Han, Yong; Wang, Congmin; Wang, Yingli; Menke, Neimule; Chen, Guofu; Fan, Meigong

    2003-04-01

    Optical data storage is a frontier in the information science. Currently, there are mainly two kinds of storage materials, i.e., thermal-optic and photonic materials. The storage methods are divided into serial and parallel modes. In the market, the mature technique is CD-RW, which uses the thermal-optic material and serial method. The storage density of the CD-RW is restricted by the size of material particles, the conduction of heat, etc. Besides, the recording speed is seriously limited by the process of heating. Photonic materials and parallel method will be the trend in the optical data storage. Because it is based on the photon reaction on the molecule scale, the storage density and speed will be greatly increased. In this paper, a new kind of organic photochromic material -- pyrrylfulgide was studied. A parallel optical data storage system was established. Using the pyrrylfulgide/PMMA film as a recording medium, micro-images and binary digital information could be recorded, readout and erased in this parallel system. The recorded information on the film can be kept for at least 8 months in dark at room temperature. So far, the storage density is 3 x 107 bit/cm2.

  3. Multiplexed Holographic Optical Data Storage In Thick Bacteriorhodopsin Films

    NASA Technical Reports Server (NTRS)

    Downie, John D.; Timucin, Dogan A.; Gary, Charles K.; Ozcan, Meric; Smithey, Daniel T.; Crew, Marshall

    1998-01-01

    The optical data storage capacity of photochromic bacteriorhodopsin films is investigated by means of theoretical calculations, numerical simulations, and experimental measurements on sequential recording of angularly multiplexed diffraction gratings inside a thick D85N BR film.

  4. A new tape product for optical data storage

    NASA Technical Reports Server (NTRS)

    Larsen, T. L.; Woodard, F. E.; Pace, S. J.

    1993-01-01

    A new tape product has been developed for optical data storage. Laser data recording is based on hole or pit formation in a low melting metallic alloy system. The media structure, sputter deposition process, and media characteristics, including write sensitivity, error rates, wear resistance, and archival storage are discussed.

  5. Quasi-light storage for optical data packets.

    PubMed

    Schneider, Thomas; Preußler, Stefan

    2014-02-06

    Today's telecommunication is based on optical packets which transmit the information in optical fiber networks around the world. Currently, the processing of the signals is done in the electrical domain. Direct storage in the optical domain would avoid the transfer of the packets to the electrical and back to the optical domain in every network node and, therefore, increase the speed and possibly reduce the energy consumption of telecommunications. However, light consists of photons which propagate with the speed of light in vacuum. Thus, the storage of light is a big challenge. There exist some methods to slow down the speed of the light, or to store it in excitations of a medium. However, these methods cannot be used for the storage of optical data packets used in telecommunications networks. Here we show how the time-frequency-coherence, which holds for every signal and therefore for optical packets as well, can be exploited to build an optical memory. We will review the background and show in detail and through examples, how a frequency comb can be used for the copying of an optical packet which enters the memory. One of these time domain copies is then extracted from the memory by a time domain switch. We will show this method for intensity as well as for phase modulated signals.

  6. Optical Digital Disks as Mass Storage Media.

    ERIC Educational Resources Information Center

    Boss, Richard W.

    1983-01-01

    Describes the optical digital disk, which stores machine-readable information in digitized form, and discusses their production, cost, present and future applications. The major companies currently active in the disk field are noted. (MBR)

  7. Plasmonic nano-structures for optical data storage.

    PubMed

    Mansuripur, M; Zakharian, A R; Lesuffleur, A; Oh, Sang-Hyun; Jones, R J; Lindquist, N C; Im, Hyungsoon; Kobyakov, A; Moloney, J V

    2009-08-03

    We propose a method of optical data storage that exploits the small dimensions of metallic nano-particles and/or nano-structures to achieve high storage densities. The resonant behavior of these particles (both individually and in small clusters) in the presence of ultraviolet, visible, and near-infrared light may be used to retrieve pre-recorded information by far-field spectroscopic optical detection. In plasmonic data storage, a very short (approximately few femtoseconds) laser pulse is focused to a diffraction-limited spot over a small region of an optical disk containing metallic nano-structures. The digital data stored in each bit-cell, comprising multiple bits of information, modifies the spectrum of the incident light pulse. This spectrum is subsequently detected, upon reflection/transmission, with the aid of an optical spectrum analyzer. We present theoretical as well as preliminary experimental results that confirm the potential of plasmonic nano-structures for high-density optical data storage applications.

  8. Bacteriorhodopsin films for optical signal processing and data storage

    NASA Technical Reports Server (NTRS)

    Walkup, John F. (Principal Investigator); Mehrl, David J. (Principal Investigator)

    1996-01-01

    This report summarizes the research results obtained on NASA Ames Grant NAG 2-878 entitled 'Investigations of Bacteriorhodopsin Films for Optical Signal Processing and Data Storage.' Specifically we performed research, at Texas Tech University, on applications of Bacteriorhodopisin film to both (1) dynamic spatial filtering and (2) holographic data storage. In addition, measurements of the noise properties of an acousto-optical matrix-vestor multiplier built for NASA Ames by Photonic Systems Inc. were performed at NASA Ames' Photonics Laboratory. This research resulted in two papers presented at major optical data processing conferences and a journal paper which is to appear in APPLIED OPTICS. A new proposal for additional BR research has recently been submitted to NASA Ames Research Center.

  9. Micro-optic lens for data storage

    NASA Technical Reports Server (NTRS)

    Milster, T. D.; Trusty, R. M.; Wang, M. S.; Froehlich, F. F.; Erwin, J. Kevin

    1991-01-01

    A new type of microlens for data storage applications that has improved off-axis performance is described. The lens consists of a micro Fresnel pattern on a curved substrate. The radius of the substrate is equal to the focal length of the lens. If the pattern and substrate are thin, the combination satisfies the Abbe sine condition. Therefore, the lens is free of coma. We analyze a 0.5 numerical aperture, 0.50 mm focal length lens in detail. A 0.16 numerical aperture lens was fabricated holographically, and results are presented.

  10. Benjamin Banneker's Mathematical Puzzles.

    ERIC Educational Resources Information Center

    Mahoney, John F.

    2003-01-01

    Benjamin Banneker, a self-taught African American mathematician, kept a journal containing a number of mathematical puzzles. Explores four of these puzzles, 200 years later, with the aid of 21st century technology. (Author/NB)

  11. Interactive Optical Disc Systems: Part 1: Analog Storage.

    ERIC Educational Resources Information Center

    Hessler, David W.

    1984-01-01

    Details distinction between digital and analog data, advantages of analog storage, and optical disc use to store analog data. Configuration and potential of three levels of laser disc systems are explained. Selection of display devices for use with laser disc systems and accessing audio data are addressed. (Continued in next issue.) (EJS)

  12. Current developments in optical data storage with organic dyes.

    PubMed

    Mustroph, Heinz; Stollenwerk, Manfred; Bressau, Volker

    2006-03-20

    The main motivation for the development of digital data storage has been the improvement in play-back quality and the increase in storage capacity. In 1982 Philips and Sony introduced the first technically and economically successful system based on this-the compact disc (CD) and a compatible player. A very broad diversity of optical data recording formats are available today, and a difference is drawn between prerecorded, recordable, and rewritable media. This Review gives an overview of the systems used, the main features of production, and then concentrates on the properties of the organic dyes that are used in recordable systems. Dyestuffs chemistry has gained the reputation of having become a mature field of activity. Is this prejudice or a justified swan song for dyestuffs chemistry? When applications in optical data storage are considered, it is evident that even today progresses such as CD-R and DVD/R would not be feasible without functional dyes.

  13. Optical distortions in electron/positron storage rings

    SciTech Connect

    Brown, K.L.; Donald, M.; Servranckx, R.

    1983-01-01

    We have studied the optical distortions in the PEP electron/positron storage ring for various optical configurations using the computer programs DIMAT, HARMON, PATRICIA, and TURTLE. The results are shown graphically by tracing several thousand trajectories from one interaction region to the next using TURTLE and by tracing a few selected rays several hundred turns using the programs DIMAT and PATRICIA. The results show an interesting correlation between the calculated optical cleanliness of a particular lattice configuration and the observed operating characteristics of the machine.

  14. Surface-enhanced raman optical data storage system

    DOEpatents

    Vo-Dinh, Tuan

    1991-01-01

    A method and apparatus for a Surface-Enhanced Raman Optical Data Storage (SERODS) System is disclosed. A medium which exhibits the Surface Enhanced Raman Scattering (SERS) phenomenon has data written onto its surface of microenvironment by means of a write-on procedure which disturbs the surface or microenvironment of the medium and results in the medium having a changed SERS emission when excited. The write-on procedure is controlled by a signal that corresponds to the data to be stored so that the disturbed regions on the storage device (e.g., disk) represent the data. After the data is written onto the storage device it is read by exciting the surface of the storage device with an appropriate radiation source and detecting changes in the SERS emission to produce a detection signal. The data is then reproduced from the detection signal.

  15. Surface-Enhanced Raman Optical Data Storage system

    DOEpatents

    Vo-Dinh, T.

    1991-03-12

    A method and apparatus for a Surface-Enhanced Raman Optical Data Storage (SERODS) System are disclosed. A medium which exhibits the Surface Enhanced Raman Scattering (SERS) phenomenon has data written onto its surface of microenvironment by means of a write-on procedure which disturbs the surface or microenvironment of the medium and results in the medium having a changed SERS emission when excited. The write-on procedure is controlled by a signal that corresponds to the data to be stored so that the disturbed regions on the storage device (e.g., disk) represent the data. After the data is written onto the storage device it is read by exciting the surface of the storage device with an appropriate radiation source and detecting changes in the SERS emission to produce a detection signal. The data is then reproduced from the detection signal. 5 figures.

  16. Method and apparatus for bistable optical information storage for erasable optical disks

    DOEpatents

    Land, Cecil E.; McKinney, Ira D.

    1990-01-01

    A method and an optical device for bistable storage of optical information, together with reading and erasure of the optical information, using a photoactivated shift in a field dependent phase transition between a metastable or a bias-stabilized ferroelectric (FE) phase and a stable antiferroelectric (AFE) phase in an lead lanthanum zirconate titanate (PLZT). An optical disk contains the PLZT. Writing and erasing of optical information can be accomplished by a light beam normal to the disk. Reading of optical information can be accomplished by a light beam at an incidence angle of 15 to 60 degrees to the normal of the disk.

  17. Method and apparatus for bistable optical information storage for erasable optical disks

    DOEpatents

    Land, C.E.; McKinney, I.D.

    1988-05-31

    A method and an optical device for bistable storage of optical information, together with reading and erasure of the optical information, using a photoactivated shift in a field dependent phase transition between a metastable or a bias-stabilized ferroelectric (FE) phase and a stable antiferroelectric (AFE) phase in a lead lanthanum zirconate titanate (PLZT). An optical disk contains the PLZT. Writing and erasing of optical information can be accomplished by a light beam normal to the disk. Reading of optical information can be accomplished by a light beam at an incidence angle of 15 to 60 degrees to the normal of the disk. 10 figs.

  18. Diffused holographic information storage and retrieval using photorefractive optical materials

    NASA Astrophysics Data System (ADS)

    McMillen, Deanna Kay

    Holography offers a tremendous opportunity for dense information storage, theoretically one bit per cubic wavelength of material volume, with rapid retrieval, of up to thousands of pages of information simultaneously. However, many factors prevent the theoretical storage limit from being reached, including dynamic range problems and imperfections in recording materials. This research explores new ways of moving closer to practical holographic information storage and retrieval by altering the recording materials, in this case, photorefractive crystals, and by increasing the current storage capacity while improving the information retrieved. As an experimental example of the techniques developed, the information retrieved is the correlation peak from an optical recognition architecture, but the materials and methods developed are applicable to many other holographic information storage systems. Optical correlators can potentially solve any signal or image recognition problem. Military surveillance, fingerprint identification for law enforcement or employee identification, and video games are but a few examples of applications. A major obstacle keeping optical correlators from being universally accepted is the lack of a high quality, thick (high capacity) holographic recording material that operates with red or infrared wavelengths which are available from inexpensive diode lasers. This research addresses the problems from two positions: find a better material for use with diode lasers, and reduce the requirements placed on the material while maintaining an efficient and effective system. This research found that the solutions are new dopants introduced into photorefractive lithium niobate to improve wavelength sensitivities and the use of a novel inexpensive diffuser that reduces the dynamic range and optical element quality requirements (which reduces the cost) while improving performance. A uniquely doped set of 12 lithium niobate crystals was specified and

  19. Electron trapping optical data storage system and applications

    NASA Technical Reports Server (NTRS)

    Brower, Daniel; Earman, Allen; Chaffin, M. H.

    1993-01-01

    A new technology developed at Optex Corporation out-performs all other existing data storage technologies. The Electron Trapping Optical Memory (ETOM) media stores 14 gigabytes of uncompressed data on a single, double-sided 130 mm disk with a data transfer rate of up to 120 megabits per second. The disk is removable, compact, lightweight, environmentally stable, and robust. Since the Write/Read/Erase (W/R/E) processes are carried out photonically, no heating of the recording media is required. Therefore, the storage media suffers no deleterious effects from repeated W/R/E cycling. This rewritable data storage technology has been developed for use as a basis for numerous data storage products. Industries that can benefit from the ETOM data storage technologies include: satellite data and information systems, broadcasting, video distribution, image processing and enhancement, and telecommunications. Products developed for these industries are well suited for the demanding store-and-forward buffer systems, data storage, and digital video systems needed for these applications.

  20. Bloch FDTD simulation of slow optical wave resonance cavity in optical storage technology

    NASA Astrophysics Data System (ADS)

    Zhang, Bin; Lin, Zhaohua; Cai, Lihua

    2013-08-01

    Long chain series resonance cavity is suitable for transferring slow optical wave, which can be served as the basic device for optical storage technology. Micro-ring resonator is one kind of such a long chain structure, which is considered to be the basic component of optical integrated circuit and optical computer in the future. The discrete energy level has the potential to distinguish digital optical data. The optical delay characteristics make such a device possible to store the information for some time. The advantage of this device is that it has the potential to construct an optical storage device in small geometrical dimension and could use mature semiconductor manufacture capability to lower the design and manufacturing expenses. Many experimental results have proved a lot of material and geometrical coefficients are very important for such an optical delay device. New theory method is needed to calculate the periodical energy transfer and time delay characteristics, which can be compared with experimental result. The Bloch FDTD is presented for analysis of such a new optical device, based on the optical Bloch energy band theory. The energy band characteristics of micro-ring periodical optical waveguide device is discussed used that analytical method. This precise calculated method could be served as a useful tool for design the structure of such resonance cavity to achieve desired slow optical wave transfer performance.

  1. SERODS optical data storage with parallel signal transfer

    DOEpatents

    Vo-Dinh, Tuan

    2003-06-24

    Surface-enhanced Raman optical data storage (SERODS) systems having increased reading and writing speeds, that is, increased data transfer rates, are disclosed. In the various SERODS read and write systems, the surface-enhanced Raman scattering (SERS) data is written and read using a two-dimensional process called parallel signal transfer (PST). The various embodiments utilize laser light beam excitation of the SERODS medium, optical filtering, beam imaging, and two-dimensional light detection. Two- and three-dimensional SERODS media are utilized. The SERODS write systems employ either a different laser or a different level of laser power.

  2. SERODS optical data storage with parallel signal transfer

    DOEpatents

    Vo-Dinh, Tuan

    2003-09-02

    Surface-enhanced Raman optical data storage (SERODS) systems having increased reading and writing speeds, that is, increased data transfer rates, are disclosed. In the various SERODS read and write systems, the surface-enhanced Raman scattering (SERS) data is written and read using a two-dimensional process called parallel signal transfer (PST). The various embodiments utilize laser light beam excitation of the SERODS medium, optical filtering, beam imaging, and two-dimensional light detection. Two- and three-dimensional SERODS media are utilized. The SERODS write systems employ either a different laser or a different level of laser power.

  3. The Proton Radius Puzzle

    NASA Astrophysics Data System (ADS)

    Downie, E. J.

    2016-03-01

    The proton radius puzzle is the difference between the proton radius as measured with electron scattering and in the excitation spectrum of atomic hydrogen, and that measured with muonic hydrogen spectroscopy. Since the inception of the proton radius puzzle in 2010 by the measurement of Pohl et al.[1], many possible resolutions to the puzzle have been postulated, but, to date, none has been generally accepted. New data are therefore necessary to resolve the issue. We briefly review the puzzle, the proposed solutions, and the new electron scattering and spectroscopy experiments planned and underway. We then introduce the MUSE experiment, which seeks to resolve the puzzle by simultaneously measuring elastic electron and muon scattering on the proton, in both charge states, thereby providing new information to the puzzle. MUSE addresses issues of two-photon effects, lepton universality and, possibly, new physics, while providing simultaneous form factor, and therefore radius, measurements with both muons and electrons.

  4. Surface-Enhanced Raman Optical Data Storage system

    DOEpatents

    Vo-Dinh, T.

    1994-06-28

    An improved Surface-Enhanced Raman Optical Data Storage System (SERODS) is disclosed. In the improved system, entities capable of existing in multiple reversible states are present on the storage device. Such entities result in changed Surface-Enhanced Raman Scattering (SERS) when localized state changes are effected in less than all of the entities. Therefore, by changing the state of entities in localized regions of a storage device, the SERS emissions in such regions will be changed. When a write-on device is controlled by a data signal, such a localized regions of changed SERS emissions will correspond to the data written on the device. The data may be read by illuminating the surface of the storage device with electromagnetic radiation of an appropriate frequency and detecting the corresponding SERS emissions. Data may be deleted by reversing the state changes of entities in regions where the data was initially written. In application, entities may be individual molecules which allows for the writing of data at the molecular level. A read/write/delete head utilizing near-field quantum techniques can provide for a write/read/delete device capable of effecting state changes in individual molecules, thus providing for the effective storage of data at the molecular level. 18 figures.

  5. Surface-enhanced raman optical data storage system

    DOEpatents

    Vo-Dinh, Tuan

    1994-01-01

    An improved Surface-Enhanced Raman Optical Data Storage System (SERODS) is disclosed. In the improved system, entities capable of existing in multiple reversible states are present on the storage device. Such entities result in changed Surface-Enhanced Raman Scattering (SERS) when localized state changes are effected in less than all of the entities. Therefore, by changing the state of entities in localized regions of a storage device, the SERS emissions in such regions will be changed. When a write-on device is controlled by a data signal, such a localized regions of changed SERS emissions will correspond to the data written on the device. The data may be read by illuminating the surface of the storage device with electromagnetic radiation of an appropriate frequency and detecting the corresponding SERS emissions. Data may be deleted by reversing the state changes of entities in regions where the data was initially written. In application, entities may be individual molecules which allows for the writing of data at the molecular level. A read/write/delete head utilizing near-field quantum techniques can provide for a write/read/delete device capable of effecting state changes in individual molecules, thus providing for the effective storage of data at the molecular level.

  6. Information storage and retrieval for probe storage using optical diffraction patterns

    NASA Astrophysics Data System (ADS)

    van Honschoten, Joost W.; de Jong, Henri W.; Koelmans, Wabe W.; Parnell, Thomas P.; Zaboronski, Oleg

    2011-11-01

    A method for fast information retrieval from a probe storage device is considered. It is shown that information can be stored and retrieved using the optical diffraction patterns obtained by the illumination of a large array of cantilevers by a monochromatic light source. In thermo-mechanical probe storage, the information is stored as a sequence of indentations on the polymer medium. To retrieve the information, the array of probes is actuated by applying a bending force to the cantilevers. Probes positioned over indentations experience deflection by the depth of the indentation, probes over the flat media remain un-deflected. Thus the array of actuated probes can be viewed as an irregular optical grating, which creates a data-dependent diffraction pattern when illuminated by laser light. We develop a low complexity modulation scheme, which allows the extraction of information stored in the pattern of indentations on the media from Fourier coefficients of the intensity of the diffraction pattern. We then derive a low-complexity maximum-likelihood sequence detection algorithm for retrieving the user information from the Fourier coefficients. The derivation of both the modulation and the detection schemes is based on the Fraunhofer formula for data-dependent diffraction patterns. The applicability of Fraunhofer diffraction theory to the optical set-up relevant for probe storage is established both theoretically and experimentally. We confirm the potential of the optical readout technique by demonstrating that the impairment characteristics of probe storage channels (channel noise, global positioning errors, small indentation depth) do not lead to an unacceptable increase in data recovery error rates. We also show that for as long as the Fresnel number F ≤ 0.1, the optimal channel detector derived from Fraunhofer diffraction theory does not suffer any significant performance degradation.

  7. Puzzling Ways to Learn

    ERIC Educational Resources Information Center

    School Shop, 1975

    1975-01-01

    Four authors present crossword and wordfind puzzles developed for students in the areas of electricity, principles of hydraulics, finishing, construction, thermoplastic materials, patternmaking, wood, occupations, and drafting. (BP)

  8. Experimental determination of storage ring optics using orbit response measurements

    NASA Astrophysics Data System (ADS)

    Safranek, J.

    1997-02-01

    The measured response matrix giving the change in orbit at beam position monitors (BPMs) with changes in steering magnet excitation can be used to accurately calibrate the linear optics in an electron storage ring [1-8]. A computer code called LOCO (Linear Optics from Closed Orbits) was developed to analyze the NSLS X-Ray Ring measured response matrix to determine: the gradients in all 56 quadrupole magnets; the calibration of the steering magnets and BPMs; the roll of the quadrupoles, steering magnets, and BPMs about the electron beam direction; the longitudinal magnetic centers of the orbit steering magnets; the horizontal dispersion at the orbit steering magnets; and the transverse mis-alignment of the electron orbit in each of the sextupoles. Random orbit measurement error from the BPMs propagated to give only 0.04% rms error in the determination of individual quadrupole gradients and 0.4 mrad rms error in the determination of individual quadrupole rolls. Small variations of a few parts in a thousand in the quadrupole gradients within an individual family were resolved. The optics derived by LOCO gave accurate predictions of the horizontal dispersion, the beta functions, and the horizontal and vertical emittances, and it gave good qualitative agreement with the measured vertical dispersion. The improved understanding of the X-Ray Ring has enabled us to increase the synchrotron radiation brightness. The LOCO code can also be used to find the quadrupole family gradients that best correct for gradient errors in quadrupoles, in sextupoles, and from synchrotron radiation insertion devices. In this way the design periodicity of a storage ring's optics can be restored. An example of periodicity restoration will be presented for the NSLS VUV Ring. LOCO has also produced useful results when applied to the ALS storage ring [8].

  9. Synthesis & Studies of New Non-Destructive Read-Out Materials for Optical Storage and Optical Switches

    DTIC Science & Technology

    2005-12-31

    studied This organic storage system, consists of two different molecular components chemically bonded to each other, a polar photochromic fulgimide...and an oxazine dye, to form a composite molecule that retains the photochromic and spectroscopic properties of each individual molecular component yet...15. NUMBER OF PAGES Optical Storage media, Non-destructive readout materials, 20 3D optical storage, Photochromic composite molecule, Optical 16

  10. Invitation to a Puzzle Party.

    ERIC Educational Resources Information Center

    Palmer, Libby

    1980-01-01

    The author describes how her personal interest in puzzles led her to create Puzzle Parties at the College of Santa Fe in New Mexico. Now regular events, these puzzle parties attract several hundred adults and children from the community. (SJL)

  11. The puzzling afterglow of GRB 050721: a rebrightening seen in the optical but not in the X-ray

    SciTech Connect

    Antonelli, L. A.; Romano, P.; Testa, V.; D'Elia, V.; Guetta, D.; Torii, K.; Malesani, D.

    2007-08-21

    We present here the analysis of the early and late multiwavelength afterglow emission, as observed by Swift a small robotic telescope, and the VLT. We compare early observations with late afterglow observations obtained with Swift and the VLT and we observe an intense rebrightening in the optical band at about one day after the burst which is not present in the X-ray band. The lack of detection in X-ray of such a strong rebrightening at lower energies may be described with a variable external density profile. In such a scenario, the combined X-ray and optical observations allow us to derive that the matter density located at {approx} 1017 cm from the burst is about a factor of 10 higher than in the inner region. This is the first time in which a rebrightening has been observed in the optical afterglow of a GRB that is clearly absent in the X-ray afterglow.

  12. The Anatomy Puzzle Book.

    ERIC Educational Resources Information Center

    Jacob, Willis H.; Carter, Robert, III

    This document features review questions, crossword puzzles, and word search puzzles on human anatomy. Topics include: (1) Anatomical Terminology; (2) The Skeletal System and Joints; (3) The Muscular System; (4) The Nervous System; (5) The Eye and Ear; (6) The Circulatory System and Blood; (7) The Respiratory System; (8) The Urinary System; (9) The…

  13. Puzzles and Hunts.

    ERIC Educational Resources Information Center

    Weissblum, Aaron

    2000-01-01

    A company designs and delivers treasure and scavenger hunts for corporate and institutional clients. Groups are divided into teams that must solve puzzles for directions or clues. The hunts build creativity, teamwork, communication skills, and an appreciation of others' strengths. An insert includes a four-puzzle mini-treasure hunt. (TD)

  14. Tangrams: Puzzles of Art

    ERIC Educational Resources Information Center

    Fee, Brenda

    2009-01-01

    Challenging one's brain is the beginning of making great art. Tangrams are a great way to keep students thinking about their latest art project long after leaving the classroom. A tangram is a Chinese puzzle. The earliest known reference to tangrams appears in a Chinese book dated 1813, but the puzzles existed long before that date. The puzzle…

  15. Optical Disc Utilized As A Data Storage System For Reconnaissance

    NASA Astrophysics Data System (ADS)

    Herzog, Donald G.

    1984-01-01

    Electra-optic and Radar sensing reconnaissance systems have many advantages including remote transmission and image data processing that conventional film camera systems do not have. However, data storage and retrieval that was naturally and easily accomplished with film must now be accommodated by other techniques. The optical disc data storage and retrieval systems offer significant advantage towards fulfilling this need. This paper will provide an overview description of the technology, some of the fundamental alternatives of configuration approach, and some examples of where it may be considered in the reconnaissance system. Silver halide film has been and still is the work horse of the image based reconnaissance field. It will not be replaced in the near future either, but rather a gradual transition to total electronic systems is expected. It is not the intent of this paper to debase film, because in fact it has its advantages. We have learned to optimize its advantages and minimize its disadvantages. However optical disc systems have a definite role to play in the reconnaissance field.

  16. Rewritable three-dimensional holographic data storage via optical forces

    NASA Astrophysics Data System (ADS)

    Yetisen, Ali K.; Montelongo, Yunuen; Butt, Haider

    2016-08-01

    The development of nanostructures that can be reversibly arranged and assembled into 3D patterns may enable optical tunability. However, current dynamic recording materials such as photorefractive polymers cannot be used to store information permanently while also retaining configurability. Here, we describe the synthesis and optimization of a silver nanoparticle doped poly(2-hydroxyethyl methacrylate-co-methacrylic acid) recording medium for reversibly recording 3D holograms. We theoretically and experimentally demonstrate organizing nanoparticles into 3D assemblies in the recording medium using optical forces produced by the gradients of standing waves. The nanoparticles in the recording medium are organized by multiple nanosecond laser pulses to produce reconfigurable slanted multilayer structures. We demonstrate the capability of producing rewritable optical elements such as multilayer Bragg diffraction gratings, 1D photonic crystals, and 3D multiplexed optical gratings. We also show that 3D virtual holograms can be reversibly recorded. This recording strategy may have applications in reconfigurable optical elements, data storage devices, and dynamic holographic displays.

  17. Photodimerization in dipeptides for high capacity optical digital storage

    SciTech Connect

    Ramanujam, P.S.; Berg, Rolf H.

    2004-09-06

    We have developed peptide materials with chromophores that undergo cycloaddition, suitable for terabit optical digital storage in a 5.25 in. disc. The rationale behind this design is that the length and rigidity of the backbone can be adjusted to facilitate the formation of a photodimer without large physical movements of the chromophores on exposure to UV light. Initially strongly absorbing films transmit up to 50% of light on irradiation at dimerizing wavelengths. This property can be utilized to record grey levels. An intensity-dependent transmission behavior has been observed that may enable data to be written and read at the same wavelength.

  18. Optical properties of a photopolymer film for digital holographic storage

    NASA Astrophysics Data System (ADS)

    Shin, Changwon; Kim, Junghoi; Kim, Nam; Lee, Hyojin; Kim, Eunkyoung

    2005-09-01

    Tir- and mono functional monomers were dispersed in a solution of polysulfone in organic solvent containing a photo initiator and other additives. New photopolymer film was prepared by dispersing acrylic monomer in a polysulfone matrix. The Polysulfone was adopted as a binder since it affords transparent thick films with low dimensional changes during holographic recording. Optical property of the photopolymer showed high diffraction efficiency (>90%) under an optimized optical condition at 532nm laser. The angular selectivity for angular multiplexing page oriented holographic memories (POHMs), the maximum diffraction efficiency of the material during holographic recording, the diffraction efficiency of the films as a function of an incident angle of two beams, exposure energy for saturation of the holographic material and application for holographic data storage will be discussed.

  19. Health information management using optical storage technology: case studies.

    PubMed

    Kohn, D

    1992-05-01

    All the health care facilities examined in the case studies addressed several important organizational issues before and during the installation of their systems. All the facilities examined employee commitment. The prudent managers considered how easily their employees adapt to changes in their jobs and work environment. They considered how enthusiastic cooperation can be fostered in the creation of a liberated and reengineered office. This was determined not only by each individual's reaction to change, but also by the health care facility's track record with other system installations. For example, document image, diagnostic image, and coded data processing systems allow the integration of divergent health care information systems within complex institutions. Unfortunately, many institutions are currently struggling with how to create an information management architecture that will integrate their mature systems, such as their patient care and financial systems. Information managers must realize that if optical storage technology-based systems are used in a strategic and planned fashion, these systems can act as focal points for systems integration, not as promises to further confuse the issue. Another issue that needed attention in all the examples was the work environment. The managers considered how the work environment was going to affect the ability to integrate optical image and data systems into the institution. For example, many of these medical centers have created alliances with clinics, HMOs, and large corporate users of medical services. This created a demand for all or part of the health information outside the confines of the original institution. Since the work environment is composed of a handful of factors such as merged medical services, as many work environment factors as possible were addressed before application of the optical storage technology solution in the institutions. And finally, the third critical issue was the organization of work

  20. Eternal 5D optical data storage in glass (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Kazansky, Peter G.; Cerkauskaite, Ausra; Drevinskas, Rokas; Zhang, Jingyu

    2016-09-01

    A decade ago it has been discovered that during femtosecond laser writing self-organized subwavelength structures with record small features of 20 nm, could be created in the volume of silica glass. On the macroscopic scale the self-assembled nanostructure behaves as a uniaxial optical crystal with negative birefringence. The optical anisotropy, which results from the alignment of nano-platelets, referred to as form birefringence, is of the same order of magnitude as positive birefringence in crystalline quartz. The two independent parameters describing birefringence, the slow axis orientation (4th dimension) and the strength of retardance (5th dimension), are explored for the optical encoding of information in addition to three spatial coordinates. The slow axis orientation and the retardance are independently manipulated by the polarization and intensity of the femtosecond laser beam. The data optically encoded into five dimensions is successfully retrieved by quantitative birefringence measurements. The storage allows unprecedented parameters including hundreds of terabytes per disc data capacity and thermal stability up to 1000°. Even at elevated temperatures of 160oC, the extrapolated decay time of nanogratings is comparable with the age of the Universe - 13.8 billion years. The recording of the digital documents, which will survive the human race, including the eternal copies of Universal Declaration of Human Rights, Newton's Opticks, Kings James Bible and Magna Carta, is a vital step towards an eternal archive. Additionally, a number of projects (such as Time Capsule to Mars, MoonMail, and the Google Lunar XPRIZE) could benefit from the technique's extreme durability, which fulfills a crucial requirement for storage on the Moon or Mars.

  1. Blood Type Puzzle.

    ERIC Educational Resources Information Center

    Kelly, Janet

    1997-01-01

    Presents a blood type puzzle that provides a visual, hands-on mechanism by which students can examine blood group reactions. Offers students an opportunity to construct their own knowledge about blood types. (JRH)

  2. SERODS: a new medium for high-density optical data storage

    NASA Astrophysics Data System (ADS)

    Vo-Dinh, Tuan; Stokes, David L.

    1998-10-01

    A new optical dada storage technology based on the surface- enhanced Raman scattering (SERS) effect has been developed for high-density optical memory and three-dimensional data storage. With the surface-enhanced Raman optical data storage (SERODS) technology, the molecular interactions between the optical layer molecules and the nanostructured metal substrate are modified by the writing laser, changing their SERS properties to encode information as bits. Since the SERS properties are extremely sensitive to molecular nano- environments, very small 'spectrochemical holes' approaching the diffraction limit can be produced for the writing process. The SERODS device uses a reading laser to induce the SERS emission of molecules on the disk and a photometric detector tuned to the frequency of the RAMAN spectrum to retrieve the stored information. The results illustrate that SERODS is capable of three-dimensional data storage and has the potential to achieve higher storage density than currently available optical data storage systems.

  3. Large Format Multifunction 2-Terabyte Optical Disk Storage System

    NASA Technical Reports Server (NTRS)

    Kaiser, David R.; Brucker, Charles F.; Gage, Edward C.; Hatwar, T. K.; Simmons, George O.

    1996-01-01

    The Kodak Digital Science OD System 2000E automated disk library (ADL) base module and write-once drive are being developed as the next generation commercial product to the currently available System 2000 ADL. Under government sponsorship with the Air Force's Rome Laboratory, Kodak is developing magneto-optic (M-O) subsystems compatible with the Kodak Digital Science ODW25 drive architecture, which will result in a multifunction (MF) drive capable of reading and writing 25 gigabyte (GB) WORM media and 15 GB erasable media. In an OD system 2000 E ADL configuration with 4 MF drives and 100 total disks with a 50% ration of WORM and M-O media, 2.0 terabytes (TB) of versatile near line mass storage is available.

  4. Certification of ICI 1012 optical data storage tape

    NASA Technical Reports Server (NTRS)

    Howell, J. M.

    1993-01-01

    ICI has developed a unique and novel method of certifying a Terabyte optical tape. The tape quality is guaranteed as a statistical upper limit on the probability of uncorrectable errors. This is called the Corrected Byte Error Rate or CBER. We developed this probabilistic method because of two reasons why error rate cannot be measured directly. Firstly, written data is indelible, so one cannot employ write/read tests such as used for magnetic tape. Secondly, the anticipated error rates need impractically large samples to measure accurately. For example, a rate of 1E-12 implies only one byte in error per tape. The archivability of ICI 1012 Data Storage Tape in general is well characterized and understood. Nevertheless, customers expect performance guarantees to be supported by test results on individual tapes. In particular, they need assurance that data is retrievable after decades in archive. This paper describes the mathematical basis, measurement apparatus and applicability of the certification method.

  5. Review of ultra-high density optical storage technologies for big data center

    NASA Astrophysics Data System (ADS)

    Hao, Ruan; Liu, Jie

    2016-10-01

    In big data center, optical storage technologies have many advantages, such as energy saving and long lifetime. However, how to improve the storage density of optical storage is still a huge challenge. Maybe the multilayer optical storage technology is the good candidate for big data center in the years to come. Due to the number of layers is primarily limited by transmission of each layer, the largest capacities of the multilayer disc are around 1 TB/disc and 10 TB/ cartridge. Holographic data storage (HDS) is a volumetric approach, but its storage capacity is also strictly limited by the diffractive nature of light. For a holographic disc with total thickness of 1.5mm, its potential capacities are not more than 4TB/disc and 40TB/ cartridge. In recent years, the development of super resolution optical storage technology has attracted more attentions. Super-resolution photoinduction-inhibition nanolithography (SPIN) technology with 9 nm feature size and 52nm two-line resolution was reported 3 years ago. However, turning this exciting principle into a real storage system is a huge challenge. It can be expected that in the future, the capacities of 10TB/disc and 100TB/cartridge can be achieved. More importantly, due to breaking the diffraction limit of light, SPIN technology will open the door to improve the optical storage capacity steadily to meet the need of the developing big data center.

  6. Musical Traditions. Puzzle Corner.

    ERIC Educational Resources Information Center

    Andrews, Ian A.

    1999-01-01

    Discusses the changes in musical experiences, such as live versus recorded music, as society has developed technologically. Presents a crossword puzzle that focuses on the traditions and musicians of baroque, classical, and romantic music each originating in Europe. Includes the clues and word list. (CMK)

  7. More Pebble Puzzles.

    ERIC Educational Resources Information Center

    Gibbs, William M.

    This booklet is a collection of puzzles, investigations, and games. They are designed to be used with large objects such as tins or stones and diagrams marked on the ground. The children are to be encouraged to use an experimental, trial-and-error approach at first, and then develop methods of solution. (MNS)

  8. Flexible storage medium for write-once optical tape

    NASA Technical Reports Server (NTRS)

    Strandjord, Andrew J. G.; Webb, Steven P.; Perettie, Donald J.; Cipriano, Robert A.

    1993-01-01

    A write-once data storage media was developed which is suitable for optical tape applications. The media is manufactured using a continuous film process to deposit a ternary alloy of tin, bismuth, and copper. This laser sensitive layer is sputter deposited onto commercial plastic web as a single-layer thin film. A second layer is sequentially deposited on top of the alloy to enhance the media performance and act as an abrasion resistant hard overcoat. The media was observed to have laser write sensitivities of less than 2.0 njoules/bit, carrier-to-noise levels of greater than 50dB's, modulation depths of approximately 100 percent, read-margins of greater than 35, uniform grain sizes of less than 200 Angstroms, and a media lifetime that exceeds 10 years. Prototype tape media was produced for use in the CREO drive system. The active and overcoat materials are first sputter deposited onto three mil PET film in a single pass through the vacuum coating system, and then converted down into multiple reels of 35mm x 880m tape. One mil PET film was also coated in this manner and then slit and packaged into 3480 tape cartridges.

  9. Delivery of video-on-demand services using local storages within passive optical networks.

    PubMed

    Abeywickrama, Sandu; Wong, Elaine

    2013-01-28

    At present, distributed storage systems have been widely studied to alleviate Internet traffic build-up caused by high-bandwidth, on-demand applications. Distributed storage arrays located locally within the passive optical network were previously proposed to deliver Video-on-Demand services. As an added feature, a popularity-aware caching algorithm was also proposed to dynamically maintain the most popular videos in the storage arrays of such local storages. In this paper, we present a new dynamic bandwidth allocation algorithm to improve Video-on-Demand services over passive optical networks using local storages. The algorithm exploits the use of standard control packets to reduce the time taken for the initial request communication between the customer and the central office, and to maintain the set of popular movies in the local storage. We conduct packet level simulations to perform a comparative analysis of the Quality-of-Service attributes between two passive optical networks, namely the conventional passive optical network and one that is equipped with a local storage. Results from our analysis highlight that strategic placement of a local storage inside the network enables the services to be delivered with improved Quality-of-Service to the customer. We further formulate power consumption models of both architectures to examine the trade-off between enhanced Quality-of-Service performance versus the increased power requirement from implementing a local storage within the network.

  10. Optical Disks Compete with Videotape and Magnetic Storage Media: Part I.

    ERIC Educational Resources Information Center

    Urrows, Henry; Urrows, Elizabeth

    1988-01-01

    Describes the latest technology in videotape cassette systems and other magnetic storage devices and their possible effects on optical data disks. Highlights include Honeywell's Very Large Data Store (VLDS); Exabyte's tape cartridge storage system; standards for tape drives; and Masstor System's videotape cartridge system. (LRW)

  11. Optical Disks Compete with Videotape and Magnetic Storage Media: Part II.

    ERIC Educational Resources Information Center

    Urrows, Henry; Urrows, Elizabeth

    1988-01-01

    Describes capabilities of Digi-Data's high-capacity computer storage tape drive, Gigastore, and FileTek's Storage Machine/1. Optical digital disk (ODD) leaders' reactions, opinions, and new products are reported. A directory of 13 ODD sources is included. (MES)

  12. Nature's Greatest Puzzles

    SciTech Connect

    Quigg, Chris; /Fermilab

    2005-02-01

    It is a pleasure to be part of the SLAC Summer Institute again, not simply because it is one of the great traditions in our field, but because this is a moment of great promise for particle physics. I look forward to exploring many opportunities with you over the course of our two weeks together. My first task in talking about Nature's Greatest Puzzles, the title of this year's Summer Institute, is to deconstruct the premise a little bit.

  13. A Microscale Oxidation Puzzle

    NASA Astrophysics Data System (ADS)

    Pelter, Michael W.; Macudzinski, Rebecca M.; Passarelli, Mary Ellen

    2000-11-01

    We have adapted oxidation of an alcohol with sodium hypochlorite solution to a "puzzle" approach by using a diol as the substrate for oxidation. The diols under investigation have both a primary and a secondary hydroxyl group. There are three possible outcomes to the reaction: (i) only the primary alcohol is oxidized to the aldehyde (or carboxylic acid); (ii) only the secondary alcohol is oxidized to the ketone; or (iii) both alcohols are oxidized. The assignment is to perform the reaction and determine the structure of the product through interpretation of the IR spectrum. Examples using two commercially available diols are shown.

  14. Pebble Puzzles. A Source Book of Simple Puzzles and Problems.

    ERIC Educational Resources Information Center

    Gibbs, William M.

    This booklet is a collection of puzzles, games, and investigations. All that children need are some stones or shells, on some of which they must write numerals. For playing with the whole class, the game or puzzles may be marked out on the floor or in sand; in that case, larger objects such as small rocks and empty tins may be used. Children are…

  15. Optical data storage for high-speed data processing and archiving

    NASA Astrophysics Data System (ADS)

    Boldis, M.; Uherek, F.; Chovan, J.

    2010-12-01

    With the invention of first laser before 50 years has been proved generation of intense, focused and narrow light beam of one wavelength, also at the same time were fulfilled assumptions for creation memories on light base - Optical Data Storages. Contemporary dynamic memories operate on base electrical impulses, manufactured as matrix arranged MOSFET transistors with capacitors, and reach time delay (latency time) in ones nanoseconds. Transfer data rates are above ones of Gbps. Current storages are approaching technologically threshold parameters, what may be barrier to further development, whereas Optical Data storages multiple exceed transfer data rates of contemporary memories, not require reverse O/E/O signal transformation, operate in pico-seconds (ps) and work at low energetic levels of femto- Joules. New end-user services lay still bigger emphasis for transferred and stored data volumes, transfer rates, quality of transmission and data processing, whereby they partly pushing out contemporary storages and create place for optical memory elements used in telecommunication networks and in devices. Optical storages with their several-fold higherdensity, high transmission rates, better quality and small dimensions are becoming a new trend for dynamic buffer or balancing memories, used for long-term data archiving in plasmonic nano-structures within Holographic Data storages.

  16. Three Puzzles for Organic Laboratory.

    ERIC Educational Resources Information Center

    Todd, David; Pickering, Miles

    1988-01-01

    Notes that laboratory work should be more oriented towards puzzle solving rather than technique or illustration. Offers three organic laboratory puzzles which can be solved by melting point alone. Involves lab work at the 100-200-mg scale but still uses conventional glassware. (MVL)

  17. Optical Disk Technology for Large Scale Mass Storage.

    DTIC Science & Technology

    1985-12-01

    rules. It is sufficient to say that the various encoding techniques provide the system’s designer with several advantages. 8. . . .-. ERROR MANAGEMENT ...characterize due to its variable nature. It is not the *intention to dismiss the characterization of the hardware and software for *error management ...system designer. The most difficult step in managing the error budget in an optical disk 2 *system is otingahigh quality media. An optical disk

  18. The non-continuous optical signal identification and data storage on the case of atmospheric disturbances

    NASA Astrophysics Data System (ADS)

    Yu, Si-yuan; Liu, Yong-kai; Ma, Jing; Tan, Li-ying

    2013-08-01

    In the link of satellite to ground laser communication, light signals received by ground terminal receivers are susceptible to interference due to the impact of atmospheric turbulence, and it will result in the degradation of communication quality or even interruption. In this situation, the conventional communication detection device would not be able to analyze the link performance. Thus, it is necessary to develop a set of non-continuous optical signal recognition and storage devices which could work under adverse atmospheric conditions and do the online analysis of the impact of atmospheric on the link of satellite to ground laser. Since the interruption of the optical signal will cause the logical disorders of the high data rate storage system, which uses the CDR output clock as the system clock, general storage device cannot meet the demand of effective storage for communication. In this paper, the usage of FPGA optical signal recovered clock frequency discriminator identified the impact of non-continuous communication signal of atmospheric disturbances effectively. Through the optimization of the system hardware design and software control, we achieved the identification and storage of the laser communication optical signal data while the factor of atmospheric scintillation varying from 0 to 1.5 and the communication data rate being 600Mbps.

  19. Digitizing stereoscopic optic nerve head photographs for storage and viewing using a personal computer.

    PubMed

    Nesher, Ronit; Zacharopoulos, Ioannis; Assia, Ehud I; Schuman, Joel S

    2005-01-01

    Careful examination and monitoring of optic nerve head changes is essential in the treatment of patients with glaucoma. This often results in accumulation of numerous photographs and required appropriate storage space. A simple, inexpensive, and efficient means of storing and viewing stereoscopic optic nerve head photographs is described. Images were acquired with a fundus camera, on a color slide film. Slides were then scanned and digitized. A handheld stereoscope was used for stereoscopic viewing on a computer monitor. A scanning resolution of 300 dpi appeared optimal. At this resolution, the storage utilization was 16 kilobytes and the scanning time was 160 seconds per patient.

  20. Six-dimensional optical storage utilizing wavelength selective, polarization sensitive, and reflectivity graded Bragg reflectors

    NASA Astrophysics Data System (ADS)

    Liu, Shangqing

    2014-09-01

    An optical storage system which stores data in three spacial and three physical dimensions is designed and investigated. Its feasibility has been demonstrated by theoretical derivation and numerical calculation. This system has comprehensive advantages including very large capacity, ultrafast throughputs, relatively simple structure and compatibility with CD and DVD. It's an actually practicable technology. With two-photon absorption writing/erasing and optical coherence tomography reading, its storage capacity is over 32 Tbytes per DVD sized disk, and its reading speed is over 25 Gbits/s with high signal-to-noise ratio of over 76 dB. The larger capacity of over 1 Pbyte per disk is potential.

  1. High-Density Optical Data Storage Enabled by the Photonic Nanojet from a Dielectric Microsphere

    NASA Astrophysics Data System (ADS)

    Kong, Soon-Cheol; Sahakian, Alan V.; Taflove, Allen; Backman, Vadim

    2009-03-01

    We discuss the usage of the photonic nanojet to detect deeply subwavelength pits in a metal substrate for the purpose of high-density optical data storage. Three-dimensional finite-difference time-domain (FDTD) computational solutions of Maxwell's equations are used to analyze and design the system. We find that nanojet-illuminated pits having lateral dimensions of only 100×150 nm2 yield a 40-dB contrast ratio. The FDTD simulation results show that pit-depth modulation and pit-width modulation can significantly increase the optical data-storage capacity.

  2. Storage and control of optical photons using Rydberg polaritons.

    PubMed

    Maxwell, D; Szwer, D J; Paredes-Barato, D; Busche, H; Pritchard, J D; Gauguet, A; Weatherill, K J; Jones, M P A; Adams, C S

    2013-03-08

    We use a microwave field to control the quantum state of optical photons stored in a cold atomic cloud. The photons are stored in highly excited collective states (Rydberg polaritons) enabling both fast qubit rotations and control of photon-photon interactions. Through the collective read-out of these pseudospin rotations it is shown that the microwave field modifies the long-range interactions between polaritons. This technique provides a powerful interface between the microwave and optical domains, with applications in quantum simulations of spin liquids, quantum metrology and quantum networks.

  3. Efficient synthesis of a new unsymmetrical photochromic diarylethene for optical recording storage

    NASA Astrophysics Data System (ADS)

    Wang, Taofeng; Liu, Gang; Liu, Weijun

    2011-11-01

    A novel unsymmetrical photochromic diarylethene bearing a benzothiazole unit, 1-[ (2,5-dimethyl-3-thienyl) ]-2-[(2-methyl-5-(2-benzothiazole)-3-thienyl)]perfluoroyclopentene (1O) have been synthesized. Its photochromic, fluorescence and optical strorage properties were investigated. The compound exhibited obviously photochromism both in hexane and in PMMA film. In hexane, the fluorescence intensity of 1O declined along with the photochromism upon irradiation with 297 nm light. This new photochromic system also exhibited remarkable optical storage characters.

  4. Efficient synthesis of a new unsymmetrical photochromic diarylethene for optical recording storage

    NASA Astrophysics Data System (ADS)

    Wang, Taofeng; Liu, Gang; Liu, Weijun

    2012-01-01

    A novel unsymmetrical photochromic diarylethene bearing a benzothiazole unit, 1-[ (2,5-dimethyl-3-thienyl) ]-2-[(2-methyl-5-(2-benzothiazole)-3-thienyl)]perfluoroyclopentene (1O) have been synthesized. Its photochromic, fluorescence and optical strorage properties were investigated. The compound exhibited obviously photochromism both in hexane and in PMMA film. In hexane, the fluorescence intensity of 1O declined along with the photochromism upon irradiation with 297 nm light. This new photochromic system also exhibited remarkable optical storage characters.

  5. Method of bistable optical information storage using antiferroelectric phase PLZT ceramics

    DOEpatents

    Land, Cecil E.

    1990-01-01

    A method for bistable storage of binary optical information includes an antiferroelectric (AFE) lead lanthanum zirconate titanate (PLZT) layer having a stable antiferroelectric first phase and a ferroelectric (FE) second phase obtained by applying a switching electric field across the surface of the device. Optical information is stored by illuminating selected portions of the layer to photoactivate an FE to AFE transition in those portions. Erasure of the stored information is obtained by reapplying the switching field.

  6. Method of bistable optical information storage using antiferroelectric phase PLZT ceramics

    DOEpatents

    Land, C.E.

    1990-07-31

    A method for bistable storage of binary optical information includes an antiferroelectric (AFE) lead lanthanum zirconate titanate (PLZT) layer having a stable antiferroelectric first phase and a ferroelectric (FE) second phase obtained by applying a switching electric field across the surface of the device. Optical information is stored by illuminating selected portions of the layer to photoactivate an FE to AFE transition in those portions. Erasure of the stored information is obtained by reapplying the switching field. 8 figs.

  7. Optical response of photopolymer materials for holographic data storage applications.

    PubMed

    Sheridan, J T; Gleeson, M R; Close, C E; Kelly, J V

    2007-01-01

    We briefly review the application of photopolymer recording materials in the area of holographic data storage. In particular we discuss the recent development of the Non-local Polymerisation Driven Diffusion model. Applying this model we develop simple first-order analytic expressions describing the spatial frequency response of photopolymer materials. The assumptions made in the derivation of these formulae are described and their ranges of validity are examined. The effects of particular physical parameters of a photopolymer on the material response are discussed.

  8. The Puzzling Ophiuchus Stream

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-01-01

    Dwarf galaxies or globular clusters orbiting the Milky Way can be pulled apart by tidal forces, leaving behind a trail of stars known as a stellar stream. One such trail, the Ophiuchus stream, has posed a serious dynamical puzzle since its discovery. But a recent study has identified four stars that might help resolve this streams mystery.Conflicting TimescalesThe stellar stream Ophiuchus was discovered around our galaxy in 2014. Based on its length, which appears to be 1.6 kpc, we can calculate the time that has passed since its progenitor was disrupted and the stream was created: ~250 Myr. But the stars within it are ~12 Gyr old, and the stream orbits the galaxy with a period of ~350 Myr.Given these numbers, we can assume that Ophiuchuss progenitor completed many orbits of the Milky Way in its lifetime. So why would it only have been disrupted 250 million years ago?Fanning StreamLed by Branimir Sesar (Max Planck Institute for Astronomy), a team of scientists has proposed an idea that might help solve this puzzle. If the Ophiuchus stellar stream is on a chaotic orbit common in triaxial potentials, which the Milky Ways may be then the stream ends can fan out, with stars spreading in position and velocity.The fanned part of the stream, however, would be difficult to detect because of its low surface brightness. As a result, the Ophiuchus stellar stream could actually be longer than originally measured, implying that it was disrupted longer ago than was believed.Search for Fan StarsTo test this idea, Sesar and collaborators performed a search around the ends of the stream, looking for stars thatare of the right type to match the stream,are at the predicted distance of the stream,are located near the stream ends, andhave velocities that match the stream and dont match the background halo stars.Histogram of the heliocentric velocities of the 43 target stars. Six stars have velocities matching the stream velocity. Two of these are located in the main stream; the other

  9. Controllable high bandwidth storage of optical information in a Bose-Einstein Condensate

    NASA Astrophysics Data System (ADS)

    Jayaseelan, Maitreyi; Schultz, Justin T.; Murphree, Joseph D.; Hansen, Azure; Bigelow, Nicholas P.

    2016-05-01

    The storage and retrieval of optical information has been of interest for a variety of applications including quantum information processing, quantum networks and quantum memories. Several schemes have been investigated and realized with weak, narrowband pulses, including techniques using EIT in solid state systems and both hot and cold atomic vapors. In contrast, we investigate the storage and manipulation of strong, high bandwidth pulses in a Bose-Einstein Condensate (BEC) of ultracold 87 Rb atoms. As a storage medium for optical pulses, BECs offer long storage times and preserve the coherence properties of the input information, suppressing unwanted thermal decoherence effects. We present numerical simulations of nanosecond pulses addressing a three-level lambda system on the D2 line of 87 Rb. The signal pulse is stored as a localized spin excitation in the condensate and can be moved or retrieved by reapplication of successive control pulses. The relative Rabi frequencies and areas of the pulses and the local atomic density in the condensate determine the storage location and readout of the signal pulse. Extending this scheme to use beams with a variety of spatial modes such as Hermite- and Laguerre-Gaussian modes offers an expanded alphabet for information storage.

  10. Coumarin-Containing Polymers for High Density Non-Linear Optical Data Storage.

    PubMed

    Gindre, Denis; Iliopoulos, Konstantinos; Krupka, Oksana; Evrard, Marie; Champigny, Emilie; Sallé, Marc

    2016-01-26

    Optical data storage was performed with various thin polymer films containing coumarin-based derivatives and by using femtosecond laser pulses as well as two-photon absorption processes. Exploring the photodimerization attribute of coumarin derivatives and using appropriate irradiation wavelengths, recording/erasing processes could be carried out in the same area. Second harmonic generation microscopy was used to read the stored information.

  11. Reversible two-photon optical data storage in coumarin-based copolymers.

    PubMed

    Iliopoulos, Konstantinos; Krupka, Oksana; Gindre, Denis; Sallé, Marc

    2010-10-20

    A functionalized polymer film allowing for a complete and straightforward second-harmonic generation (SHG)-assisted high-contrast writing-reading-erasing-writing sequence is proposed. The whole process is supported by the reversible photoinduced dimerization of a coumarin chromophore and enables efficient optical data storage that can be detected only by SHG imaging.

  12. The Use of WORM Optical Disc Storage for Newspaper Cuttings in a Public Library.

    ERIC Educational Resources Information Center

    Fulton, Alan R.

    1990-01-01

    Describes the collection of the Local History Department of the Central Library in Aberdeen (which includes 2,300 volumes of locally produced newspapers and 101,000 sheets of press cuttings) and the use of an optical disk system to help solve the problems of storage and access to these materials. (CLB)

  13. Optically Addressed Nanostructures for High Density Data Storage

    DTIC Science & Technology

    2005-10-14

    advanced several approaches to calculate the clique-based capacity of these structures. We have considered and bounded statistical cross-talk between...positioned in the requisite matrix using optical tweezer technologies . This fabrication approach is being analyzed further to understand its limitations... gain -doublet in which a pair of Lorentzian gain lines are used to achieve significant pulse delay relative to a single-line system. A factor of 6.25

  14. [The Parkinson puzzle].

    PubMed

    Guseo, András

    2012-12-30

    Parkinson's disease is one of the most frequent progressive degenerative disorders with unknown origin of the nervous system. The commutation of the disease on Guam led to the discovery of a neurotoxin which was also found in other continents. This neurotoxin was identified in the common cyanobacteria (blue-green algae). Early clinical observations suggested some loose correlations with gastric and duodenal ulcer and Parkinson's disease, while recent studies revealed a toxin, almost identical to that found in cyanobacteria in one strain of Helicobacter pylori, which proved to cause Parkinson like symptoms in animals. Therefore, it cannot be ruled out that there is a slowly progressive poisoning in Parkinson's disease. The disease specific alpha-sinuclein inclusions can be found in nerve cells of the intestinal mucosa far before the appearance of clinical symptoms indicating that the disease may start in the intestines. These results are strengthened by the results of Borody's fecal transplants, after which in Parkinson patients showed a symptomatic improvement. Based on these observations the Parkinson puzzle is getting complete. Although these observations are not evidence based, they may indicate a new way for basic clinical research, as well as a new way of thinking for clinicians. These new observations in psycho-neuro-immunology strengthen the fact that immunological factors may also play a critical factor facilitating local cell necrosis which may be influenced easily.

  15. Optimizing the optical field distribution of near-field SIL optical storage system using five-zone binary phase filters

    NASA Astrophysics Data System (ADS)

    Fang, Chaolong; Zhang, Yaoju; Zhu, Haiyong

    2012-06-01

    Five-zone binary phase filters (FBPFs) are proposed for decreasing the spot size and/or increasing the focal depth of the near-field optical storage system with a hemisphere solid immersion lens (SIL). The design of filters is based on the vector diffraction theory and the MATLAB optimizing toolbox. Three FBPFs with rotationally symmetrical pupil function have been designed, where the one FBPF is for increasing the focal depth as big as possible, the second FBPF is for improving the resolution as high as possible, and the third FBPF integrate the increase of focal depth with the improvement of resolution. Numerical results show that compared with the three-zone amplitude filter, the designed five-zone binary phase-only filters have more prominent performances in improving the focal depth and the resolution of the near-field SIL optical storage system.

  16. Implementation of an optical disk system for medical record storage.

    PubMed

    Mahoney, M E

    1990-09-01

    MARS was a joint developmental effort between Maine Medical Center and Advanced Healthcare Systems, Inc. It has taken nearly three years to get the system (hardware, software, and staff) to a point where it can now meet daily production requirements. This project was truly unique, so there was no opportunity to learn from the experiences of others. The optical disk system has been an attractive solution to some of the problems experienced at Maine Medical Center. The result was worth the effort in terms of both dollars and other less quantifiable benefits that have had a positive impact on patient care.

  17. New method of two-photon multi-layer optical disc storage

    NASA Astrophysics Data System (ADS)

    Jiang, Bing; Shen, Zhaolong; Cai, Jianwen; Tang, Huohong; Xing, Hui; Huang, Wenhao

    2006-02-01

    Multi-layer data storage based on nonlinear effect caused by two-photon absorption is an attractive approach in the field of mass data storage. A two-photon multi-layer optical disc storage system with disc rotation structure has been proposed. The multi-layer fluorescent disc used in this system consists of three layers. A transparent substrate (under layer) and a thin reflective layer (middle layer) are bonded together forming a kind of structure similar to DVD disc, which is necessary to servo the vertical and radial deviation. Two-photon bits are recorded in top layer. The storage system has two modules: servo module and confocal module. The former keeps following the vertical and radial deviations by means of focusing and tracking servo technologies used in current two-dimensional optical storage devices, so the system can be compatible with CD/DVD. According to the driving signal of actuators in servo pick-up, the confocal module can also follow the disc deviation in both recording and reading processes. The servo module has been finished and the result of preliminary experiment is presented. Using the actuator and the objective lens (NA 0.6) in SANYO pick-up, we successfully recorded and read three data layers in photobleaching material with a homemade femtosecond laser. The layer separation was 15μm and the transverse bit separation was 4 μm.

  18. An emerging network storage management standard: Media error monitoring and reporting information (MEMRI) - to determine optical tape data integrity

    NASA Technical Reports Server (NTRS)

    Podio, Fernando; Vollrath, William; Williams, Joel; Kobler, Ben; Crouse, Don

    1998-01-01

    Sophisticated network storage management applications are rapidly evolving to satisfy a market demand for highly reliable data storage systems with large data storage capacities and performance requirements. To preserve a high degree of data integrity, these applications must rely on intelligent data storage devices that can provide reliable indicators of data degradation. Error correction activity generally occurs within storage devices without notification to the host. Early indicators of degradation and media error monitoring 333 and reporting (MEMR) techniques implemented in data storage devices allow network storage management applications to notify system administrators of these events and to take appropriate corrective actions before catastrophic errors occur. Although MEMR techniques have been implemented in data storage devices for many years, until 1996 no MEMR standards existed. In 1996 the American National Standards Institute (ANSI) approved the only known (world-wide) industry standard specifying MEMR techniques to verify stored data on optical disks. This industry standard was developed under the auspices of the Association for Information and Image Management (AIIM). A recently formed AIIM Optical Tape Subcommittee initiated the development of another data integrity standard specifying a set of media error monitoring tools and media error monitoring information (MEMRI) to verify stored data on optical tape media. This paper discusses the need for intelligent storage devices that can provide data integrity metadata, the content of the existing data integrity standard for optical disks, and the content of the MEMRI standard being developed by the AIIM Optical Tape Subcommittee.

  19. Optical phase information writing and storage in populations of metastable quantum states

    SciTech Connect

    Djotyan, G. P.; Sandor, N.; Bakos, J. S.; Soerlei, Zs.

    2009-10-15

    We propose a scheme for robust writing and storage of optical phase information in populations of metastable states of the atoms with a tripod structure of levels by using frequency-chirped laser pulses. The method provides much longer storage times compared with the schemes based on the collective atomic spin coherences. A negligible excitation of the atom provides immunity to decoherence induced by decay of the excited states. The method is robust against small-to-medium variations in the laser pulse intensity and speed of the chirp and, being insensitive to resonance conditions, it is effective both in homogeneously and inhomogeneously broadened media.

  20. Quantum storage of entangled telecom-wavelength photons in an erbium-doped optical fibre

    NASA Astrophysics Data System (ADS)

    Saglamyurek, Erhan; Jin, Jeongwan; Verma, Varun B.; Shaw, Matthew D.; Marsili, Francesco; Nam, Sae Woo; Oblak, Daniel; Tittel, Wolfgang

    2015-02-01

    The realization of a future quantum Internet requires the processing and storage of quantum information at local nodes and interconnecting distant nodes using free-space and fibre-optic links. Quantum memories for light are key elements of such quantum networks. However, to date, neither an atomic quantum memory for non-classical states of light operating at a wavelength compatible with standard telecom fibre infrastructure, nor a fibre-based implementation of a quantum memory, has been reported. Here, we demonstrate the storage and faithful recall of the state of a 1,532 nm wavelength photon entangled with a 795 nm photon, in an ensemble of cryogenically cooled erbium ions doped into a 20-m-long silica fibre, using a photon-echo quantum memory protocol. Despite its currently limited efficiency and storage time, our broadband light-matter interface brings fibre-based quantum networks one step closer to reality.

  1. Photorefractive Three-Dimensional Disks for Optical Data Storage and Artificial Neural Networks

    NASA Astrophysics Data System (ADS)

    Li, Hsin-Yu Sidney

    This thesis is on the application of 3-D photorefractive crystals disks for holographic optical data storage and optical neural networks. Chapter 1 gives some introductory background and motivation for the materials given in this thesis. In Chapter 2, the coupled-mode analysis and Born's approximation in anisotropic crystals is reviewed. The results are similar to that of isotropic materials. However, there are approximations that are often neglected in the literature. Chapter 3 starts with the description of the holographic 3-D disk for data storage, and analyzes the various alignment errors and tolerance problems for a 3-D disk system. Of particular interest is the effects in image reconstruction caused by rotational angle error. An optimum configuration is found that minimizes this error. Chapter 4 examines the data storage density of 3-D disks and volume holographic storage systems that utilize wavelength/angle and spatial multiplexing. The maximum storage density and the geometry that achieves this density is derived. Chapter 5 discusses the diffraction efficiency of 3-D disks fabricated with photorefractive crystals. Practical geometries and crystal orientations for achieving maximum uniform diffraction efficiency are given and compared to the maximum obtainable diffraction efficiencies using arbitrary cut crystals. Experimental results are shown. Also derived in this chapter are the double grating effect from crystal anisotropy, and the optimum configuration for getting maximum diffraction efficiency using the 90 degree recording geometry. The Khuktarev band-transport model of the photorefractive effect is examined briefly with emphasis on the anisotropy of the material. The proper expression for the permittivity term in the space-charge field formula is derived. Chapter 6 gives an example of an optical neural network that uses photorefractive crystals. It is the real time face-recognition system. The setup and experiments are described. Some properties of

  2. Molecular Electronics for Frequency Domain Optical Storage. Persistent Spectral Hole-Burning. A Review.

    DTIC Science & Technology

    1985-03-25

    if applicable) Office of Naval Research IBM Almaden Research Center Chemistry Division, Code 1113 6c. ADDRESS (City, State, and ZIP Code) 7b...NOTATION Journal of Molecular Electronics 17. .* COSATI CODES 18. SUBJECT TERMS (Continue on reverse of necessary and identify by block number) FIEL GRUP SB...GOUP Molecular electronics, spectral hole-burning, frequency I I domain. optical storage, solid state photo chemistry , * I photon gating. 19. ABSTRACT

  3. Single-photon-level optical storage in a solid-state spin-wave memory

    NASA Astrophysics Data System (ADS)

    Timoney, N.; Usmani, I.; Jobez, P.; Afzelius, M.; Gisin, N.

    2013-08-01

    A long-lived quantum memory is a firm requirement for implementing a quantum repeater scheme. Recent progress in solid-state rare-earth-ion-doped systems justifies their status as very strong candidates for such systems. Nonetheless an optical memory based on spin-wave storage at the single-photon level has not been shown in such a system to date, which is crucial for achieving the long storage times required for quantum repeaters. In this paper we show that it is possible to execute a complete atomic frequency comb (AFC) scheme, including spin-wave storage, with weak coherent pulses of n¯=2.5±0.6 photons per pulse. We discuss in detail the experimental steps required to obtain this result and demonstrate the coherence of a stored time-bin pulse. We show a noise level of (7.1±2.3)×10-3 photons per mode during storage, and this relatively low noise level paves the way for future quantum optics experiments using spin waves in rare-earth-doped crystals.

  4. Two-Photon Optical Storage in Photorefractive Polymers in the Near-Infrared Spectral Range

    NASA Astrophysics Data System (ADS)

    Day, Daniel; Gu, Min; Smallridge, Andrew

    We report the use of a polymer-based photorefractive material for three-dimensional bit optical data storage using near-infrared illumination. The research was conducted using photorefractive materials that were fabricated in two polymer matrices: poly(N-vinylcarbazole) (PVK) and poly(Methyl Methacrylate) (PMMA). The recording samples also consisted of the following compounds in various proportions: 2,5-dimethyl-4-(p-nitrophenylazo)anisole (DMNPAA), 2,4,7-trinitro-9-fluorenone (TNF) and N-ethylcarbazole (ECZ). Two-photon excitation was used as the recording mechanism to achieve rewritable bit data storage in a photorefractive polymer. As a result of two-photon excitation, the quadratic dependence of the excitation on the incident intensity produces an excitation volume that is confined to the focal region in both the transverse and axial directions. The use of ultrashort pulsed lasers, while effective, is not a practical solution for an optical data storage system. This research demonstrates the ability to produce three-dimensional rewritable bit data storage using continuous-wave illumination. Using this technology it has been possible to achieve a density of 88 Gbits/cm3, which in the future could be increased to 3.5 Tbits/cm3.

  5. Controllable all-optical stochastic logic gates and their delay storages based on the cascaded VCSELs with optical-injection

    NASA Astrophysics Data System (ADS)

    Zhong, Dongzhou; Luo, Wei; Xu, Geliang

    2016-09-01

    Using the dynamical properties of the polarization bistability that depends on the detuning of the injected light, we propose a novel approach to implement reliable all-optical stochastic logic gates in the cascaded vertical cavity surface emitting lasers (VCSELs) with optical-injection. Here, two logic inputs are encoded in the detuning of the injected light from a tunable CW laser. The logic outputs are decoded from the two orthogonal polarization lights emitted from the optically injected VCSELs. For the same logic inputs, under electro-optic modulation, we perform various digital signal processing (NOT, AND, NAND, XOR, XNOR, OR, NOR) in the all-optical domain by controlling the logic operation of the applied electric field. Also we explore their delay storages by using the mechanism of the generalized chaotic synchronization. To quantify the reliabilities of these logic gates, we further demonstrate their success probabilities. Project supported by the National Natural Science Foundation of China (Grant No. 61475120) and the Innovative Projects in Guangdong Colleges and Universities, China (Grant Nos. 2014KTSCX134 and 2015KTSCX146).

  6. Ultra-high density optical data storage in common transparent plastics

    NASA Astrophysics Data System (ADS)

    Kallepalli, Deepak L. N.; Alshehri, Ali M.; Marquez, Daniela T.; Andrzejewski, Lukasz; Scaiano, Juan C.; Bhardwaj, Ravi

    2016-05-01

    The ever-increasing demand for high data storage capacity has spurred research on development of innovative technologies and new storage materials. Conventional GByte optical discs (DVDs and Bluray) can be transformed into ultrahigh capacity storage media by encoding multi-level and multiplexed information within the three dimensional volume of a recording medium. However, in most cases the recording medium had to be photosensitive requiring doping with photochromic molecules or nanoparticles in a multilayer stack or in the bulk material. Here, we show high-density data storage in commonly available plastics without any special material preparation. A pulsed laser was used to record data in micron-sized modified regions. Upon excitation by the read laser, each modified region emits fluorescence whose intensity represents 32 grey levels corresponding to 5 bits. We demonstrate up to 20 layers of embedded data. Adjusting the read laser power and detector sensitivity storage capacities up to 0.2 TBytes can be achieved in a standard 120 mm disc.

  7. Ultra-high density optical data storage in common transparent plastics

    PubMed Central

    Kallepalli, Deepak L. N.; Alshehri, Ali M.; Marquez, Daniela T.; Andrzejewski, Lukasz; Scaiano, Juan C.; Bhardwaj, Ravi

    2016-01-01

    The ever-increasing demand for high data storage capacity has spurred research on development of innovative technologies and new storage materials. Conventional GByte optical discs (DVDs and Bluray) can be transformed into ultrahigh capacity storage media by encoding multi-level and multiplexed information within the three dimensional volume of a recording medium. However, in most cases the recording medium had to be photosensitive requiring doping with photochromic molecules or nanoparticles in a multilayer stack or in the bulk material. Here, we show high-density data storage in commonly available plastics without any special material preparation. A pulsed laser was used to record data in micron-sized modified regions. Upon excitation by the read laser, each modified region emits fluorescence whose intensity represents 32 grey levels corresponding to 5 bits. We demonstrate up to 20 layers of embedded data. Adjusting the read laser power and detector sensitivity storage capacities up to 0.2 TBytes can be achieved in a standard 120 mm disc. PMID:27221758

  8. Chemistry of Art and Color Sudoku Puzzles

    ERIC Educational Resources Information Center

    Welsh, Michael J.

    2007-01-01

    Sudoku puzzle format was used to teach light science and chemistry terms to students of Chemistry of Art and Color. The puzzles were used to motivate and encourage students to learn chemistry in an easier and in friendly fashion.

  9. LIGHT SOURCE: Optics for the lattice of the compact storage ring for a Compton X-ray source

    NASA Astrophysics Data System (ADS)

    Yu, Pei-Cheng; Wang, Yu; Shen, Xiao-Zhe; Huang, Wen-Hui; Yan, Li-Xin; Du, Ying-Chao; Li, Ren-Kai; Tang, Chuan-Xiang

    2009-06-01

    We present two types of optics for the lattice of a compact storage ring for a Compton X-ray source. The optics design for different operation modes of the storage ring are discussed in detail. For the pulse mode optics, an IBS-suppression scheme is applied to optimize the optics for lower IBS emittance growth rate; as for the steady mode, the method to control momentum compact factor is adopted [Gladkikh P, Phys. Rev. ST Accel. Beams 8, 050702] to obtain stability of the electron beam.

  10. On a Perplexing Polynomial Puzzle

    ERIC Educational Resources Information Center

    Richmond, Bettina

    2010-01-01

    It seems rather surprising that any given polynomial p(x) with nonnegative integer coefficients can be determined by just the two values p(1) and p(a), where a is any integer greater than p(1). This result has become known as the "perplexing polynomial puzzle." Here, we address the natural question of what might be required to determine a…

  11. Sudoku Puzzles as Chemistry Learning Tools

    ERIC Educational Resources Information Center

    Crute, Thomas D.; Myers, Stephanie A.

    2007-01-01

    A sudoku puzzle was designed that incorporated lists of chemistry terms like polyatomic ions, organic functional groups or strong nucleophiles that students need to learn. It was found that students enjoyed solving such puzzles and also such puzzles made the boring tasks of memorizing basic chemical terms an exciting one.

  12. Ultrathin reduced graphene oxide films for high performance optical data storage

    NASA Astrophysics Data System (ADS)

    Xing, Fei; Yang, Yong; Zhu, Siwei; Yuan, Xiaocong

    2015-10-01

    Optical data storage (ODS) represents revolutionary progress for the field of information storage capacity. When the thickness of data recording layer is similar to a few nanometer even atomic scale, the data point dimension can decrease to the minimum with stable mechanical property. Thus the new generation of ODS requires data recording layer in nanoscale to improve areal storage density, so that the more digital information can be stored in limited zone. Graphene, a novel two-dimensional (2D) material, is a type of monolayer laminated structure composed of carbon atoms and is currently the thinnest known material (the thickness of monolayer graphene is 3.35 Å). It is an ideal choice as a active layer for ODS media. Reduced graphene oxide, a graphene derivative, has outstanding polarization-dependent absorption characteristics under total internal reflection (TIR). The strong broadband absorption of reduced graphene oxide causes it to exhibit different reflectance for transverse electric (TE) and transverse magnetic (TM) modes under TIR, and the maximum reflectance ratio between TM and TE modes is close to 8 with 8 nm reduced graphene oxide films. It opens a door for a high signal to noise ratio (SNR) graphene-based optical data storage. Here, 8 nm high-temperature reduced graphene oxide (h-rGO) films was used for the ultrathin active layer of ODS. The data writing was performed on the h-rGO active layer based on photolithography technology. Under TIR, a balanced detection technology in the experiment converts the optical signals into electric signals and simultaneously amplifies them. The reading results show a stable SNR up to 500, and the graphene-based ODS medium has a high transparency performance.

  13. New optical architecture for holographic data storage system compatible with Blu-ray Disc™ system

    NASA Astrophysics Data System (ADS)

    Shimada, Ken-ichi; Ide, Tatsuro; Shimano, Takeshi; Anderson, Ken; Curtis, Kevin

    2014-02-01

    A new optical architecture for holographic data storage system which is compatible with a Blu-ray Disc™ (BD) system is proposed. In the architecture, both signal and reference beams pass through a single objective lens with numerical aperture (NA) 0.85 for realizing angularly multiplexed recording. The geometry of the architecture brings a high affinity with an optical architecture in the BD system because the objective lens can be placed parallel to a holographic medium. Through the comparison of experimental results with theory, the validity of the optical architecture was verified and demonstrated that the conventional objective lens motion technique in the BD system is available for angularly multiplexed recording. The test-bed composed of a blue laser system and an objective lens of the NA 0.85 was designed. The feasibility of its compatibility with BD is examined through the designed test-bed.

  14. Squeezing red blood cells on an optical waveguide to monitor cell deformability during blood storage.

    PubMed

    Ahluwalia, Balpreet Singh; McCourt, Peter; Oteiza, Ana; Wilkinson, James S; Huser, Thomas R; Hellesø, Olav Gaute

    2015-01-07

    Red blood cells squeeze through micro-capillaries as part of blood circulation in the body. The deformability of red blood cells is thus critical for blood circulation. In this work, we report a method to optically squeeze red blood cells using the evanescent field present on top of a planar waveguide chip. The optical forces from a narrow waveguide are used to squeeze red blood cells to a size comparable to the waveguide width. Optical forces and pressure distributions on the cells are numerically computed to explain the squeezing process. The proposed technique is used to quantify the loss of blood deformability that occurs during blood storage lesion. Squeezing red blood cells using waveguides is a sensitive technique and works simultaneously on several cells, making the method suitable for monitoring stored blood.

  15. From the surface to volume: concepts for the next generation of optical-holographic data-storage materials.

    PubMed

    Bruder, Friedrich-Karl; Hagen, Rainer; Rölle, Thomas; Weiser, Marc-Stephan; Fäcke, Thomas

    2011-05-09

    Optical data storage has had a major impact on daily life since its introduction to the market in 1982. Compact discs (CDs), digital versatile discs (DVDs), and Blu-ray discs (BDs) are universal data-storage formats with the advantage that the reading and writing of the digital data does not require contact and is therefore wear-free. These formats allow convenient and fast data access, high transfer rates, and electricity-free data storage with low overall archiving costs. The driving force for development in this area is the constant need for increased data-storage capacity and transfer rate. The use of holographic principles for optical data storage is an elegant way to increase the storage capacity and the transfer rate, because by this technique the data can be stored in the volume of the storage material and, moreover, it can be optically processed in parallel. This Review describes the fundamental requirements for holographic data-storage materials and compares the general concepts for the materials used. An overview of the performance of current read-write devices shows how far holographic data storage has already been developed.

  16. Acousto-optic parallel read/write head for optical disk data storage.

    PubMed

    McLeod, Robert R; Walter, Sarah K

    2006-09-20

    Parallel read and write of optical disks has traditionally used a static grating for read or a linear array of independent lasers for read and write. Depending on the implementation, these systems suffer from coherent cross talk, excessive space between spots, and an inability to independently track. We show that a dynamic acousto-optic grating can generate multiple parallel read/write spots on the disk, each of which can be independently modulated and tracked and all of which are incoherent in less that a bit period. The resulting disk pickup can potentially reach gigabit per second transfer rates with only a modest increase in the drive complexity.

  17. Acousto-optic parallel read/write head for optical disk data storage

    NASA Astrophysics Data System (ADS)

    McLeod, Robert R.; Walter, Sarah K.

    2006-09-01

    Parallel read and write of optical disks has traditionally used a static grating for read or a linear array of independent lasers for read and write. Depending on the implementation, these systems suffer from coherent cross talk, excessive space between spots, and an inability to independently track. We show that a dynamic acousto-optic grating can generate multiple parallel read/write spots on the disk, each of which can be independently modulated and tracked and all of which are incoherent in less that a bit period. The resulting disk pickup can potentially reach gigabit per second transfer rates with only a modest increase in the drive complexity.

  18. Development of photorefractive polymers for real-time optical information storage

    NASA Astrophysics Data System (ADS)

    Mangaiyarkarasi, D.; Palanisamy, P. K.; Kannan, P.

    1999-03-01

    A large number of strong nonlinear optical and electro optical molecules and crystals are identified recently. With the discovery of the photorefractive (PR) effect and early realization of its potential utility, PR materials are of considerable interest for the development of all optical devices, such as high density optical data storage and image processing techniques. Organic materials are known to show strong electro optic effects. In organic materials, the properties required for the PR effect including photosensitivity, photoconductivity and electro optic response are provided by different molecules. As a result, the properties can be optimized separately, unlike in inorganic PR crystals such as LiNbO3. This paper describes the utilization of third order non-linearity induced in Xanthene dye doped gelatin and poly (eosin acrylate) & poly (eosin acrylate-co-isobutyl acrylate) films resulting in direct storage without the need for any further processing i.e., no wet chemical or post thermal/photochemical processing are required. With required amount of solvent and monomer in the presence of benzoyl peroxide (initiator), polymerization reaction was carried out under nitrogen atmosphere. Polymer samples were characterized by NMR, IR, FT-IR & TGA. The polymers were soluble in THF, DMSO, DMF & DMAC solvents and form good optical quality films by spin as well as dip coating. Polymer thin films were prepared with different concentrations of polymer solution onto the glass slides. The UV-visible absorption spectra of the spin coated polymer films showed a maximum at 538 nm. In our simplest optical system, Q- switched, second harmonic Nd-YAG laser light at wavelength 532 nm was used for recording. Two beams split from the same laser were made to superpose with path difference less than the coherent length. One of the beam acted as information carrying beam while the other acted as reference beam. In this present study, we report the direction formation of surface

  19. Optical-NIR spectroscopy of the puzzling γ-ray source 3FGL 1603.9-4903/PMN J1603-4904 with X-Shooter

    NASA Astrophysics Data System (ADS)

    Goldoni, P.; Pita, S.; Boisson, C.; Müller, C.; Dauser, T.; Jung, I.; Krauß, F.; Lenain, J.-P.; Sol, H.

    2016-02-01

    Context. The Fermi/LAT instrument has detected about two thousand extragalactic high energy (E ≥ 100 MeV) γ-ray sources. One of the brightest is 3FGL J1603.9-4903; it is associated to the radio source PMN J1603-4904. Its nature is not yet clear, it could be either a very peculiar BL Lac or a compact symmetric object radio source which are considered as the early stage of a radio galaxy. The latter, if confirmed, would be the first detection in γ-rays for this class of objects. A redshift z = 0.18 ± 0.01 has recently been claimed on the basis of the detection of a single X-ray line at 5.44 ± 0.05 keV which has been interpreted as a 6.4 keV (rest frame) fluorescent line. Aims: We aim to investigate the nature of 3FGL J1603.9-4903/PMN J1603-4904 using optical-to near-IR (NIR) spectroscopy. Methods: We observed PMN J1603-4904 with the UV-NIR VLT/X-Shooter spectrograph for two hours. We extracted spectra in the visible and NIR range that we calibrated in flux and corrected for telluric absorption. We systematically searched for absorption and emission features. Results: The source was detected starting from ~6300 Å down to 24 000 Å with an intensity similar to that of its 2MASS counterpart and a mostly featureless spectrum. The continuum lacks absorption features and thus is non-stellar in origin and most likely non-thermal. In addition to this spectrum, we detected three emission lines that we interpret as the Hα-[NII] complex, the [SII]λ,λ6716, 6731 doublet and the [SIII]λ 9530 line; we obtain a redshift estimate of z = 0.2321 ± 0.0004. The line ratios suggest that a LINER/Seyfert nucleus powers the emission. This new redshift measurement implies that the X-ray line previously detected should be interpreted as a 6.7 keV line which is very peculiar. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile, under program 095.B-0400(A). The raw FITS data files are available in the ESO archive.

  20. Inspection of commercial optical devices for data storage using a three Gaussian beam microscope interferometer

    SciTech Connect

    Flores, J. Mauricio; Cywiak, Moises; Servin, Manuel; Juarez P, Lorenzo

    2008-09-20

    Recently, an interferometric profilometer based on the heterodyning of three Gaussian beams has been reported. This microscope interferometer, called a three Gaussian beam interferometer, has been used to profile high quality optical surfaces that exhibit constant reflectivity with high vertical resolution and lateral resolution near {lambda}. We report the use of this interferometer to measure the profiles of two commercially available optical surfaces for data storage, namely, the compact disk (CD-R) and the digital versatile disk (DVD-R). We include experimental results from a one-dimensional radial scan of these devices without data marks. The measurements are taken by placing the devices with the polycarbonate surface facing the probe beam of the interferometer. This microscope interferometer is unique when compared with other optical measuring instruments because it uses narrowband detection, filters out undesirable noisy signals, and because the amplitude of the output voltage signal is basically proportional to the local vertical height of the surface under test, thus detecting with high sensitivity. We show that the resulting profiles, measured with this interferometer across the polycarbonate layer, provide valuable information about the track profiles, making this interferometer a suitable tool for quality control of surface storage devices.

  1. Inspection of commercial optical devices for data storage using a three Gaussian beam microscope interferometer.

    PubMed

    Flores, J Mauricio; Cywiak, Moisés; Servín, Manuel; Juárez, Lorenzo

    2008-09-20

    Recently, an interferometric profilometer based on the heterodyning of three Gaussian beams has been reported. This microscope interferometer, called a three Gaussian beam interferometer, has been used to profile high quality optical surfaces that exhibit constant reflectivity with high vertical resolution and lateral resolution near lambda. We report the use of this interferometer to measure the profiles of two commercially available optical surfaces for data storage, namely, the compact disk (CD-R) and the digital versatile disk (DVD-R). We include experimental results from a one-dimensional radial scan of these devices without data marks. The measurements are taken by placing the devices with the polycarbonate surface facing the probe beam of the interferometer. This microscope interferometer is unique when compared with other optical measuring instruments because it uses narrowband detection, filters out undesirable noisy signals, and because the amplitude of the output voltage signal is basically proportional to the local vertical height of the surface under test, thus detecting with high sensitivity. We show that the resulting profiles, measured with this interferometer across the polycarbonate layer, provide valuable information about the track profiles, making this interferometer a suitable tool for quality control of surface storage devices.

  2. Low-cost medical image storage and manipulation using optical disk subsystems

    NASA Astrophysics Data System (ADS)

    Glenn, William V., Jr.; Marx, Peter S.

    1990-08-01

    Traditionally, medical imaging has required large capital investments into workstations and storage subsystems. Many vendors have chosen to offer proprietary systems which are expensive to develop and costly to the institutions which purchase them. Our experience has been that this is unnecessary; most traditional imaging functions in the digital modalities of computed tomography (CT) and magnetic resonance imaging (MM) can be performed using off-the-shelf hardware with relatisely inexpensive software. In order to reduce the cost of medical imaging, our approach has been to choose computers and storage subsystems that are efficient, inexpensive, and easy-to-use (after all, the users are interested in practicing medicine, not computer science.) With these goals in mind, we chose to use a general purpose computer (the Apple Macintosh Ilci) with two types of high-capacity optical storage devices (both magneto-optical and write once, read multiple (WORM) disc subsystems.) We have developed a powerful, yet user-friendly medical imaging workstation oriented towards radiologists, orthopadic surgeons, neurosurgeons, and other users of medical images. In addition to providing inexpensive storage, the workstation is capable of multiplanar reformatting (MPR), 3D MM angiography, and other image processing functions. The resulting images may be annotated, windowed, and filmed on to 14x17" radiology film for presentation to the referring physicians and their patients. This system can be considered to be a picture archiving and communication system (PACS) for private physicians and small clinics; further, it is small enough for desktop environments and inexpensive enough for clinicians to purchase.

  3. Optical memory development. Volume 2: Gain-assisted holographic storage media

    NASA Technical Reports Server (NTRS)

    Gange, R. A.; Mezrich, R. S.

    1972-01-01

    Thin deformable films were investigated for use as the storage medium in a holographic optical memory. The research was directed toward solving the problems of material fatigue, selective heat addressing, electrical charging of the film surface and charge patterning by light. A number of solutions to these problems were found but the main conclusion to be drawn from the work is that deformable media which employ heat in the recording process are not satisfactory for use in a high-speed random-access read/write holographic memory. They are, however, a viable approach in applications where either high speed or random-access is not required.

  4. Neutron star news and puzzles

    NASA Astrophysics Data System (ADS)

    Prakash, Madappa

    2014-08-01

    Gerry Brown has had the most influence on my career in Physics, and my life after graduate studies. This article gives a brief account of some of the many ways in which Gerry shaped my research. Focus is placed on the significant strides on neutron star research made by the group at Stony Brook, which Gerry built from scratch. Selected puzzles about neutron stars that remain to be solved are noted.

  5. Construction-Paper Puzzle Masterpieces

    ERIC Educational Resources Information Center

    Vance, Shelly

    2010-01-01

    Creating an appreciation of art history in her junior-high students has always been one of the author's greatest challenges as an art teacher. In this article, the author describes how her eighth-grade students re-created a famous work of art--piece by piece, like a puzzle or a stained-glass window--out of construction paper. (Contains 1 resource.)

  6. Rapid production of structural color images with optical data storage capabilities

    NASA Astrophysics Data System (ADS)

    Rezaei, Mohamad; Jiang, Hao; Qarehbaghi, Reza; Naghshineh, Mohammad; Kaminska, Bozena

    2015-03-01

    In this paper, we present novel methods to produce structural color image for any given color picture using a pixelated generic stamp named nanosubstrate. The nanosubstrate is composed of prefabricated arrays of red, green and blue subpixels. Each subpixel has nano-gratings and/or sub-wavelength structures which give structural colors through light diffraction. Micro-patterning techniques were implemented to produce the color images from the nanosubstrate by selective activation of subpixels. The nano-grating structures can be nanohole arrays, which after replication are converted to nanopillar arrays or vice versa. It has been demonstrated that visible and invisible data can be easily stored using these fabrication methods and the information can be easily read. Therefore the techniques can be employed to produce personalized and customized color images for applications in optical document security and publicity, and can also be complemented by combined optical data storage capabilities.

  7. Achieve both multiwavelength and multilevel optical storage on compact disk by diarylethene

    NASA Astrophysics Data System (ADS)

    Liu, Xuedong; Pu, Shouzhi; Zhao, Fuqun; Qi, Guosheng; Zhang, Fushi

    2005-01-01

    The novel photochromism, diarylethene derivatives, 1,2-bis(2,5-dimethyl-thien-3-yl)perfluoro cyclopentene (1a) and 1,2-bis(2-methyl-5-carbonylphenyl)-thien-3-yl) perfluorocyclo pentene(2a) were synthesized. And the PC discs of these two diarylethenes were prepared by spin-coating and vacuum evaporating method. To some extent, the high density recording was carried out the multi-wavelength and multi-level optical storage system. On the PC disc, single-wavelength and eight-level recording was realized by 2a, and two laser beams of 532nm and 650nm were used in two-wavelength eight-level recording and readout simultaneously. The results show that the reflectivity differences between the recording region and unrecording region is greater than 50%. The creation is that the two-wavelength and four-step optical recording on the PC disc achieved first time.

  8. Surface-micromachined optical polarizers for magneto-optical data storage

    NASA Astrophysics Data System (ADS)

    Pu, Chuan; Zhu, Zuhua; Lo, Yu-Hwa

    1998-07-01

    Polarizers and polarization beam splitters are the most important devices in magneto-optical readout system. With a commercially available foundry polysilicon surface micromachining process (Multi-User Means ProcesS, or MUMPS) offered by MCNC (Mems Center at North Carolina), we have realized, on a single Si chip, an integrated polarization beam splitting system with a binary phase Fresnel lens for collimation. Polarization extinction ratios of 10 dB for the transmitted light and over 20 dB for the reflected light have been achieved. The whole system is prealigned using Computer-Aided Design on a Si substrate and is then lifted up perpendicular to the substrate after structure release.

  9. Monolayer optical memory cells based on artificial trap-mediated charge storage and release

    NASA Astrophysics Data System (ADS)

    Lee, Juwon; Pak, Sangyeon; Lee, Young-Woo; Cho, Yuljae; Hong, John; Giraud, Paul; Shin, Hyeon Suk; Morris, Stephen M.; Sohn, Jung Inn; Cha, Seungnam; Kim, Jong Min

    2017-03-01

    Monolayer transition metal dichalcogenides are considered to be promising candidates for flexible and transparent optoelectronics applications due to their direct bandgap and strong light-matter interactions. Although several monolayer-based photodetectors have been demonstrated, single-layered optical memory devices suitable for high-quality image sensing have received little attention. Here we report a concept for monolayer MoS2 optoelectronic memory devices using artificially-structured charge trap layers through the functionalization of the monolayer/dielectric interfaces, leading to localized electronic states that serve as a basis for electrically-induced charge trapping and optically-mediated charge release. Our devices exhibit excellent photo-responsive memory characteristics with a large linear dynamic range of ~4,700 (73.4 dB) coupled with a low OFF-state current (<4 pA), and a long storage lifetime of over 104 s. In addition, the multi-level detection of up to 8 optical states is successfully demonstrated. These results represent a significant step toward the development of future monolayer optoelectronic memory devices.

  10. Monolayer optical memory cells based on artificial trap-mediated charge storage and release.

    PubMed

    Lee, Juwon; Pak, Sangyeon; Lee, Young-Woo; Cho, Yuljae; Hong, John; Giraud, Paul; Shin, Hyeon Suk; Morris, Stephen M; Sohn, Jung Inn; Cha, SeungNam; Kim, Jong Min

    2017-03-24

    Monolayer transition metal dichalcogenides are considered to be promising candidates for flexible and transparent optoelectronics applications due to their direct bandgap and strong light-matter interactions. Although several monolayer-based photodetectors have been demonstrated, single-layered optical memory devices suitable for high-quality image sensing have received little attention. Here we report a concept for monolayer MoS2 optoelectronic memory devices using artificially-structured charge trap layers through the functionalization of the monolayer/dielectric interfaces, leading to localized electronic states that serve as a basis for electrically-induced charge trapping and optically-mediated charge release. Our devices exhibit excellent photo-responsive memory characteristics with a large linear dynamic range of ∼4,700 (73.4 dB) coupled with a low OFF-state current (<4 pA), and a long storage lifetime of over 10(4) s. In addition, the multi-level detection of up to 8 optical states is successfully demonstrated. These results represent a significant step toward the development of future monolayer optoelectronic memory devices.

  11. Acoustic emission detection with fiber optical sensors for dry cask storage health monitoring

    NASA Astrophysics Data System (ADS)

    Lin, Bin; Bao, Jingjing; Yu, Lingyu; Giurgiutiu, Victor

    2016-04-01

    The increasing number, size, and complexity of nuclear facilities deployed worldwide are increasing the need to maintain readiness and develop innovative sensing materials to monitor important to safety structures (ITS). In the past two decades, an extensive sensor technology development has been used for structural health monitoring (SHM). Technologies for the diagnosis and prognosis of a nuclear system, such as dry cask storage system (DCSS), can improve verification of the health of the structure that can eventually reduce the likelihood of inadvertently failure of a component. Fiber optical sensors have emerged as one of the major SHM technologies developed particularly for temperature and strain measurements. This paper presents the development of optical equipment that is suitable for ultrasonic guided wave detection for active SHM in the MHz range. An experimental study of using fiber Bragg grating (FBG) as acoustic emission (AE) sensors was performed on steel blocks. FBG have the advantage of being durable, lightweight, and easily embeddable into composite structures as well as being immune to electromagnetic interference and optically multiplexed. The temperature effect on the FBG sensors was also studied. A multi-channel FBG system was developed and compared with piezoelectric based AE system. The paper ends with conclusions and suggestions for further work.

  12. MeV ion-beam analysis of optical data storage films

    NASA Technical Reports Server (NTRS)

    Leavitt, J. A.; Mcintyre, L. C., Jr.; Lin, Z.

    1993-01-01

    Our objectives are threefold: (1) to accurately characterize optical data storage films by MeV ion-beam analysis (IBA) for ODSC collaborators; (2) to develop new and/or improved analysis techniques; and (3) to expand the capabilities of the IBA facility itself. Using H-1(+), He-4(+), and N-15(++) ion beams in the 1.5 MeV to 10 MeV energy range from a 5.5 MV Van de Graaff accelerator, film thickness (in atoms/sq cm), stoichiometry, impurity concentration profiles, and crystalline structure were determined by Rutherford backscattering (RBS), high-energy backscattering, channeling, nuclear reaction analysis (NRA) and proton induced X-ray emission (PIXE). Most of these techniques are discussed in detail in the ODSC Annual Report (February 17, 1987), p. 74. The PIXE technique is briefly discussed in the ODSC Annual Report (March 15, 1991), p. 23.

  13. Systems Issues Pertaining to Holographic Optical Data Storage in Thick Bacteriorhodopsin Films

    NASA Technical Reports Server (NTRS)

    Downie, John D.; Timucin, Dogan A.; Gary, Charles K.; Oezcan, Meric; Smithey, Daniel T.; Crew, Marshall; Lau, Sonie (Technical Monitor)

    1998-01-01

    The optical data storage capacity and raw bit-error-rate achievable with thick photochromic bacteriorhodopsin (BR) films are investigated for sequential recording and read- out of angularly- and shift-multiplexed digital holograms inside a thick blue-membrane D85N BR film. We address the determination of an exposure schedule that produces equal diffraction efficiencies among each of the multiplexed holograms. This exposure schedule is determined by numerical simulations of the holographic recording process within the BR material, and maximizes the total grating strength. We also experimentally measure the shift selectivity and compare the results to theoretical predictions. Finally, we evaluate the bit-error-rate of a single hologram, and of multiple holograms stored within the film.

  14. Ring-toric lens for focus-error sensing in optical data storage.

    PubMed

    Descour, M R; Simon, D I; Yeh, W H

    1999-03-10

    We discuss the design and performance of diffractive ring-toric lenses for focus-error sensing in optical data storage. A ring-toric lens images a point source of light to a ring-shaped image. Focus-error sensing is accomplished by means of monitoring the change in ring radius: The ring expands in response to a diverging wave front, and the ring contracts in response to a converging wave front. We describe the use of a segmented phi detector to generate a focus-error signal (FES). We found that the FES slope, a measure of sensitivity to disk defocus, is higher for the ring-toric lenses described in this paper than for other techniques such as the astigmatic and the obscuration methods. We measured an FES slope of 0.7 per micrometer of disk defocus (microm(-1)). The corresponding theoretical FES slope is 0.96 microm(-1).

  15. Preparation and optical properties of BaFCl:Eu 2+ X-ray storage phosphor

    NASA Astrophysics Data System (ADS)

    Secu, M.; Matei, L.; Serban, T.; Apostol, E.; Aldica, Gh; Silion, C.

    2000-11-01

    A new method for the preparation of BaFCl:Eu 2+ has been developed. A coprecipitation chemical reaction between BaCl 2 and NaF acidified aqueous solution has been used. Doping with Eu 2+ was carried out by adding EuF 3 during preparation time. A thermal treatment in vacuum similar to those used in the sintering process of supraconductive ceramics was used in order to accomplish the chemical reaction and to improve the homogeneity of europium ion distribution. Finally, a fine powder consisting of microcrystalline, 4-5 μm grains was obtained. The product has been checked by X-ray diffractometry and characterised by optical methods. Photoluminescence (PL) measurements attest the europium impurification and oxygen contamination during preparation, which has a great importance for the photostimulability properties of the compound. Photostimulated luminescence (PSL) of the X-irradiated samples shows good performance as X-ray storage phosphor.

  16. Solar optics-based active panel for solar energy storage and disinfection of greywater.

    PubMed

    Lee, W; Song, J; Son, J H; Gutierrez, M P; Kang, T; Kim, D; Lee, L P

    2016-09-01

    Smart city and innovative building strategies are becoming increasingly more necessary because advancing a sustainable building system is regarded as a promising solution to overcome the depleting water and energy. However, current sustainable building systems mainly focus on energy saving and miss a holistic integration of water regeneration and energy generation. Here, we present a theoretical study of a solar optics-based active panel (SOAP) that enables both solar energy storage and photothermal disinfection of greywater simultaneously. Solar collector efficiency of energy storage and disinfection rate of greywater have been investigated. Due to the light focusing by microlens, the solar collector efficiency is enhanced from 25% to 65%, compared to that without the microlens. The simulation of greywater sterilization shows that 100% disinfection can be accomplished by our SOAP for different types of bacteria including Escherichia coli. Numerical simulation reveals that our SOAP as a lab-on-a-wall system can resolve the water and energy problem in future sustainable building systems.

  17. Threshold response using modulated continuous wave illumination for multilayer 3D optical data storage

    NASA Astrophysics Data System (ADS)

    Saini, A.; Christenson, C. W.; Khattab, T. A.; Wang, R.; Twieg, R. J.; Singer, K. D.

    2017-01-01

    In order to achieve a high capacity 3D optical data storage medium, a nonlinear or threshold writing process is necessary to localize data in the axial dimension. To this end, commercial multilayer discs use thermal ablation of metal films or phase change materials to realize such a threshold process. This paper addresses a threshold writing mechanism relevant to recently reported fluorescence-based data storage in dye-doped co-extruded multilayer films. To gain understanding of the essential physics, single layer spun coat films were used so that the data is easily accessible by analytical techniques. Data were written by attenuating the fluorescence using nanosecond-range exposure times from a 488 nm continuous wave laser overlapping with the single photon absorption spectrum. The threshold writing process was studied over a range of exposure times and intensities, and with different fluorescent dyes. It was found that all of the dyes have a common temperature threshold where fluorescence begins to attenuate, and the physical nature of the thermal process was investigated.

  18. The Crossword Puzzle in Teaching Earth Science

    ERIC Educational Resources Information Center

    McKenny, Charles J.

    1970-01-01

    By way of change of pace, students are asked to use as many terms as possible in the construction of a puzzle pattern on a blank matrix. The instructor selects one pattern and completes it in the form of a crossword puzzle to be used at the end of the unit. An example is given from a weather and climate unit. (NH)

  19. Metaphors, Puzzles, and Teachers' Professional Knowledge.

    ERIC Educational Resources Information Center

    Munby, Hugh

    This paper presents two puzzles that have emerged in a series of completed and ongoing studies at Queen's University, Ontario. These puzzles concern teachers' professional knowledge, a term used to refer to the non-propositional forms of knowledge assumed to be of importance to professional action. This research assumed that the professional…

  20. Guerrilla Puzzling: A Model for Research

    ERIC Educational Resources Information Center

    Zimmer, Marc

    2007-01-01

    There are two main settings for puzzle solving in higher education: graduate programs, with professors and both graduate and postdoctoral students; and predominantly undergraduate institutions, with professors and students. Research programs at large universities are well-oiled puzzle-solving machines. Graduate students there work long, hard hours…

  1. Optical data storage system with a planoellipsoidal solid immersion mirror illuminated directly by a point light source.

    PubMed

    Zhang, Yaoju

    2006-12-01

    A new solid immersion mirror called the planoellipsoidal (PE) solid immersion mirror (SIM) for the near-field optical storage is proposed and developed. The PE SIM has a small aperture on the apex of the ellipsoidal surface. The intensity distribution of the transmitted field is calculated by using the vector diffraction theory. Compared with a conventional solid immersion lens (SIL), the proposed PE SIM has the following features. A PE SIM replaces three optical elements of the collimator, objective, and SIL in a conventional SIL optical storage system, so that the optical system equipped with the PE SIM is not only simple in its assembly but is also effective in making an optical head unit. The PE SIM obtains light from a point light source and focuses it directly on the recording layer, which may be useful for a compact optical data storage system. The convex ellipsoidal surface of the PE SIM can reduce the risk of the SIM touching the surface of the recording medium. In addition, the spreading of the spot size with the increase of distance is very small in the PE SIM.

  2. Weird Stellar Pair Puzzles Scientists

    NASA Astrophysics Data System (ADS)

    2008-05-01

    Astronomers have discovered a speedy spinning pulsar in an elongated orbit around an apparent Sun-like star, a combination never seen before, and one that has them puzzled about how the strange system developed. Orbital Comparison Comparing Orbits of Pulsar and Its Companion to our Solar System. CREDIT: Bill Saxton, NRAO/AUI/NSF Click on image for full caption information and available graphics. "Our ideas about how the fastest-spinning pulsars are produced do not predict either the kind of orbit or the type of companion star this one has," said David Champion of the Australia Telescope National Facility. "We have to come up with some new scenarios to explain this weird pair," he added. Astronomers first detected the pulsar, called J1903+0327, as part of a long-term survey using the National Science Foundation's Arecibo radio telescope in Puerto Rico. They made the discovery in 2006 doing data analysis at McGill University, where Champion worked at the time. They followed up the discovery with detailed studies using the Arecibo telescope, the NSF's Robert C. Byrd Green Bank Telescope (GBT) in West Virginia, the Westerbork radio telescope in the Netherlands, and the Gemini North optical telescope in Hawaii. The pulsar, a city-sized superdense stellar corpse left over after a massive star exploded as a supernova, is spinning on its axis 465 times every second. Nearly 21,000 light-years from Earth, it is in a highly-elongated orbit that takes it around its companion star once every 95 days. An infrared image made with the Gemini North telescope in Hawaii shows a Sun-like star at the pulsar's position. If this is an orbital companion to the pulsar, it is unlike any companions of other rapidly rotating pulsars. The pulsar, a neutron star, also is unusually massive for its type. "This combination of properties is unprecedented. Not only does it require us to figure out how this system was produced, but the large mass may help us understand how matter behaves at extremely

  3. Optical Storage Systems for Records and Information Management: Overview, Recommendations and Guidelines for Local Governments. Local Government Records Technical Information Series. Number 45.

    ERIC Educational Resources Information Center

    Schwartz, Stanley F.

    This publication discusses optical storage, a term encompassing technologies that use laser-produced light to record and store information in digital form. The booklet also discusses how optical storage systems relate to records management, in particular to the management of local government records in New York State. It describes components of…

  4. Java-Library for the Access, Storage and Editing of Calibration Metadata of Optical Sensors

    NASA Astrophysics Data System (ADS)

    Firlej, M.; Kresse, W.

    2016-06-01

    The standardization of the calibration of optical sensors in photogrammetry and remote sensing has been discussed for more than a decade. Projects of the German DGPF and the European EuroSDR led to the abstract International Technical Specification ISO/TS 19159-1:2014 "Calibration and validation of remote sensing imagery sensors and data - Part 1: Optical sensors". This article presents the first software interface for a read- and write-access to all metadata elements standardized in the ISO/TS 19159-1. This interface is based on an xml-schema that was automatically derived by ShapeChange from the UML-model of the Specification. The software interface serves two cases. First, the more than 300 standardized metadata elements are stored individually according to the xml-schema. Secondly, the camera manufacturers are using many administrative data that are not a part of the ISO/TS 19159-1. The new software interface provides a mechanism for input, storage, editing, and output of both types of data. Finally, an output channel towards a usual calibration protocol is provided. The interface is written in Java. The article also addresses observations made when analysing the ISO/TS 19159-1 and compiles a list of proposals for maturing the document, i.e. for an updated version of the Specification.

  5. High-speed optoelectronic IC for multi-standards of optical storage system

    NASA Astrophysics Data System (ADS)

    Cha, Sanghyun; Jeong, Hawoong; Go, Chaedong; Park, Deukhee; Lee, Changseok; Kwon, Kyoungsoo; Lee, Jeashin

    2010-05-01

    The conventional scheme of optical pick-up unit (OPU) should require two or three optoelectronic integrated circuits (OEICs) to cover triple-wavelength λ =780nm, 650nm and 405nm). In order to reduce cost and waste of resources, onechip solution of the OEIC is required. In this paper, the OEIC is designed which can cover triple-wavelength and three optical storage standards which are compact disk (CD), digital versatile disk (DVD) and Blue-Ray. The OEIC has dualarrays of photodiodes because focus of laser is varied depending on wavelength. One of arrays senses the laser of λ =780nm and another senses the lasers of λ =650nm and λ =405nm. For low power consumption and small die area, one wideband transimpedance amplifier (TIA) is used for two photodiodes which are for CD and DVD or Blue-Ray, respectively. And two small size switches are included to select photodiodes. The PIN fingerdiode with N+ fingercathode is integrated to guarantee high performances for λ =405nm and 650nm. And the isolation area between adjacent photodiodes is made by floated P+ implant for reducing power-loss. The measured cutoff bandwidth of the OEIC is 210MHz for λ =405nm. The OEIC is fabricated in a 0.6- μm BiCMOS technology and dissipates 150mW for a single supply voltage of 5V. The active area is 1.4x1.2mm2.

  6. Halbach array type focusing actuator for small and thin optical data storage device

    NASA Astrophysics Data System (ADS)

    Lee, Sung Q.; Park, Kang-Ho; Paek, Mun Chul

    2004-09-01

    The small form factor optical data storage devices are developing rapidly nowadays. Since it is designed for portable and compatibility with flesh memory, its components such as disk, head, focusing actuator, and spindle motor should be assembled within 5 mm. The thickness of focusing actuator is within 2 mm and the total working range is +/-100um, with the resolution of less than 1μm. Since the thickness is limited tightly, it is hard to place the yoke that closes the magnetic circuit and hard to make strong flux density without yoke. Therefore, Halbach array is adopted to increase the magnetic flux of one side without yoke. The proposed Halbach array type focusing actuator has the advantage of thin actuation structure with sacrificing less flex density than conventional magnetic array. The optical head unit is moved on the swing arm type tracking actuator. Focusing coil is attached to swing arm, and Halbach magnet array is positioned at the bottom of deck along the tracking line, and focusing actuator exerts force by the Fleming's left hand rule. The dynamics, working range, control resolution of focusing actuator are analyzed and performed.

  7. LEPTON ACCELERATORS AND COLLIDERS: Linear optics calibration and nonlinear optimization during the commissioning of the SSRF storage ring

    NASA Astrophysics Data System (ADS)

    Tian, Shun-Qiang; Zhang, Wen-Zhi; Li, Hao-Hu; Zhang, Man-Zhou; Hou, Jie; Zhou, Xue-Mei; Liu, Gui-Min

    2009-06-01

    Phase I commissioning of the SSRF storage ring on 3.0 GeV beam energy was started at the end of December 2007. A lot of encouraging results have been obtained so far. In this paper, calibrations of the linear optics during the commissioning are discussed, and some measured results about the nonlinearity given. Calibration procedure emphasizes correcting quadrupole magnetic coefficients with the Linear Optics from Closed Orbit (LOCO) technique. After fitting the closed orbit response matrix, the linear optics of the four test modes is substantially corrected, and the measured physical parameters agree well with the designed ones.

  8. Archive Storage Media Alternatives.

    ERIC Educational Resources Information Center

    Ranade, Sanjay

    1990-01-01

    Reviews requirements for a data archive system and describes storage media alternatives that are currently available. Topics discussed include data storage; data distribution; hierarchical storage architecture, including inline storage, online storage, nearline storage, and offline storage; magnetic disks; optical disks; conventional magnetic…

  9. PSQP -- Puzzle Solving by Quadratic Programming.

    PubMed

    Andalo, Fernanda; Taubin, Gabriel; Goldenstein, Siome

    2016-03-25

    In this article we present the first effective global method for the reconstruction of image puzzles comprising rectangle pieces - Puzzle Solving by Quadratic Programming (PSQP). The proposed novel mathematical formulation reduces the problem to the maximization of a constrained quadratic function, which is solved via a gradient ascent approach. The proposed method is deterministic and can deal with arbitrary identical rectangular pieces. We provide experimental results showing its effectiveness when compared to state-of-the-art approaches. Although the method was developed to solve image puzzles, we also show how to apply it to the reconstruction of simulated strip-shredded documents, broadening its applicability.

  10. PSQP: Puzzle Solving by Quadratic Programming.

    PubMed

    Andalo, Fernanda A; Taubin, Gabriel; Goldenstein, Siome

    2017-02-01

    In this article we present the first effective method based on global optimization for the reconstruction of image puzzles comprising rectangle pieces-Puzzle Solving by Quadratic Programming (PSQP). The proposed novel mathematical formulation reduces the problem to the maximization of a constrained quadratic function, which is solved via a gradient ascent approach. The proposed method is deterministic and can deal with arbitrary identical rectangular pieces. We provide experimental results showing its effectiveness when compared to state-of-the-art approaches. Although the method was developed to solve image puzzles, we also show how to apply it to the reconstruction of simulated strip-shredded documents, broadening its applicability.

  11. The Mass Puzzle in Cosmology

    NASA Astrophysics Data System (ADS)

    Peebles, P. J. E.

    1993-05-01

    Attempts to fill in some of the details of the standard hot expanding world picture by appeal to the observational evidence lead to some fascinating dilemmas, many related to the puzzles of the nature and amount of the dark matter. Well tested approaches yield two quite different values for the distance scale, h ~ 0.5 and h ~ 0.8 (where Hubble's constant is H_o=100h km s(-1) Mpc(-1) ). If the shorter scale proved to be right the expansion timescale in an Einstein-de Sitter universe would be unacceptable; we would have to live in a low density universe, maybe with a significant cosmological constant. This is in the direction suggested by dynamical studies on scales <~ 10h(-1) Mpc, which quite consistently indicate a mean mass density Omega ~ 0.1 times the critical Einstein-de Sitter value. Dynamical measures on larger scales are less well explored, but there is a reasonable case that Omega is close to unity, as could fit the longer distance scale. But if Omega =1 we have a challenge: why does some 90%\\ of the mass appear to have resisted clustering on scales <~ 10h(-1) Mpc? Astrophysical biasing scenarios postulate galaxy formation was inhibited by unhealthy conditions in protovoids. But if the gross properties of galaxies were sensitive to environment, why do the galaxies that survived exhibit the striking environment-independent regularities of the Tully-Fisher relation and the fundamental planes? In some versions of the Omega = 1 cold dark matter and mixed dark matter models galaxies are assembled at low redshifts. If so, perhaps the Carlberg velocity biasing effect can account for the low apparent Omega in the small-scale dynamical tests. Galaxy assembly at low redshift certainly could agree with the apparent immaturity of galaxies at zgap 0.7, as indicated by the Butcher-Oemler effect and the alignment effect in radio galaxies. But if galaxy assembly were a recent phenomenon why do the Wolfe clouds at z ~ 3 look like young galaxies in an already well

  12. Structural and optical properties of In doped Se-Te phase-change thin films: A material for optical data storage

    NASA Astrophysics Data System (ADS)

    Pathak, H. P.; Shukla, Nitesh; Kumar, Vipin; Dwivedi, D. K.

    2016-02-01

    Se75-xTe25Inx (x = 0, 3, 6, & 9) bulk glasses were obtained by melt quench technique. Thin films of thickness 400 nm were prepared by thermal evaporation technique at a base pressure of 10-6 Torr onto well cleaned glass substrate. a-Se75-xTe25Inx thin films were annealed at different temperatures for 2 h. As prepared and annealed films were characterized by X-ray diffraction and UV-Vis spectroscopy. The X-ray diffraction results show that the as-prepared films are of amorphous nature while it shows some poly-crystalline structure in amorphous phases after annealing. The optical absorption spectra of these films were measured in the wavelength range 400-1100 nm in order to derive the extinction and absorption coefficient of these films. It was found that the mechanism of optical absorption follows the rule of allowed non-direct transition. The optical band gap of as prepared and annealed films as a function of photon energy has been studied. The optical band gap is found to decrease with increase in annealing temperature in the present glassy system. It happens due to crystallization of amorphous films. The decrease in optical band gap due to annealing is an interesting behavior for a material to be used in optical storage. The optical band gap has been observed to decrease with the increase of In content in Se-Te glassy system.

  13. Optical cell for combinatorial in situ Raman spectroscopic measurements of hydrogen storage materials at high pressures and temperatures.

    PubMed

    Hattrick-Simpers, Jason R; Hurst, Wilbur S; Srinivasan, Sesha S; Maslar, James E

    2011-03-01

    An optical cell is described for high-throughput backscattering Raman spectroscopic measurements of hydrogen storage materials at pressures up to 10 MPa and temperatures up to 823 K. High throughput is obtained by employing a 60 mm diameter × 9 mm thick sapphire window, with a corresponding 50 mm diameter unobstructed optical aperture. To reproducibly seal this relatively large window to the cell body at elevated temperatures and pressures, a gold o-ring is employed. The sample holder-to-window distance is adjustable, making this cell design compatible with optical measurement systems incorporating lenses of significantly different focal lengths, e.g., microscope objectives and single element lenses. For combinatorial investigations, up to 19 individual powder samples can be loaded into the optical cell at one time. This cell design is also compatible with thin-film samples. To demonstrate the capabilities of the cell, in situ measurements of the Ca(BH(4))(2) and nano-LiBH(4)-LiNH(2)-MgH(2) hydrogen storage systems at elevated temperatures and pressures are reported.

  14. Green-Light Static Rewritable Optical Storage Properties of a Novel CuTCNQ Derivative Thin Film

    NASA Astrophysics Data System (ADS)

    Huang, Wu-Qiao; Wu, Yi-Qun; Gu, Dong-Hong; Gan, Fu-Xi

    2003-12-01

    A novel charge-transfer complex film: copper-(n-propyl ester 7,7,8,8- tetracyanoquinodimethane-2,5-ylene-(3-propionic acid)) (Cu-TCNQ(C2H4COOC3H7)2) was prepared by spin-coating. Absorption spectra, green-light (514.5 nm) static rewritable optical recording properties and rewritable mechanism of this film were studied. The results show that there are two strong absorption peaks at 388 nm and 675 nm, which can be assigned to electronic transitions in anion radical TCNQ(C2H4COOC3H7)2-. Green-light optical storage experimental results of this film were as follows: write-in power was 9 mW, pulse duration was 80 ns erasing power was 4 mW, pulse duration was 500 ns the reflectivity contrast Cgeq15% number of write-erase cycles Ngeq100. It is found that the realization of rewritable optical storage of the Cu-TCNQ(C2H4COOC3H7)2 film is related to the reversible changes of the optical properties, which is caused by the reversible charge transfer between copper and n-propyl ester 7,7,8,8- tetracyanoquinodimethane-2,5-ylene-(3-propionic acid) in the complex through inducement of laser irradiation.

  15. Use of optical storage for patent image retrieval: the U.S. Patent and Trademark Office's automated patent system

    NASA Astrophysics Data System (ADS)

    Jacobson, Stephen R.

    1990-08-01

    The Automated Patent System (APS) was designed, among other things, to assist the patent examiner in performing the patent search. It is a fully distributed system that uses custom-built high-resolution dual-display intelligent workstations, optical file servers, mainframes, and support computers networked together using Ethernet technology. The system is composed of two parts which are highly integrated: a full text search system and a patent image retrieval system. When fully deployed, APS will have an image data base of up to 30 terabytes being accessed from over 1000 workstations. The U.S. Patent and Trademark Office (PTO) has had problems with their optical drives, and although they are fairly stable today, we still experience a moderately high hardware failure rate. The optical drive problems include media instability, hardware design errors, vendor problems, and configuration control failures. We intend to purchase additional drives in the future, and are re-evaluating the exclusive use of optical storage in light of recent advances in magnetic storage technology.

  16. Creating Word Search Puzzles with a Pedagogical Purpose.

    ERIC Educational Resources Information Center

    Kunz, Jay

    2002-01-01

    Examines ways that word search puzzles can be created and modified for use in the foreign language classroom. Examples show how word search puzzles can focus on a wide variety of vocabulary, grammar topics, and skills. (Author/VWL)

  17. Studying the Proton Spin Puzzle with PHENIX

    NASA Astrophysics Data System (ADS)

    Daugherity, Michael

    2012-03-01

    The proton spin puzzle remains one of the biggest mysteries in fundamental particle physics today. This talk will explore how the PHENIX Collaboration's forward W-boson program uses RHIC, the world's only polarized proton-proton collider, to probe the spin structure of the proton.

  18. Exploring Organic Mechanistic Puzzles with Molecular Modeling

    ERIC Educational Resources Information Center

    Horowitz, Gail; Schwartz, Gary

    2004-01-01

    The molecular modeling was used to reinforce more general skills such as deducing and drawing reaction mechanisms, analyzing reaction kinetics and thermodynamics and drawing reaction coordinate energy diagrams. This modeling was done through the design of mechanistic puzzles, involving reactions not familiar to the students.

  19. Bullet-Block Science Video Puzzle

    ERIC Educational Resources Information Center

    Shakur, Asif

    2015-01-01

    A science video blog, which has gone viral, shows a wooden block shot by a vertically aimed rifle. The video shows that the block hit dead center goes exactly as high as the one shot off-center. (Fig. 1). The puzzle is that the block shot off-center carries rotational kinetic energy in addition to the gravitational potential energy. This leads a…

  20. Puzzle Pedagogy: A Use of Riddles in Mathematics Education

    ERIC Educational Resources Information Center

    Farnell, Elin

    2017-01-01

    In this article, I present a collection of puzzles appropriate for use in a variety of undergraduate courses, along with suggestions for relevant discussion. Logic puzzles and riddles have long been sources of amusement for mathematicians and the general public alike. I describe the use of puzzles in a classroom setting, and argue for their use as…

  1. Puzzles in modern biology. I. Male sterility, failure reveals design.

    PubMed

    Frank, Steven A

    2016-01-01

    Many human males produce dysfunctional sperm. Various plants frequently abort pollen. Hybrid matings often produce sterile males. Widespread male sterility is puzzling. Natural selection prunes reproductive failure. Puzzling failure implies something that we do not understand about how organisms are designed. Solving the puzzle reveals the hidden processes of design.

  2. Puzzles in modern biology. I. Male sterility, failure reveals design

    PubMed Central

    Frank, Steven A.

    2016-01-01

    Many human males produce dysfunctional sperm. Various plants frequently abort pollen. Hybrid matings often produce sterile males. Widespread male sterility is puzzling. Natural selection prunes reproductive failure. Puzzling failure implies something that we do not understand about how organisms are designed. Solving the puzzle reveals the hidden processes of design. PMID:28004842

  3. Carbon/Ternary Alloy/Carbon Optical Stack on Mylar as an Optical Data Storage Medium to Potentially Replace Magnetic Tape

    SciTech Connect

    Wang, Hao; Lunt, Barry M.; Gates, Richard J.; Asplund, Matthew C.; Shutthanandan, V.; Davis, Robert C.; Linford, Matthew R.

    2013-09-11

    A novel write-once-read-many (WORM) optical stack on Mylar tape is proposed as a replacement for magnetic tape for archival data storage. This optical tape contains a cosputtered bismuth–tellurium–selenium (BTS) alloy as the write layer sandwiched between thin, protective films of reactively sputtered carbon. The composition and thickness of the BTS layer were confirmed by Rutherford Backscattering (RBS) and atomic force microscopy (AFM), respectively. The C/BTS/C stack on Mylar was written to/marked by 532 nm laser pulses. Under the same conditions, control Mylar films without the optical stack were unaffected. Marks, which showed craters/movement of the write material, were characterized by optical microscopy and AFM. The threshold laser powers for making marks on C/BTS/C stacks with different thicknesses were explored. Higher quality marks were made with a 60× objective compared to a 40× objective in our marking apparatus. Finally, the laser writing process was simulated with COMSOL.

  4. The SeaWiFS Bio-Optical Archive and Storage System (SeaBASS): Current Architecture and Implementation

    NASA Technical Reports Server (NTRS)

    Werdell, P. Jeremy; Fargion, Giulietta S. (Editor); McClain, Charles R. (Editor); Bailey, Sean W.

    2002-01-01

    Satellite ocean color missions require an abundance of high-quality in situ measurements for bio-optical and atmospheric algorithm development and post-launch product validation and sensor calibration. To facilitate the assembly of a global data set, the NASA Sea-viewing Wide Field-of-view (SeaWiFS) Project developed the Seafaring Bio-optical Archive and Storage System (SeaBASS), a local repository for in situ data regularly used in their scientific analyses. The system has since been expanded to contain data sets collected by the NASA Sensor Intercalibration and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) Project, as part of NASA Research Announcements NRA-96-MTPE-04 and NRA-99-OES-99. SeaBASS is a well moderated and documented hive for bio-optical data with a simple, secure mechanism for locating and extracting data based on user inputs. Its holdings are available to the general public with the exception of the most recently collected data sets. Extensive quality assurance protocols, comprehensive data and system documentation, and the continuation of an archive and relational database management system (RDBMS) suitable for bio-optical data all contribute to the continued success of SeaBASS. This document provides an overview of the current operational SeaBASS system.

  5. Laser Optical Disk: The Coming Revolution in On-Line Storage.

    ERIC Educational Resources Information Center

    Fujitani, Larry

    1984-01-01

    Review of similarities and differences between magnetic-based and optical disk drives includes a discussion of the electronics necessary for their operation; describes benefits, possible applications, and future trends in development of laser-based drives; and lists manufacturers of laser optical disk drives. (MBR)

  6. Application of Electron Beams in Space for Energy Storage and Optical Beam Generation,

    DTIC Science & Technology

    1978-04-01

    MIRROR -DRIFT __ SPACE BUNCHER OUTPUT RADIATION Fig. 6-Optical klystron I/ // CATCHER MAGNET - / PAIR OF CORNER MAGNETSI ~FORM AN ACHROMATIC SERVCO.Rl I...optical link will be unable to penetrate heavy cloud formations and will thus present availability problems in most regions of the world. CONCLUDING

  7. Development of a software interface for optical disk archival storage for a new life sciences flight experiments computer

    NASA Technical Reports Server (NTRS)

    Bartram, Peter N.

    1989-01-01

    The current Life Sciences Laboratory Equipment (LSLE) microcomputer for life sciences experiment data acquisition is now obsolete. Among the weaknesses of the current microcomputer are small memory size, relatively slow analog data sampling rates, and the lack of a bulk data storage device. While life science investigators normally prefer data to be transmitted to Earth as it is taken, this is not always possible. No down-link exists for experiments performed in the Shuttle middeck region. One important aspect of a replacement microcomputer is provision for in-flight storage of experimental data. The Write Once, Read Many (WORM) optical disk was studied because of its high storage density, data integrity, and the availability of a space-qualified unit. In keeping with the goals for a replacement microcomputer based upon commercially available components and standard interfaces, the system studied includes a Small Computer System Interface (SCSI) for interfacing the WORM drive. The system itself is designed around the STD bus, using readily available boards. Configurations examined were: (1) master processor board and slave processor board with the SCSI interface; (2) master processor with SCSI interface; (3) master processor with SCSI and Direct Memory Access (DMA); (4) master processor controlling a separate STD bus SCSI board; and (5) master processor controlling a separate STD bus SCSI board with DMA.

  8. Exciton storage in type-II quantum dots using the optical Aharonov-Bohm effect

    SciTech Connect

    Climente, Juan I.; Planelles, Josep

    2014-05-12

    We investigate the bright-to-dark exciton conversion efficiency in type-II quantum dots subject to a perpendicular magnetic field. To this end, we take the exciton storage protocol recently proposed by Simonin and co-workers [Phys. Rev. B 89, 075304 (2014)] and simulate its coherent dynamics. We confirm the storage is efficient in perfectly circular structures subject to weak external electric fields, where adiabatic evolution is dominant. In practice, however, the efficiency rapidly degrades with symmetry lowering. Besides, the use of excited states is likely unfeasible owing to the fast decay rates. We then propose an adaptation of the protocol which does not suffer from these limitations.

  9. Precision Spectroscopy of Atomic Hydrogen and the Proton Size Puzzle

    NASA Astrophysics Data System (ADS)

    Udem, Thomas

    2016-05-01

    Precise determination of transition frequencies of simple atomic systems are required for a number of fundamental applications such as tests of quantum electrodynamics (QED), the determination of fundamental constants and nuclear charge radii. The sharpest transition in atomic hydrogen occurs between the metastable 2S state and the 1S ground state. Its transition frequency has now been measured with almost 15 digits accuracy using an optical frequency comb and a cesium atomic clock as a reference. A recent measurement of the Lamb shift in muonic hydrogen is in significant contradiction to the hydrogen data if QED calculations are assumed to be correct. We hope to contribute to the resolution of this so called `proton size puzzle' by providing additional experimental input from the hydrogen side.

  10. VUV optical ring resonator for Duke storage ring free electron laser

    SciTech Connect

    Park, S.H.; Litvinenko, V.N.; Madey, J.M.J.

    1995-12-31

    The conceptual design of the multifaceted-mirror ring resonator for Duke storage ring VUV FEL is presented. The expected performance of the OK-4 FEL with ring resonator is described. We discuss in this paper our plans to study reflectivity of VUV mirrors and their resistivity to soft X-ray spontaneous radiation from OK-4 undulator.

  11. How to resolve the proton radius puzzle?

    NASA Astrophysics Data System (ADS)

    Paz, Gil

    2016-09-01

    In 2010 the first measurement of the proton charge radius from spectroscopy of muonic hydrogen was found to be five standard deviations away from the regular hydrogen value. Six years later, this ``proton radius puzzle'' is still unresolved. One of the most promising avenues to test the muonic hydrogen result is a new muon-proton scattering experiment called MUSE. We describe how effective field theory methods will allow to directly connect muonic hydrogen spectroscopy to muon-proton scattering.

  12. Optimized six-dimensional optical storage: a practicable way to large capacity and fast throughputs

    NASA Astrophysics Data System (ADS)

    Liu, Shangqing

    2015-08-01

    An optimized six-dimensional storage system has been investigated theoretically. The system uses multiple beams to create overlapped micro gratings as each storage cell. The cell capacity depends exponentially on the beam wavelength number. With two-photon absorption writing, coherence tomography reading and superresolving beam focusing, this system has extra-large capacity of >1 Pbyte per DVD sized disk (potential ~60 Pbytes per disk), extra-fast reading speed of >117 Gbits/s with high signal-to-noise ratio of >66 dB, large cell sizes (~0.3μm × 6μm) which greatly reduce data addressing difficulties and a standard drive like structure compatible with the CD and DVD disks.

  13. Channel simulation and development of signal processing techniques for a scanner-based optical storage system

    NASA Astrophysics Data System (ADS)

    Pillai, Usha; Vijaya Kumar, Bhagavatula

    1998-10-01

    A scanner-based storage system employs a head mounted on a scanner which oscillates over the moving media. The head moves in an approximately sinusoidal path relative to the media at a high frequency, time-multiplexing the read/write signals of several tracks. The resulting multi-channel readback can yield higher data rates over a conventional system with a head that moves linearly relative to the media. Scanner-based storage systems are not commercially available at present. We are envisioning a system that uses an opto-electronic scanner, developed at CMU, in which the deflection of a laser beam is controlled by an input voltage. Since no mechanical motion is involved, this scanner has a high bandwidth which makes it well suited to our application.

  14. Storage capacity of an optically formed spatial filter for character recognition.

    PubMed

    Burckhardt, C B

    1967-08-01

    Optical spatial filtering has been proposed as a means of character recognition. The cross correlations between the unknown character and a number of stored masks are performed optically. In this paper an estimate is derived for the capacity of such a system, i.e., the number of masks one can store. Two estimates are made for the capacity. One holds for a noiseless optical system. The derivation of the second estimate takes into account noise of the photographic plate. Noise measurements of Kodak 649F plates are given. A numerical example shows the order of magnitude of the capacity. While, in our specific example, a capacity of several hundred thousand is computed for the noiseless system, this figure is reduced by two orders of magnitudes for the noisy system.

  15. Improved optical storage properties of NaAlSiO4: Tb3+ induced by Bi3+

    NASA Astrophysics Data System (ADS)

    Zhou, Junhe; Yu, Xue; Wang, Ting; Zhou, Dacheng; Qiu, Jianbei

    2016-07-01

    NaAlSiO4: Tb3+, Bi3+ phosphor was synthesized with green long persistent luminescence (LPL) and photo-stimulated luminescence (PSL) observed. The influence of metal ion Bi3+ on the optical storage properties of NaAlSiO4: Tb3+ was investigated in detail. The emitter Tb3+ introduced two kinds of traps located at 350 K (TA) and 440 K (TB) in the thermoluminescence (TL) glow curve. Bi3+ as a codopant ion introduced a new trap peaking at 390 K (TC), which contributed to the improved LPL properties. Besides, owing to the existence of deep and stable trap TB, green PSL can still be observed after 72 h since the excitation was stopped. Accordingly, the mechanism of LPL and PSL process was discussed briefly.

  16. Early puzzle play: a predictor of preschoolers' spatial transformation skill.

    PubMed

    Levine, Susan C; Ratliff, Kristin R; Huttenlocher, Janellen; Cannon, Joanna

    2012-03-01

    Individual differences in spatial skill emerge prior to kindergarten entry. However, little is known about the early experiences that may contribute to these differences. The current study examined the relation between children's early puzzle play and their spatial skill. Children and parents (n = 53) were observed at home for 90 min every 4 months (6 times) between 2 and 4 years of age (26 to 46 months). When children were 4 years 6 months old, they completed a spatial task involving mental transformations of 2-dimensional shapes. Children who were observed playing with puzzles performed better on this task than those who did not, controlling for parent education, income, and overall parent word types. Moreover, among those children who played with puzzles, frequency of puzzle play predicted performance on the spatial transformation task. Although the frequency of puzzle play did not differ for boys and girls, the quality of puzzle play (a composite of puzzle difficulty, parent engagement, and parent spatial language) was higher for boys than for girls. In addition, variation in puzzle play quality predicted performance on the spatial transformation task for girls but not for boys. Implications of these findings as well as future directions for research on the role of puzzle play in the development of spatial skill are discussed.

  17. Room temperature optical image storage devices based on novel photo-responsive chiral azobenzene liquid crystal dopants

    NASA Astrophysics Data System (ADS)

    Chen, Si; Chen, Yining; Tong, Xiaoqian; Wu, Bozhen; Ma, Meng; Shi, Yanqin; Wang, Xu

    2016-11-01

    A room temperature optical image storage device based on a novel kind of chiral azobenzene liquid crystal compound (Azo-CC) dopant was reported in this paper, which could realize room temperature photocatalytic phase transition when doping in host liquid crystal E7. With a comparation of the referential achiral compound (Azo-ACC), the chemical structure, liquid crystalline and photoresponsive properties of the compounds were characterized by 1H-NMR, POM and UV-vis, respectively. The result showed that the compound with chiral group (Azo-CC) exhibited better photoresponsive properties than the referential achiral compound (Azo-ACC), indicating the introduction of chiral group is the key factor to provide E7 host room temperature photosensitive properties, which could not only made the liquid crystal molecular reoriented but also could change the whole nematic host liquid crystal to helical-twisted matrix. In addition, to understand the optical-switching behavior into detail, the photoisomerization dynamics of the systems o was also analyzed.

  18. TOPICAL REVIEW The cosmological constant puzzle

    NASA Astrophysics Data System (ADS)

    Bass, Steven D.

    2011-04-01

    The accelerating expansion of the Universe points to a small positive vacuum energy density and negative vacuum pressure. A strong candidate is the cosmological constant in Einstein's equations of general relativity. Possible contributions are zero-point energies and the condensates associated with spontaneous symmetry breaking. The vacuum energy density extracted from astrophysics is 1056 times smaller than the value expected from quantum fields and standard model particle physics. Is the vacuum energy density time dependent? We give an introduction to the cosmological constant puzzle and ideas how to solve it.

  19. Optical and thermal properties of nickel(II) hydrazone complex for recordable blu-ray storage

    NASA Astrophysics Data System (ADS)

    Chen, Zhimin; Wu, Yiqun; Gu, Donghong; Gan, Fuxi

    2009-08-01

    A nickel(II) hydrazone complex was synthesized in order to obtain a suitable optical recording medium for the new generation recordable blu-ray disk. Smooth thin films of the nickel(II) hydrazone complex were prepared by using the spin-coating method. Absorption and reflectance spectra of the thin films were evaluated in the wavelength 300-700 nm. Thermal properties of the nickel(II) complex were investigated by thermogravimetry (TG) and differential scanning calorimetry (DSC). Optical constants (complex refractive indices N=n+ik) and thickness of the thin film, prepared on single-crystal silicon substrate, were investigated on a rotating analyzer-polarizer scanning ellipsometer in the wavelength 285-705 nm. In addition, in order to examine its possible use as a blu-ray recording medium, the spin-coated film of the nickel(II) complex was prepared on K9 glass substrate with a silver reflective layer, and was studied by static optical recording testing system with a 406.7 nm laser. It is found that the absorption spectra of the thin film has an strong absorption band in the wavelength region 360-420 nm and a moderate absorbance at the 405 nm side, which indicates that the absorption of the film is well matched with the laser wavelength of the 405 nm. The reflectance spectra show that a high reflectivity of the thin film at 405 nm wavelength can be obtained by an optimum film thickness and an appropriate metal reflective layer. The thin film of the nickel(II) complex gives a high n value of 1.62 and a low k value of 0.33, corresponding to the wavelength of the blue laser of 405 nm. Measurements of the thermal properties show that the nickel(II) complex holds a high thermal stability (~ 300 °C) and a sharp weight loss which are helpful to fabricate a small and sharp recording mark edge. The results of the static optical recording test, using the nickel(II) complex thin film as the recording layer, demonstrate that high reflectivity contrast (>50 %) can be obtained at

  20. Magic star puzzle for educational mathematics

    NASA Astrophysics Data System (ADS)

    Gan, Yee Siang; Fong, Wan Heng; Sarmin, Nor Haniza

    2013-04-01

    One of the interesting fields in recreational mathematics is the magic number arrangement. There are different kinds of arrays in the arrangement for a group of numbers. In particular, one of the arrays in magic number arrangement is called magic star. In fact, magic star involves combinatorics that contributes to geometrical analysis and number theory. Hence, magic star is suitable to be introduced as educational mathematics to cultivate interest in different area of mathematics. To obtain the solutions of normal magic stars of order six, the possible sets of numbers for every line in a magic star have been considered. Previously, the calculation for obtaining the solutions has been done manually which is time-consuming. Therefore, a programming code to generate all the fundamental solutions for normal magic star of order six without including the properties of rotation and reflection has been done. In this puzzle, a magic star puzzle is created by using Matlab software, which enables a user to verify the entries for the cells of magic star of order six. Moreover, it is also user-friendly as it provides interactive commands on the inputs given by the user, which enables the user to detect the incorrect inputs. In addition, user can also choose to view all the fundamental solutions as generated by the programming code.

  1. Useful laser source criteria for optical storage employing extended eye-diagram jitter theory

    NASA Astrophysics Data System (ADS)

    Kubota, Shigeo; Oka, Michio; Eguchi, Naoya; Fukumoto, Atsushi; Akiyama, Yoshiyuki

    1995-03-01

    In view of the recent progress in visible lasers for next-generation optical disks, we describe the influence of source wavelength, aberration, and noise on eye-diagram jitter, which determines the ultimate disk density. The analysis indicates that the sources used in a readout of a 6 \\times areal density, (4,22) run-length-limited code with a minimum mark length of 0.4 mu m must have a wavelength that satisfies the Nyquist condition of relationship between the spot size and the minimum mark length, a wave-front aberration of less than 0.035 rms lambda , and relative intensity noise of less than -125 dB/Hz.

  2. Optical storage in azobenzene-containing epoxy polymers processed as Langmuir Blodgett films.

    PubMed

    Fernández, Raquel; Mondragon, Iñaki; Sanfelice, Rafaela C; Pavinatto, Felippe J; Oliveira, Osvaldo N; Oyanguren, Patricia; Galante, María J

    2013-04-01

    In this study, azocopolymers containing different main-chain segments have been synthesized with diglycidyl ether of bisphenol A (DGEBA, DER 332, n=0.03) and the azochromophore Disperse Orange 3 (DO3) cured with two monoamines, viz. benzylamine (BA) and m-toluidine (MT). The photoinduced birefringence was investigated in films produced with these azopolymers using the spin coating (SC) and Langmuir Blodgett (LB) techniques. In the LB films, birefringence increased with the content of azochromophore and the film thickness, as expected. The nanostructured nature of the LB films led to an enhanced birefringence and faster dynamics in the writing process, compared to the SC films. In summary, the combination of azocopolymers and the LB method may allow materials with tuned properties for various optical applications, including in biological systems were photoisomerization may be used to trigger actions such as drug delivery.

  3. A Puzzle Used to Teach the Cardiac Cycle

    ERIC Educational Resources Information Center

    Marcondes, Fernanda K.; Moura, Maria J. C. S.; Sanches, Andrea; Costa, Rafaela; Oliveira de Lima, Patricia; Groppo, Francisco Carlos; Amaral, Maria E. C.; Zeni, Paula; Gaviao, Kelly Cristina; Montrezor, Luís H.

    2015-01-01

    The aim of the present article is to describe a puzzle developed for use in teaching cardiac physiology classes. The puzzle presents figures of phases of the cardiac cycle and a table with five columns: phases of cardiac cycle, atrial state, ventricular state, state of atrioventricular valves, and pulmonary and aortic valves. Chips are provided…

  4. WAIS-IV visual puzzles in a mixed clinical sample.

    PubMed

    Fallows, Robert R; Hilsabeck, Robin C

    2012-01-01

    Little is known about which cognitive functions underlie the new Visual Puzzles subtest of the Wechsler Adult Intelligence Scale - Fourth Edition (WAIS-IV). The purpose of this study was to investigate relationships between Visual Puzzles and common neuropsychological measures in a mixed clinical sample. A total of 44 veterans (75% men) were administered the WAIS-IV as part of a neuropsychological evaluation. Average age was 47.4 years (SD = 11.8), and average education was 13.8 years (SD = 2.3). Correlations were conducted to examine relationships between Visual Puzzles, demographic variables, and neuropsychological measures. Hierarchical regression analysis was used to determine which measures contributed the most variance to Visual Puzzles. Visual Puzzles correlated significantly with measures of visuospatial reasoning, verbal learning and recall, mental flexibility, processing speed, and naming, which accounted for 50% of the variance in Visual Puzzles performance. The results indicate that Visual Puzzles is not a pure measure of visuoperceptual reasoning, at least in a mixed clinical sample, because memory, mental flexibility, processing speed, and language abilities also contribute to successful performance of the task. Thus it may be important to consider other aspects of cognitive functioning when interpreting Visual Puzzles performance.

  5. Enumerating Small Sudoku Puzzles in a First Abstract Algebra Course

    ERIC Educational Resources Information Center

    Lorch, Crystal; Lorch, John

    2008-01-01

    Two methods are presented for counting small "essentially different" sudoku puzzles using elementary group theory: one method (due to Jarvis and Russell) uses Burnside's counting formula, while the other employs an invariant property of sudoku puzzles. Ideas are included for incorporating this material into an introductory abstract algebra course.…

  6. Sudoku Puzzles for First-Year Organic Chemistry Students

    ERIC Educational Resources Information Center

    Perez, Alice L.; Lamoureux, G.

    2007-01-01

    Sudoku puzzle was designed to teach about amino acids and functional groups to the students of undergraduate organic chemistry students. The puzzles focus on helping the student learn the name, 3-letter code and 1-letter code of common amino acids and functional groups.

  7. Crossword Puzzles as Learning Tools in Introductory Soil Science

    ERIC Educational Resources Information Center

    Barbarick, K. A.

    2010-01-01

    Students in introductory courses generally respond favorably to novel approaches to learning. To this end, I developed and used three crossword puzzles in spring and fall 2009 semesters in Introductory Soil Science Laboratory at Colorado State University. The first hypothesis was that crossword puzzles would improve introductory soil science…

  8. Jigsaw Puzzles. Australian Early Childhood Resource Booklets, No. 3.

    ERIC Educational Resources Information Center

    Fleer, Marilyn

    This booklet examines the educational value of jigsaw puzzles and gives practical suggestions on how to select and make them for use by children ages 1 through 8. It asserts that jigsaw puzzles provide children with the opportunity to develop problem-solving strategies, and discusses a theory of adult-child interaction that encourages the…

  9. Accelerating Student Learning of Technology Terms: "The Crossword Puzzle Exercise"

    ERIC Educational Resources Information Center

    Whisenand, Thomas G.; Dunphy, Steven M.

    2010-01-01

    The authors suggest using an alternative teaching methodology to impart knowledge regarding information systems phraseology and vocabulary. Specifically, a series of crossword puzzles or scrabbles are used to present information system (IS) terminology to students in an introductory business information systems course. The puzzle terms and answers…

  10. Sharing Skills: Reach for a Book; Book Week Puzzle Packet.

    ERIC Educational Resources Information Center

    Bauer, Caroline Feller

    1986-01-01

    Reach for a Book is the theme for Children's Book Week 1986, and book presentations, activities, and exhibits to emphasize the joy of reading are listed. A Book Week Puzzle Packet provides two puzzles designed to reinforce the idea of using the card catalog to find materials on specific subjects. (EM)

  11. A method for simultaneous linear optics and coupling correction for storage rings with turn-by-turn beam position monitor data

    NASA Astrophysics Data System (ADS)

    Yang, Xi; Huang, Xiaobiao

    2016-08-01

    We propose a method to simultaneously correct linear optics errors and linear coupling for storage rings using turn-by-turn (TbT) beam position monitor (BPM) data. The independent component analysis (ICA) method is used to isolate the betatron normal modes from the measured TbT BPM data. The betatron amplitudes and phase advances of the projections of the normal modes on the horizontal and vertical planes are then extracted, which, combined with dispersion measurement, are used to fit the lattice model. The fitting results are used for lattice correction. The method has been successfully demonstrated on the NSLS-II storage ring.

  12. A method for simultaneous linear optics and coupling correction for storage rings with turn-by-turn beam position monitor data

    SciTech Connect

    Yang, Xi; Huang, Xiaobiao

    2016-05-13

    Here, we propose a method to simultaneously correct linear optics errors and linear coupling for storage rings using turn-by-turn (TbT) beam position monitor (BPM) data. The independent component analysis (ICA) method is used to isolate the betatron normal modes from the measured TbT BPM data. The betatron amplitudes and phase advances of the projections of the normal modes on the horizontal and vertical planes are then extracted, which, combined with dispersion measurement, are used to fit the lattice model. The fitting results are used for lattice correction. Finally, the method has been successfully demonstrated on the NSLS-II storage ring.

  13. A method for simultaneous linear optics and coupling correction for storage rings with turn-by-turn beam position monitor data

    SciTech Connect

    Yang, Xi; Huang, Xiaobiao

    2016-08-01

    We propose a method to simultaneously correct linear optics errors and linear coupling for storage rings using turn-by-turn (TbT) beam position monitor (BPM) data. The independent component analysis (ICA) method is used to isolate the betatron normal modes from the measured TbT BPM data. The betatron amplitudes and phase advances of the projections of the normal modes on the horizontal and vertical planes are then extracted, which, combined with dispersion measurement, are used to fit the lattice model. Furthermore, the fitting results are used for lattice correction. Our method has been successfully demonstrated on the NSLS-II storage ring.

  14. Calibration of Fast Fiber-Optic Beam Loss Monitors for the Advanced Photon Source Storage Ring Superconducting Undulators

    SciTech Connect

    Dooling, J.; Harkay, K.; Ivanyushenkov, Y.; Sajaev, V.; Xiao, A.; Vella, Andrea K.

    2015-01-01

    We report on the calibration and use of fast fiber-optic (FO) beam loss monitors (BLMs) in the Advanced Photon Source storage ring (SR). A superconducting undulator prototype (SCU0) has been operating in SR Sector 6 (“ID6”) since the beginning of CY2013, and another undulator SCU1 (a 1.1-m length undulator that is three times the length of SCU0) is scheduled for installation in Sector 1 (“ID1”) in 2015. The SCU0 main coil often quenches during beam dumps. MARS simulations have shown that relatively small beam loss (<1 nC) can lead to temperature excursions sufficient to cause quenchingwhen the SCU0windings are near critical current. To characterize local beam losses, high-purity fused-silica FO cables were installed in ID6 on the SCU0 chamber transitions and in ID1 where SCU1 will be installed. These BLMs aid in the search for operating modes that protect the SCU structures from beam-loss-induced quenching. In this paper, we describe the BLM calibration process that included deliberate beam dumps at locations of BLMs. We also compare beam dump events where SCU0 did and did not quench.

  15. High flux circularly polarized gamma beam factory: coupling a Fabry-Perot optical cavity with an electron storage ring

    NASA Astrophysics Data System (ADS)

    Chaikovska, I.; Cassou, K.; Chiche, R.; Cizeron, R.; Cornebise, P.; Delerue, N.; Jehanno, D.; Labaye, F.; Marie, R.; Martens, A.; Peinaud, Y.; Soskov, V.; Variola, A.; Zomer, F.; Cormier, E.; Lhermite, J.; Dolique, V.; Flaminio, R.; Michel, C.; Pinard, L.; Sassolas, B.; Akagi, T.; Araki, S.; Honda, Y.; Omori, T.; Terunuma, N.; Urakawa, J.; Miyoshi, S.; Takahashi, T.; Yoshitama, H.

    2016-11-01

    We report and discuss high-flux generation of circularly polarized γ-rays by means of Compton scattering. The γ-ray beam results from the collision of an external-cavity-enhanced infrared laser beam and a low emittance relativistic electron beam. By operating a non-planar bow-tie high-finesse optical Fabry-Perot cavity coupled to a storage ring, we have recorded a flux of up to (3.5 ± 0.3) × 108 photons per second with a mean measured energy of 24 MeV. The γ-ray flux has been sustained for several hours. In particular, we were able to measure a record value of up to 400 γ-rays per collision in a full bandwidth. Moreover, the impact of Compton scattering on the electron beam dynamics could be observed resulting in a reduction of the electron beam lifetime correlated to the laser power stored in the Fabry-Perot cavity. We demonstrate that the electron beam lifetime provides an independent and consistent determination of the γ-ray flux. Furthermore, a reduction of the γ-ray flux due to intrabeam scattering has clearly been identified. These results, obtained on an accelerator test facility, warrant potential scaling and revealed both expected and yet unobserved effects. They set the baseline for further scaling of the future Compton sources under development around the world.

  16. Color-Coded Batteries - Electro-Photonic Inverse Opal Materials for Enhanced Electrochemical Energy Storage and Optically Encoded Diagnostics.

    PubMed

    O'Dwyer, Colm

    2016-07-01

    For consumer electronic devices, long-life, stable, and reasonably fast charging Li-ion batteries with good stable capacities are a necessity. For exciting and important advances in the materials that drive innovations in electrochemical energy storage (EES), modular thin-film solar cells, and wearable, flexible technology of the future, real-time analysis and indication of battery performance and health is crucial. Here, developments in color-coded assessment of battery material performance and diagnostics are described, and a vision for using electro-photonic inverse opal materials and all-optical probes to assess, characterize, and monitor the processes non-destructively in real time are outlined. By structuring any cathode or anode material in the form of a photonic crystal or as a 3D macroporous inverse opal, color-coded "chameleon" battery-strip electrodes may provide an amenable way to distinguish the type of process, the voltage, material and chemical phase changes, remaining capacity, cycle health, and state of charge or discharge of either existing or new materials in Li-ion or emerging alternative battery types, simply by monitoring its color change.

  17. High flux circularly polarized gamma beam factory: coupling a Fabry-Perot optical cavity with an electron storage ring

    PubMed Central

    Chaikovska, I.; Cassou, K.; Chiche, R.; Cizeron, R.; Cornebise, P.; Delerue, N.; Jehanno, D.; Labaye, F.; Marie, R.; Martens, A.; Peinaud, Y.; Soskov, V.; Variola, A.; Zomer, F.; Cormier, E.; Lhermite, J.; Dolique, V.; Flaminio, R.; Michel, C.; Pinard, L.; Sassolas, B.; Akagi, T.; Araki, S.; Honda, Y.; Omori, T.; Terunuma, N.; Urakawa, J.; Miyoshi, S.; Takahashi, T.; Yoshitama, H.

    2016-01-01

    We report and discuss high-flux generation of circularly polarized γ-rays by means of Compton scattering. The γ-ray beam results from the collision of an external-cavity-enhanced infrared laser beam and a low emittance relativistic electron beam. By operating a non-planar bow-tie high-finesse optical Fabry-Perot cavity coupled to a storage ring, we have recorded a flux of up to (3.5 ± 0.3) × 108 photons per second with a mean measured energy of 24 MeV. The γ-ray flux has been sustained for several hours. In particular, we were able to measure a record value of up to 400 γ-rays per collision in a full bandwidth. Moreover, the impact of Compton scattering on the electron beam dynamics could be observed resulting in a reduction of the electron beam lifetime correlated to the laser power stored in the Fabry-Perot cavity. We demonstrate that the electron beam lifetime provides an independent and consistent determination of the γ-ray flux. Furthermore, a reduction of the γ-ray flux due to intrabeam scattering has clearly been identified. These results, obtained on an accelerator test facility, warrant potential scaling and revealed both expected and yet unobserved effects. They set the baseline for further scaling of the future Compton sources under development around the world. PMID:27857146

  18. The electron screening puzzle and nuclear clustering

    SciTech Connect

    Spitaleri, C.; Bertulani, C. A.; Fortunato, L.; Vitturi, A.

    2016-02-12

    Accurate measurements of nuclear reactions of astrophysical interest within, or close to, the Gamow peak show evidence of an unexpected effect attributed to the presence of atomic electrons in the target. The experiments need to include an effective "screening" potential to explain the enhancement of the cross sections at the lowest measurable energies. Despite various theoretical studies conducted over the past 20 years and numerous experimental measurements, a theory has not yet been found that can explain the cause of the exceedingly high values of the screening potential needed to explain the data. Furthermore, in this letter we show that instead of an atomic physics solution of the "electron screening puzzle", the reason for the large screening potential values is in fact due to clusterization effects in nuclear reactions, in particular for reaction involving light nuclei.

  19. The electron screening puzzle and nuclear clustering

    DOE PAGES

    Spitaleri, C.; Bertulani, C. A.; Fortunato, L.; ...

    2016-02-12

    Accurate measurements of nuclear reactions of astrophysical interest within, or close to, the Gamow peak show evidence of an unexpected effect attributed to the presence of atomic electrons in the target. The experiments need to include an effective "screening" potential to explain the enhancement of the cross sections at the lowest measurable energies. Despite various theoretical studies conducted over the past 20 years and numerous experimental measurements, a theory has not yet been found that can explain the cause of the exceedingly high values of the screening potential needed to explain the data. Furthermore, in this letter we show thatmore » instead of an atomic physics solution of the "electron screening puzzle", the reason for the large screening potential values is in fact due to clusterization effects in nuclear reactions, in particular for reaction involving light nuclei.« less

  20. A PUZZLE INVOLVING GALACTIC BULGE MICROLENSING EVENTS

    SciTech Connect

    Cohen, Judith G.; Gould, Andrew; Johnson, Jennifer A.; Thompson, Ian B.; Feltzing, Sofia; Bensby, Thomas; Huang Wenjin; Melendez, Jorge; Lucatello, Sara; Asplund, Martin E-mail: gould@astronomy.ohio-state.edu E-mail: ian@obs.carnegiescience.edu E-mail: tbensby@eso.org E-mail: jorge@astro.up.pt E-mail: asplund@MPA-Garching.MPG.DE

    2010-03-01

    We study a sample of 16 microlensed Galactic bulge main-sequence turnoff region stars for which high-dispersion spectra have been obtained with detailed abundance analyses. We demonstrate that there is a very strong and highly statistically significant correlation between the maximum magnification of the microlensed bulge star and the value of the [Fe/H] deduced from the high resolution spectrum of each object. Physics demands that this correlation, assuming it to be real, be the result of some sample bias. We suggest several possible explanations, but are forced to reject them all, and are left puzzled. To obtain a reliable metallicity distribution in the Galactic bulge based on microlensed dwarf stars, it will be necessary to resolve this issue through the course of additional observations.

  1. Puzzle patterns: Research day interactive strategy.

    PubMed

    Bassendowski, Sandra L; Petrucka, Pammla M

    2006-01-01

    The article describes the planning, implementation, and assessment of an interactive strategy designed for a research day at the College of Nursing, University of Saskatchewan. A decision was made to use a creative, interactive strategy involving the use of large, blank jigsaw puzzles to generate a visual depiction of research interests and challenges faced by participants who represented graduate and undergraduate nursing students, faculty, and invited guests from government, health regions, and professional associations. Participants were asked the following questions - "What are you curious about in nursing and health care," and "What situations or questions in nursing need answers"? The strategy demonstrated the comprehensiveness of information that can be obtained through a short-turn around interactive strategy. Further, it also attests to the broad spectrum of interests within a single nursing education program and posits the potential for educators to undertake further thematic analysis to synthesize the data to inform research agendas.

  2. Building programmable jigsaw puzzles with RNA.

    PubMed

    Chworos, Arkadiusz; Severcan, Isil; Koyfman, Alexey Y; Weinkam, Patrick; Oroudjev, Emin; Hansma, Helen G; Jaeger, Luc

    2004-12-17

    One challenge in supramolecular chemistry is the design of versatile, self-assembling building blocks to attain total control of arrangement of matter at a molecular level. We have achieved reliable prediction and design of the three-dimensional structure of artificial RNA building blocks to generate molecular jigsaw puzzle units called tectosquares. They can be programmed with control over their geometry, topology, directionality, and addressability to algorithmically self-assemble into a variety of complex nanoscopic fabrics with predefined periodic and aperiodic patterns and finite dimensions. This work emphasizes the modular and hierarchical characteristics of RNA by showing that small RNA structural motifs can code the precise topology of large molecular architectures. It demonstrates that fully addressable materials based on RNA can be synthesized and provides insights into self-assembly processes involving large populations of RNA molecules.

  3. SOLVING THE PUZZLE OF SUBHALO SPINS

    SciTech Connect

    Wang, Yang; Lin, Weipeng; Pearce, Frazer R.; Lux, Hanni; Onions, Julian; Muldrew, Stuart I. E-mail: linwp@shao.ac.cn

    2015-03-10

    Investigating the spin parameter distribution of subhalos in two high-resolution isolated halo simulations, recent work by Onions et al. suggested that typical subhalo spins are consistently lower than the spin distribution found for field halos. To further examine this puzzle, we have analyzed simulations of a cosmological volume with sufficient resolution to resolve a significant subhalo population. We confirm the result of Onions et al. and show that the typical spin of a subhalo decreases with decreasing mass and increasing proximity to the host halo center. We interpret this as the growing influence of tidal stripping in removing the outer layers, and hence the higher angular momentum particles, of the subhalos as they move within the host potential. Investigating the redshift dependence of this effect, we find that the typical subhalo spin is smaller with decreasing redshift. This indicates a temporal evolution, as expected in the tidal stripping scenario.

  4. Storage Media for Microcomputers.

    ERIC Educational Resources Information Center

    Trautman, Rodes

    1983-01-01

    Reviews computer storage devices designed to provide additional memory for microcomputers--chips, floppy disks, hard disks, optical disks--and describes how secondary storage is used (file transfer, formatting, ingredients of incompatibility); disk/controller/software triplet; magnetic tape backup; storage volatility; disk emulator; and…

  5. The Meibomian Puzzle: Combining Pieces Together

    PubMed Central

    Butovich, Igor A.

    2009-01-01

    The purpose of this review was to summarize the available information on lipidomic analysis of human meibum and tear film, and critically evaluate the pertinent past and present analytical procedures and results obtained in various laboratories. Human meibum was shown to be a very complex mixture of lipids of various classes. For decades, their exact structures have remained elusive. Because of the limitations of the then-current techniques, most of the complex lipids that constitute meibum could not be analyzed as whole molecules and required prior hydrolysis and/or transesterification of the entire lipid pool. These procedures effectively made it very difficult, and often impossible, to reconstruct the complete structures of the original intact compounds, which prompted us to call this The Meibomian Puzzle. Modern techniques such as high-performance liquid chromatography in combination with mass spectrometry help in solving this puzzle by allowing a researcher to detect and analyze intact molecules of complex lipid compounds, even if present in extremely low concentrations. This current de-facto standard procedure in lipidomic analysis of natural lipids and their mixtures is compared with other experimental techniques such as nuclear magnetic resonance spectroscopy, infrared spectroscopy, gas chromatography, and thin layer chromatography, among the others. The results obtained by older techniques, and their limitations and deficiencies are discussed. It appears that some of the earlier findings did not withstand a scrupulous re-evaluation and need to be modified and/or corrected. The most intriguing development is the virtual absence in meibum of typical phospholipids – an important group of amphiphilic compounds whose role in the human tear film was thought to be to stabilize the entire tear film structure. Instead, another group of previously unidentified compounds, very long chain (O-acyl)-omega-hydroxy fatty acids, appears to be a stabilizing factor which

  6. Solar System Puzzle Kit: An Activity for Earth and Space Science.

    ERIC Educational Resources Information Center

    Vogt, Gregory L.; Rosenberg, Carla B.

    This Solar System Puzzle Kit for grades 5-8, allows students to create an eight-cube paper puzzle of the solar system and may be duplicated for classroom use or used as a take home activity for children and parents. By assembling the puzzle, hand-coloring the bodies of the solar system, and viewing the puzzle's 12 sides, students can reinforce…

  7. Teaching the Blue-Eyed Islanders Puzzle in a Liberal Arts Mathematics Course

    ERIC Educational Resources Information Center

    Shea, Stephen

    2012-01-01

    The blue-eyed islanders puzzle is an old and challenging logic puzzle. This is a narrative of an experience introducing a variation of this puzzle on the first day of classes in a liberal arts mathematics course for non-majors. I describe an exercise that was used to facilitate the class's understanding of the puzzle.

  8. Puzzling through General Chemistry: A Light-Hearted Approach to Engaging Students with Chemistry Content

    ERIC Educational Resources Information Center

    Boyd, Susan L.

    2007-01-01

    Several puzzles are designed to be used by chemistry students as learning tools and teach them basic chemical concepts. The topics of the puzzles are based on the chapters from Chemistry, The Central Science used in general chemistry course and the puzzles are in various forms like crosswords, word searches, number searches, puzzles based on…

  9. Permanent Electronic Storage of Angiographic Images in the Catheterization Laboratory: High-Resolution and Real-Time Acquisition on Optical Laserdiscs.

    PubMed

    Azancot; Krone; Eiferman; Guermonprez; Metzger; Le Dref O; Steg; Bonan; Lesperance; Hudon; Friolo; Beaufils

    1997-03-01

    The use of electronic ÒfilmlessÓ media for long-term archiving of coronary angiograms has been impeded by the problems of image storage and data transfer among institutions. Although long-term analogue storage of the images is presently feasible, and much less costly than digital storage, processing has been limited to a 625 lines video format, not optimal for high quality images. We developed a bi-directional 1249/625 lines converter, able to store and to replay high resolution (1249 lines) video images, from Component Record Video (CRV) Optical Laser (Analogue) Videodisks. Image quality and medical relevance were evaluated five ways: 1) Outside experts compared 593 static images stored on CRV discs to the same images stored in a high-resolution digital format blinded to source of image. The four experts found no visual or medical difference in 98% of evaluated images and minor differences in the remainder. The differences in the remaining images were not consistent among experts. 2) Two of the experts also compared the enhanced CRV optically stored image to the image obtained on simultaneously recorded 35mm cine film, and found the enhanced CRV stored image to be superior or similar, but never inferior to the film image. 3) 90 representatives from 63 outside institutions compared images from both a digital hard drive and the enhanced CRV optical (analogue) storage displayed at a Windows based digital workstation. During the test they were blinded as to the source of the images. The representatives found no difference in image resolution, quality, diagnostic accuracy, and medical relevance. 4) We evaluated quantitative coronary angiography (QCA) on standard coronary test phantoms using enhanced CRV stored images digitally processed. The correlation of the enhanced CRV image to the actual size of the phantom vessels was similar to the results obtained in the literature from digitally stored images. 5) 78 arterial measurements ranging 0.65 to 4.85 mm were

  10. Formative Assessment Probes: Mountaintop Fossil: A Puzzling Phenomenon

    ERIC Educational Resources Information Center

    Keeley, Page

    2015-01-01

    This column focuses on promoting learning through assessment. This month's issue describes using formative assessment probes to uncover several ways of thinking about the puzzling discovery of a marine fossil on top of a mountain.

  11. Unwinding the von Willebrand factor strings puzzle.

    PubMed

    De Ceunynck, Karen; De Meyer, Simon F; Vanhoorelbeke, Karen

    2013-01-10

    von Willebrand factor (VWF) is amongst others synthesized by endothelial cells and stored as ultra-large (UL) VWF multimers in Weibel-Palade bodies. Although UL-VWF is proteolysed by ADAMTS13 (a disintegrin-like and metalloprotease domain with thrombospondin type-1 motif, number 13) on secretion from endothelial cells, in vitro experiments in the absence of ADAMTS13 have demonstrated that a proportion of these UL-VWF multimers remain anchored to the activated endothelium. These multimers unravel, bind platelets, and wave in the direction of the flow. These so-called VWF "strings" have also been visualized in vivo, lining the lumen of activated mesenteric veins of Adamts13(-/-) mice. Various studies have demonstrated the extraordinary length of these VWF strings, the availability of their platelet binding and ADAMTS13 cleavage sites, and the possible nature of their endothelial attachment. VWF strings are also capable of tethering leukocytes and parasite-infected red blood cells. However, the majority of studies have been performed in the absence of ADAMTS13, a condition only experienced in thrombotic thrombocytopenic purpura. A normal functional role of VWF strings in healthy persons or in other disease pathologies remains unclear. In this review, we discuss some of the puzzling characteristics of VWF strings, and we debate whether the properties of VWF strings in the absence of ADAMTS13 might be relevant for understanding (patho)physiologic mechanisms.

  12. Holography and Optical Storage

    NASA Astrophysics Data System (ADS)

    Imlau, Mirco; Fally, Martin; Burr, Geoffrey W.; Sincerbox, Glenn T.

    The term holography is composed of the Greek words holos (= whole) and graphein (= to record, to write), and thus summarizes the key aspects of its underlying principle: recording the complete wavefront of an object, i.e., its intensity as well as its phase. Interference and diffraction phenomena are employed to record and retrieve the full information, a technique pioneered by Dennis Gabor in 1948. He was honored with the Nobel prize in Physics in 1971, reflecting the general impact of holography on modern physics.

  13. X-rays from Saturn Pose Puzzles

    NASA Astrophysics Data System (ADS)

    2004-03-01

    The first clear detection of X-rays from the giant, gaseous planet Saturn has been made with NASA's Chandra X-ray Observatory. Chandra's image shows that the X-rays are concentrated near Saturn's equator, a surprising result since Jupiter's X-ray emission is mainly concentrated near the poles. Existing theories cannot easily explain the intensity or distribution of Saturn's X-rays. Chandra observed Saturn for about 20 hours in April of 2003. The spectrum, or distribution with energy of the X-rays, was found to be very similar to that of X-rays from the Sun. "This indicates that Saturn's X-ray emission is due to the scattering of solar X-rays by Saturn's atmosphere," said Jan-Uwe Ness, of the University of Hamburg in Germany and lead author of a paper discussing the Saturn results in an upcoming issue of Astronomy & Astrophysics. "It's a puzzle, since the intensity of Saturn's X-rays requires that Saturn reflects X-rays fifty times more efficiently than the Moon." The observed 90 megawatts of X-ray power from Saturn's equatorial region is roughly consistent with previous observations of the X-radiation from Jupiter's equatorial region. This suggests that both giant, gaseous planets reflect solar X-rays at unexpectedly high rates. Further observations of Jupiter will be needed to test this possibility. The weak X-radiation from Saturn's south-polar region presents another puzzle (the north pole was blocked by Saturn's rings during this observation). Saturn's magnetic field, like that of Jupiter, is strongest near the poles. X-radiation from Jupiter is brightest at the poles because of auroral activity due to the enhanced interaction of high-energy particles from the Sun with its magnetic field. Since spectacular ultraviolet polar auroras have been observed to occur on Saturn, Ness and colleagues expected that Saturn's south pole might be bright in X-rays. It is not clear whether the auroral mechanism does not produce X-rays on Saturn, or for some reason concentrates

  14. Digital image storage.

    PubMed

    Wallack, Seth

    2008-01-01

    Digital image archival requires less physical storage space, allows for rapid storage and retrieval and avoids loss in image quality over time or with image duplication compared with film storage. Because medical imaging data are critically important and, by law, must be stored in a safe, accessible manner, it is imperative not to have one computer error destroy all copies of the image data. Several options for image storage media are available including magnetic tape, optical media, spinning disks and solid state. Other considerations include on-site vs. off-site storage, redundancy, on-line vs. off-line storage, and removable storage media for disaster recovery. The different storage media can be used in different configurations to provide sufficient protection of digital data. Choose a storage system that will keep your data safe from unauthorized access, hardware failure, and clinic disasters.

  15. Heavy quarkonium: progress, puzzles, and opportunities

    SciTech Connect

    Petreczky, P.; Brambilla, N.; Eidelman,S; B.K. Heltsley; Vogt, R.; Bodwiny, G.T.; Eichteny, E., et. al.

    2011-02-08

    A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the $B$-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations. The plethora of newly-found quarkonium-like states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c{bar c}, b{bar b}, and b{bar c} bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hot- and cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.

  16. Heavy quarkonium: progress, puzzles, and opportunities

    SciTech Connect

    Brambilla, N; Heltsley, B K; Vogt, R; Bodwin, G T; Eichten, E; Frawley, A D; Meyer, A B; Mitchell, R E; Papdimitriou, V; Petreczky, P; Petrov, A A; Robbe, P; Vairo, A; Andronic, A; Arnaldi, R; Artoisenet, P; Bali, G; Bertolin, A; Bettoni, D; Brodzicka, J; Bruno, G E; Caldwell, A; Catmore, J; Chang, C -H; Chao, K -T; Chudakov, E; Cortese, P; Crochet, P; Drutskoy, A; Ellwanger, U; Faccioli, P; Gabareen Mokhtar, A; Garcia i Tormo, X; Hanhart, C; Harris, F A; Kaplan, D M; Klein, S R; Kowalski, H; Lansberg, J -P; Levichev, E; Lombardo, V; Loureno, C; Maltoni, F; Mocsy, A; Mussa, R; Navarra, F S; Negrini, M; Nielsen, M; Olsen, S L; Pakhlov, P; Pakhlova, G; Peters, K; Polosa, A D; Qian, W; Qiu, J -W; Rong, G; Sanchis-Lozano, M A; Scomparin, E; Senger, P; Simon, F; Stracka, S; Sumino, Y; Voloshin, M; Weiss, C; Wohri, H K; Yuan, C -Z

    2011-02-01

    A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the $B$-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA, JLab, and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations. The plethora of newly-found quarkonium-like states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c\\bar{c}, b\\bar{b}, and b\\bar{c} bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hot- and cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.

  17. SeaWiFS technical report series. Volume 20: The SeaWiFS bio-optical archive and storage system (SeaBASS), part 1

    NASA Technical Reports Server (NTRS)

    Hooker, Stanford B. (Editor); Mcclain, Charles R.; Firestone, James K.; Westphal, Todd L.; Yeh, Eueng-Nan; Ge, Yuntao; Firestone, Elaine R.

    1994-01-01

    This document provides an overview of the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) Bio-Optical Archive and Storage System (SeaBASS), which will serve as a repository for numerous data sets of interest to the SeaWiFS Science Team and other approved investigators in the oceanographic community. The data collected will be those data sets suitable for the development and evaluation of bio-optical algorithms which include results from SeaWiFS Intercalibration Round-Robin Experiments (SIRREXs), prelaunch characterization of the SeaWiFS instrument by its manufacturer -- Hughes/Santa Barbara Research Center (SBRC), Marine Optical Characterization Experiment (MOCE) cruises, Marine Optical Buoy (MOBY) deployments and refurbishments, and field studies of other scientists outside of NASA. The primary goal of the data system is to provide a simple mechanism for querying the available archive and requesting specific items, while assuring that the data is made available only to authorized users. The design, construction, and maintenance of SeaBASS is the responsibility of the SeaWiFS Calibration and Validation Team (CVT). This report is concerned with documenting the execution of this task by the CVT and consists of a series of chapters detailing the various data sets involved. The topics presented are as follows: 1) overview of the SeaBASS file architecture, 2) the bio-optical data system, 3) the historical pigment database, 4) the SIRREX database, and 5) the SBRC database.

  18. Three Modes of Hydrogeophysical Investigation: Puzzles, Mysteries, and Conundrums

    NASA Astrophysics Data System (ADS)

    Ferre, P. A.

    2011-12-01

    In an article in the New Yorker in 2007, Malcolm Gladwell discussed the distinction that national security expert Gregory Treverton has made between puzzles and mysteries. Specifically, puzzles are problems that we understand and that will eventually be solved when we amass enough information. (Think crossword puzzles.) Mysteries are problems for which we have the necessary information, but it is often overwhelmed by irrelevant or misleading input. To solve a mystery, we require improved analysis. (Think find-a-word.) Gladwell goes on to explain that, in the national security realm, the Cold War was a puzzle while the current national security condition is a mystery. I will discuss the past, current, and future trajectories of hydrogeophysics in terms of puzzles and mysteries. I will also add a third class of problem: conundrums - those for which we lack sufficient information about their structure to know how to solve them. A conundrum is a mystery with an unexpected twist. I hope to make the case that the future growth of hydrogeophysics lies in our ability to address this more challenging and more interesting class of problem.

  19. Laser-induced phase transitions of Ge2Sb2Te5 thin films used in optical and electronic data storage and in thermal lithography.

    PubMed

    Chu, Cheng Hung; Shiue, Chiun Da; Cheng, Hsuen Wei; Tseng, Ming Lun; Chiang, Hai-Pang; Mansuripur, Masud; Tsai, Din Ping

    2010-08-16

    Amorphous thin films of Ge(2)Sb(2)Te(5), sputter-deposited on a ZnS-SiO(2) dielectric layer, are investigated for the purpose of understanding the structural phase-transitions that occur under the influence of tightly-focused laser beams. Selective chemical etching of recorded marks in conjunction with optical, atomic force, and electron microscopy as well as local electron diffraction analysis are used to discern the complex structural features created under a broad range of laser powers and pulse durations. Clarifying the nature of phase transitions associated with laser-recorded marks in chalcogenide Ge(2)Sb(2)Te(5) thin films provides useful information for reversible optical and electronic data storage, as well as for phase-change (thermal) lithography.

  20. International Trade Network: Fractal Properties and Globalization Puzzle

    NASA Astrophysics Data System (ADS)

    Karpiarz, Mariusz; Fronczak, Piotr; Fronczak, Agata

    2014-12-01

    Globalization is one of the central concepts of our age. The common perception of the process is that, due to declining communication and transport costs, distance becomes less and less important. However, the distance coefficient in the gravity model of trade, which grows in time, indicates that the role of distance increases rather than decreases. This, in essence, captures the notion of the globalization puzzle. Here, we show that the fractality of the international trade system (ITS) provides a simple solution for the puzzle. We argue that the distance coefficient corresponds to the fractal dimension of ITS. We provide two independent methods, the box counting method and spatial choice model, which confirm this statement. Our results allow us to conclude that the previous approaches to solving the puzzle misinterpreted the meaning of the distance coefficient in the gravity model of trade.

  1. International trade network: fractal properties and globalization puzzle.

    PubMed

    Karpiarz, Mariusz; Fronczak, Piotr; Fronczak, Agata

    2014-12-12

    Globalization is one of the central concepts of our age. The common perception of the process is that, due to declining communication and transport costs, distance becomes less and less important. However, the distance coefficient in the gravity model of trade, which grows in time, indicates that the role of distance increases rather than decreases. This, in essence, captures the notion of the globalization puzzle. Here, we show that the fractality of the international trade system (ITS) provides a simple solution for the puzzle. We argue that the distance coefficient corresponds to the fractal dimension of ITS. We provide two independent methods, the box counting method and spatial choice model, which confirm this statement. Our results allow us to conclude that the previous approaches to solving the puzzle misinterpreted the meaning of the distance coefficient in the gravity model of trade.

  2. The B → πK puzzle and supersymmetry

    NASA Astrophysics Data System (ADS)

    Imbeault, Maxime; Baek, Seungwon; London, David

    2008-06-01

    At present, there are discrepancies between the measurements of several observables in B → πK decays and the predictions of the Standard Model (the " B → πK puzzle"). Although the effect is not yet statistically significant-it is at the level of ≳ 3 σ-it does hint at the presence of new physics. In this Letter, we explore whether supersymmetry (SUSY) can explain the B → πK puzzle. In particular, we consider the SUSY model of Grossman, Neubert and Kagan (GNK). We find that it is extremely unlikely that GNK explains the B → πK data. We also find a similar conclusion in many other models of SUSY. And there are serious criticisms of the two SUSY models that do reproduce the B → πK data. If the B → πK puzzle remains, it could pose a problem for SUSY models.

  3. Molecular-level interactions of an azopolymer and poly(dodecylmethacrylate) in mixed Langmuir and Langmuir-Blodgett films for optical storage.

    PubMed

    Ceridório, Lucinéia F; Balogh, Débora T; Caseli, Luciano; Cardoso, Marcos R; Viitala, Tapani; Mendonça, Cleber R; Oliveira, Osvaldo N

    2010-06-01

    The applicability of azopolymers in optical storage can be extended through the use of nanostructured films produced with the Langmuir-Blodgett (LB) technique, but the film properties need to be optimized since these polymers generally do not form stable Langmuir films to be transferred onto solid substrates. Here, photoinduced birefringence was investigated for mixed Langmuir-Blodgett films from the homopolymers 4-[N-ethyl-N-(2-methacryloxyethyl)]-4'-nitroazobenzene (HPDR1-MA) and poly(dodecylmethacrylate) (HPDod-MA). The interactions between these polymers were studied in Langmuir and LB films. Surface pressure-area isotherms pointed to molecular-level interactions for proportions of 51 mf%, 41 mf% and 31 mf% of HPDR1-MA. Phase segregation was not apparent in the BAM images, in which the morphology of the blend film was clearly different from that of the Langmuir films of neat homopolymers. Through PM-IRRAS, we noted that the interaction between the azopolymer and HPDod-MA affected the orientation of carbonyl groups. Strong interactions for the mixture with 41 mf% of poly(dodecylmethacrylate) led to stable Langmuir films that were transferred onto solid supports as LB films. The photoinduced birefringence of 101-layer mixed LB films show features that make these films useful for optical storage, with the advantage of short writing times in comparison to other azopolymer films.

  4. Finding optimal solutions to the twenty-four puzzle

    SciTech Connect

    Korf, R.E.; Taylor, L.A.

    1996-12-31

    We have found the first optimal solutions to random instances of the Twenty-Four Puzzle, the 5 x 5 version of the well-known sliding-tile puzzles. Our new contribution to this problem is a more powerful admissible heuristic function. We present a general theory for the automatic discovery of such heuristics, which is based on considering multiple subgoals simultaneously. In addition, we apply a technique for pruning duplicate nodes in depth-first search using a finite-state machine. Finally, we observe that as heuristic search problems are scaled up, more powerful heuristic functions become both necessary and cost-effective.

  5. Heavy quarkonium: progress, puzzles, and opportunities

    NASA Astrophysics Data System (ADS)

    Brambilla, N.; Eidelman, S.; Heltsley, B. K.; Vogt, R.; Bodwin, G. T.; Eichten, E.; Frawley, A. D.; Meyer, A. B.; Mitchell, R. E.; Papadimitriou, V.; Petreczky, P.; Petrov, A. A.; Robbe, P.; Vairo, A.; Andronic, A.; Arnaldi, R.; Artoisenet, P.; Bali, G.; Bertolin, A.; Bettoni, D.; Brodzicka, J.; Bruno, G. E.; Caldwell, A.; Catmore, J.; Chang, C.-H.; Chao, K.-T.; Chudakov, E.; Cortese, P.; Crochet, P.; Drutskoy, A.; Ellwanger, U.; Faccioli, P.; Gabareen Mokhtar, A.; Garcia i Tormo, X.; Hanhart, C.; Harris, F. A.; Kaplan, D. M.; Klein, S. R.; Kowalski, H.; Lansberg, J.-P.; Levichev, E.; Lombardo, V.; Lourenço, C.; Maltoni, F.; Mocsy, A.; Mussa, R.; Navarra, F. S.; Negrini, M.; Nielsen, M.; Olsen, S. L.; Pakhlov, P.; Pakhlova, G.; Peters, K.; Polosa, A. D.; Qian, W.; Qiu, J.-W.; Rong, G.; Sanchis-Lozano, M. A.; Scomparin, E.; Senger, P.; Simon, F.; Stracka, S.; Sumino, Y.; Voloshin, M.; Weiss, C.; Wöhri, H. K.; Yuan, C.-Z.

    2011-02-01

    A golden age for heavy-quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the B-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations at BESIII, the LHC, RHIC, FAIR, the Super Flavor and/or Tau-Charm factories, JLab, the ILC, and beyond. The list of newly found conventional states expanded to include h c (1 P), χ c2(2 P), Bc+, and η b (1 S). In addition, the unexpected and still-fascinating X(3872) has been joined by more than a dozen other charmonium- and bottomonium-like " XYZ" states that appear to lie outside the quark model. Many of these still need experimental confirmation. The plethora of new states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of cbar{c}, bbar{b}, and bbar{c} bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. Lattice QCD has grown from a tool with computational possibilities to an industrial-strength effort now

  6. The puzzle of Freud's puzzle analogy: Reviving a struggle with doubt and conviction in Freud's Moses and monotheism.

    PubMed

    Blass, Rachel B

    2003-06-01

    In this paper the author points to a puzzle raised by Freud's contradictory use of an analogy of a jigsaw puzzle. She shows how, through the attempt to resolve this puzzle, meanings and implications of Freud's difficult struggle with his search for truth in Moses and monotheism come alive, both in Freud's writing and in the author herself. Central to this struggle is an encounter with the sources of doubt and conviction that ultimately allows one to embrace ideas experienced as true, although they are not demonstrable evidentially. The paper sheds light on the importance of Moses and monotheism as a theoretical text that reflects on developments in Freud's thinking on truth, and the possibility, dangers and inherent difficulties of grasping it.

  7. Crossword puzzles: self-learning tool in pharmacology.

    PubMed

    Gaikwad, Nitin; Tankhiwale, Suresh

    2012-12-01

    Students of the second professional MBBS course of the Indian medical curriculum (II MBBS) perceive pharmacology as a 'Volatile Subject' because they often find it difficult to remember and recall drug names. We evaluated the usefulness of crossword puzzles as a self-learning tool to help pharmacology students to remember drug names. We also measured the students' satisfaction with this learning method. This was an open-label randomized, two-arm intervention study, conducted with II MBBS students (n = 70), randomly selected and assigned to two groups A (n = 35) and B (n = 35). Two self-learning modules containing crossword puzzles with antihypertensive and antiepileptic drug terms were prepared and pre-validated. Hard copies of both crossword puzzles were administered to Group A (Intervention group) on two different occasions. One hour was allotted to solve a puzzle. Students were allowed to refer to their textbooks. Group B (Control group) underwent the self-learning module without the crossword puzzles. In both groups, pre- and post-test knowledge was assessed. Students' perceptions of the crossword puzzles were assessed using a pre-validated 10-item questionnaire. Responses to items 1-8 were recorded using a 5-point Likert scale. Responses to item 9 were recorded on a 10-point rating scale while item 10 was an open-ended question. The crossword completion index was 92.86 %. In group A, the average pre-test score was 6.09 whereas the average post-test score was 12.87 (p < 0.05). In group B, average pre- and post-test scores were 6.03 and 9.74, respectively. A significant difference (p < 0.001) was observed between the post-test scores of the two groups. The absolute learning gain was 33.9 % in Group A and 18.55 % in Group B. The response rate for the questionnaire was 100 %. Of the students, 71.43 % strongly agreed that crossword puzzles enhanced their knowledge of antihypertensive and antiepileptic drugs and were helpful for remembering and

  8. Energy Storage.

    ERIC Educational Resources Information Center

    Eaton, William W.

    Described are technological considerations affecting storage of energy, particularly electrical energy. The background and present status of energy storage by batteries, water storage, compressed air storage, flywheels, magnetic storage, hydrogen storage, and thermal storage are discussed followed by a review of development trends. Included are…

  9. OLYMPUS and the proton form factor puzzle

    NASA Astrophysics Data System (ADS)

    Ice, Lauren; Alarcon, Ricardo; Olympus Collaboration

    2012-02-01

    Recent measurements of the proton electric to magnetic form factor ratio using polarization techniques reveal a large discrepancy with measurements found using the Rosenbluth separation technique. It has been proposed that this discrepancy is due to a non-negligible multiple photon exchange contribution in the electron-proton elastic scattering cross section. The OLYMPUS experiment will measure the multiple photon exchange contribution by finding the cross section ratio of positron-proton to electron-proton scattering within 1%. The experiment will be carried out at the DESY laboratory in Hamburg Germany using the electron and positron storage ring DORIS and an internal unpolarized hydrogen gas target. The scattered particles will be detected using the Bates Large Acceptance Spectrometer Toroid (BLAST).

  10. The Potential of Crossword Puzzles in Aiding English Language Learners

    ERIC Educational Resources Information Center

    Merkel, Warren

    2016-01-01

    In an academic environment, teachers utilize crossword puzzles to help students learn or remember terminology. Outside the classroom, typically in daily newspapers, crosswords aid in vocabulary development, used as a learning tool, a leisure activity, or both. However, both the content and the grid structure of the crosswords in these two…

  11. Unraveling "Braid": Puzzle Games and Storytelling in the Imperative Mood

    ERIC Educational Resources Information Center

    Arnott, Luke

    2012-01-01

    "Unraveling Braid" analyzes how unconventional, non-linear narrative fiction can help explain the ways in which video games signify. Specifically, this essay looks at the links between the semiotic features of Jonathan Blow's 2008 puzzle-platform video game Braid and similar elements in Georges Perec's 1978 novel "Life A User's Manual," as well as…

  12. Using Building-Block Puzzles to Practice Drawing Organic Mechanisms

    ERIC Educational Resources Information Center

    Erdik, Ender

    2005-01-01

    A study uses a thought-provoking, pencil-and-paper activity to aid students in writing organic reaction mechanisms. Organic and functional groups that constitute the formulas of organic and inorganic reactants, ionic intermediates, and products are presented as building blocks, which must be placed correctly in a given puzzle so that they bind…

  13. To Txt or Not to Txt: That's the Puzzle

    ERIC Educational Resources Information Center

    Goh, Tiong-Thye; Hooper, Val

    2007-01-01

    This paper describes the potential use of a mobile phone Short Message Service (SMS) crossword puzzle system to promote interaction through learning activities in a large classroom environment. While personal response systems (PRS) have been used in the classroom environment to foster interaction, it is not an ideal tool with respect to cost and…

  14. A Geometric Puzzle That Leads To Fibonacci Sequences.

    ERIC Educational Resources Information Center

    Rulf, Benjamin

    1998-01-01

    Illustrates how mathematicians work and do mathematical research through the use of a puzzle. Demonstrates how general rules, then theorems develop from special cases. This approach may be used as a research project in high school classrooms or math club settings with the teacher helping to formulate questions, set goals, and avoid becoming…

  15. The Use of Word Puzzles in Teaching English

    ERIC Educational Resources Information Center

    Ridout, Ronald

    1977-01-01

    Word puzzles can be useful in FL teaching. They provide motivation. But they should be limited by the learner's linguistic competence, and should be carefully designed, with clear information, so as to create a high probability of successful solution. Method is discussed, using 3 examples. (IFS/WGA)

  16. A Jigsaw Puzzle Approach To Learning History in Introductory Psychology.

    ERIC Educational Resources Information Center

    Krauss, Judith

    1999-01-01

    Believes that it may be daunting for some students to learn about the history of psychology. Describes a teaching strategy that uses jigsaw puzzles to teach about the historical terms of structuralism, functionalism, and gestalt psychology. Finds that students performed better on test questions related to these three concepts after using this…

  17. Teaching Proofs and Algorithms in Discrete Mathematics with Online Visual Logic Puzzles

    ERIC Educational Resources Information Center

    Cigas, John; Hsin, Wen-Jung

    2005-01-01

    Visual logic puzzles provide a fertile environment for teaching multiple topics in discrete mathematics. Many puzzles can be solved by the repeated application of a small, finite set of strategies. Explicitly reasoning from a strategy to a new puzzle state illustrates theorems, proofs, and logic principles. These provide valuable, concrete…

  18. Update On the Puzzling Boyajian's Star

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-09-01

    Photometric time series for a neighboring star thats 25 NNW of Boyajians Star. No significant long-term dimming is seen which constrains the size of potential material obscuring Boyajians Star. [Wright et al. 2016/Benjamin Montet]Whats causing the mysterious light-curve dips of the so-called alien megastructure star, Boyajians Star? A recent study analyzes a variety of possible explanations to determine which ones are the most plausible.An Unusual Light CurveEarlier this year, astronomer Tabetha Boyajian reported on the unusual light curve of the star KIC 8462852. This star, now nicknamed Tabbys Star or Boyajians Star, showsunusual dips on day-long timescales that are too large to be explained by planet transits or similar phenomena.In addition to these short dips in luminosity, recent observations have also indicated that the star has faded by roughly 20% over the past hundred years. What could be causing both the short-term dips in the stars light and the long-term dimming over a century?Could the dimming be caused by an alien megastructure built by an extraterrestrial civilization? The authors find that a spherical structure is very unlikely. [Danielle Futselaar/SETI International]Alien Megastructures? Or Another Explanation?Boyajians Star was vaulted into the media spotlight when astronomer Jason Wright (Pennsylvania State University and University of California, Berkeley) proposed that its unusual light curve could potentially be explained by a surrounding megastructure built by an extraterrestrial civilization.Now Wright is back with co-author Steinn Sigurdsson (Pennsylvania State University). In a new study, Wright and Sigurdsson analyze an extensive list of explanations for the puzzling apparent behavior of Boyajians Star, based on our latest knowledge about this strange object.The Realm of PossibilitiesHere are just a few possible causes of Boyajians Stars dimming, as well as the authors assessment of their plausibility. For the full list, see the authors

  19. Optical disk archiving using a personal computer: a solution to image storage problems in diagnostic imaging departments.

    PubMed

    Parkin, A; Norwood, H; Erdentug, A; Hall, A J

    1990-01-01

    The paper describes an approach to solving the problem of providing a large-capacity image archive for diagnostic imaging departments at reasonable cost. Optical disk stores, when fitted retrospectively to scanners, are very expensive and may not be compatible with existing computer hardware. We describe the use of an industry standard personal computer (PC) linked to a standard 5 1/4-in. optical disk drive as a 'stand-alone' image store. Image data are transferred from the scanner using 8-in. floppy disks, and these are read into the PC using an attached 8-in. floppy disk drive and then transferred to the optical disk. The patient details (patient name, ID, date, etc.) are entered into a database program held on the PC and these are used to generate a reference pointer to the optical disk file through which the data can be retrieved. Data retrieval involves entering the patient details into the data base and inserting a blank 8-in. floppy disk into the drive attached to the PC. A sector copy is then made from the optical disk to the 8-in. floppy disk, which can then be used at the viewing station at the scanner. The system is flexible since it can accept data from a variety of sources in any format; it is also low cost and operates independently of the scanner. The hardware is industry standard, ensuring low maintenance costs.

  20. Five-membered rings as diazo components in optical data storage devices: an ab initio investigation of the lowest singlet excitation energies

    NASA Astrophysics Data System (ADS)

    Åstrand, Per-Olof; Sommer-Larsen, Peter; Hvilsted, Søren; Ramanujam, P. S.; Bak, Keld L.; Sauer, Stephan P. A.

    2000-07-01

    The two lowest singlet excitation energies of 18 azo dyes have been studied by ab initio quantum-chemical methods within the second-order polarization propagator approximation (SOPPA). Various combinations of five-membered rings (furan, thiophene, pyrrole, oxazole, thiazole, and imidazole) have been investigated as diazo components for a potential use in optical data storage materials. It is found that the diazo compounds with two heterocyclic five-membered rings have π→π ∗ excitation energies corresponding to laser wavelengths in the region 450-500 nm whereas one five-membered ring and a phenyl group as diazo components results in wavelengths in the region 400-435 nm.

  1. Storage Technology: Present and Future.

    ERIC Educational Resources Information Center

    Goldstein, Charles M.

    1984-01-01

    Reviews terminology inherent in discussing microcomputer storage technologies and addresses aspects of magnetic storage and present and near-future technologies, including floppy disks, Winchester and removable hard disks, optical digital disks, optical video disks, (audio) compact disks, perpendicular magnetic recording, and erasable optical…

  2. External insulation systems for cryogenic storage systems. Volume 1: Optical properties of Kapton and report of process variable study

    NASA Technical Reports Server (NTRS)

    Frank, A. M.

    1974-01-01

    Investigations are conducted into the optical properties of the glass and Kapton substrate materials, and three variables were chosen: deposition rate, sputter gas pressure, and film contamination time. Substrate tests have shown that fabrication of an dielectric broadband reflector would require an extremely complex and expensive filter design.

  3. Optical properties and storage capabilities in AB2O4:Cr3+ (A=Zn, Mg, B=Ga, Al)

    NASA Astrophysics Data System (ADS)

    Sharma, S. K.; Bessiere, A.; Gourier, D.; Sraiki, G.; Viana, B.; Dereń, P. J.; Rudnicka, D.; Watras, A.; Basavaraju, N.; Priolkar, K. R.; Maldiney, T.; Scherman, D.; Richard, C.

    2014-03-01

    Red emitting long-lasting phosphorescence (LLP) material, are useful biomarker for small animal in vivo imaging. We report here our investigations on the optical features of chromium doped AB2O4 spinels (A=Zn, Mg and B=Ga, Al…) suitable for such applications. It is possible to tune the emission wavelengths of Cr3+ by a crystal field variation to be well centered in the biological window and it is also possible to adjust the traps depth in order to better control the release of the traps. These traps are therefore stable at room temperature and could be emptied by thermal or near infrared source making this material a potential new photostimulated/optically compound. Photoluminescence (PL) and thermally stimulated luminescence (TSL) studies are reported.

  4. Synthesis of novel fluorene-based two-photon absorbing molecules and their applications in optical data storage, microfabrication, and stimulated emission depletion

    NASA Astrophysics Data System (ADS)

    Yanez, Ciceron

    2009-12-01

    Two-photon absorption (2PA) has been used for a number of scientific and technological applications, exploiting the fact that the 2PA probability is directly proportional to the square of the incident light intensity (while one-photon absorption bears a linear relation to the incident light intensity). This intrinsic property of 2PA leads to 3D spatial localization, important in fields such as optical data storage, fluorescence microscopy, and 3D microfabrication. The spatial confinement that 2PA enables has been used to induce photochemical and photophysical events in increasingly smaller volumes and allowed nonlinear, 2PA-based, technologies to reach sub-diffraction limit resolutions. The primary focus of this dissertation is the development of novel, efficient 2PA, fluorene-based molecules to be used either as photoacid generators (PAGs) or fluorophores. A second aim is to develop more effective methods of synthesizing these compounds. As a third and final objective, the new molecules were used to develop a write-once-read many (WORM) optical data storage system, and stimulated emission depletion probes for bioimaging. In Chapter I, the microwave-assisted synthesis of triarylsulfonium salt photoacid generators (PAGs) from their diphenyliodonium counterparts is reported. The microwave-assisted synthesis of these novel sulfonium salts afforded reaction times 90 to 420 times faster than conventional thermal conditions, with photoacid quantum yields of new sulfonium PAGs ranging from 0.01 to 0.4. These PAGs were used to develop a fluorescence readout-based, nonlinear three-dimensional (3D) optical data storage system (Chapter II). In this system, writing was achieved by acid generation upon two-photon absorption (2PA) of a PAG (at 710 or 730 nm). Readout was then performed by interrogating two-photon absorbing dyes, after protonation, at 860 nm. Two-photon recording and readout of voxels was demonstrated in five and eight consecutive, crosstalk-free layers within a

  5. Tetsuo Nozoe's Autograph Books: poems, puzzles and playfulness.

    PubMed

    Seeman, Jeffrey I

    2015-02-01

    The Nozoe Autograph Books contain entries from, literally, around the world of organic chemistry. Many of the inscriptions showed the poetic or even musical side of their signees. This Essay presents a diverse selection of the poetic entries of the autograph books, starting with a musical puzzle. This Essay and the interactive website that accompanies the Nozoe Autograph Book project are available free-access for at least a three-year period at http://www.tcr.wiley-vch.de/nozoe.

  6. High-energy cosmic neutrino puzzle: a review.

    PubMed

    Ahlers, Markus; Halzen, Francis

    2015-12-01

    We appraise the status of high-energy neutrino astronomy and summarize the observations that define the 'IceCube puzzle.' The observations are closing in on the source candidates that may contribute to the observation. We highlight the potential of multi-messenger analysis to assist in the identification of the sources. We also give a brief overview of future search strategies that include the realistic possibility of constructing a next-generation detector larger by one order of magnitude in volume.

  7. Puzzles about 1/8 magic doping in cuprate

    NASA Astrophysics Data System (ADS)

    Feng, D. L.; Shen, Z.-X.; Zhou, X. J.; Shen, K. M.; Lu, D. H.; Marel, D. V. D.

    2006-01-01

    We discuss the puzzles surrounding the interpretation of the 1/8 anomaly in cuprates, highlighting the tension between the real and reciprocal space ways to look at the problem. This issue is relevant to the current discussion on the nature of charge ordering in the form of ‘stripe’ and ‘checker-board’ as derived from neutron and STM experiments. A resolution of this tension is important to fully understand the electronic structure.

  8. Entanglement, teleportation, and single-photon storage with two-level atoms inside an optical parametric oscillator

    SciTech Connect

    Rice, Perry R.

    2005-07-01

    I consider several interesting aspects of a new light source, a two-level atom, or N two-level atoms inside an optical parametric oscillator. I find that in the weak driving limit, detection of a transmitted or fluorescent photon generates a highly entangled state of the atom and the cavity. This entanglement can be used with beam splitters to create more complex quantum states and implement teleportation protocols. Also, one can store a single photon in the atoms, along the lines of recent slow and stopped light proposals and experiments.

  9. Study of thermal effects and optical properties of an innovative absorber in integrated collector storage solar water heater

    NASA Astrophysics Data System (ADS)

    Taheri, Yaser; Alimardani, Kazem; Ziapour, Behrooz M.

    2015-10-01

    Solar passive water heaters are potential candidates for enhanced heat transfer. Solar water heaters with an integrated water tank and with the low temperature energy resource are used as the simplest and cheapest recipient devices of the solar energy for heating and supplying hot water in the buildings. The solar thermal performances of one primitive absorber were determined by using both the experimental and the simulation model of it. All materials applied for absorber such as the cover glass, the black colored sands and the V shaped galvanized plate were submerged into the water. The water storage tank was manufactured from galvanized sheet of 0.0015 m in thickness and the effective area of the collector was 0.67 m2. The absorber was installed on a compact solar water heater. The constructed flat-plate collectors were tested outdoors. However the simulation results showed that the absorbers operated near to the gray materials and all experimental results showed that the thermal efficiencies of the collector are over than 70 %.

  10. Emerging Network Storage Management Standards for Intelligent Data Storage Subsystems

    NASA Technical Reports Server (NTRS)

    Podio, Fernando; Vollrath, William; Williams, Joel; Kobler, Ben; Crouse, Don

    1998-01-01

    This paper discusses the need for intelligent storage devices and subsystems that can provide data integrity metadata, the content of the existing data integrity standard for optical disks and techniques and metadata to verify stored data on optical tapes developed by the Association for Information and Image Management (AIIM) Optical Tape Committee.

  11. Evaluation of the heat-storage capability of shallow aquifers using active heat tracer tests and Fiber-Optics Distributed-Temperature-Sensing

    NASA Astrophysics Data System (ADS)

    Suibert Oskar Seibertz, Klodwig; Chirila, Marian Andrei; Bumberger, Jan; Dietrich, Peter; Vienken, Thomas

    2015-04-01

    In the course of the energy transition, geothermal energy storage and heat generation and cooling have proven to be environmental friendly alternatives to conventional energy. However, to ensure sustain usage, the heat transport behavior of aquifers and its distribution has to be studied. A tool to achieve this is the active heat tracer test, eg. Leaf et al. (2012). If active heat tracer tests are combined with in aquifer heat testing via electric heating-cables, eg. Liu et al. (2013), it is possible to observe heat transport and temperature signal decay without disturbing the original pressure field within the aquifer. In this field study a two channel High-Resolution-Fiber-Optic-Distributed-Temperature-Sensing and Pt100 were used to measure temperature signals within in two wells of 1.4 m distance, where the temperature difference was generated using a self regulating heating cable in the upstream well. High resolution Distributed-Temperature-Sensing measurements were achieved by coiling the fiber around screened plastic tubes. The upstream well was also used to observe heating (Δ Tmax approx. 24K) and temperature signal decay, while the downstream well was used to observe heat transport between both wells. The data was analyzed and compared to thermal conductivity of soil samples and Direct-Push (DP) Electrical-Conductivity-Logging and DP Hydraulic-Profiling results. The results show good agreement between DP data and temperature measurements proving the active heat tracer test is a suitable tool for providing reliable information on aquifer heat-storage capability. References Leaf, A.T., Hart, D.J., Bahr, J.M.: Active Thermal Tracer Tests for Improved Hydrostratigraphic Characterization. Ground Water, vol. 50, 2012 Liu, G., Knobbe, S., Butler, J.J.Jr.: Resolving centimeter-scale flows in aquifers and their hydrostratigraphic controls. Geophysical Research Letters, vol. 40, 2013

  12. Crossword Puzzles as a Tool to Enhance Learning About Anti-Ulcer Agents

    PubMed Central

    Lynch, Launa M. J.; Macias-Moriarity, Lilia Z.

    2010-01-01

    Objective To design, implement, and evaluate the use of crossword puzzles as a low-stakes educational tool for enhancing learning about anti-ulcer agents. Design Crossword puzzles were created using a free Internet resource and administered to students during 3 consecutive lectures covering the pharmacology and medicinal chemistry of anti-ulcer agents. Student perceptions of the crossword puzzle were examined using an 8-item survey instrument. Assessment Over 90% of students indicated that crossword puzzles enhanced their learning, oriented them to the important topics, and served as good reviews of the lecture material. Conclusion Students perceived that crossword puzzles enhanced their learning of anti-ulcer agents. Use of crossword puzzles provides a simple and creative way to incorporate active learning into pharmacy classroom instruction. PMID:21088722

  13. Strategies and correlates of jigsaw puzzle and visuospatial performance by persons with Prader-Willi syndrome.

    PubMed

    Verdine, Brian N; Troseth, Georgene L; Hodapp, Robert M; Dykens, Elisabeth M

    2008-09-01

    Some individuals with Prader-Willi syndrome exhibit strengths in solving jigsaw puzzles. We compared visuospatial ability and jigsaw puzzle performance and strategies of 26 persons with Prader-Willi syndrome and 26 MA-matched typically developing controls. Individuals with Prader-Willi syndrome relied on piece shape. Those in the control group used a different, picture-focused strategy. Individuals with Prader-Willi syndrome performed better than did the control group on an achromatic interlocking puzzle, whereas scores on puzzles with pictures (interlocking or noninterlocking) did not differ. Visuospatial scores related to performance on all puzzles in the control group and on the noninterlocking puzzle in the Prader-Willi syndrome group. The most proficient jigsaw puzzlers with Prader-Willi syndrome tended to be older and have shape-based strategies.

  14. Storage and retrieval of SNOP-coded pathologic diagnoses using offsite computing and optical character recognizing systems.

    PubMed

    Cechner, R L; Carter, J R

    1976-05-01

    A computerized cross-reference system for retrieving autopsy and surgical pathology cases on the basis of case number or diagnosis has been implemented. The system achieves economy and flexibility by using offsite computer service bureaus for job production, eliminating the need for expensive onsite equipment. Coded diagnoses may be typed using the OCR (Optical Character Recognition) font simultaneously with or separately from the clinical documentation. The flexibility of new OCR equipment permits production of machine-readable code sheets with an ordinary pencil and completely eliminates the need for typing. The system produces year-to-date books that list all diagnoses, on an accumulating basis, in alphabetic order by SNOP* topology, morphology, etiology and function, and will be compatible with SNOMed. Because all data are stored on magnetic tape, they may be manipulated and retrieved as desired through user programming. The initial setup cost was dollar 1,000 for programming and testing, and production runs and all report printing cost about dollar 1,000 per year (autopsies and surgical pathology cases), which is about 1.1 cents per diagnosis.

  15. Toward a resolution of the proton size puzzle

    SciTech Connect

    Miller, G. A.; Thomas, A. W.; Carroll, J. D.; Rafelski, J.

    2011-08-15

    We show that off-mass-shell effects arising from the internal structure of the proton provide a new proton polarization mechanism in the Lamb shift, proportional to the lepton mass to the fourth power. This effect is capable of resolving the current puzzle regarding the difference in the proton radius extracted from muonic compared with electronic hydrogen experiments. These off-mass-shell effects could be probed in several other experiments. A significant ambiguity appearing in dispersion relation evaluations of the proton polarizability contribution to the Lamb shift is noted.

  16. The Puzzle of a Marble in a Spinning Pipe

    DTIC Science & Technology

    2015-05-01

    MAY 2015 2. REPORT TYPE 3. DATES COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE The Puzzle of a Marble in a Spinning Pipe 5a. CONTRACT...Approved for public release; distribution unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT What trajectory does a marble follow if it is held...298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 Physics Education 50 (3) 279 1. Problem statement A marble is placed one-third of the length along a

  17. Tiny bubbles challenge giant turbines: Three Gorges puzzle.

    PubMed

    Li, Shengcai

    2015-10-06

    Since the birth of the first prototype of the modern reaction turbine, cavitation as conjectured by Euler in 1754 always presents as a challenge. Following his theory, the evolution of modern reaction (Francis and Kaplan) turbines has been completed by adding the final piece of the element 'draft-tube' that enables turbines to explore water energy at efficiencies of almost 100%. However, during the last two and a half centuries, with increasing unit capacity and specific speed, the problem of cavitation has been manifested and complicated by the draft-tube surges rather than being solved. Particularly, during the last 20 years, the fierce competition in the international market for extremely large turbines with compact design has encouraged the development of giant Francis turbines of 700-1000 MW. The first group (24 units) of such giant turbines of 700 MW each was installed in the Three Gorges project. Immediately after commission, a strange erosion phenomenon appeared on the guide vane of the machines that has puzzled professionals. From a multi-disciplinary analysis, this Three Gorges puzzle could reflect an unknown type of cavitation inception presumably triggered by turbulence production from the boundary-layer streak transitional process. It thus presents a fresh challenge not only to this old turbine industry, but also to the fundamental sciences.

  18. Tiny bubbles challenge giant turbines: Three Gorges puzzle

    PubMed Central

    Li, Shengcai

    2015-01-01

    Since the birth of the first prototype of the modern reaction turbine, cavitation as conjectured by Euler in 1754 always presents as a challenge. Following his theory, the evolution of modern reaction (Francis and Kaplan) turbines has been completed by adding the final piece of the element ‘draft-tube’ that enables turbines to explore water energy at efficiencies of almost 100%. However, during the last two and a half centuries, with increasing unit capacity and specific speed, the problem of cavitation has been manifested and complicated by the draft-tube surges rather than being solved. Particularly, during the last 20 years, the fierce competition in the international market for extremely large turbines with compact design has encouraged the development of giant Francis turbines of 700–1000 MW. The first group (24 units) of such giant turbines of 700 MW each was installed in the Three Gorges project. Immediately after commission, a strange erosion phenomenon appeared on the guide vane of the machines that has puzzled professionals. From a multi-disciplinary analysis, this Three Gorges puzzle could reflect an unknown type of cavitation inception presumably triggered by turbulence production from the boundary-layer streak transitional process. It thus presents a fresh challenge not only to this old turbine industry, but also to the fundamental sciences. PMID:26442144

  19. Three Puzzles in Galactic Extra-planar H I

    NASA Astrophysics Data System (ADS)

    Lockman, F. J.

    2012-09-01

    Many phenomena first detected in Galactic H i, such as high velocity clouds and gaseous warps, have now been detected and studied in nearby galaxies. Given this valuable perspective I examine three aspects of Galactic extra-planar gas that appear somewhat puzzling from our vantage in the Milky Way disk. I. Spiral galaxies have a rotation curve that decreases with distance above their mid-plane; where is the lagging halo in the Milky Way? II. Other systems show clear evidence for accretion of neutral gas; where is this gas in the Milky Way? III. Warps of the H i layer are common in the outskirts of disk galaxies; are we confident that we've correctly parameterized our own warp? The answers appear to be that lagging halo gas could well be present in the Galaxy but would be difficult to detect; that there is now solid evidence for the accretion of high-velocity H i clouds by the disk, though the details are still mysterious, and that the warp continues to baffle us, as it exhibits a puzzling morphology and kinematics.

  20. An ecological examination of rapport using a dyadic puzzle task.

    PubMed

    Grahe, Jon E; Sherman, Ryne A

    2007-10-01

    Previous studies have indicated that situational context impacts the rapport experience (e.g., F. J. Bernieri, J. S. Gillis, J. M. Davis, & J. E. Grahe, 1996; N. M. Puccinelli, L. Tickle-Degnen, & R. Rosenthal, 2003). The authors designed the present study to further document the behavioral and experiential predictors of dyadic rapport and to evaluate dyadic rapport experiences when contributions were required from both interactants. Participants (N = 60) were paired into dyads and instructed to complete children's puzzles. However, the dyadic members were restricted in how they could accomplish this task: Only one interactant was allowed to work on the puzzle and had to do so blindfolded, while the second interactant gave instructions. Results suggested that less attribution of responsibility to the worker and the instructor's experience of enjoyment and frustration were indicative of higher rapport. Other characteristics of dyads reporting higher dyadic rapport included difficulty completing the task and more communicative behavior. The results provide important information for the understanding of the dyadic experience of rapport.

  1. Yet another possible explanation of the solar-neutrino puzzle

    SciTech Connect

    Kolb, E.W.; Turner, M.S.; Walker, T.P.

    1986-04-01

    Mikheyev and Smirnov have shown that the interactions of neutrinos with matter can result in the conversion of electron neutrinos produced in the center of the sun to muon neutrinos. Bethe has exploited this and has pointed out that the solar-neutrino puzzle can be resolved if the mass difference squared of the two neutrinos is m/sub 2//sup 2/ - m /sub 1//sup 2/ approx. = 6 x 10/sup -5/ eV/sup 2/, and the mixing angle satisfies sin theta/sub v/ > 0.0065. We discuss a qualitatively different solution to the solar-neutrino puzzle which requires 1.0 x 10/sup -8/ < (m/sub 2//sup 2/ - m/sub 1//sup 2/) (sin/sup 2/ 2theta/sub v//cos 2theta/sub v/) < 6.1 x 10/sup -8/ eV/sup 2/. Our solutions result in a much smaller flux of neutrinos from the p - p process than predicted by standard solar models, while Bethe's solution results in a flux of neutrinos from the p - process that is about the same as standard solar models.

  2. The puzzling unsolved mysteries of liquid water: Some recent progress

    NASA Astrophysics Data System (ADS)

    Stanley, H. E.; Kumar, P.; Xu, L.; Yan, Z.; Mazza, M. G.; Buldyrev, S. V.; Chen, S.-H.; Mallamace, F.

    2007-12-01

    Water is perhaps the most ubiquitous, and the most essential, of any molecule on earth. Indeed, it defies the imagination of even the most creative science fiction writer to picture what life would be like without water. Despite decades of research, however, water's puzzling properties are not understood and 63 anomalies that distinguish water from other liquids remain unsolved. We introduce some of these unsolved mysteries, and demonstrate recent progress in solving them. We present evidence from experiments and computer simulations supporting the hypothesis that water displays a special transition point (which is not unlike the “tipping point” immortalized by Malcolm Gladwell). The general idea is that when the liquid is near this “tipping point,” it suddenly separates into two distinct liquid phases. This concept of a new critical point is finding application to other liquids as well as water, such as silicon and silica. We also discuss related puzzles, such as the mysterious behavior of water near a protein.

  3. The King and Prisoner Puzzle: A Way of Introducing the Components of Logical Structures

    ERIC Educational Resources Information Center

    Roh, Kyeong Hah; Lee, Yong Hah; Tanner, Austin

    2016-01-01

    The purpose of this paper is to provide issues related to student understanding of logical components that arise when solving word problems. We designed a logic problem called the King and Prisoner Puzzle--a linguistically simple, yet logically challenging problem. In this paper, we describe various student solutions to the puzzle and discuss the…

  4. A Teacher's Ready-to-Use Packet of General Business Subjects Crossword Puzzles.

    ERIC Educational Resources Information Center

    Yacyk, Peter

    Eleven crossword puzzles, designed to give the student practice with the correct spelling and usage of those words needed to indicate his mastery of the concepts and understandings taught in business courses, are contained, with answer keys, in a teacher's packet. Any puzzle can be reproduced by ditto or by transparency for classroom use. There is…

  5. Two-Dimensional Parson's Puzzles: The Concept, Tools, and First Observations

    ERIC Educational Resources Information Center

    Ihantola, Petri; Karavirta, Ville

    2011-01-01

    Parson's programming puzzles are a family of code construction assignments where lines of code are given, and the task is to form the solution by sorting and possibly selecting the correct code lines. We introduce a novel family of Parson's puzzles where the lines of code need to be sorted in two dimensions. The vertical dimension is used to order…

  6. Crossword Puzzle Makes It Fun: Introduce Green Manufacturing in Wood Technology Courses

    ERIC Educational Resources Information Center

    Iley, John L.; Hague, Doug

    2012-01-01

    Sustainable, or "green," manufacturing and its practices are becoming more and more a part of today's industry, including wood product manufacturing. This article provides introductory information on green manufacturing in wood technology and a crossword puzzle based on green manufacturing terms. The authors use the puzzle at the college level to…

  7. An Alternative Evaluation: Online Puzzle as a Course-End Activity

    ERIC Educational Resources Information Center

    Genç, Zülfü; Aydemir, Emrah

    2015-01-01

    Purpose: The purpose of this study is to determine whether the use of online puzzles in the instructional process has an effect on student achievement and learning retention. This study examined students ' perception and experiences on use of puzzle as an alternative evaluation tool. To achieve this aim, the following hypotheses were tested: using…

  8. Strategies and Correlates of Jigsaw Puzzle and Visuospatial Performance by Persons with Prader-Willi Syndrome

    ERIC Educational Resources Information Center

    Verdine, Brian N.; Troseth, Georgene L.; Hodapp, Robert M.; Dykens, Elisabeth M.

    2008-01-01

    Some individuals with Prader-Willi syndrome exhibit strengths in solving jigsaw puzzles. We compared visuospatial ability and jigsaw puzzle performance and strategies of 26 persons with Prader-Willi syndrome and 26 MA-matched typically developing controls. Individuals with Prader-Willi syndrome relied on piece shape. Those in the control group…

  9. Using the Tower of Hanoi Puzzle to Infuse Your Mathematics Classroom with Computer Science Concepts

    ERIC Educational Resources Information Center

    Marzocchi, Alison S.

    2016-01-01

    This article suggests that logic puzzles, such as the well-known Tower of Hanoi puzzle, can be used to introduce computer science concepts to mathematics students of all ages. Mathematics teachers introduce their students to computer science concepts that are enacted spontaneously and subconsciously throughout the solution to the Tower of Hanoi…

  10. Alliteration in medicine: a puzzling profusion of p's

    PubMed Central

    Hayden, Gregory F

    1999-01-01

    Problem Puzzling, progressive profusion of alliterative “p's” in published papers. Purpose To depict this particular “p” predominance with pinpoint precision. Plan Periodic, painstaking perusal of periodicals by a professor of paediatrics. Proposal The “p” plethora is positively perplexing and potentially perturbing. Alliteration is a literary device consisting of repetition of the same starting sound in several words in a sentence.1 Consider, for example, Shakespeare's playful parody of alliteration in Peter Quince's prologue in A Midsummer Night's Dream: “Whereat with blade, with bloody blameful blade, He bravely broach'd his boiling bloody breast.” Alliteration has appeared frequently in the medical literature—for example: “Respiratory syncytial virus—from chimps with colds to conundrums and cures;”2 “The choreas: of faints, fevers, and families;”3 “Coronary artery stents—gauging, gorging, and gouging;”4 “Moschcowitz, multimers, and metalloprotease;”5 “Alagille syndrome: a nutritional niche for Notch;”6 “Theodor Billroth: success with sutures and strings.”7 Perusing the medical literature with alliteration in mind, I have become perplexed by a peculiar propensity for the letter “p” to be placed in prominent positions. Consider for a moment the alliterative content of the BMJ, a prestigious periodical also published in Pakistani, Polish, and Portuguese. Perhaps the prime example is a piece entitled “A potpourri of parasites in poetry and proverb,”8 but the journal has presented articles addressing such topics as paracetamol poisoning,9 practitioners' pressure to prescribe,10 physicians' partnerships with patients,11 partnerships for prevention in public playgrounds,12 and pregnancy outcomes which have been persistently poor.13 Other topics have included patients' priorities,14 the political process of puzzling out private versus public priorities,15 and the ponderous problem of whether the priorities in

  11. Energy storage

    NASA Astrophysics Data System (ADS)

    Kaier, U.

    1981-04-01

    Developments in the area of energy storage are characterized, with respect to theory and laboratory, by an emergence of novel concepts and technologies for storing electric energy and heat. However, there are no new commercial devices on the market. New storage batteries as basis for a wider introduction of electric cars, and latent heat storage devices, as an aid for solar technology applications, with satisfactory performance standards are not yet commercially available. Devices for the intermediate storage of electric energy for solar electric-energy systems, and for satisfying peak-load current demands in the case of public utility companies are considered. In spite of many promising novel developments, there is yet no practical alternative to the lead-acid storage battery. Attention is given to central heat storage for systems transporting heat energy, small-scale heat storage installations, and large-scale technical energy-storage systems.

  12. Gaia's view of the λ Boo star puzzle

    NASA Astrophysics Data System (ADS)

    Murphy, Simon J.; Paunzen, Ernst

    2017-04-01

    The evolutionary status of the chemically peculiar class of λ Boo stars has been intensely debated. It is now agreed that the λ Boo phenomenon affects A stars of all ages, from star formation to the terminal age main sequence, but the cause of the chemical peculiarity is still a puzzle. We revisit the debate of their ages and temperatures in order to shed light on the phenomenon, using the new parallaxes in Gaia Data Release 1 with existing Hipparcos parallaxes and multicolour photometry. We find that no single formation mechanism is able to explain all the observations, and suggest that there are multiple channels producing λ Boo spectra. The relative importance of these channels varies with age, temperature and environment.

  13. Peelle's pertinent puzzle using the Monte Carlo technique

    SciTech Connect

    Kawano, Toshihiko; Talou, Patrick; Burr, Thomas; Pan, Feng

    2009-01-01

    We try to understand the long-standing problem of the Peelle's Pertinent Puzzle (PPP) using the Monte Carlo technique. We allow the probability density functions to be any kind of form to assume the impact of distribution, and obtain the least-squares solution directly from numerical simulations. We found that the standard least squares method gives the correct answer if a weighting function is properly provided. Results from numerical simulations show that the correct answer of PPP is 1.1 {+-} 0.25 if the common error is multiplicative. The thought-provoking answer of 0.88 is also correct, if the common error is additive, and if the error is proportional to the measured values. The least squares method correctly gives us the most probable case, where the additive component has a negative value. Finally, the standard method fails for PPP due to a distorted (non Gaussian) joint distribution.

  14. Resolution to the B{yields}{pi}K puzzle

    SciTech Connect

    Li Hsiangnan; Mishima, Satoshi; Sanda, A.I.

    2005-12-01

    We calculate the important next-to-leading-order contributions to the B{yields}{pi}K, {pi}{pi} decays from the vertex corrections, the quark loops, and the magnetic penguins in the perturbative QCD approach. It is found that the latter two reduce the leading-order penguin amplitudes by about 10% and modify only the B{yields}{pi}K branching ratios. The main effect of the vertex corrections is to increase the small color-suppressed tree amplitude by a factor of 3, which then resolves the large difference between the direct CP asymmetries of the B{sup 0}{yields}{pi}{sup {+-}}K{sup {+-}} and B{sup {+-}}{yields}{pi}{sup 0}K{sup {+-}} modes. The puzzle from the large B{sup 0}{yields}{pi}{sup 0}{pi}{sup 0} branching ratio still remains.

  15. A Jigsaw Puzzle Layer Cake of Spatial Data

    NASA Astrophysics Data System (ADS)

    Ma, Xiaogang; Fox, Peter

    2014-05-01

    The Infrastructure for Spatial Information in Europe (INSPIRE; http://inspire.jrc.ec.europa.eu) is a European Union (EU) directive that aims to provide a legal framework to share environmental spatial data among public sector organizations across Europe and to facilitate public access to data. To meet these goals, INSPIRE's organization is analogous to a layer cake in which each layer is composed of interlocking pieces of a jigsaw puzzle. The metaphor, although mixed, is apt (see additional supporting information in the online version of this article), and as researchers outside the program, we offer our perspective on how INSPIRE may address challenges raised by the variety of data themes and the wide coverage of collaborators.

  16. The puzzling reliability of the Force Concept Inventory

    NASA Astrophysics Data System (ADS)

    Lasry, Nathaniel; Rosenfield, Steven; Dedic, Helena; Dahan, Ariel; Reshef, Orad

    2011-09-01

    The Force Concept Inventory (FCI) has influenced the development of many research-based pedagogies. However, no data exists on the FCI's internal consistency or test-retest reliability. The FCI was administered twice to one hundred students during the first week of classes in an electricity and magnetism course with no review of mechanics between test administrations. High Kuder-Richardson reliability coefficient values, which estimate the average correlation of scores obtained on all possible halves of the test, suggest strong internal consistency. However, 31% of the responses changed from test to retest, suggesting weak reliability for individual questions. A chi-square analysis shows that change in responses was neither consistent nor completely random. The puzzling conclusion is that although individual FCI responses are not reliable, the FCI total score is highly reliable.

  17. Data storage technology comparisons

    NASA Technical Reports Server (NTRS)

    Katti, Romney R.

    1990-01-01

    The role of data storage and data storage technology is an integral, though conceptually often underestimated, portion of data processing technology. Data storage is important in the mass storage mode in which generated data is buffered for later use. But data storage technology is also important in the data flow mode when data are manipulated and hence required to flow between databases, datasets and processors. This latter mode is commonly associated with memory hierarchies which support computation. VLSI devices can reasonably be defined as electronic circuit devices such as channel and control electronics as well as highly integrated, solid-state devices that are fabricated using thin film deposition technology. VLSI devices in both capacities play an important role in data storage technology. In addition to random access memories (RAM), read-only memories (ROM), and other silicon-based variations such as PROM's, EPROM's, and EEPROM's, integrated devices find their way into a variety of memory technologies which offer significant performance advantages. These memory technologies include magnetic tape, magnetic disk, magneto-optic disk, and vertical Bloch line memory. In this paper, some comparison between selected technologies will be made to demonstrate why more than one memory technology exists today, based for example on access time and storage density at the active bit and system levels.

  18. Striped tertiary storage arrays

    NASA Technical Reports Server (NTRS)

    Drapeau, Ann L.

    1993-01-01

    Data stripping is a technique for increasing the throughput and reducing the response time of large access to a storage system. In striped magnetic or optical disk arrays, a single file is striped or interleaved across several disks; in a striped tape system, files are interleaved across tape cartridges. Because a striped file can be accessed by several disk drives or tape recorders in parallel, the sustained bandwidth to the file is greater than in non-striped systems, where access to the file are restricted to a single device. It is argued that applying striping to tertiary storage systems will provide needed performance and reliability benefits. The performance benefits of striping for applications using large tertiary storage systems is discussed. It will introduce commonly available tape drives and libraries, and discuss their performance limitations, especially focusing on the long latency of tape accesses. This section will also describe an event-driven tertiary storage array simulator that is being used to understand the best ways of configuring these storage arrays. The reliability problems of magnetic tape devices are discussed, and plans for modeling the overall reliability of striped tertiary storage arrays to identify the amount of error correction required are described. Finally, work being done by other members of the Sequoia group to address latency of accesses, optimizing tertiary storage arrays that perform mostly writes, and compression is discussed.

  19. Optical Digital Image Storage System

    DTIC Science & Technology

    1991-03-18

    Reading Room which is not 12X or 24X. NARA has a Minolta microfilm reader printer with a 17X lens, but this machine is an outmoded electrostatic wet ...melting point, and is not susceptible to oxidation . A protective layer and adhesive layer are next. A disk is really two disks that are glued together to...lioer travels along the track at a certain rate looking for its reflection (see Figure A-18). Whei it encounters a hole or a blister, the beam is

  20. Genome puzzle master (GPM): an integrated pipeline for building and editing pseudomolecules from fragmented sequences

    PubMed Central

    Zhang, Jianwei; Kudrna, Dave; Mu, Ting; Li, Weiming; Copetti, Dario; Yu, Yeisoo; Goicoechea, Jose Luis; Lei, Yang; Wing, Rod A.

    2016-01-01

    Motivation: Next generation sequencing technologies have revolutionized our ability to rapidly and affordably generate vast quantities of sequence data. Once generated, raw sequences are assembled into contigs or scaffolds. However, these assemblies are mostly fragmented and inaccurate at the whole genome scale, largely due to the inability to integrate additional informative datasets (e.g. physical, optical and genetic maps). To address this problem, we developed a semi-automated software tool—Genome Puzzle Master (GPM)—that enables the integration of additional genomic signposts to edit and build ‘new-gen-assemblies’ that result in high-quality ‘annotation-ready’ pseudomolecules. Results: With GPM, loaded datasets can be connected to each other via their logical relationships which accomplishes tasks to ‘group,’ ‘merge,’ ‘order and orient’ sequences in a draft assembly. Manual editing can also be performed with a user-friendly graphical interface. Final pseudomolecules reflect a user’s total data package and are available for long-term project management. GPM is a web-based pipeline and an important part of a Laboratory Information Management System (LIMS) which can be easily deployed on local servers for any genome research laboratory. Availability and Implementation: The GPM (with LIMS) package is available at https://github.com/Jianwei-Zhang/LIMS Contacts: jzhang@mail.hzau.edu.cn or rwing@mail.arizona.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:27318200

  1. Optical energy storage and reemission based weak localization of light and accompanying random lasing action in disordered Nd{sup 3+} doped (Pb, La)(Zr, Ti)O{sub 3} ceramics

    SciTech Connect

    Xu, Long; Zhao, Hua; Xu, Caixia; Zhang, Siqi; Zhang, Jingwen

    2014-08-14

    Multi-mode random lasing action and weak localization of light were evidenced and studied in normally transparent but disordered Nd{sup 3+} doped (Pb,La)(Zr,Ti)O{sub 3} ceramics. Noticeable localized zone and multi-photon process were observed under strong pumping power. A tentative phenomenological physical picture was proposed by taking account of diffusive process, photo-induced scattering, and optical energy storage process as dominant factors in elucidating the weak localization of light observed. Both the decreased transmittance (increased reflectivity) of light and the observed long lasting fading-off phenomenon supported the physical picture proposed by us.

  2. Fibromyalgia: A Puzzling and Painful Condition | NIH MedlinePlus the Magazine

    MedlinePlus

    ... of this page please turn JavaScript on. Feature: Fibromyalgia Fibromyalgia: A Puzzling and Painful Condition Past Issues / Spring ... or internal organs. Wise Choices: Feeling Better with Fibromyalgia Get enough sleep. Getting the right kind of ...

  3. A Play on Words: Using Cognitive Computing as a Basis for AI Solvers in Word Puzzles

    NASA Astrophysics Data System (ADS)

    Manzini, Thomas; Ellis, Simon; Hendler, James

    2015-12-01

    In this paper we offer a model, drawing inspiration from human cognition and based upon the pipeline developed for IBM's Watson, which solves clues in a type of word puzzle called syllacrostics. We briefly discuss its situation with respect to the greater field of artificial general intelligence (AGI) and how this process and model might be applied to other types of word puzzles. We present an overview of a system that has been developed to solve syllacrostics.

  4. Mitigating Distributed Denial of Service Attacks in an Anonymous Routing Environment: Client Puzzles and Tor

    DTIC Science & Technology

    2006-03-01

    by a distributed system like Tor. The protocol must account for Tor’s threat environment and also address any secondary DDoS or anonymity attacks...Mitigating Distributed Denial of Service Attacks in an Anonymous Routing Environment: Client Puzzles and Tor THESIS Nicholas A. Fraser, Captain, USAF... Anonymous Routing Environment: Client Puzzles and Tor THESIS Presented to the Faculty Department of Electrical and Computer Engineering Graduate

  5. The 30Mg(t ,p )32Mg "puzzle" reexamined

    NASA Astrophysics Data System (ADS)

    Macchiavelli, A. O.; Crawford, H. L.; Campbell, C. M.; Clark, R. M.; Cromaz, M.; Fallon, P.; Jones, M. D.; Lee, I. Y.; Salathe, M.; Brown, B. A.; Poves, A.

    2016-11-01

    Background: Competing interpretations of the results of a 30Mg(t ,p )32Mg measurement populating the ground state and 02+ state in 32Mg, both limited to a two-state mixing description, have left an open question regarding the nature of the 32Mg ground state. Purpose: Inspired by recent shell-model calculations, we explore the possibility of a consistent interpretation of the available data for the low-lying 0+ states in 32Mg by expanding the description from two-level to three-level mixing. Methods: A phenomenological three-level mixing model of unperturbed 0p0h, 2p2h, and 4p4h states is applied to describe both the excitation energies in 32Mg and the transfer reaction cross sections. Results: Within this approach, self-consistent solutions exist that provide good agreement with the available experimental information obtained from the 30Mg(t ,p )32Mg reaction. Conclusion: The inclusion of the third state, namely the 4p4h configuration, resolves the "puzzle" that results from a two-levelmodel interpretation of the same data. In our analysis, the 32Mg ground state emerges naturally as dominated by intruder (2p2h and 4p4h) configurations, at the 95% level.

  6. Graphene spintronics: puzzling controversies and challenges for spin manipulation

    NASA Astrophysics Data System (ADS)

    Roche, Stephan; Valenzuela, Sergio O.

    2014-03-01

    This article presents the current puzzling controversy between theory and experimental results concerning the mechanisms leading to spin relaxation in graphene-based materials. On the experimental side, it is surprising that regardless of the quality of the graphene monolayer, which is characterized by the carrier mobility, the typical Hanle precession measurements yield spin diffusion times (τs) in the order of τs ˜ 0.1-1 ns (at low temperatures), which is several orders of magnitude below the theoretical estimates based on the expected low intrinsic spin-orbit coupling in graphene. The results are weakly dependent on whether graphene is deposited onto SiO2 or boron-nitride substrates or is suspended, with the mobility spanning 3 orders of magnitude. On the other hand, extraction form two-terminal magnetoresistance measurements, accounting for contact effects results in τs ˜ 0.1 µs, and corresponding diffusion lengths of about 100 µm up to room temperature. Such discrepancy jeopardizes further progress towards spin manipulation on a lateral graphene two-dimensional platform. After a presentation of basic concepts, we here discuss state-of-the-art literature and the limits of all known approaches to describe spin transport in massless-Dirac fermions, in which the effects of strong local spin-orbit coupling ceases to be accessible with perturbative approaches. We focus on the limits of conventional views of spin transport in graphene and offer novel perspectives for further progress.

  7. Desiccation tolerance of Sphagnum revisited: a puzzle resolved.

    PubMed

    Hájek, T; Vicherová, E

    2014-07-01

    As ecosystem engineers, Sphagnum mosses control their surroundings through water retention, acidification and peat accumulation. Because water retention avoids desiccation, sphagna are generally intolerant to drought; however, the literature on Sphagnum desiccation tolerance (DT) provides puzzling results, indicating the inducible nature of their DT. To test this, various Sphagnum species and other mesic bryophytes were hardened to drought by (i) slow drying; (ii) ABA application and (iii) chilling or frost. DT tolerance was assessed as recovery of chlorophyll fluorescence parameters after severe desiccation. We monitored the seasonal course of DT in bog bryophytes. Under laboratory conditions, following initial de-hardening, untreated Sphagnum shoots lacked DT; however, DT was induced by all hardening treatments except chilling, notably by slow drying, and in Sphagnum species of the section Cuspidata. In the field, sphagna in hollows and lawns developed DT several times during the growing season, responding to reduced precipitation and a lowered water table. Hummock and aquatic species developed DT only in late autumn, probably as a response to frost. Sphagnum protonemata failed to develop DT; hence, desiccation may limit Sphagnum establishment in drier habitats with suitable substrate chemistry. Desiccation avoiders among sphagna form compact hummocks or live submerged; thus, they do not develop DT in the field, lacking the initial desiccation experience, which is frequent in hollow and lawn habitats. We confirmed the morpho-physiological trade-off: in contrast to typical hollow sphagna, hummock species invest more resources in water retention (desiccation avoidance), while they have a lower ability to develop physiological DT.

  8. The Puzzling Case of Hyperexcitability in Amyotrophic Lateral Sclerosis

    PubMed Central

    Bae, Jong Seok; Simon, Neil G.; Menon, Parvathi; Vucic, Steve

    2013-01-01

    The development of hyperexcitability in amyotrophic lateral sclerosis (ALS) is a well-known phenomenon. Despite controversy as to the underlying mechanisms, cortical hyperexcitability appears to be closely related to the interplay between excitatory corticomotoneurons and inhibitory interneurons. Hyperexcitability is not a static phenomenon but rather shows a pattern of progression in a spatiotemporal aspect. Cortical hyperexcitability may serve as a trigger to the development of anterior horn cell degeneration through a 'dying forward' process. Hyperexcitability appears to develop during the early disease stages and gradually disappears in the advanced stages of the disease, linked to the destruction of corticomotorneuronal pathways. As such, a more precise interpretation of these unique processes may provide new insight regarding the pathophysiology of ALS and its clinical features. Recently developed technologies such as threshold tracking transcranial magnetic stimulation and automated nerve excitability tests have provided some clues about underlying pathophysiological processes linked to hyperexcitability. Additionally, these novel techniques have enabled clinicians to use the specific finding of hyperexcitability as a useful diagnostic biomarker, enabling clarification of various ALS-mimic syndromes, and the prediction of disease development in pre-symptomatic carriers of familial ALS. In terms of nerve excitability tests for peripheral nerves, an increase in persistent Na+ conductances has been identified as a major determinant of peripheral hyperexcitability in ALS, inversely correlated with the survival in ALS. As such, the present Review will focus primarily on the puzzling theory of hyperexcitability in ALS and summarize clinical and pathophysiological implications for current and future ALS research. PMID:23626643

  9. Is the proton radius puzzle evidence of extra dimensions?

    NASA Astrophysics Data System (ADS)

    Dahia, F.; Lemos, A. S.

    2016-08-01

    The proton charge radius inferred from muonic hydrogen spectroscopy is not compatible with the previous value given by CODATA-2010, which, on its turn, essentially relies on measurements of the electron-proton interaction. The proton's new size was extracted from the 2S-2P Lamb shift in the muonic hydrogen, which showed an energy excess of 0.3 meV in comparison to the theoretical prediction, evaluated with the CODATA radius. Higher-dimensional gravity is a candidate to explain this discrepancy, since the muon-proton gravitational interaction is stronger than the electron-proton interaction and, in the context of braneworld models, the gravitational potential can be hugely amplified in short distances when compared to the Newtonian potential. Motivated by these ideas, we study a muonic hydrogen confined in a thick brane. We show that the muon-proton gravitational interaction modified by extra dimensions can provide the additional separation of 0.3 meV between the 2S and 2P states. In this scenario, the gravitational energy depends on the higher-dimensional Planck mass and indirectly on the brane thickness. Studying the behavior of the gravitational energy with respect to the brane thickness in a realistic range, we find constraints for the fundamental Planck mass that solve the proton radius puzzle and are consistent with previous experimental bounds.

  10. The puzzling origin of the Martian Northern Lowlands.

    NASA Astrophysics Data System (ADS)

    Altieri, F.; Carrozzo, G.; Carli, C.; Geminale, A.; Bellucci, G.

    Surface studies of the northern lowlands of Mars have shown that this region has undergone a complex history including volcanism, sedimentary deposition and secondary modification by climate change. Despite these analyses, the origin and the evolution of this region are still debated. No clear and definitive evidences have been found so far to conclude whether these plains were formed by a giant impact, were once covered by an ocean or were filled by a large quantity of lavas. In the visible and infrared spectral range, the northern lowlands differ from southern terrains in the NIR negative slope while they exhibit VNIR spectra similar to the southern pyroxene-rich areas (Carrozzo et al., 2012). These observations, combined with both recent detection of mafic minerals at higher spatial resolution by CRISM (Salvatore et al., 2010) and recent results of Horgan and Bell (2012), supports that their mineralogy is linked to weathered basalts with a glassy component. In addition to this, the spectral similarity of Acidalia area with the northern circumpolar sand dunes, apart from the hydration features, suggests that the weathering processes that took place there could be related to past glacial activity, in agreement with superficial morphology showing glacial structures. Aim of this work is to combine the OMEGA mineralogical maps with morphological features (Tanaka et al., 2011) and investigate possible terrestrial analogues in order to give some constrains on the composition and origin of these puzzling Martian terrains.

  11. Wolves in the Great Lakes region: a phylogeographic puzzle.

    PubMed

    Randi, Ettore

    2010-10-01

    Empirical studies demonstrate that natural hybridization in animals is more common than thought so far (Mallet 2005), particularly among species that originated recently through cycles of population contraction-expansion arising from climate changes over the last glacial period, the Pleistocene. In addition, the post-glacial global growth of human populations has fostered anthropogenic hybridization events, mediated by habitat changes, the persecution of large predators and the introduction of alien species (Allendorf et al. 2001). The Canis lineage shows cases of both natural and anthropogenic hybridization, exacerbating the controversy about the number of species that should be formally validated in the taxonomic lists, the evolutionary role of genetic introgression and the ways to manage hybrids with invading wild or domesticated populations. The study by Wheeldon et al. (2010), published in this issue of Molecular Ecology, adds a new piece to the intricate puzzle of evolution and taxonomy of Canis in North America. They show that sympatric wolves (C. lupus) and coyotes (C. latrans) are not (extensively) hybridizing in the western North American Great Lakes region (GLR). Widespread hybridization between coyotes and a genetically distinct, but closely related, wolf-like population (the eastern wolf) occurred in the northeastern regions of North America. In Wheeldon et al.'s (2010) opinion, these data should prove definitely that two different species of wolf (the western gray wolf C. lupus and the eastern wolf C. lycaon) and their hybrids are distributed across the GLR.

  12. Effect of a puzzle on the process of students' learning about cardiac physiology.

    PubMed

    Cardozo, Lais Tono; Miranda, Aline Soares; Moura, Maria José Costa Sampaio; Marcondes, Fernanda Klein

    2016-09-01

    The aim of the present study was to evaluate the effects of using a puzzle to learn about cardiac physiology. Students were divided into control and game groups. In class 1, the control group had a 2-h theoretical class about cardiac physiology, including a detailed description of the phases of the cardiac cycle, whereas the game group had a 50-min theoretical class without the description of the cardiac cycle. In class 2, the control group did an assessment exercise before an activity with the cardiac puzzle and the game group answered questions after the above-mentioned activity. While solving the puzzle, the students had to describe the cardiac cycle by relating the concepts of heart morphology and physiology. To evaluate short-term learning, the number of wrong answers and grades in the assessment exercise were compared between the control and game groups. To evaluate medium-term learning, we compared the grades obtained by students of the control and game groups in questions about cardiac physiology that formed part of the academic exam. In the assessment exercise, the game group presented a lower number of errors and higher score compared with the control group. In the academic exam, applied after both groups had used the puzzle, there was no difference in the scores obtained by the control and game groups in questions about cardiac physiology. These results showed a positive effect of the puzzle on students' learning about cardiac physiology compared with those not using the puzzle.

  13. Economics, human biology and inequality: A review of "puzzles" and recent contributions from a Deatonian perspective.

    PubMed

    Baten, Joerg

    2016-11-18

    The Nobel laureate Angus Deaton concentrated his work on puzzling developments and phenomena in economics. Puzzles are exciting elements in economics, because readers feel challenged by the question of how they can be solved. Among the puzzles analyzed by Deaton are: (1) Mortality increase of white, U.S. non-Hispanic men (2000 to today); (2) Why are height and income sometimes closely correlated, but not always?; (3) Height inequality among males and females; and (4) The Indian puzzle of declining consumption of calories during overall expenditure growth. This article reviews these "puzzles" and the main insights that Deaton derived from their discussion insofar as they pertain to the biological aspects of human development. I will focus on the field of this journal, Economics and Human Biology, in which Deaton has been very active over the last two decades. I will also document some of the responses by other scholars and their contributions to these puzzles, as they relate to the field of economics and human biology.

  14. Optical disks

    NASA Technical Reports Server (NTRS)

    Lopez-Swafford, B.

    1986-01-01

    A comprehensive overview of the different types of optical storage technology is presented. Research efforts to integrate this technology into the VAX/VMS environment are discussed. In addition, plans for future applications of optical disk technology are described. The applications should prove to be beneficial to the NSSDC user community as a whole. Of particular interest is the concentration on the collaboration with the Dynamics Explorer project.

  15. ON THE PUZZLE OF SPACE WEATHERING ALTERATION OF BASALTIC ASTEROIDS

    SciTech Connect

    Marchi, S.; Lazzarin, M.; Magrin, S.; De Sanctis, M. C. E-mail: monica.lazzarin@unipd.i E-mail: mariacristina.desanctis@iasf-roma.inaf.i

    2010-10-01

    The majority of basaltic asteroids are found in the inner main belt, although a few have also been observed in the outer main belt and near-Earth space. These asteroids-referred to as V-types-have surface compositions that resemble that of the 530 km sized asteroid Vesta. Besides the compositional similarity, dynamical evidence also links many V-type asteroids to Vesta. Moreover, Vesta is one of the few asteroids to have been identified as source of specific classes of meteorites, the howardite, eucrite, and diogenite achondrites (HEDs). Despite the general consensus on the outlined scenario, several questions remain unresolved. In particular, it is not clear if the observed spectral diversity among Vesta, V-types, and HEDs is due to space weathering, as is thought to be the case for S-type asteroids. In this Letter, SDSS photometry is used to address the question of whether the spectral diversity among candidate V-types and HEDs can be explained by space weathering. We show that visible spectral slopes of V-types are systematically redder with respect to HEDs, in a similar way to what is found for ordinary chondrite meteorites and S-types. On the assumption that space weathering is responsible for the slope mismatch, we estimated an upper limit for the reddening timescale of about 0.5 Ga. Nevertheless, the observed slope mismatch between HEDs and V-types poses several puzzles to understanding its origin. The implication of our findings is also discussed in light of the Dawn mission to Vesta.

  16. Hyperon puzzle, hadron-quark crossover and massive neutron stars

    NASA Astrophysics Data System (ADS)

    Masuda, Kota; Hatsuda, Tetsuo; Takatsuka, Tatsuyuki

    2016-03-01

    Bulk properties of cold and hot neutron stars are studied on the basis of the hadron-quark crossover picture where a smooth transition from the hadronic phase to the quark phase takes place at finite baryon density. By using a phenomenological equation of state (EOS) "CRover", which interpolates the two phases at around 3 times the nuclear matter density (ρ0, it is found that the cold NSs with the gravitational mass larger than 2M_{odot} can be sustained. This is in sharp contrast to the case of the first-order hadron-quark transition. The radii of the cold NSs with the CRover EOS are in the narrow range (12.5 ± 0.5) km which is insensitive to the NS masses. Due to the stiffening of the EOS induced by the hadron-quark crossover, the central density of the NSs is at most 4 ρ0 and the hyperon-mixing barely occurs inside the NS core. This constitutes a solution of the long-standing hyperon puzzle. The effect of color superconductivity (CSC) on the NS structures is also examined with the hadron-quark crossover. For the typical strength of the diquark attraction, a slight softening of the EOS due to two-flavor CSC (2SC) takes place and the maximum mass is reduced by about 0.2M_{odot}. The CRover EOS is generalized to the supernova matter at finite temperature to describe the hot NSs at birth. The hadron-quark crossover is found to decrease the central temperature of the hot NSs under isentropic condition. The gravitational energy release and the spin-up rate during the contraction from the hot NS to the cold NS are also estimated.

  17. Emergence of Life on Earth: A Physicochemical Jigsaw Puzzle.

    PubMed

    Spitzer, Jan

    2017-01-01

    We review physicochemical factors and processes that describe how cellular life can emerge from prebiotic chemical matter; they are: (1) prebiotic Earth is a multicomponent and multiphase reservoir of chemical compounds, to which (2) Earth-Moon rotations deliver two kinds of regular cycling energies: diurnal electromagnetic radiation and seawater tides. (3) Emerging colloidal phases cyclically nucleate and agglomerate in seawater and consolidate as geochemical sediments in tidal zones, creating a matrix of microspaces. (4) Some microspaces persist and retain memory from past cycles, and others re-dissolve and re-disperse back into the Earth's chemical reservoir. (5) Proto-metabolites and proto-biopolymers coevolve with and within persisting microspaces, where (6) Macromolecular crowding and other non-covalent molecular forces govern the evolution of hydrophilic, hydrophobic, and charged molecular surfaces. (7) The matrices of microspaces evolve into proto-biofilms of progenotes with rudimentary but evolving replication, transcription, and translation, enclosed in unstable cell envelopes. (8) Stabilization of cell envelopes 'crystallizes' bacteria-like genetics and metabolism with low horizontal gene transfer-life 'as we know it.' These factors and processes constitute the 'working pieces' of the jigsaw puzzle of life's emergence. They extend the concept of progenotes as the first proto-cellular life, connected backward in time to the cycling chemistries of the Earth-Moon planetary system, and forward to the ancient cell cycle of first bacteria-like organisms. Supra-macromolecular models of 'compartments first' are preferred: they facilitate macromolecular crowding-a key abiotic/biotic transition toward living states. Evolutionary models of metabolism or genetics 'first' could not have evolved in unconfined and uncrowded environments because of the diffusional drift to disorder mandated by the second law of thermodynamics.

  18. Holographic data storage crystals for LDEF (A0044)

    NASA Technical Reports Server (NTRS)

    Callen, W. R.; Gaylord, T. K.

    1984-01-01

    Electro-optic holographic recording systems were developed. The spaceworthiness of electro-optic crystals for use in ultrahigh capacity space data storage and retrieval systems are examined. The crystals for this experiment are included with the various electro-optical components of LDEF experiment. The effects of long-duration exposure on active optical system components is investigated. The concept of data storage in an optical-phase holographic memory is illustrated.

  19. Basics of Videodisc and Optical Disk Technology.

    ERIC Educational Resources Information Center

    Paris, Judith

    1983-01-01

    Outlines basic videodisc and optical disk technology describing both optical and capacitance videodisc technology. Optical disk technology is defined as a mass digital image and data storage device and briefly compared with other information storage media including magnetic tape and microforms. The future of videodisc and optical disk is…

  20. Storage Technology: A Review of Options and Their Implications for Electronic Publishing.

    ERIC Educational Resources Information Center

    Arnold, Stephen E.

    1991-01-01

    Describes computer storage devices and suggests implications for electronic publishing. Highlights include magnetic storage media, including digital audio tape (DAT); high-capacity magnetic drives; optical storage technologies, including CD-ROM and WORM; magneto-optical drives; and a sidebar that discusses other storage technologies. (21…

  1. The role of inhibitory control in children's cooperative behaviors during a structured puzzle task.

    PubMed

    Giannotta, Fabrizia; Burk, William J; Ciairano, Silvia

    2011-11-01

    This study examined the role of inhibitory control (measured by Stroop interference) in children's cooperative behaviors during a structured puzzle task. The sample consisted of 250 8-, 10-, and 12-year-olds (117 girls and 133 boys) attending classrooms in three primary schools in Northern Italy. Children individually completed an elaborated Stroop task, were paired with classmates into 125 dyads, and were observed during a 10-min puzzle task. Results confirmed that interaction partners exhibited similar levels of cooperative behaviors, and the cooperative behaviors of children predicted changes in the cooperative behaviors of their partners throughout the puzzle task. Cooperative behaviors of each interaction partner were predicted by the child's own inhibitory control as well as the inhibitory control of the partner. Findings are discussed within a developmental contextual framework.

  2. Puzzle Imaging: Using Large-Scale Dimensionality Reduction Algorithms for Localization

    PubMed Central

    Glaser, Joshua I.; Zamft, Bradley M.; Church, George M.; Kording, Konrad P.

    2015-01-01

    Current high-resolution imaging techniques require an intact sample that preserves spatial relationships. We here present a novel approach, “puzzle imaging,” that allows imaging a spatially scrambled sample. This technique takes many spatially disordered samples, and then pieces them back together using local properties embedded within the sample. We show that puzzle imaging can efficiently produce high-resolution images using dimensionality reduction algorithms. We demonstrate the theoretical capabilities of puzzle imaging in three biological scenarios, showing that (1) relatively precise 3-dimensional brain imaging is possible; (2) the physical structure of a neural network can often be recovered based only on the neural connectivity matrix; and (3) a chemical map could be reproduced using bacteria with chemosensitive DNA and conjugative transfer. The ability to reconstruct scrambled images promises to enable imaging based on DNA sequencing of homogenized tissue samples. PMID:26192446

  3. The DS86 neutron dosimetry enigma: Some missing pieces to the puzzle

    SciTech Connect

    Gold, R.

    1994-12-31

    International programs have been conducted over the last four decades to quantify the exposure of atom bomb survivors from Hiroshima and Nagasaki. Unfortunately, the quest for accurate gamma-ray and neutron exposure doses of atom bomb survivors has proven illusive. Efforts in the most recent of these programs, designated as Dosimetry System 1986 (DS86), have revealed a serious and persistent discrepancy between neutron transport calculations and thermal neutron activation measurements at the Hiroshima site, which will be called the DS86 neutron dosimetry enigma. It is established that this enigma is a complex puzzle that precludes simple solutions. This conclusion is deduced through the identification of a number of missing pieces to the puzzle. Implications and conclusions that can be inferred from these missing puzzle pieces are advanced.

  4. The Puzzle of HCN in Comets: Is it both a Product and a Primary Species?

    NASA Astrophysics Data System (ADS)

    Mumma, Michael J.; Bonev, Boncho P.; Charnley, Steven B.; Cordiner, Martin A.; DiSanti, Michael A.; Gibb, Erika L.; Magee-Sauer, Karen; Paganini, Lucas; Villanueva, Geronimo L.

    2014-11-01

    Hydrogen cyanide has long been regarded as a primary volatile in comets, stemming from its presence in dense molecular cloud cores and its supposed storage in the cometary nucleus. Here, we examine the observational evidence for and against that hypothesis, and argue that HCN may also result from near-nucleus chemical reactions in the coma. The distinction (product vs. primary species) is important for multiple reasons: 1. HCN is often used as a proxy for water when the dominant species (H2O) is not available for simultaneous measurement, as at radio wavelengths. 2. HCN is one of the few volatile carriers of nitrogen accessible to remote sensing. If HCN is mainly a product species, its precursor becomes the more important metric for compiling a taxonomic classification based on nitrogen chemistry. 3. The stereoisomer HNC is now confirmed as a product species. Could reaction of a primary precursor (X-CN) with a hydrocarbon co-produce both HNC and HCN? 4. The production rate for CN greatly exceeds that of HCN in some comets, demonstrating the presence of another (more important) precursor of CN. Several puzzling lines of evidence raise issues about the origin of HCN: a. The production rates of HCN measured through rotational (radio) and vibrational (infrared) spectroscopy agree in some comets - in others the infrared rate exceeds the radio rate substantially. b. With its strong dipole moment and H-bonding character, HCN should be linked more strongly in the nuclear ice to other molecules with similar properties (H2O, CH3OH), but instead its spatial release in some comets seems strongly coupled to volatiles that lack a dipole moment and thus do not form H-bonds (methane, ethane). c. The nucleus-centered rotational temperatures measured for H2O and other species (C2H6, CH3OH) usually agree within error, but those for HCN are often slightly smaller. d. In comet ISON, ALMA maps of HCN and the dust continuum show a slight displacement 80 km) in the centroids. We will

  5. RNA-Puzzles Round III: 3D RNA structure prediction of five riboswitches and one ribozyme.

    PubMed

    Miao, Zhichao; Adamiak, Ryszard W; Antczak, Maciej; Batey, Robert T; Becka, Alexander J; Biesiada, Marcin; Boniecki, Michał J; Bujnicki, Janusz; Chen, Shi-Jie; Cheng, Clarence Yu; Chou, Fang-Chieh; Ferré-D'Amaré, Adrian R; Das, Rhiju; Dawson, Wayne K; Feng, Ding; Dokholyan, Nikolay V; Dunin-Horkawicz, Stanisław; Geniesse, Caleb; Kappel, Kalli; Kladwang, Wipapat; Krokhotin, Andrey; Łach, Grzegorz E; Major, François; Mann, Thomas H; Magnus, Marcin; Pachulska-Wieczorek, Katarzyna; Patel, Dinshaw J; Piccirilli, Joseph A; Popenda, Mariusz; Purzycka, Katarzyna J; Ren, Aiming; Rice, Greggory M; Santalucia, John; Sarzynska, Joanna; Szachniuk, Marta; Tandon, Arpit; Trausch, Jeremiah J; Tian, Siqi; Wang, Jian; Weeks, Kevin M; Williams, Benfeard; Xiao, Yi; Xu, Xiaojun; Zhang, Dong; Zok, Tomasz; Westhof, Eric

    2017-01-30

    RNA-Puzzles is a collective experiment in blind 3D RNA structure prediction. We report here a third round of RNA-Puzzles. Five puzzles, 4, 8, 12, 13, 14, all structures of riboswitch aptamers and puzzle 7, a ribozyme structure, are included in this round of the experiment. The riboswitch structures include biological binding sites for small molecules (S-adenosyl methionine, cyclic diadenosine monophosphate, 5-amino 4-imidazole carboxamide riboside 5'-triphosphate, glutamine) and proteins (YbxF) and one set describes large conformational changes between ligand-free and ligand-bound states; the Varkud satellite ribozyme is the most recently solved structure of a known large ribozyme. All the puzzles have established biological functions and require structural understanding to appreciate their molecular mechanisms. Through the use of fast-track experimental data, including multidimensional chemical mapping, and accurate prediction of RNA secondary structure, a large portion of the contacts in 3D have been predicted correctly leading to similar topologies for the top ranking predictions. Template-based and homology-derived predictions could predict structures to particularly high accuracies. However, achieving biological insights from de novo prediction of RNA 3D structures still depends on the size and complexity of the RNA. Blind computational predictions of RNA structures already appear to provide useful structural information in many cases. Similar to the previous RNA-Puzzles Round II experiment, the prediction of non-Watson-Crick interactions and the observed high atomic clash scores reveal notable need for algorithm of improvement. All prediction models and assessment results are available at http://ahsoka.u-strasbg.fr/rnapuzzles/.

  6. Using the Tower of Hanoi puzzle to infuse your mathematics classroom with computer science concepts

    NASA Astrophysics Data System (ADS)

    Marzocchi, Alison S.

    2016-07-01

    This article suggests that logic puzzles, such as the well-known Tower of Hanoi puzzle, can be used to introduce computer science concepts to mathematics students of all ages. Mathematics teachers introduce their students to computer science concepts that are enacted spontaneously and subconsciously throughout the solution to the Tower of Hanoi puzzle. These concepts include, but are not limited to, conditionals, iteration, and recursion. Lessons, such as the one proposed in this article, are easily implementable in mathematics classrooms and extracurricular programmes as they are good candidates for 'drop in' lessons that do not need to fit into any particular place in the typical curriculum sequence. As an example for readers, the author describes how she used the puzzle in her own Number Sense and Logic course during the federally funded Upward Bound Math/Science summer programme for college-intending low-income high school students. The article explains each computer science term with real-life and mathematical examples, applies each term to the Tower of Hanoi puzzle solution, and describes how students connected the terms to their own solutions of the puzzle. It is timely and important to expose mathematics students to computer science concepts. Given the rate at which technology is currently advancing, and our increased dependence on technology in our daily lives, it has become more important than ever for children to be exposed to computer science. Yet, despite the importance of exposing today's children to computer science, many children are not given adequate opportunity to learn computer science in schools. In the United States, for example, most students finish high school without ever taking a computing course. Mathematics lessons, such as the one described in this article, can help to make computer science more accessible to students who may have otherwise had little opportunity to be introduced to these increasingly important concepts.

  7. Energy Storage

    SciTech Connect

    Mukundan, Rangachary

    2014-09-30

    Energy storage technology is critical if the U.S. is to achieve more than 25% penetration of renewable electrical energy, given the intermittency of wind and solar. Energy density is a critical parameter in the economic viability of any energy storage system with liquid fuels being 10 to 100 times better than batteries. However, the economical conversion of electricity to fuel still presents significant technical challenges. This project addressed these challenges by focusing on a specific approach: efficient processes to convert electricity, water and nitrogen to ammonia. Ammonia has many attributes that make it the ideal energy storage compound. The feed stocks are plentiful, ammonia is easily liquefied and routinely stored in large volumes in cheap containers, and it has exceptional energy density for grid scale electrical energy storage. Ammonia can be oxidized efficiently in fuel cells or advanced Carnot cycle engines yielding water and nitrogen as end products. Because of the high energy density and low reactivity of ammonia, the capital cost for grid storage will be lower than any other storage application. This project developed the theoretical foundations of N2 catalysis on specific catalysts and provided for the first time experimental evidence for activation of Mo 2N based catalysts. Theory also revealed that the N atom adsorbed in the bridging position between two metal atoms is the critical step for catalysis. Simple electrochemical ammonia production reactors were designed and built in this project using two novel electrolyte systems. The first one demonstrated the use of ionic liquid electrolytes at room temperature and the second the use of pyrophosphate based electrolytes at intermediate temperatures (200 – 300 ºC). The mechanism of high proton conduction in the pyrophosphate materials was found to be associated with a polyphosphate second phase contrary to literature claims and ammonia production rates as high as 5X 10

  8. Cathodochromic storage device

    NASA Technical Reports Server (NTRS)

    Bosomworth, D. R.; Moles, W. H.

    1969-01-01

    A memory and display device has been developed by combing a fast phosphor layer with a cathodochromic layer in a cathode ray tube. Images are stored as patterns of electron beam induced optical density in the cathodo-chromic material. The stored information is recovered by exciting the backing, fast phosphor layer with a constant current electron beam and detecting the emitted radiation which is modulated by absorption in the cathodochromic layer. The storage can be accomplished in one or more TV frames (1/30 sec each). More than 500 TV line resolution and close to 2:1 contrast ratio are possible. The information storage time in a dark environment is approximately 24 hours. A reconstituted (readout) electronic video signal can be generated continuously for times in excess of 10 minutes or periodically for several hours.

  9. Jigsaw puzzle metasurface for multiple functions: polarization conversion, anomalous reflection and diffusion.

    PubMed

    Zhao, Yi; Cao, Xiangyu; Gao, Jun; Liu, Xiao; Li, Sijia

    2016-05-16

    We demonstrate a simple reconfigurable metasurface with multiple functions. Anisotropic tiles are investigated and manufactured as fundamental elements. Then, the tiles are combined in a certain sequence to construct a metasurface. Each of the tiles can be adjusted independently which is like a jigsaw puzzle and the whole metasurface can achieve diverse functions by different layouts. For demonstration purposes, we realize polarization conversion, anomalous reflection and diffusion by a jigsaw puzzle metasurface with 6 × 6 pieces of anisotropic tile. Simulated and measured results prove that our method offers a simple and effective strategy for metasurface design.

  10. A Puzzling Alcohol Dehydration Reaction Solved by GC-MS Analysis

    NASA Astrophysics Data System (ADS)

    Pelter, Michael W.; Macudzinski, Rebecca M.

    1999-06-01

    We have adapted the dehydration of 2-methyl-2-propanol to a "puzzle" approach for use in our second-semester chemistry major organic laboratory. The reaction of 2-methyl-2-propanol with ~50% sulfuric acid at 100 °C yields isobutylene, which reacts further by a "puzzling" reaction. By coupling the GC/MS analysis of the product mixture with their knowledge of the mechanism of alcohol dehydration and alkene reactivity, students are able to identify the major products of this reaction.

  11. First-principles calculations of structural, elastic, electronic, and optical properties of perovskite-type KMgH3 crystals: novel hydrogen storage material.

    PubMed

    Reshak, Ali H; Shalaginov, Mikhail Y; Saeed, Yasir; Kityk, I V; Auluck, S

    2011-03-31

    We report a first-principles study of structural and phase stability in three different structures of perovskite-types KMgH(3) according to H position. While electronic and optical properties were measured only for stable perovskite-type KMgH(3), our calculated structural parameters are found in good agreement with experiment and other theoretical results. We also study the electronic charge density space distribution contours in the (200), (101), and (100) crystallographic planes, which gives better insight picture of chemical bonding between K-H, K-Mg-H, and Mg-H. Moreover, we have calculated the electronic band structure dispersion, total, and partial density of electron states to study the band gap origin and the contribution of s-band of H, s and p-band of Mg in the valence band, and d-band of K in the conduction band. Furthermore, optical features such as dielectric functions, refractive indices, extinction coefficient, optical reflectivity, absorption coefficients, optical conductivities, and loss functions of stable KMgH(3) were calculated for photon energies up to 40 eV.

  12. Utility of Self-Made Crossword Puzzles as an Active Learning Method to Study Biochemistry in Undergraduate Education

    ERIC Educational Resources Information Center

    Coticone, Sulekha Rao

    2013-01-01

    To incorporate an active learning component in a one-semester biochemistry course, students were asked to create crossword puzzles using key concepts. Student observations on the use of self-made crossword puzzles as an active-learning instructional tool were collected using a 5-point Likert survey at the end of the semester. A majority of the…

  13. An Easy & Fun Way to Teach about How Science "Works": Popularizing Haack's Crossword-Puzzle Analogy

    ERIC Educational Resources Information Center

    Pavlova, Iglika V.; Lewis, Kayla C.

    2013-01-01

    Science is a complex process, and we must not teach our students overly simplified versions of "the" scientific method. We propose that students can uncover the complex realities of scientific thinking by exploring the similarities and differences between solving the familiar crossword puzzles and scientific "puzzles."…

  14. Having Fun and Accepting Challenges Are Natural Instincts: Jigsaw Puzzles to Challenge Students and Test Their Abilities While Having Fun!

    ERIC Educational Resources Information Center

    Rodenbaugh, Hanna R.; Lujan, Heidi L.; Rodenbaugh, David W.; DiCarlo, Stephen E.

    2014-01-01

    Because jigsaw puzzles are fun, and challenging, students will endure and discover that persistence and grit are rewarded. Importantly, play and fun have a biological place just like sleep and dreams. Students also feel a sense of accomplishment when they have completed a puzzle. Importantly, the reward of mastering a challenge builds confidence…

  15. Hydrogen Storage

    SciTech Connect

    2008-11-01

    This 2-page fact sheet provides a brief introduction to hydrogen storage technologies. Intended for a non-technical audience, it explains the different ways in which hydrogen can be stored, as well as the technical challenges and research goals for storing hydrogen on board a vehicle.

  16. Storage-ring Electron Cooler for Relativistic Ion Beams

    SciTech Connect

    Lin, Fanglei; Derbenev, Yaroslav; Douglas, David R.; Guo, Jiquan; Johnson, Rolland P.; Krafft, Geoffrey A.; Morozov, Vasiliy; Zhang, Yuhong

    2016-05-01

    Application of electron cooling at ion energies above a few GeV has been limited due to reduction of electron cooling efficiency with energy and difficulty in producing and accelerating a high-current high-quality electron beam. A high-current storage-ring electron cooler offers a solution to both of these problems by maintaining high cooling beam quality through naturally-occurring synchrotron radiation damping of the electron beam. However, the range of ion energies where storage-ring electron cooling can be used has been limited by low electron beam damping rates at low ion energies and high equilibrium electron energy spread at high ion energies. This paper reports a development of a storage ring based cooler consisting of two sections with significantly different energies: the cooling and damping sections. The electron energy and other parameters in the cooling section are adjusted for optimum cooling of a stored ion beam. The beam parameters in the damping section are adjusted for optimum damping of the electron beam. The necessary energy difference is provided by an energy recovering SRF structure. A prototype linear optics of such storage-ring cooler is presented.

  17. Nanotechnology for Data Storage Applications

    NASA Astrophysics Data System (ADS)

    Sarid, Dror; McCarthy, Brendan; Jabbour, Ghassan

    This chapter considers atomic force microscopy (AFM) as an enabling technology for data storage applications, considering already existing technologies such as hard disk drives (HDD), optical disk drives (ODD) and flash memories that currently dominate the nonvolatile data storage market, together with future devices based on magnetoresistive and phase change effects. The issue at hand is the question of whether the novel AFM-based storage, dubbed probe storage, can offer a competing approach to the currently available technologies by playing the role of a disruptive technology. Probe storage will be contrasted to HDD and ODD, which are purely mechanical as they are based on a rotating disk that uses just a single probe to address billions of bits of data, and nonvolatile random-access memory (RAM) that has no moving parts yet requires billions of interconnects. In particular, capacity, areal density, transfer rate, form factor and the cost of various data storage devices will be discussed and the unique opportunity offered by probe storage in employing massive parallelism will be outlined. It will be shown that probe storage bridges the gap between HDD, ODD and other nonvolatile RAM, drawing from the strength of each one of these and adding a significant attribute neither of these has; namely, the possibility of addressing a very large number of nanoscale bits of data in parallel. This chapter differs from the other chapters in this book in that it addresses the important issue of whether a given scientific effort, namely, probe storage, is mature enough to evolve into a commercially viable technology. The answer seems to indicate that there is indeed a huge niche in the data storage arena that such a technology is uniquely qualified to fill, which is large enough to justify a major investment in research and development. Indeed, as other chapters indicate, such an effort is developing at a rapid pace, with hopes of having a viable product within a few years.

  18. Nanotechnology for Data Storage Applications

    NASA Astrophysics Data System (ADS)

    Sarid, Dror; McCarthy, Brendan; Jabbour, Ghassan E.

    This chapter considers atomic force microscopy (AFM) as an enabling technology for data storage applications, considering already existing technologies such as hard disk drives (HDD), optical disk drives (ODD) and Flash Memories that currently dominate the nonvolatile data storage market, together with future devices based on magnetoresistive and phase change effects. The issue at hand is the question of whether the novel AFM-based storage, dubbed "Probe Storage", can offer a competing approach to the currently available technologies by playing the role of a disruptive technology. Probe Storage will be contrasted to HDD and ODD who are purely mechanical, as they are based on a rotating disk that uses just a single probe to address billions of bits of data, and nonvolatile RAM that has no moving parts yet requires billions of interconnects. In particular, capacity, areal density, transfer rate, form factor and cost of various data storage devices will be discussed and the unique opportunity offered by Probe Storage in employing massive parallelism will be outlined. It will be shown that Probe Storage bridges the gap between HDD, ODD and other nonvolatile RAM, drawing from the strength of each one of these and adding a significant attribute neither of these has; namely, the possibility of addressing a very large number of nanoscale bits of data in parallel. This chapter differs from the other chapters in this book in that it addresses the important issue of whether a given scientific effort, namely, Probe Storage, is mature enough to evolve into a commercially viable technology. The answer seems to indicate that there indeed is a huge niche in the data storage arena that such a technology is uniquely qualified to fill, which is large enough to justify a major investment in research and development. Indeed, as other chapters indicate, such an effort is developing at a rapid pace, with hopes of having a viable product within a few years.

  19. Enhancing the Understanding of Government and Nonprofit Accounting with THE PUZZLE GAME: A Pilot Study

    ERIC Educational Resources Information Center

    Elson, Raymond J.; Ostapski, S. Andrew; O'Callaghan, Susanne; Walker, John P.

    2012-01-01

    Nontraditional teaching aids such as crossword puzzles have been successfully used in the classroom to enhance student learning. Government and nonprofit accounting is a confusing course for students since it has strange terminologies and contradicts the accounting concepts learned in other courses. As such, it is an ideal course for a…

  20. Schooling, Cognitive Skills, and the Latin American Growth Puzzle. NBER Working Paper No. 15066

    ERIC Educational Resources Information Center

    Hanushek, Eric A.; Woessmann, Ludger

    2009-01-01

    Economic development in Latin America has trailed most other world regions over the past four decades despite its relatively high initial development and school attainment levels. This puzzle can be resolved by considering the actual learning as expressed in tests of cognitive skills, on which Latin American countries consistently perform at the…

  1. The Retention Puzzle Reconsidered: Second Year Student Attitudes and Experiences with Advising

    ERIC Educational Resources Information Center

    Walsh, Michael Edward

    2013-01-01

    College student retention has been described as a puzzle because retention rates have stagnated, and in some cases declined, despite over seventy years of research into the problem. The magnitude of the problem is that 50 percent of college students will leave their institution before obtaining a degree (Braxton, Hirschy, & McClendon, 2011).…

  2. New Light on Autism and Other Puzzling Disorders of Childhood. Science Reports.

    ERIC Educational Resources Information Center

    Yahraes, Herbert

    The pamphlet discusses several puzzling disorders of childhood, including autism, atypical personality development (childhood psychosis), psychosocial dwarfism, and Tourette's syndrome. Psychosocial dwarfism is said to be characterized by a marked reduction in physical development and by immaturity in behavior, while Tourette's syndrome involves…

  3. Sequential Monte Carlo for Maximum Weight Subgraphs with Application to Solving Image Jigsaw Puzzles.

    PubMed

    Adluru, Nagesh; Yang, Xingwei; Latecki, Longin Jan

    2015-05-01

    We consider a problem of finding maximum weight subgraphs (MWS) that satisfy hard constraints in a weighted graph. The constraints specify the graph nodes that must belong to the solution as well as mutual exclusions of graph nodes, i.e., pairs of nodes that cannot belong to the same solution. Our main contribution is a novel inference approach for solving this problem in a sequential monte carlo (SMC) sampling framework. Usually in an SMC framework there is a natural ordering of the states of the samples. The order typically depends on observations about the states or on the annealing setup used. In many applications (e.g., image jigsaw puzzle problems), all observations (e.g., puzzle pieces) are given at once and it is hard to define a natural ordering. Therefore, we relax the assumption of having ordered observations about states and propose a novel SMC algorithm for obtaining maximum a posteriori estimate of a high-dimensional posterior distribution. This is achieved by exploring different orders of states and selecting the most informative permutations in each step of the sampling. Our experimental results demonstrate that the proposed inference framework significantly outperforms loopy belief propagation in solving the image jigsaw puzzle problem. In particular, our inference quadruples the accuracy of the puzzle assembly compared to that of loopy belief propagation.

  4. Sequential Monte Carlo for Maximum Weight Subgraphs with Application to Solving Image Jigsaw Puzzles

    PubMed Central

    Adluru, Nagesh; Yang, Xingwei; Latecki, Longin Jan

    2015-01-01

    We consider a problem of finding maximum weight subgraphs (MWS) that satisfy hard constraints in a weighted graph. The constraints specify the graph nodes that must belong to the solution as well as mutual exclusions of graph nodes, i.e., pairs of nodes that cannot belong to the same solution. Our main contribution is a novel inference approach for solving this problem in a sequential monte carlo (SMC) sampling framework. Usually in an SMC framework there is a natural ordering of the states of the samples. The order typically depends on observations about the states or on the annealing setup used. In many applications (e.g., image jigsaw puzzle problems), all observations (e.g., puzzle pieces) are given at once and it is hard to define a natural ordering. Therefore, we relax the assumption of having ordered observations about states and propose a novel SMC algorithm for obtaining maximum a posteriori estimate of a high-dimensional posterior distribution. This is achieved by exploring different orders of states and selecting the most informative permutations in each step of the sampling. Our experimental results demonstrate that the proposed inference framework significantly outperforms loopy belief propagation in solving the image jigsaw puzzle problem. In particular, our inference quadruples the accuracy of the puzzle assembly compared to that of loopy belief propagation. PMID:26052182

  5. Instructional Media Production for Early Childhood Education: A. B. C. Jig-Saw Puzzle, a Model

    ERIC Educational Resources Information Center

    Yusuf, Mudashiru Olalere; Olanrewaju, Olatayo Solomon; Soetan, Aderonke K.

    2015-01-01

    In this paper, a. b. c. jig-saw puzzle was produced for early childhood education using local materials. This study was a production based type of research, to serve as a supplemental or total learning resource. Its production followed four phases of development referred to as information, design, production and evaluation. The storyboard cards,…

  6. Puzzle task ERP response: time-frequency and source localization analysis.

    PubMed

    Almurshedi, Ahmed; Ismail, Abd Khamim

    2015-01-01

    Perceptual decision making depends on the choices available for the presented task. Most event-related potential (ERP) experiments are designed with two options, such as YES or NO. In some cases, however, subjects may become confused about the presented task in such a way that they cannot provide a behavioral response. This study aims to put subjects into such a puzzled state in order to address the following questions: How does the brain respond during puzzling moments? And what is the brain's response to a non-answerable task? To address these questions, ERP were acquired from the brain during a scintillation grid illusion task. The subjects were required to count the number of illusory dots, a task that was impossible to perform. The results showed the presence of N130 over the parietal area during the puzzling task. Coherency among the brain hemispheres was enhanced with the complexity of the task. The neural generators' source localizations were projected to a multimodal complex covering the left postcentral gyrus, supramarginal gyrus, and angular gyrus. This study concludes that the brain component N130 is strongly related to perception in a puzzling task network but not the visual processing network.

  7. Review of experimental and theoretical status of the proton radius puzzle

    NASA Astrophysics Data System (ADS)

    Hill, Richard J.

    2017-03-01

    The discrepancy between the measured Lamb shift in muonic hydrogen and expectations from electron-proton scattering and regular hydrogen spectroscopy has become known as the proton radius puzzle, whose most "mundane" resolution requires a > 5σ shift in the value of the fundamental Rydberg constant. I briefly review the status of spectroscopic and scattering measurements, recent theoretical developments, and implications for fundamental physics.

  8. The Quark Puzzle: A Novel Approach to Visualizing the Color Symmetries of Quarks

    ERIC Educational Resources Information Center

    Gettrust, Eric

    2010-01-01

    This paper describes a simple hands-on and visual-method designed to introduce physics students of many age groups to the topic of quarks and their role in forming composite particles (baryons and mesons). A set of puzzle pieces representing individual quarks that fit together in ways consistent with known restrictions of flavor, color, and charge…

  9. (Mis)perception of Sleep in Insomnia: A Puzzle and a Resolution

    ERIC Educational Resources Information Center

    Harvey, Allison G.; Tang, Nicole K. Y.

    2012-01-01

    Insomnia is prevalent, causing severe distress and impairment. This review focuses on illuminating the puzzling finding that many insomnia patients misperceive their sleep. They overestimate their sleep onset latency (SOL) and underestimate their total sleep time (TST), relative to objective measures. This tendency is ubiquitous (although not…

  10. Puzzle task ERP response: time-frequency and source localization analysis

    PubMed Central

    Almurshedi, Ahmed; Ismail, Abd Khamim

    2015-01-01

    Perceptual decision making depends on the choices available for the presented task. Most event-related potential (ERP) experiments are designed with two options, such as YES or NO. In some cases, however, subjects may become confused about the presented task in such a way that they cannot provide a behavioral response. This study aims to put subjects into such a puzzled state in order to address the following questions: How does the brain respond during puzzling moments? And what is the brain’s response to a non-answerable task? To address these questions, ERP were acquired from the brain during a scintillation grid illusion task. The subjects were required to count the number of illusory dots, a task that was impossible to perform. The results showed the presence of N130 over the parietal area during the puzzling task. Coherency among the brain hemispheres was enhanced with the complexity of the task. The neural generators’ source localizations were projected to a multimodal complex covering the left postcentral gyrus, supramarginal gyrus, and angular gyrus. This study concludes that the brain component N130 is strongly related to perception in a puzzling task network but not the visual processing network. PMID:28123804

  11. Gardner's Two Children Problems and Variations: Puzzles with Conditional Probability and Sample Spaces

    ERIC Educational Resources Information Center

    Taylor, Wendy; Stacey, Kaye

    2014-01-01

    This article presents "The Two Children Problem," published by Martin Gardner, who wrote a famous and widely-read math puzzle column in the magazine "Scientific American," and a problem presented by puzzler Gary Foshee. This paper explains the paradox of Problems 2 and 3 and many other variations of the theme. Then the authors…

  12. Engaging Students in a Large Lecture: An Experiment Using Sudoku Puzzles

    ERIC Educational Resources Information Center

    Brophy, Caroline; Hahn, Lukas

    2014-01-01

    In this paper, we describe an in-class experiment that is easy to implement with large groups of students. The experiment takes approximately 15-20 minutes to run and involves each student completing one of four types of Sudoku puzzles and recording the time it takes to completion. The resulting data set can be used as a teaching tool at an…

  13. Fibonacci Numbers and an Area Puzzle: Connecting Geometry and Algebra in the Mathematics Classroom.

    ERIC Educational Resources Information Center

    Sullivan, Mary M.; Panasuk, Regina M.

    1997-01-01

    Presents a mathematical puzzle that asks about "missing" area and leads to an exploration of the Fibonacci sequence as well as genuine inquiry in plane geometry connected to algebra. Discusses the inquiry, the concepts, the solution, and an extension that deepens all students' understanding of the connections between algebra and…

  14. High-mass twins & resolution of the reconfinement, masquerade and hyperon puzzles of compact star interiors

    SciTech Connect

    Blaschke, David; Alvarez-Castillo, David E.

    2016-01-22

    We aim at contributing to the resolution of three of the fundamental puzzles related to the still unsolved problem of the structure of the dense core of compact stars (CS): (i) the hyperon puzzle: how to reconcile pulsar masses of 2 M{sub ⊙} with the hyperon softening of the equation of state (EoS); (ii) the masquerade problem: modern EoS for cold, high density hadronic and quark matter are almost identical; and (iii) the reconfinement puzzle: what to do when after a deconfinement transition the hadronic EoS becomes favorable again? We show that taking into account the compositeness of baryons (by excluded volume and/or quark Pauli blocking) on the hadronic side and confining and stiffening effects on the quark matter side results in an early phase transition to quark matter with sufficient stiffening at high densities which removes all three present-day puzzles of CS interiors. Moreover, in this new class of EoS for hybrid CS falls the interesting case of a strong first order phase transition which results in the observable high mass twin star phenomenon, an astrophysical observation of a critical endpoint in the QCD phase diagram.

  15. Jigsaw Puzzles and River Banks: Two Ways of Picturing Our Future

    ERIC Educational Resources Information Center

    Kretchmar, R. Scott

    2005-01-01

    The papers presented at the 2004 Academy meetings can be thought of as pieces from jigsaw puzzles. While the employment of this metaphor over the years has been useful, we may be ready for a new image, one that is both more accurate and inspiring. We can picture ourselves working at different locations along a river bank. Some of us work upstream,…

  16. (Mis)Aligned Ambitions? Parent Resources, Student Alignment, and Piecing Together the Hispanic College Puzzle

    ERIC Educational Resources Information Center

    Ryan, Sarah Margaret

    2012-01-01

    The fact that Latina/o students are losing ground to their non-Latino White peers in four-year college enrollment and bachelor's degree attainment even as Latino college enrollment and graduation rates are at an all time high constitutes a perplexing puzzle. In order to realize the potential "demographic dividend" embedded in the…

  17. Parents' Attributions of Their Child's Jigsaw-Puzzle Performance: Comparing Two Genetic Syndromes

    ERIC Educational Resources Information Center

    Ly, Tran M.; Hodapp, Robert M.

    2005-01-01

    Parents' attributions of the jigsaw-puzzle performance of their child with Prader-Willi syndrome (n = 20) or Williams syndrome (n = 21) were examined. Parents in both groups placed more importance on internal versus external attributions. Parents of children with Prader-Willi syndrome exhibited a hedonic bias by attributing their child's success…

  18. Purim Puzzles and Laughs: A Project for Mixed-Ability Classes.

    ERIC Educational Resources Information Center

    Adler, Harry

    1996-01-01

    Discusses the use of puzzles and jokes to encourage student interest in an English-as-a-Second-Language class. The object of this project was to relate to a more human context, the playfulness that pushes aside arbitrary school time each spring when Purim comes. (CK)

  19. Understanding the proton radius puzzle: Nuclear structure effects in light muonic atoms

    NASA Astrophysics Data System (ADS)

    Ji, Chen; Hernandez, Oscar Javier; Nevo Dinur, Nir; Bacca, Sonia; Barnea, Nir

    2016-03-01

    We present calculations of nuclear structure effects to the Lamb shift in light muonic atoms. We adopt a modern ab-initio approach by combining state-of-the-art nuclear potentials with the hyperspherical harmonics method. Our calculations are instrumental to the determination of nuclear charge radii in the Lamb shift measurements, which will shed light on the proton radius puzzle.

  20. A Public-Key Based Authentication and Key Establishment Protocol Coupled with a Client Puzzle.

    ERIC Educational Resources Information Center

    Lee, M. C.; Fung, Chun-Kan

    2003-01-01

    Discusses network denial-of-service attacks which have become a security threat to the Internet community and suggests the need for reliable authentication protocols in client-server applications. Presents a public-key based authentication and key establishment protocol coupled with a client puzzle protocol and validates it through formal logic…

  1. Research Studies on Advanced Optical Module/Head Designs for Optical Disk Recording Devices

    NASA Technical Reports Server (NTRS)

    Burke, James J.; Seery, Bernard D.

    1993-01-01

    The Annual Report of the Optical Data Storage Center of the University of Arizona is presented. Summary reports on continuing projects are presented. Research areas include: magneto-optic media, optical heads, and signal processing.

  2. The Optical Disc Roundup.

    ERIC Educational Resources Information Center

    Galbreath, Jeremy

    1993-01-01

    Provides an update on optical disk technology as a means of digital media storage and explains why it may become a standard storage technology for telemedia technology. Topics discussed include read-only formats; write-once formats, including WORM and CD-WORM; rewritable formats; videodiscs; and future possibilities. (LRW)

  3. Recent Advances in Photonic Devices for Optical Computing and the Role of Nonlinear Optics-Part II

    NASA Technical Reports Server (NTRS)

    Abdeldayem, Hossin; Frazier, Donald O.; Witherow, William K.; Banks, Curtis E.; Paley, Mark S.

    2007-01-01

    The twentieth century has been the era of semiconductor materials and electronic technology while this millennium is expected to be the age of photonic materials and all-optical technology. Optical technology has led to countless optical devices that have become indispensable in our daily lives in storage area networks, parallel processing, optical switches, all-optical data networks, holographic storage devices, and biometric devices at airports. This chapters intends to bring some awareness to the state-of-the-art of optical technologies, which have potential for optical computing and demonstrate the role of nonlinear optics in many of these components. Our intent, in this Chapter, is to present an overview of the current status of optical computing, and a brief evaluation of the recent advances and performance of the following key components necessary to build an optical computing system: all-optical logic gates, adders, optical processors, optical storage, holographic storage, optical interconnects, spatial light modulators and optical materials.

  4. A Review of the Evolution of Naval Data Automation and the Optical Media Mass Storage Alternatives Related to Naval Aviation Technical Documentation.

    DTIC Science & Technology

    1987-09-01

    pioneering corporations’ attempts to develop and market optical media: problems encountered. signficance of the compact aisc audio inaustr, success and...audio and ROM discs, the annual sales of the -M niant is in -he order )f SS billion FRef. 1’: p. 341 . Additionally. several other established...5.25 12.00 5.25 10.50 14.00 4.72 5.25 (in.) REEL Access Time .03-.30 •03-.40 .003-. 05 1-40 .01-.08 .5-1.5 .01-.5 (sec) Density (bits,in.) 15,000

  5. Research studies on advanced optical module/head designs for optical devices

    NASA Technical Reports Server (NTRS)

    Burke, James J.

    1991-01-01

    A summary is presented of research in optical data storage materials and of research at the center. The first section contains summary reports under the general headings of: (1) Magnetooptic media: modeling, design, fabrication, characterization, and testing; (2) Optical heads: holographic optical elements; and (3) Optical heads: integrated optics. The second section consist of a proposal entitled, Signal Processing Techniques for Optical Data Storage. And section three presents various publications prepared by the center.

  6. Mass storage at NSA

    NASA Technical Reports Server (NTRS)

    Shields, Michael F.

    1993-01-01

    The need to manage large amounts of data on robotically controlled devices has been critical to the mission of this Agency for many years. In many respects this Agency has helped pioneer, with their industry counterparts, the development of a number of products long before these systems became commercially available. Numerous attempts have been made to field both robotically controlled tape and optical disk technology and systems to satisfy our tertiary storage needs. Custom developed products were architected, designed, and developed without vendor partners over the past two decades to field workable systems to handle our ever increasing storage requirements. Many of the attendees of this symposium are familiar with some of the older products, such as: the Braegen Automated Tape Libraries (ATL's), the IBM 3850, the Ampex TeraStore, just to name a few. In addition, we embarked on an in-house development of a shared disk input/output support processor to manage our every increasing tape storage needs. For all intents and purposes, this system was a file server by current definitions which used CDC Cyber computers as the control processors. It served us well and was just recently removed from production usage.

  7. Coherent Population Oscillation-Based Light Storage.

    PubMed

    Neveu, P; Maynard, M-A; Bouchez, R; Lugani, J; Ghosh, R; Bretenaker, F; Goldfarb, F; Brion, E

    2017-02-17

    We theoretically study the propagation and storage of a classical field in a Λ-type atomic medium using coherent population oscillations (CPOs). We show that the propagation eigenmodes strongly relate to the different CPO modes of the system. Light storage in such modes is discussed by introducing a "populariton" quantity, a mixture of populations and field, by analogy to the dark state polariton used in the context of electromagnetically induced transparency light storage protocol. As experimentally shown, this memory relies on populations and is then-by contrast with usual Raman coherence optical storage protocols-robust to dephasing effects.

  8. Coherent Population Oscillation-Based Light Storage

    NASA Astrophysics Data System (ADS)

    Neveu, P.; Maynard, M.-A.; Bouchez, R.; Lugani, J.; Ghosh, R.; Bretenaker, F.; Goldfarb, F.; Brion, E.

    2017-02-01

    We theoretically study the propagation and storage of a classical field in a Λ -type atomic medium using coherent population oscillations (CPOs). We show that the propagation eigenmodes strongly relate to the different CPO modes of the system. Light storage in such modes is discussed by introducing a "populariton" quantity, a mixture of populations and field, by analogy to the dark state polariton used in the context of electromagnetically induced transparency light storage protocol. As experimentally shown, this memory relies on populations and is then—by contrast with usual Raman coherence optical storage protocols—robust to dephasing effects.

  9. First principles study of hydrogen storage material NaBH4 and LiAlH4 compounds: electronic structure and optical properties

    NASA Astrophysics Data System (ADS)

    Ghellab, T.; Charifi, Z.; Baaziz, H.; Uğur, Ş.; Uğur, G.; Soyalp, F.

    2016-04-01

    A comprehensive study of structure, phase stability, optical and electronic properties of LiAlH4 and NaBH4 light-metal hydrides is presented. The calculations are carried out within density functional theory using the full potential linear augmented plane wave method. The exchange-correlation potential is treated within the local density approximation and the generalized gradient approximation (GGA) to calculate the total energy. Furthermore, the Engel-Vosko GGA approach is employed to compute electronic and optical properties such as reflectivity spectra. The phases α, β and γ of LiAlH4 and NaBH4 hydrides are investigated, the phase transition from the β to the high-pressure γ phase is determined for NaBH4 and is accompanied by a 1% volume decrease. For LiAlH4, no phase transition is detected. The materials under consideration are classified as wide band gap compounds. From the analysis of the structures at different phases, it is deduced that the hydrides show strong covalent interaction between B (Al) and H in the [BH4]- ([AlH4]-) anions and ionic bonding character between [BH4]- and Na+ for NaBH4, and [AlH4]- and Li+ for LiAlH4. The complex dielectric function, absorption coefficient and the reflectivity spectra are also computed and analyzed in different phases.

  10. CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES: Artificial Modulation of Ferroelectric Thin Films into Antiferroelectric through H+ Implantation for High-Density Charge Storage

    NASA Astrophysics Data System (ADS)

    Zhang, Yan-Jun; Fei, Jin-Wen; Tang, Ting-Ao; Jiang, An-Quan

    2008-05-01

    Hydrogen ions are implanted into Pb(Zr0.3Ti0.7)O3 thin films at the energy of 40 keV with a flux of 5 × 1014 ions/cm2. Pseudo-antiferroelectric behaviour in the implanted thin films is observed, as confirmed by the measurements of polarization versus electric hysteresis loops and capacitance versus voltage curves. X-ray diffraction patterns show the film structures before and after H+ implantation both to be perovskite of a tetragonal symmetry. These findings indicate that hydrogen ions exist as stable dopants within the films. It is believed that the dopants change domain-switching behaviour via the boundary charge compensation. Meanwhile, time dependence of leakage current density after time longer than 10s indicates the enhancement of the leakage current nearly in one order for the implanted film, but the current at time shorter than 1 s is mostly the same as that of the original film without the ionic implantation. The artificial tailoring of the antiferroelectric behaviour through H+ implantation in ferroelectric thin films is finally proven to be achievable for the device application of high-density charge storage.

  11. Optical Technology: Interacting with Traditional Systems.

    ERIC Educational Resources Information Center

    McConnell, Karen

    1987-01-01

    Reviews optical technology products currently on the market, including their storage capacities, formats and uses, and outlines the benefits of integrating optical storage devices with online databases. A description of the HAYSTACK system is offered as a model of optical technology for library applications. A suggested reading list is provided.…

  12. Geoscience Data Puzzles: Developing Students' Ability to Make Meaning from Data

    NASA Astrophysics Data System (ADS)

    Kastens, K. A.; Turrin, M.

    2010-12-01

    One of the most fundamental aspects of geoscience expertise is the ability to extract insights from observational earth data. Where an expert might see trends, patterns, processes, and candidate causal relationships, a novice could look at the same data representation and see dots, wiggles and blotches of color. The problem is compounded when the student was not personally involved in collecting the data or samples and thus has no experiential knowledge of the Earth setting that the data represent. In other words, the problem is especially severe when students tap into the vast archives of professionally-collected data that the geoscience community has worked so hard to make available for instructional use over the internet. Moreover, most high school and middle school teachers did not themselves learn Earth Science through analyzing data, and they may lack skills and/or confidence needed to scaffold students through the process of learning to interpret realistically-complex data sets. We have developed “Geoscience Data Puzzles” with the paired goals of (a) helping students learn about the earth from data, and (b) helping teachers learn to teach with data. Geoscience Data Puzzles are data-using activities that purposefully present a low barrier-to-entry for teachers and a high ratio of insight-to-effort for students. Each Puzzle uses authentic geoscience data, but the data are carefully pre-selected in order to illuminate a fundamental Earth process within tractable snippets of data. Every Puzzle offers "Aha" moments, when the connection between data and process comes clear in a rewarding burst of insight. Every Puzzle is accompanied by a Pedagogical Content Knowledge (PCK) guide, which explicates the chain of reasoning by which the puzzle-solver can use the evidence provided by the data to construct scientific claims. Four types of reasoning are stressed: spatial reasoning, in which students make inferences from observations about location, orientation, shape

  13. Submillisecond Optical Knife-Edge Testing

    NASA Technical Reports Server (NTRS)

    Thurlow, P.

    1983-01-01

    Fast computer-controlled sampling of optical knife-edge response (KER) signal increases accuracy of optical system aberration measurement. Submicrosecond-response detectors in optical focal plane convert optical signals to electrical signals converted to digital data, sampled and feed into computer for storage and subsequent analysis. Optical data are virtually free of effects of index-of-refraction gradients.

  14. Gas storage materials, including hydrogen storage materials

    DOEpatents

    Mohtadi, Rana F; Wicks, George G; Heung, Leung K; Nakamura, Kenji

    2014-11-25

    A material for the storage and release of gases comprises a plurality of hollow elements, each hollow element comprising a porous wall enclosing an interior cavity, the interior cavity including structures of a solid-state storage material. In particular examples, the storage material is a hydrogen storage material, such as a solid state hydride. An improved method for forming such materials includes the solution diffusion of a storage material solution through a porous wall of a hollow element into an interior cavity.

  15. Gas storage materials, including hydrogen storage materials

    DOEpatents

    Mohtadi, Rana F; Wicks, George G; Heung, Leung K; Nakamura, Kenji

    2013-02-19

    A material for the storage and release of gases comprises a plurality of hollow elements, each hollow element comprising a porous wall enclosing an interior cavity, the interior cavity including structures of a solid-state storage material. In particular examples, the storage material is a hydrogen storage material such as a solid state hydride. An improved method for forming such materials includes the solution diffusion of a storage material solution through a porous wall of a hollow element into an interior cavity.

  16. The Muon Scattering Experiment (MUSE) at PSI and the proton radius puzzle

    NASA Astrophysics Data System (ADS)

    Kohl, Michael

    2014-11-01

    The unexplained large discrepancy of the proton charge radius measurements with muonic hydrogen Lamb shift and determinations from elastic electron scattering and Lamb shift in regular hydrogen of seven standard deviations is known as the proton radius puzzle. Suggested solutions of the puzzle range from possible errors in the experiments through unexpectedly large hadronic physics effects to new physics beyond the Standard Model. A new approach to verify the radius discrepancy in a systematic manner will be pursued with the Muon Scattering Experiment (MUSE) at PSI. The experiment aims to compare elastic cross sections, the proton elastic form factors, and the extracted proton charge radius with scattering of electrons and muons of either charge and under identical conditions. The difference in the observed radius will be probed with a high precision to verify the discrepancy. An overview of the experiment and the current status will be presented.

  17. Health inequalities and welfare state regimes: theoretical insights on a public health 'puzzle'.

    PubMed

    Bambra, Clare

    2011-09-01

    Welfare states are important determinants of health. Comparative social epidemiology has almost invariably concluded that population health is enhanced by the relatively generous and universal welfare provision of the Scandinavian countries. However, most international studies of socioeconomic inequalities in health have thrown up something of a public health 'puzzle' as the Scandinavian welfare states do not, as would generally be expected, have the smallest health inequalities. This essay outlines and interrogates this puzzle by drawing upon existing theories of health inequalities--artefact, selection, cultural--behavioural, materialist, psychosocial and life course--to generate some theoretical insights. It discusses the limits of these theories in respect to cross-national research; it questions the focus and normative paradigm underpinning contemporary comparative health inequalities research; and it considers the future of comparative social epidemiology.

  18. (Mis)Perception of Sleep in Insomnia: A puzzle and a resolution

    PubMed Central

    Harvey, Allison G.; Tang, Nicole

    2011-01-01

    Insomnia is prevalent, causing severe distress and impairment. This review focuses on illuminating the puzzling finding that many insomnia patients misperceive their sleep. They overestimate their sleep onset latency (SOL) and underestimate their total sleep time (TST), relative to objective measures. This tendency is ubiquitous (although not universal). Resolving this puzzle has clinical, theoretical, and public health importance. There are implications for assessment, definition, and treatment. Moreover, solving the puzzle creates an opportunity for "real world" applications of theories from clinical, perceptual, and social psychology as well as neuroscience. Herein we evaluate thirteen possible resolutions to the puzzle. Specifically, we consider the possible contribution, to misperception, of: (1) features inherent to the context of sleep (e.g., darkness); (2) the definition of sleep onset which may lack sensitivity for insomnia patients; (3) insomnia being an exaggerated sleep complaint; (4) psychological distress causing magnification; (5) a deficit in time estimation ability; (6) sleep being misperceived as wake; (7) worry and selective attention toward sleep-related threats; (8) a memory bias influenced by current symptoms and emotions, a confirmation bias/belief bias or a recall bias linked to the intensity/recency of symptoms; (9) heightened physiological arousal; (10) elevated cortical arousal; (11) the presence of brief awakenings; (12) a fault in neuronal circuitry; and (13) there being two insomnia subtypes (one with and one without misperception). The best supported resolutions were misperception of sleep as wake, worry, and brief awakenings. A deficit in time estimation ability was not supported. We conclude by proposing several integrative solutions. PMID:21967449

  19. Toward a virtual reconstruction of an antique three-dimensional marble puzzle

    NASA Astrophysics Data System (ADS)

    Benamar, Fatima Zahra; Fauvet, Eric; Hostein, Antony; Laligant, Olivier; Truchetet, Frederic

    2017-01-01

    The reconstruction of broken objects is an important field of research for many applications, such as art restoration, surgery, forensics, and solving puzzles. In archaeology, the reconstruction of broken artifacts is a very time-consuming task due to the handling of fractured objects, which are generally fragile. However, it can now be supported by three-dimensional (3-D) data acquisition devices and computer processing. Those techniques are very useful in this domain because they allow the remote handling of very accurate models of fragile parts, they permit the extensive testing of reconstruction solutions, and they provide access to the parts for the entire research community. An interesting problem has recently been proposed by archaeologists in the form of a huge puzzle composed of a thousand fragments of Pentelic marble of different sizes found in Autun (France), and all attempts to reconstruct the puzzle during the last two centuries have failed. Archaeologists are sure that some fragments are missing and that some of the ones we have come from different slabs. We propose an inexpensive transportable system for 3-D acquisition setup and a 3-D reconstruction method that is applied to this Roman inscription but is also relevant to other applications.

  20. Evolutionary, neurobiological, gene-based solution of the ideological "puzzle" of human altruism and cooperation.

    PubMed

    Baschetti, Riccardo

    2007-01-01

    Despite hundreds of published articles about humankind's eusocial behaviours, most scholars still regard the origin of human altruism and cooperation as an enduring puzzle, because it seems incompatible with two central tenets of evolution, namely, the competition between individuals and the consequent selective advantages of selfish traits. This "puzzle", however, rather than being due to insurmountable scientific difficulties, is to be attributed to two powerful ideologies, which are politically opposite, but nevertheless concurred to prevent scholars from solving it. One ideology rejects the concept of genetic determinism, whereas the other dislikes the concept of group selection. As a consequence, these widespread ideologies, which are common in the scientific community, too, kept scholars from realising that the puzzle of human altruism and cooperation can only be solved by proposing a theoretical model that is based precisely on both genetic determinism and group selection. This model, which was never advanced in published papers, is presented here. This article also proposes to regard ancestral environments as determinants of human eusociality. By contrast, virtually all previous articles about it leave primitive habitats unmentioned. To support the hypothesis that human unselfish behaviours represent genetically conserved traits that evolved ancestrally, not products of cultural transmission, this paper also discusses six groups of arguments in the section "Genes versus culture". Finally, this article advances a purely genetic evolutionary explanation for the uniqueness of human eusociality, thereby challenging prevailing cultural explanations for the incomparably developed levels of cooperation in humankind, which are observed in no other social species.

  1. Extreme ultraviolet lithography: A few more pieces of the puzzle

    SciTech Connect

    Anderson, Christopher N.

    2009-05-20

    dissertation describes MOSAIC, a new wavefront metrology that enables complete wavefront recovery from print or aerial image based measurements. This new technique, based on measuring the local focal length of the optic at sampled positions in the pupil, recovers the curvature of the aberration and uses the curvature to recover the aberration itself. In a modeled EUV implementation, MOSAIC is shown to recover the SEMATECH Berkeley MET wavefront with a 4.2% RMS error: a 4% improvement over the reported errors of the original lateral shearing interferometry wavefront measurement.

  2. Interactive Educational Multimedia: Coping with the Need for Increasing Data Storage.

    ERIC Educational Resources Information Center

    Malhotra, Yogesh; Erickson, Ranel E.

    1994-01-01

    Discusses the storage requirements for data forms used in interactive multimedia education and presently available storage devices. Highlights include characteristics of educational multimedia; factors determining data storage requirements; storage devices for video and audio needs; laserdiscs and videodiscs; compact discs; magneto-optical drives;…

  3. Biomarker for Glycogen Storage Diseases

    ClinicalTrials.gov

    2016-08-25

    Fructose Metabolism, Inborn Errors; Glycogen Storage Disease; Glycogen Storage Disease Type I; Glycogen Storage Disease Type II; Glycogen Storage Disease Type III; Glycogen Storage Disease Type IV; Glycogen Storage Disease Type V; Glycogen Storage Disease Type VI; Glycogen Storage Disease Type VII; Glycogen Storage Disease Type VIII

  4. Diffractive optics: Design, fabrication, and applications

    NASA Technical Reports Server (NTRS)

    Morris, G. Michael

    1993-01-01

    The topics are presented in viewgraph form and include the following: features, applications, surface relief diffractive optics, optical data storage, waveguide lenses, diffractive lense imaging, phase grating synthesis, sub-wavelength structured surfaces, etc.

  5. Archival storage solutions for PACS

    NASA Astrophysics Data System (ADS)

    Chunn, Timothy

    1997-05-01

    While they are many, one of the inhibitors to the wide spread diffusion of PACS systems has been robust, cost effective digital archive storage solutions. Moreover, an automated Nearline solution is key to a central, sharable data repository, enabling many applications such as PACS, telemedicine and teleradiology, and information warehousing and data mining for research such as patient outcome analysis. Selecting the right solution depends on a number of factors: capacity requirements, write and retrieval performance requirements, scaleability in capacity and performance, configuration architecture and flexibility, subsystem availability and reliability, security requirements, system cost, achievable benefits and cost savings, investment protection, strategic fit and more.This paper addresses many of these issues. It compares and positions optical disk and magnetic tape technologies, which are the predominant archive mediums today. Price and performance comparisons will be made at different archive capacities, plus the effect of file size on storage system throughput will be analyzed. The concept of automated migration of images from high performance, high cost storage devices to high capacity, low cost storage devices will be introduced as a viable way to minimize overall storage costs for an archive. The concept of access density will also be introduced and applied to the selection of the most cost effective archive solution.

  6. Seasonal thermal energy storage

    SciTech Connect

    Allen, R.D.; Kannberg, L.D.; Raymond, J.R.

    1984-05-01

    This report describes the following: (1) the US Department of Energy Seasonal Thermal Energy Storage Program, (2) aquifer thermal energy storage technology, (3) alternative STES technology, (4) foreign studies in seasonal thermal energy storage, and (5) economic assessment.

  7. Goddard Conference on Mass Storage Systems and Technologies, volume 2

    NASA Technical Reports Server (NTRS)

    Kobler, Ben (Editor); Hariharan, P. C. (Editor)

    1993-01-01

    Papers and viewgraphs from the conference are presented. Discussion topics include the IEEE Mass Storage System Reference Model, data archiving standards, high-performance storage devices, magnetic and magneto-optic storage systems, magnetic and optical recording technologies, high-performance helical scan recording systems, and low end helical scan tape drives. Additional discussion topics addressed the evolution of the identifiable unit for processing (file, granule, data set, or some similar object) as data ingestion rates increase dramatically, and the present state of the art in mass storage technology.

  8. Optical Circuit Switched Protocol

    NASA Technical Reports Server (NTRS)

    Monacos, Steve P. (Inventor)

    2000-01-01

    The present invention is a system and method embodied in an optical circuit switched protocol for the transmission of data through a network. The optical circuit switched protocol is an all-optical circuit switched network and includes novel optical switching nodes for transmitting optical data packets within a network. Each optical switching node comprises a detector for receiving the header, header detection logic for translating the header into routing information and eliminating the header, and a controller for receiving the routing information and configuring an all optical path within the node. The all optical path located within the node is solely an optical path without having electronic storage of the data and without having optical delay of the data. Since electronic storage of the header is not necessary and the initial header is eliminated by the first detector of the first switching node. multiple identical headers are sent throughout the network so that subsequent switching nodes can receive and read the header for setting up an optical data path.

  9. Mass Storage and Retrieval at Rome Laboratory

    NASA Technical Reports Server (NTRS)

    Kann, Joshua L.; Canfield, Brady W.; Jamberdino, Albert A.; Clarke, Bernard J.; Daniszewski, Ed; Sunada, Gary

    1996-01-01

    As the speed and power of modern digital computers continues to advance, the demands on secondary mass storage systems grow. In many cases, the limitations of existing mass storage reduce the overall effectiveness of the computing system. Image storage and retrieval is one important area where improved storage technologies are required. Three dimensional optical memories offer the advantage of large data density, on the order of 1 Tb/cm(exp 3), and faster transfer rates because of the parallel nature of optical recording. Such a system allows for the storage of multiple-Gbit sized images, which can be recorded and accessed at reasonable rates. Rome Laboratory is currently investigating several techniques to perform three-dimensional optical storage including holographic recording, two-photon recording, persistent spectral-hole burning, multi-wavelength DNA recording, and the use of bacteriorhodopsin as a recording material. In this paper, the current status of each of these on-going efforts is discussed. In particular, the potential payoffs as well as possible limitations are addressed.

  10. A new optoelectronic reversible storage medium (Review)

    NASA Astrophysics Data System (ADS)

    Basov, N. G.; Plotnikov, A. F.; Popov, Iu. M.; Seleznev, V. N.

    1987-03-01

    The characteristics of reversible storage media designed for optical data recording (such as thermomagnetic media used in disk storages) are analyzed. Consideration is given to a new class of optoelectronic media based on MNOS structures. It is shown that the data recording density in these media can reach 100,000 bit/sq mm and that the energy of the light pulse which controls the recording will not exceed 10 to the -12th J. The use of these media broadens the possibilities for optical programming and redundancy. The data exchange rate in the optoelectronic memory can reach 10 to the 11th bit/s.

  11. Energy storage criteria handbook

    NASA Astrophysics Data System (ADS)

    Hull, J. R.; Cole, R. L.; Hull, A. B.

    1982-10-01

    The purpose of this handbook is to provide information and criteria necessary for the selection and sizing of energy storage technologies for use at U.S. Naval facilities. The handbook gives Naval base personnel procedures and information to select the most viable energy storage options to provide the space conditioning (heating and cooling) and domestic hot water needs of their facility. The handbook may also be used by contractors, installers, designers, engineers, architects, and manufacturers who intend to enter the energy storage business. The handbook is organized into three major sections: a general section, a technical section, and an example section. While a technical background is assumed for the latter two sections, the general section is simply written and can serve as an introduction to the field of energy storage. The technical section examines the following energy storage technologies: sensible heat storage, latent heat storage, cold storage, thermochemical storage, mechanical storage, pumped hydro storage, and electrochemical storage. The example section is limited to thermal storage and includes examples for: water tank storage, rockbed storage, latent heat storage, and cold water storage.

  12. Durable High-Density Data Storage

    NASA Technical Reports Server (NTRS)

    Lamartine, Bruce C.; Stutz, Roger A.

    1996-01-01

    The focus ion beam (FIB) micromilling process for data storage provides a new non-magnetic storage method for archiving large amounts of data. The process stores data on robust materials such as steel, silicon, and gold coated silicon. The storage process was developed to provide a method to insure the long term storage life of data. We estimate that the useful life of data written on silicon or gold-coated silicon to be on the order of a few thousand years without the need to rewrite the data every few years. The process uses an ion beam to carve material from the surface, much like stone cutters in ancient civilizations removed material from stone. The deeper the information is carved into the media, the longer the expected life of the information. The process can record information in three formats: (1) binary at densities of 23 Gbits/square inch, (2) alphanumeric at optical or non-optical density, and (3) graphical at optical and non-optical density. The formats can be mixed on the same media; and thus, it is possible to record, in a human-viewable format, instructions that can be read using an optical microscope. These instructions provide guidance on reading the remaining higher density information.

  13. Durable high-density data storage

    SciTech Connect

    Stutz, R.A.; Lamartine, B.C.

    1996-09-01

    This paper will discuss the Focus Ion Beam (FIB) milling process, media life considerations, and methods of reading the micromilled data. The FIB process for data storage provides a new non-magnetic storage method for archiving large amounts of data. The process stores data on robust materials such as steel, silicon, and gold coated silicon. The storage process was developed to provide a method to insure the long term storage life of data. We estimate the useful life of data written on silicon or gold coated silicon to be a few thousand years. The process uses an ion beam to carve material from the surface much like stone cutting. The deeper information is carved into the media the longer the expected life of the information. The process can read information in three formats: (1) binary at densities of 3.5 Gbits/cm{sup 2}, (2) alphanumeric at optical or non-optical density, and (3) graphical at optical and non-optical density. The formats can be mixed on the same media; and thus it is possible to record, in a human readable format, instructions that can be read using an optical microscope. These instructions provide guidance on reading the higher density information.

  14. Rewritable optical disk technologies

    NASA Astrophysics Data System (ADS)

    Mansuripur, Masud

    2000-11-01

    The two mainstream technologies for rewritable optical data storage are based on magneto-optical (MO) and phase-change (PC) media. In both cases a focused laser beam is used to raise the temperature of the medium beyond a certain critical temperature (i.e., melting and crystallization temperatures in the case of PC, and the Curie temperature in the case of MO) for writing, erasure, and overwriting of data. The readout of information from these media relies on the change of reflectivity of the medium (PC), or the effect of the medium on the state of polarization of the laser beam (MO). The performance of these data storage systems is characterized by the storage density of the media, achievable data rates during recording and readout, longevity, reliability, and cost of the finished products. These performance criteria in turn are determined by a host of physical and technological factors, among them: (1) Wavelength of the available semiconductor laser diodes; (2) Type of optics used in shaping the laser beam and confining it to sub-micron regions (i.e., conventional optics, near-field optics, flying lasers, integrated optics, etc.); (3) Availability of one- or two- dimensional arrays of lasers and the corresponding optics; (4) Miniature magnetic heads for thermally-assisted writing (inductive) and magneto-resistive readout; (5) Adaptive optics for beam-shaping and/or polarization control; (6) Availability of low-noise media that can deliver large readout signals; (7) Advanced signal processing techniques (both optical and electronic); (8) Multi-layer recording on stacked layers of media; (9) Novel encoding/decoding schemes for efficient use of available space on the media; (10) Mass-production of flat, rigid, low-noise patterned substrates (plastic or glass); (11) Multi-level recording. We discuss the present state of the art in optical data storage, describe the potentials and pitfalls of the existing technologies, and draw conclusions about the future of this

  15. An Interactive 3D Virtual Anatomy Puzzle for Learning and Simulation - Initial Demonstration and Evaluation.

    PubMed

    Messier, Erik; Wilcox, Jascha; Dawson-Elli, Alexander; Diaz, Gabriel; Linte, Cristian A

    2016-01-01

    To inspire young students (grades 6-12) to become medical practitioners and biomedical engineers, it is necessary to expose them to key concepts of the field in a way that is both exciting and informative. Recent advances in medical image acquisition, manipulation, processing, visualization, and display have revolutionized the approach in which the human body and internal anatomy can be seen and studied. It is now possible to collect 3D, 4D, and 5D medical images of patient specific data, and display that data to the end user using consumer level 3D stereoscopic display technology. Despite such advancements, traditional 2D modes of content presentation such as textbooks and slides are still the standard didactic equipment used to teach young students anatomy. More sophisticated methods of display can help to elucidate the complex 3D relationships between structures that are so often missed when viewing only 2D media, and can instill in students an appreciation for the interconnection between medicine and technology. Here we describe the design, implementation, and preliminary evaluation of a 3D virtual anatomy puzzle dedicated to helping users learn the anatomy of various organs and systems by manipulating 3D virtual data. The puzzle currently comprises several components of the human anatomy and can be easily extended to include additional organs and systems. The 3D virtual anatomy puzzle game was implemented and piloted using three display paradigms - a traditional 2D monitor, a 3D TV with active shutter glass, and the DK2 version Oculus Rift, as well as two different user interaction devices - a space mouse and traditional keyboard controls.

  16. A 17 keV neutrino and large magnetic moment solution of the solar neutrino puzzle

    NASA Astrophysics Data System (ADS)

    Akhmedov, E. Kh.; Senjanovic, G.; Tao, Zhijian; Berezhiani, Z. G.

    1992-08-01

    Zee-type models with Majorons naturally incorporate the 17 keV neutrino but in their minimal version fail to simultaneously solve the solar neutrino puzzle. If there is a sterile neutrino state, a particularly simple solution is found to the solar neutrino problem, which besides nu(sub 17) predicts a light Zeldovich-Konopinski-Mahmoud neutrino nu(sub light) = nu(sub e) + nu(sub mu)(sup c) with a magnetic moment being easily as large as 10(exp -11)(mu)(sub B) through the Barr-Freire-Zee mechanism.

  17. 17 keV neutrino and large magnetic moment solution of the solar neutrino puzzle

    NASA Astrophysics Data System (ADS)

    Akhmedov, Eugeni Kh.; Berezhiani, Zurab G.; Senjanović, Goran; Tao, Zhijian

    1993-01-01

    Zee-type models with majorons naturally incorporate the 17 keV neutrino but in their minimal version fail to simultaneously solve the solar neutrino puzzle. If there is a sterile neutrino state, we find a particularly simple solution to the solar neutrino problem, which besides ν17 predicts a light Zeldovich-Konopinski-Mahmoud neutrino νlight = νe + νcμ with a magnetic moment being easily as large as 10 -11μB through the Barr-Freire-Zee mechanism.

  18. Exchange rate regimes, saving glut and the Feldstein Horioka puzzle: The East Asian experience

    NASA Astrophysics Data System (ADS)

    Kaya-Bahçe, Seçil; Özmen, Erdal

    2008-04-01

    This paper investigates whether the recent experience of the emerging East Asian countries with current account surpluses is consistent with the “saving glut” hypothesis and the Feldstein and Horioka puzzle. The evidence suggests that the saving retention coefficients declined substantially in most of the countries after an endogenous break date coinciding with a major exchange rate regime change with the 1997-1998 crisis. Exchange rate flexibility appears to be enhancing financial integration. The results are consistent with an “investment slump” explanation rather than the “saving glut” postulation.

  19. Tectonic Puzzles.

    ERIC Educational Resources Information Center

    Caballero, Julio Faustino; Harris, Delphia F.

    1996-01-01

    Presents an activity that uses the study of earthquakes to provide a rich educational experience to reinforce and expand students' knowledge of the structure of the Earth, provide an application of physics concepts such as force and energy, and present these topics integrated with a unit on mathematics. (JRH)

  20. Ultra-Dense Optical Mass Storage

    DTIC Science & Technology

    1991-02-11

    Plenum Press, (1976) p 45-48. 20. H.S. Carslaw and J.C. Jaeger, Conduction of Hsat in Solids, 2nd Edition, Clarendon Press, (1986) 130. 21. Charles ... Kittel , Introduction to Solid State Physics 4th Edition, John Wiley and Sons Inc., (1971) 230.3 22. A. Renn, A.J. Meixner, U.P. Wild and F.A. Burkhalter

  1. Ultra-Defense Optical Mass Storage

    DTIC Science & Technology

    1992-07-30

    an etalon both of which can be mechanically adjusted by motorized micrometers so as to permit direct access to any desired wavelength. The combination...lead to hot 9 spots and non- linearities .) Once the polarizer is set, the phase code used is created by a simple random number generator, and encoded...capability to provide the I/O control of all the system components. Standard interface cards provide communication to the shutters, motorized micrometers, the

  2. Eta Carinae: A Box of Puzzles...Some Solved, Others Await

    NASA Technical Reports Server (NTRS)

    Gull, Theodore

    2010-01-01

    In the l840's, Eta Carinae brightened to rival Sirius, then faded. Today we see a marginally naked-eye binary with an expanding, very dusty bipolar Homunculus. The energetics of the ejected mass (>l2 to 40 solar masses at 500-700 km/s plus outer bullets/strings up to 3000 km/s} approach that of a supernova. Extragalactic SN surveys detect near-supernovae thought to be like the Great Eruption of the 1840's. Eta Carinae presents an abundance of puzzles: rich in N, but 1/100th the solar C and O abundances; Ti, V, Sr, Sc persist in atomic states.... yet an abundance of molecules and dust exists in the Homunculus. How did molecules and dust form with low C and O? A near supernova occurred in the l840m, yet both binary companions, with total mass > 120 solar masses, survive in a very eccentric orbit. What is the near future of this system: a GRB? a SN? or just two WR stars that ultimately become two SNs? These and other puzzles will be presented

  3. A Hybrid alldifferent-Tabu Search Algorithm for Solving Sudoku Puzzles.

    PubMed

    Soto, Ricardo; Crawford, Broderick; Galleguillos, Cristian; Paredes, Fernando; Norero, Enrique

    2015-01-01

    The Sudoku problem is a well-known logic-based puzzle of combinatorial number-placement. It consists in filling a n(2) × n(2) grid, composed of n columns, n rows, and n subgrids, each one containing distinct integers from 1 to n(2). Such a puzzle belongs to the NP-complete collection of problems, to which there exist diverse exact and approximate methods able to solve it. In this paper, we propose a new hybrid algorithm that smartly combines a classic tabu search procedure with the alldifferent global constraint from the constraint programming world. The alldifferent constraint is known to be efficient for domain filtering in the presence of constraints that must be pairwise different, which are exactly the kind of constraints that Sudokus own. This ability clearly alleviates the work of the tabu search, resulting in a faster and more robust approach for solving Sudokus. We illustrate interesting experimental results where our proposed algorithm outperforms the best results previously reported by hybrids and approximate methods.

  4. Heavy flavor puzzle at LHC: a serendipitous interplay of jet suppression and fragmentation.

    PubMed

    Djordjevic, Magdalena

    2014-01-31

    Both charged hadrons and D mesons are considered to be excellent probes of QCD matter created in ultrarelativistic heavy ion collisions. Surprisingly, recent experimental observations at LHC show the same jet suppression for these two probes, which--contrary to pQCD expectations--may suggest similar energy losses for light quarks and gluons in the QCD medium. We here use our recently developed energy loss formalism in a finite-size dynamical QCD medium to analyze this phenomenon that we denote as the "heavy flavor puzzle at LHC." We show that this puzzle is a consequence of an unusual combination of the suppression and fragmentation patterns and, in fact, does not require invoking the same energy loss for light partons. Furthermore, we show that this combination leads to a simple relationship between the suppressions of charged hadrons and D mesons and the corresponding bare quark suppressions. Consequently, a coincidental matching of jet suppression and fragmentation allows considerably simplifying the interpretation of the corresponding experimental data.

  5. A Hybrid alldifferent-Tabu Search Algorithm for Solving Sudoku Puzzles

    PubMed Central

    Crawford, Broderick; Paredes, Fernando; Norero, Enrique

    2015-01-01

    The Sudoku problem is a well-known logic-based puzzle of combinatorial number-placement. It consists in filling a n2 × n2 grid, composed of n columns, n rows, and n subgrids, each one containing distinct integers from 1 to n2. Such a puzzle belongs to the NP-complete collection of problems, to which there exist diverse exact and approximate methods able to solve it. In this paper, we propose a new hybrid algorithm that smartly combines a classic tabu search procedure with the alldifferent global constraint from the constraint programming world. The alldifferent constraint is known to be efficient for domain filtering in the presence of constraints that must be pairwise different, which are exactly the kind of constraints that Sudokus own. This ability clearly alleviates the work of the tabu search, resulting in a faster and more robust approach for solving Sudokus. We illustrate interesting experimental results where our proposed algorithm outperforms the best results previously reported by hybrids and approximate methods. PMID:26078751

  6. Understanding the ``Proton Radius Puzzle'': Nuclear Polarizability Correction in μD

    NASA Astrophysics Data System (ADS)

    Hernandez, Oscar J.; Dinur, Nir Nevo; Ji, Chen; Bacca, Sonia; Barnea, Nir

    2016-09-01

    The accuracy of the proton radius was improved ten-fold by new spectroscopic measurements in muonic hydrogen but it differs by 7 σ from hydrogen determinations. This discrepancy, has been coined the ``proton radius puzzle''. The results of new high-precision experiments on muonic deuterium indicate a new deuterium radius puzzle. The accuracy of the nuclear charge radius determination from these measurements is limited by the uncertainty in the nuclear structure effects. We have calculated this correction in Ref. including the first estimate of the nuclear-model dependence. Due to the importance of constraining the uncertainty, we will determine the statistical and systematic uncertainties of the χEFT potentials by determining the co-variance matrices of our predictions. I will also discuss an alternate method that may reduce the theoretical uncertainty. TRIUMF receives federal funding via a contribution agreement with the National Research Council of Canada. This work was supported in parts by the Natural Sciences and Engineering Research Council (Grant Number SAPIN-2015-00031).

  7. Optical memory system technology. Citations from the International Aerospace Abstracts data base

    NASA Technical Reports Server (NTRS)

    Zollars, G. F.

    1980-01-01

    Approximately 213 citations from the international literature which concern the development of the optical data storage system technology are presented. Topics covered include holographic computer storage devices, crystal, magneto, and electro-optics, imaging techniques, in addition to optical data processing and storage.

  8. Optomechanical light storage in a silica microresonator

    NASA Astrophysics Data System (ADS)

    Fiore, Victor; Dong, Chunhua; Kuzyk, Mark C.; Wang, Hailin

    2013-02-01

    Coherent interconversion between an optical and a mechanical excitation in an optomechanical resonator can be used for the storage of an optical pulse as an excitation in a mechanical oscillator. This optomechanical light storage is enabled by external writing and readout pulses at one mechanical frequency below the optical resonance. In this paper, we expand an earlier experimental study [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.107.133601 107, 133601 (2011)] on storing an optical pulse as a radial breathing mode in a silica microsphere. We show that the heterodyne beating between a readout pulse and the corresponding retrieved pulse features a periodic oscillation with a well-defined phase and with the beating period given by the mechanical frequency, demonstrating directly the coherent nature of the light storage process. The coherent interconversion accelerates with increasing optomechanical coupling rates, providing an effective mechanism for tailoring the temporal profile of the retrieved pulse. Experimental studies on both light storage and optomechanically induced transparency under nearly the same conditions also illustrate the connections between these two closely related processes.

  9. Initial blood storage experiment

    NASA Technical Reports Server (NTRS)

    Surgenor, Douglas MACN.

    1988-01-01

    The possibility of conducting experiments with the formed elements of the blood under conditions of microgravity opens up important opportunities to improve the understanding of basic formed element physiology, as well as, contribution to improved preservation of the formed elements for use in transfusion. The physiological, biochemical, and physical changes of the membrane of the erythrocyte, platelet, and leukocyte was studied during storage under two specific conditions: standard blood bank conditions and microgravity, utilizing three FDA approved plastic bags. Storage lesions; red cell storage on Earth; platelet storage on Earth; and leukocyte storage Earth were examined. The interaction of biomaterials and blood cells was studied during storage.

  10. Storage and flood routing

    USGS Publications Warehouse

    Carter, R.W.; Godfrey, R.G.

    1960-01-01

    The basic equations used in flood routing are developed from the law of continuity. In each method the assumptions are discussed to enable the user to select an appropriate technique. In the stage-storage method the storage is related to the mean gage height in the reach under consideration. In the discharge-storage method the storage is determined, from weighted values of inflow and outflow discharge. In the reservoir-storage method the storage is considered as a function of outflow discharge alone. A detailed example is given for each method to illustrate that particular technique.

  11. Optical Circuitry Cooperative

    NASA Astrophysics Data System (ADS)

    Gibbs, H. M.; Gibson, U.; Peyghambarian, N.; Sarid, D.; Stegeman, G.

    1985-01-01

    An Optical Circuitry Cooperative (OCC) has been formed as an NSF cooperative research center in which six or more companies contribute financial support; NSF provides support which declines to zero in five years. Companies benefit from a center by early access to research results, leverage for their research dollars, participation in research selection, and improved relations with faculty and students. The university receives support for a major research program that increases its research capability, provides reasonably stable funding, and opens more opportunities for graduate students. The potential of optical circuitry has been discussed for many years, but the excitement is growing rapidly on the strength of the success of optical fibers for optical transmission, the generation of subpicosecond opitcal pulses, and the development of promising optical logic elements, such as optical bistable devices. And yet, much research remains to be done to discover the best nonlinear optical materials and fabrication techniques. OCC will perform research to provide a data base to allow the development of optical circuitry devices. The areas encompassed by OCC include all-optical logic, picosecond decision-making, guided-wave preprocessors, opti-cal interconnects within computers (both fiber and whole-array imaging), optical storage, and optical computer architecture and devices.

  12. Holographic data storage using azobenzene polymer

    NASA Astrophysics Data System (ADS)

    Wang, Michael R.; Yang, Jianwen; Yan, Xingzhong; DeMasi, Ralph

    2001-10-01

    It is well known that holographic data storage can significantly increase data storage capacity. However, the technological maturity of holographic data storage is believed to be impeded by the lack of good holographic material that can be erased and recorded optically with almost unlimited rewriting cycles, large index modulation for large capacity multiplexed data recording, long lifetime, and immunity to destructive readout for archival applications. The performance of an azobenzene polymer is presented for holographic data storage applications. Initial experiments demonstrated that it is capable of satisfying many of above requirements. Recording of holograms without follow-up processing and being stable in application environment are its most attractive features. Applications of such material to other adaptive structures are possible.

  13. Multiplexed image storage by electromagnetically induced transparency in a solid

    NASA Astrophysics Data System (ADS)

    Heinze, G.; Rentzsch, N.; Halfmann, T.

    2012-11-01

    We report on frequency- and angle-multiplexed image storage by electromagnetically induced transparency (EIT) in a Pr3+:Y2SiO5 crystal. Frequency multiplexing by EIT relies on simultaneous storage of light pulses in atomic coherences, driven in different frequency ensembles of the inhomogeneously broadened solid medium. Angular multiplexing by EIT relies on phase matching of the driving laser beams, which permits simultaneous storage of light pulses propagating under different angles into the crystal. We apply the multiplexing techniques to increase the storage capacity of the EIT-driven optical memory, in particular to implement multiplexed storage of larger two-dimensional amounts of data (images). We demonstrate selective storage and readout of images by frequency-multiplexed EIT and angular-multiplexed EIT, as well as the potential to combine both multiplexing approaches towards further enhanced storage capacities.

  14. Passive storage technologies

    NASA Technical Reports Server (NTRS)

    Kittel, P.

    1984-01-01

    Advances in storage technology and how passive techniques could be applied to the storage of propellants at the space station are described. The devices considered are passive orbital disconnect struts, cooled shield optimization, liftweight shields and catalytic converters.

  15. Multichannel optical sensing device

    DOEpatents

    Selkowitz, S.E.

    1985-08-16

    A multichannel optical sensing device is disclosed, for measuring the outdoor sky luminance or illuminance or the luminance or illuminance distribution in a room, comprising a plurality of light receptors, an optical shutter matrix including a plurality of liquid crystal optical shutter elements operable by electrical control signals between light transmitting and light stopping conditions, fiber optical elements connected between the receptors and the shutter elements, a microprocessor based programmable control unit for selectively supplying control signals to the optical shutter elements in a programmable sequence, a photodetector including an optical integrating spherical chamber having an input port for receiving the light from the shutter matrix and at least one detector element in the spherical chamber for producing output signals corresponding to the light, and output units for utilizing the output signals including a storage unit having a control connection to the microprocessor based programmable control unit for storing the output signals under the sequence control of the programmable control unit.

  16. Multichannel optical sensing device

    DOEpatents

    Selkowitz, Stephen E.

    1990-01-01

    A multichannel optical sensing device is disclosed, for measuring the outr sky luminance or illuminance or the luminance or illuminance distribution in a room, comprising a plurality of light receptors, an optical shutter matrix including a plurality of liquid crystal optical shutter elements operable by electrical control signals between light transmitting and light stopping conditions, fiber optic elements connected between the receptors and the shutter elements, a microprocessor based programmable control unit for selectively supplying control signals to the optical shutter elements in a programmable sequence, a photodetector including an optical integrating spherical chamber having an input port for receiving the light from the shutter matrix and at least one detector element in the spherical chamber for producing output signals corresponding to the light, and output units for utilizing the output signals including a storage unit having a control connection to the microprocessor based programmable control unit for storing the output signals under the sequence control of the programmable control unit.

  17. Energy Storage Criteria Handbook.

    DTIC Science & Technology

    1982-10-01

    of energy storage. A glossary defines most of the technical terms used. , The general section first outlines the available energy storage technologies...the end of each chapter and in the sources listed in the bibliography. The example section is limited to thermal energy storage. First , the . currently...a technical back’ )und wanting to thoroughly under- stand one or more areas of energy storage -chnology should first read Chapter 2, and possibly

  18. Thermal energy storage

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The planning and implementation of activities associated with lead center management role and the technical accomplishments pertaining to high temperature thermal energy storage subsystems are described. Major elements reported are: (1) program definition and assessment; (2) research and technology development; (3) industrial storage applications; (4) solar thermal power storage applications; and (5) building heating and cooling applications.

  19. Tracking the Footprints Puzzle: The Problematic Persistence of Science-as-Process in Teaching the Nature and Culture of Science

    ERIC Educational Resources Information Center

    Ault, Charles R., Jr.; Dodick, Jeff

    2010-01-01

    For many decades, science educators have asked, "In what ways should learning the content of traditional subjects serve as the means to more general ends, such as understanding the nature of science or the processes of scientific inquiry?" Acceptance of these ends reduces the role of disciplinary context; the "Footprints Puzzle" and Oregon's…

  20. An Effective Method of Introducing the Periodic Table as a Crossword Puzzle at the High School Level

    ERIC Educational Resources Information Center

    Joag, Sushama D.

    2014-01-01

    A simple method to introduce the modern periodic table of elements at the high school level as a game of solving a crossword puzzle is presented here. A survey to test the effectiveness of this new method relative to the conventional method, involving use of a wall-mounted chart of the periodic table, was conducted on a convenience sample. This…

  1. Puzzling out Form: Design Visualization--New Technology Often Presents the Opportunity for the Designer to Imagine New Forms

    ERIC Educational Resources Information Center

    Funk, Roger L.

    2004-01-01

    This article addresses how to help students develop an aptitude for seeing relationships between elements and puzzling out new forms in doing so. Four different approaches are presented. Each illustrates a way that industrial designers work in considering the form of a product. A classroom activity is included.

  2. KnowledgePuzzle: A Browsing Tool to Adapt the Web Navigation Process to the Learner's Mental Model

    ERIC Educational Resources Information Center

    AlAgha, Iyad

    2012-01-01

    This article presents KnowledgePuzzle, a browsing tool for knowledge construction from the web. It aims to adapt the structure of web content to the learner's information needs regardless of how the web content is originally delivered. Learners are provided with a meta-cognitive space (e.g., a concept mapping tool) that enables them to plan…

  3. Optic glioma

    MedlinePlus

    Glioma - optic; Optic nerve glioma; Juvenile pilocytic astrocytoma; Brain cancer - optic glioma ... Optic gliomas are rare. The cause of optic gliomas is unknown. Most optic gliomas are slow-growing ...

  4. Puzzle test: A tool for non-analytical clinical reasoning assessment

    PubMed Central

    Monajemi, Alireza; Yaghmaei, Minoo

    2016-01-01

    Most contemporary clinical reasoning tests typically assess non-automatic thinking. Therefore, a test is needed to measure automatic reasoning or pattern recognition, which has been largely neglected in clinical reasoning tests. The Puzzle Test (PT) is dedicated to assess automatic clinical reasoning in routine situations. This test has been introduced first in 2009 by Monajemi et al in the Olympiad for Medical Sciences Students.PT is an item format that has gained acceptance in medical education, but no detailed guidelines exist for this test’s format, construction and scoring. In this article, a format is described and the steps to prepare and administer valid and reliable PTs are presented. PT examines a specific clinical reasoning task: Pattern recognition. PT does not replace other clinical reasoning assessment tools. However, it complements them in strategies for assessing comprehensive clinical reasoning. PMID:28210603

  5. Puzzles in modern biology. III.Two kinds of causality in age-related disease.

    PubMed

    Frank, Steven A

    2016-01-01

    The two primary causal dimensions of age-related disease are rate and function. Change in rate of disease development shifts the age of onset. Change in physiological function provides necessary steps in disease progression. A causal factor may alter the rate of physiological change, but that causal factor itself may have no direct physiological role. Alternatively, a causal factor may provide a necessary physiological function, but that causal factor itself may not alter the rate of disease onset. The rate-function duality provides the basis for solving puzzles of age-related disease. Causal factors of cancer illustrate the duality between rate processes of discovery, such as somatic mutation, and necessary physiological functions, such as invasive penetration across tissue barriers. Examples from cancer suggest general principles of age-related disease.

  6. The puzzling Venusian polar atmospheric structure reproduced by a general circulation model

    PubMed Central

    Ando, Hiroki; Sugimoto, Norihiko; Takagi, Masahiro; Kashimura, Hiroki; Imamura, Takeshi; Matsuda, Yoshihisa

    2016-01-01

    Unlike the polar vortices observed in the Earth, Mars and Titan atmospheres, the observed Venus polar vortex is warmer than the midlatitudes at cloud-top levels (∼65 km). This warm polar vortex is zonally surrounded by a cold latitude band located at ∼60° latitude, which is a unique feature called ‘cold collar' in the Venus atmosphere. Although these structures have been observed in numerous previous observations, the formation mechanism is still unknown. Here we perform numerical simulations of the Venus atmospheric circulation using a general circulation model, and succeed in reproducing these puzzling features in close agreement with the observations. The cold collar and warm polar region are attributed to the residual mean meridional circulation enhanced by the thermal tide. The present results strongly suggest that the thermal tide is crucial for the structure of the Venus upper polar atmosphere at and above cloud levels. PMID:26832195

  7. Oestrogen and the cardiovascular system: the good, the bad and the puzzling.

    PubMed

    Gray, G A; Sharif, I; Webb, D J; Seckl, J R

    2001-03-01

    The concept that oestrogen replacement therapy is cardioprotective has been challenged recently by the negative results of randomized clinical trials in coronary heart disease. These data have come at a time of rapid advances in our understanding of the cellular mechanisms of oestrogen. In particular, the cloning of the classical oestrogen receptor (ERalpha), the identification of a novel ER isoform (ERbeta), the availability of specific ERalpha and ERbeta knockout mice models, and the elucidation of receptor functions and signalling pathways linked to non-genomic actions of oestrogen are helping to unravel this complex biology. In this article, these advances will be discussed with particular emphasis on the regulation of nitric oxide synthesis by oestrogen. Furthermore, the puzzling issues that have emerged and the potential for development of novel and specific therapeutic approaches will be highlighted.

  8. Completing the nuclear reaction puzzle of the nucleosynthesis of 92Mo

    NASA Astrophysics Data System (ADS)

    Tveten, G. M.; Spyrou, A.; Schwengner, R.; Naqvi, F.; Larsen, A. C.; Eriksen, T. K.; Bello Garrote, F. L.; Bernstein, L. A.; Bleuel, D. L.; Crespo Campo, L.; Guttormsen, M.; Giacoppo, F.; Görgen, A.; Hagen, T. W.; Hadynska-Klek, K.; Klintefjord, M.; Meyer, B. S.; Nyhus, H. T.; Renstrøm, T.; Rose, S. J.; Sahin, E.; Siem, S.; Tornyi, T. G.

    2016-08-01

    One of the greatest questions for modern physics to address is how elements heavier than iron are created in extreme astrophysical environments. A particularly challenging part of that question is the creation of the so-called p -nuclei, which are believed to be mainly produced in some types of supernovae. The lack of needed nuclear data presents an obstacle in nailing down the precise site and astrophysical conditions. In this work, we present for the first time measurements on the nuclear level density and average γ strength function of 92Mo. State-of-the-art p -process calculations systematically underestimate the observed solar abundance of this isotope. Our data provide stringent constraints on the 91Nb(p ,γ )92Mo reaction rate, which is the last unmeasured reaction in the nucleosynthesis puzzle of 92Mo. Based on our results, we conclude that the 92Mo abundance anomaly is not due to the nuclear physics input to astrophysical model calculations.

  9. Height of female Americans in the 19th century and the antebellum puzzle.

    PubMed

    Carson, Scott Alan

    2011-03-01

    Using 19th century state prison records, this study contrasts the biological standard of living of comparable US African-American and white females during a period of relatively rapid economic development. White females were consistently taller than black females by about 1.5 cm (0.6 in.). Whites from Great Lakes and Plains states and black Southwestern females were the tallest. US females were tall compared to their European counterparts. The height of females began to decline in the antebellum period, possibly before that of males. The recovery of physical stature was also earlier among females than among males. This implies that the biological standard of lower-class men and women did not move in parallel during the onset of modern economic growth. It also implies that the antebellum puzzle was most likely rooted in the endogenous forces of socio-economic change rather than the exogenous changes in the disease environment.

  10. Natural killer cells: the journey from puzzles in biology to treatment of cancer.

    PubMed

    Bodduluru, Lakshmi Narendra; Kasala, Eshvendar Reddy; Madhana, Rajaram Mohan Rao; Sriram, Chandra Shaker

    2015-02-28

    Natural Killer (NK) cells are innate immune effectors that are primarily involved in immunosurveillance to spontaneously eliminate malignantly transformed and virally infected cells without prior sensitization. NK cells trigger targeted attack through release of cytotoxic granules, and secrete various cytokines and chemokines to promote subsequent adaptive immune responses. NK cells selectively attack target cells with diminished major histocompatibility complex (MHC) class I expression. This "Missing-self" recognition by NK cells at first puzzled researchers in the early 1990s, and the mystery was solved with the discovery of germ line encoded killer immunoglobulin receptors that recognize MHC-I molecules. This review summarizes the biology of NK cells detailing the phenotypes, receptors and functions; interactions of NK cells with dendritic cells (DCs), macrophages and T cells. Further we discuss the various strategies to modulate NK cell activity and the practice of NK cells in cancer immunotherapy employing NK cell lines, autologous, allogeneic and genetically engineered cell populations.

  11. Puzzle test: A tool for non-analytical clinical reasoning assessment.

    PubMed

    Monajemi, Alireza; Yaghmaei, Minoo

    2016-01-01

    Most contemporary clinical reasoning tests typically assess non-automatic thinking. Therefore, a test is needed to measure automatic reasoning or pattern recognition, which has been largely neglected in clinical reasoning tests. The Puzzle Test (PT) is dedicated to assess automatic clinical reasoning in routine situations. This test has been introduced first in 2009 by Monajemi et al in the Olympiad for Medical Sciences Students.PT is an item format that has gained acceptance in medical education, but no detailed guidelines exist for this test's format, construction and scoring. In this article, a format is described and the steps to prepare and administer valid and reliable PTs are presented. PT examines a specific clinical reasoning task: Pattern recognition. PT does not replace other clinical reasoning assessment tools. However, it complements them in strategies for assessing comprehensive clinical reasoning.

  12. Puzzling Hard X-ray Emission from Hot Single White Dwarfs

    NASA Astrophysics Data System (ADS)

    Chu, You-Hua

    2012-10-01

    The hot white dwarf WD2226-210 is the central star of the Helix Nebula. It shows soft X-ray photospheric emission and a hard component peaking near 1 keV, which is puzzling as WD2226-210 has neither a binary companion nor a fast wind. Such hard X-rays are rare among single WDs but more common among central stars of PNe. We request 300 ks XMM-Newton observations of WD2226-210, using RGS spectra to determine plasma temperatures, abundances, and ionization equilibrium, and using EPIC data to study temporal variations of the 1 keV emission. We also request short observations of three other WDs with hard X-ray emission. The results will allow us to critically address different emission mechanisms for hard X-rays and their implications on stellar evolution and binary mergers.

  13. The solar neutrino puzzle and the vL --> vR conversion hypothesis

    NASA Astrophysics Data System (ADS)

    Barbieri, R.; Fiorentini, G.

    As a possible explanation of the solar neutrino puzzle, several authors have invoked a neutrino helicity rotation (vL --> vR) in the solar magnetic field, coupled to a neutrino magnetic moment. We discuss: (i) the effect on the vL --> vR conversion probability of the different coherent interaction with matter of the two neutrino helicity states; (ii) the azimuthal asymmetry in the elastic v-e scattering of solar neutrinos, due to the interference between the weak and the electromagnetic amplitude. We also briefly comment on the theoretical problem posed by a neutrino magnetic moment as large as 10-10μB. Dipartimento di Fisica, Università di Cagliari, Italy.

  14. OLD PUZZLE, NEW INSIGHTS: A LITHIUM-RICH GIANT QUIETLY BURNING HELIUM IN ITS CORE

    SciTech Connect

    Aguirre, V. Silva; Christensen-Dalsgaard, J.; Jessen-Hansen, J.; Ruchti, G. R.; Hekker, S.; Cassisi, S.; Datta, A.; Jendreieck, A.; Mazumdar, A.; Mosser, B.; Stello, D.; Beck, P. G.; De Ridder, J.

    2014-03-20

    About 1% of giant stars have been shown to have large surface Li abundances, which is unexpected according to standard stellar evolution models. Several scenarios for lithium production have been proposed, but it is still unclear why these Li-rich giants exist. A missing piece in this puzzle is the knowledge of the exact stage of evolution of these stars. Using low- and-high-resolution spectroscopic observations, we have undertaken a survey of lithium-rich giants in the Kepler field. In this Letter, we report the finding of the first confirmed Li-rich core-helium-burning giant, as revealed by asteroseismic analysis. The evolutionary timescales constrained by its mass suggest that Li production most likely took place through non-canonical mixing at the RGB tip, possibly during the helium flash.

  15. Puzzles in modern biology. III.Two kinds of causality in age-related disease

    PubMed Central

    Frank, Steven A.

    2017-01-01

    The two primary causal dimensions of age-related disease are rate and function. Change in rate of disease development shifts the age of onset. Change in physiological function provides necessary steps in disease progression. A causal factor may alter the rate of physiological change, but that causal factor itself may have no direct physiological role. Alternatively, a causal factor may provide a necessary physiological function, but that causal factor itself may not alter the rate of disease onset. The rate-function duality provides the basis for solving puzzles of age-related disease. Causal factors of cancer illustrate the duality between rate processes of discovery, such as somatic mutation, and necessary physiological functions, such as invasive penetration across tissue barriers. Examples from cancer suggest general principles of age-related disease. PMID:28184283

  16. Flaxion: a minimal extension to solve puzzles in the standard model

    NASA Astrophysics Data System (ADS)

    Ema, Yohei; Hamaguchi, Koichi; Moroi, Takeo; Nakayama, Kazunori

    2017-01-01

    We propose a minimal extension of the standard model which includes only one additional complex scalar field, flavon, with flavor-dependent global U(1) symmetry. It not only explains the hierarchical flavor structure in the quark and lepton sector (including neutrino sector), but also solves the strong CP problem by identifying the CP-odd component of the flavon as the QCD axion, which we call flaxion. Furthermore, the flaxion model solves the cosmological puzzles in the standard model, i.e., origin of dark matter, baryon asymmetry of the universe, and inflation. We show that the radial component of the flavon can play the role of inflaton without isocurvature nor domain wall problems. The dark matter abundance can be explained by the flaxion coherent oscillation, while the baryon asymmetry of the universe is generated through leptogenesis.

  17. Gold-nanoparticle-mediated jigsaw-puzzle-like assembly of supersized plasmonic DNA origami.

    PubMed

    Yao, Guangbao; Li, Jiang; Chao, Jie; Pei, Hao; Liu, Huajie; Zhao, Yun; Shi, Jiye; Huang, Qing; Wang, Lianhui; Huang, Wei; Fan, Chunhai

    2015-03-02

    DNA origami has rapidly emerged as a powerful and programmable method to construct functional nanostructures. However, the size limitation of approximately 100 nm in classic DNA origami hampers its plasmonic applications. Herein, we report a jigsaw-puzzle-like assembly strategy mediated by gold nanoparticles (AuNPs) to break the size limitation of DNA origami. We demonstrated that oligonucleotide-functionalized AuNPs function as universal joint units for the one-pot assembly of parent DNA origami of triangular shape to form sub-microscale super-origami nanostructures. AuNPs anchored at predefined positions of the super-origami exhibited strong interparticle plasmonic coupling. This AuNP-mediated strategy offers new opportunities to drive macroscopic self-assembly and to fabricate well-defined nanophotonic materials and devices.

  18. The role of genetics in estrogen responses: a critical piece of an intricate puzzle

    PubMed Central

    Wall, Emma H.; Hewitt, Sylvia C.; Case, Laure K.; Lin, Chin-Yo; Korach, Kenneth S.; Teuscher, Cory

    2014-01-01

    The estrogens are female sex hormones that are involved in a variety of physiological processes, including reproductive development and function, wound healing, and bone growth. They are mainly known for their roles in reproductive tissues—specifically, 17β-estradiol (E2), the primary estrogen, which is secreted by the ovaries and induces cellular proliferation and growth of the uterus and mammary glands. In addition to the role of estrogens in promoting tissue growth and development during normal physiological states, they have a well-established role in determining susceptibility to disease, particularly cancer, in reproductive tissues. The responsiveness of various tissues to estrogen is genetically controlled, with marked quantitative variation observed across multiple species, including humans. This variation presents both researchers and clinicians with a veritable physiological puzzle, the pieces of which—many of them unknown—are complex and difficult to fit together. Although genetics is known to play a major role in determining sensitivity to estrogens, there are other factors, including parent of origin and the maternal environment, that are intimately linked to heritable phenotypes but do not represent genotype, per se. The objectives of this review article were to summarize the current knowledge of the role of genotype, and uterine and neonatal environments, in phenotypic variation in the response to estrogens; to discuss recent findings and the potential mechanisms involved; and to highlight exciting research opportunities for the future.—Wall, E. H., Hewitt, S. C., Case, L. K, Lin, C.-Y., Korach, K. S., Teuscher, C. The role of genetics in estrogen responses: a critical piece of an intricate puzzle. PMID:25212221

  19. Multiplexed Holographic Data Storage in Bacteriorhodopsin

    NASA Technical Reports Server (NTRS)

    Mehrl, David J.; Krile, Thomas F.

    1997-01-01

    High density optical data storage, driven by the information revolution, remains at the forefront of current research areas. Much of the current research has focused on photorefractive materials (SBN and LiNbO3) and polymers, despite various problems with expense, durability, response time and retention periods. Photon echo techniques, though promising, are questionable due to the need for cryogenic conditions. Bacteriorhodopsin (BR) films are an attractive alternative recording medium. Great strides have been made in refining BR, and materials with storage lifetimes as long as 100 days have recently become available. The ability to deposit this robust polycrystalline material as high quality optical films suggests the use of BR as a recording medium for commercial optical disks. Our own recent research has demonstrated the suitability of BR films for real time spatial filtering and holography. We propose to fully investigate the feasibility of performing holographic mass data storage in BR. Important aspects of the problem to be investigated include various data multiplexing techniques (e.g. angle- amplitude- and phase-encoded multiplexing, and in particular shift-multiplexing), multilayer recording techniques, SLM selection and data readout using crossed polarizers for noise rejection. Systems evaluations of storage parameters, including access times, memory refresh constraints, erasure, signal-to-noise ratios and bit error rates, will be included in our investigations.

  20. Goddard Conference on Mass Storage Systems and Technologies, Volume 1

    NASA Technical Reports Server (NTRS)

    Kobler, Ben (Editor); Hariharan, P. C. (Editor)

    1993-01-01

    Copies of nearly all of the technical papers and viewgraphs presented at the Goddard Conference on Mass Storage Systems and Technologies held in Sep. 1992 are included. The conference served as an informational exchange forum for topics primarily relating to the ingestion and management of massive amounts of data and the attendant problems (data ingestion rates now approach the order of terabytes per day). Discussion topics include the IEEE Mass Storage System Reference Model, data archiving standards, high-performance storage devices, magnetic and magneto-optic storage systems, magnetic and optical recording technologies, high-performance helical scan recording systems, and low end helical scan tape drives. Additional topics addressed the evolution of the identifiable unit for processing purposes as data ingestion rates increase dramatically, and the present state of the art in mass storage technology.

  1. Air-storage systems

    SciTech Connect

    Doherty, T.J.

    1981-10-01

    The air storage system, the critical component making CAES technically and economically feasible, is described in three of its forms. All have geological containments and reflect economics of scale requiring fairly large plant ratings and storage capacities. All three systems also are based on good precedent experience and there are a number of willing bidders in the engineering and construction field attesting to the readiness of the technology. The salient features of each storage system type are summarized. Hard rock caverns have the widest siting opportunity in a variety of geology, are well within construction capability in good quality rock with maximum control of system design through engineering, have the highest cost of the storage system options study and the potential for longest time to startup, are difficult and expensive to expand for increased storage or plant rating. The salt-solutioned cavern has limited siting opportunities, is a very economical storage system, and storage increase is possible through cavern additions.

  2. A media maniac's guide to removable mass storage media

    NASA Technical Reports Server (NTRS)

    Kempster, Linda S.

    1996-01-01

    This paper addresses at a high level, the many individual technologies available today in the removable storage arena including removable magnetic tapes, magnetic floppies, optical disks and optical tape. Tape recorders represented below discuss logitudinal, serpantine, logitudinal serpantine,and helical scan technologies. The magnetic floppies discussed will be used for personal electronic in-box applications.Optical disks still fill the role for dense long-term storage. The media capacities quoted are for native data. In some cases, 2 KB ASC2 pages or 50 KB document images will be referenced.

  3. Efficiency optimization for atomic frequency comb storage

    SciTech Connect

    Bonarota, M.; Ruggiero, J.; Le Goueet, J.-L.; Chaneliere, T.

    2010-03-15

    We study the efficiency of the atomic frequency comb storage protocol. We show that for a given optical depth, the preparation procedure can be optimize to significantly improve the retrieval. Our prediction is well supported by the experimental implementation of the protocol in a Tm{sup 3+}:YAG crystal. We observe a net gain in efficiency from 10 to 17% by applying the optimized preparation procedure. In the perspective of high bandwidth storage, we investigate the protocol under different magnetic fields. We analyze the effect of the Zeeman and superhyperfine interaction.

  4. Development of Large Capacity Lead-Carbon Hybrid Ultracapacitors for Energy Storage

    DTIC Science & Technology

    2012-07-01

    storage devices. Among various hybrid ultraultracapacitors, PbO2 ? Activated Carbon is an attractive system owing to its high cell voltage that...provides it both high energy and power densities. In this project, we have designed and developed 12V / kF-range Lead-Carbon (LC) HUCs with absorbent-glass...electrode. 15. SUBJECT TERMS ultra capacitors, ultra capacitors, power storage, power storage, Magneto-optical imaging , Magneto-optical imaging , lead

  5. Challenges in hydrogen storage

    NASA Astrophysics Data System (ADS)

    Schüth, F.

    2009-09-01

    Hydrogen is one possible medium for energy storage and transportation in an era beyond oil. Hydrogen appears to be especially promising in connection with electricity generation in polymer electrolyte membrane (PEM) fuel cells in cars. However, before such technologies can be implemented on a larger scale, satisfactory solutions for on-board storage of hydrogen are required. This is a difficult task due to the low volumetric and gravimetric storage density on a systems level which can be achieved so far. Possibilities include cryogenic storage as liquid hydrogen, high pressure storage at 70 MPa, (cryo)adsorptive storage, or various chemical methods of binding and releasing hydrogen. This survey discusses the different options and the associated advantages and disadvantages.

  6. Statistical analysis of cross-talk noise and storage capacity in volume holographic memory: image plane holograms

    NASA Astrophysics Data System (ADS)

    Yi, Xianmin; Campbell, Scott; Yeh, Pochi; Gu, Claire

    1995-04-01

    We investigate the cross-talk noise in optical storage based on angle-multiplexed image plane volume holograms. Simple expressions for the signal-to-noise ratio and the storage density are obtained. The cross-talk noise is found to limit the size of the pixels and the number of recorded holograms. The cross-talk-limited storage density of image plane holographic storage is found to be close to that of Fourier plane holographic storage.

  7. Electronic nose to detect volatile compound profile and quality changes in 'spring Belle' peach (Prunus persica L.) during cold storage in relation to fruit optical properties measured by time-resolved reflectance spectroscopy.

    PubMed

    Rizzolo, Anna; Bianchi, Giulia; Vanoli, Maristella; Lurie, Susan; Spinelli, Lorenzo; Torricelli, Alessandro

    2013-02-27

    The aim of this research was to study the relationships between electronic nose (E-nose) pattern, maturity class of peaches assessed at harvest by means of absorption coefficient at 670 nm (μ(a)670) measured in fruit pulp by time-resolved reflectance spectroscopy (TRS), and quality evolution during a 4 week cold storage. 'Spring Belle' peaches were measured for μ(a)670 by TRS, ranked according to decreasing μ(a)670 value, divided into three TRS maturity classes (less (LeM), medium (MeM), and more (MoM) mature), and randomized into 9 samples of 30 fruit each, so that fruits from the whole μ(a)670 range were present in each sample. At harvest and after 1, 2, 3, and 4 weeks of storage at 0 and 4 °C, fruits of each sample were evaluated for firmness, expressible juice, μ(a)670, and ethylene production. LeM and MoM peaches of each sample were analyzed for aroma pattern by a commercial electronic nose and by static HS-GC and for sugar (glucose, fructose, sucrose, and sorbitol) and organic acid (quinic, malic, and citric acids) compositions by HPLC. Principal component analysis (PCA) of electronic nose data emphasized the ability of the E-nose to assess the ripening stage of fruit associated with maturity class, storage time, and storage temperature. The sensors having the highest influence on the pattern were W5S in PC-1, W1S in PC-2, and W2S in PC-3. From linear correlation analysis between PCs and firmness, flavor, and volatile compounds, it was found that PC-1 was related to ethylene production and volatile compounds (mainly acetate esters and ethanol); the highest PC-1 scores were found for fruit belonging to the MoM class after 2 weeks of storage at 4 °C, which showed the rise in ethylene production coupled with the highest total volatile production and sugar and acid composition of ripe peach fruits. PC-2 correlated with hexanal, ethyl acetate, and sugar composition, and PC-3 was mainly related to flavor compounds; both functions significantly changed with

  8. Optical mass memory investigation

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The MASTER 1 optical mass storage system advanced working model (AWM) was designed to demonstrate recording and playback of imagery data and to enable quantitative data to be derived as to the statistical distribution of raw errors experienced through the system. The AWM consists of two subsystems, the recorder and storage and retrieval. The recorder subsystem utilizes key technologies such as an acoustic travelling wave lens to achieve recording of digital data on fiche at a rate of 30 Mbits/sec, whereas the storage and retrieval reproducer subsystem utilizes a less complex optical system that employs an acousto-optical beam deflector to achieve data readout at a 5 Mbits/sec rate. The system has the built in capability for detecting and collecting error statistics. The recorder and storage and retrieval subsystems operate independent of one another and are each constructed in modular form with each module performing independent functions. The operation of each module and its interface to other modules is controlled by one controller for both subsystems.

  9. Biophysical Puzzles Concerning Magnetite-Based Magnetoreception in the Common Nematode, Caenorhabditis elegans.

    NASA Astrophysics Data System (ADS)

    Kirschvink, J. L.; Kobayashi, A. K.

    2015-12-01

    A recent report demonstrating magnetotactic behavior in the nematode worm, C. elegans, presents two intriguing biophysical puzzles. Vidal-Gadea et al. (2015, DOI: 10.7554/eLife.07493) show that wild-type, well-fed populations from both Hemispheres migrate upwards when their soil environment is moist and wet, and downward when starved. Their data show that inverting the vertical component of the magnetic field reverses the migration direction, indicating that it is a magnetically polar (not axial) response. Also, the angle of magnetic migration varies with the inclination angle of the local geomagnetic field at the native site, minimizing travel time. This ancestral magnetic migration direction persists even when strains are taken to different areas. We note that only a single-domain ferromagnetic magnetoreceptor (e.g, magnetite) is capable of producing a polar magnetotactic response, and in support there is one report of magnetosomes in C. elegans (Cranfield et al., 2004;DOI 10.1098/rsbl.2004.0209). However, the polarity of a magnetosome is determined at the time it grows across the SPM/SD threshold, and the magnetic orientation will lock-in randomly unless biased by the strong field of adjacent magnetosomes. Hence, the persistence of a North or South seeking direction preference within these populations demands that stable magnetosome chains of fixed polarity must be transmitted from parents, to the eggs, to the larvae, and then to the new adults. This is similar to the non-genetic inheritance process by which populations of magnetotactic bacteria can maintain North- or South-seeking swimming preference. Furthermore, for a magnetotactic organism to maintain a consistent angle from the magnetic axis is not enough to make it go vertical; it would go in a cone. For them to go vertical as reported (or to deviate at their natal magnetic inclination) demands that they must have a separate gravity sensor with which to measure the inclination angle relative to the

  10. Robo-line storage: Low latency, high capacity storage systems over geographically distributed networks

    NASA Technical Reports Server (NTRS)

    Katz, Randy H.; Anderson, Thomas E.; Ousterhout, John K.; Patterson, David A.

    1991-01-01

    Rapid advances in high performance computing are making possible more complete and accurate computer-based modeling of complex physical phenomena, such as weather front interactions, dynamics of chemical reactions, numerical aerodynamic analysis of airframes, and ocean-land-atmosphere interactions. Many of these 'grand challenge' applications are as demanding of the underlying storage system, in terms of their capacity and bandwidth requirements, as they are on the computational power of the processor. A global view of the Earth's ocean chlorophyll and land vegetation requires over 2 terabytes of raw satellite image data. In this paper, we describe our planned research program in high capacity, high bandwidth storage systems. The project has four overall goals. First, we will examine new methods for high capacity storage systems, made possible by low cost, small form factor magnetic and optical tape systems. Second, access to the storage system will be low latency and high bandwidth. To achieve this, we must interleave data transfer at all levels of the storage system, including devices, controllers, servers, and communications links. Latency will be reduced by extensive caching throughout the storage hierarchy. Third, we will provide effective management of a storage hierarchy, extending the techniques already developed for the Log Structured File System. Finally, we will construct a protototype high capacity file server, suitable for use on the National Research and Education Network (NREN). Such research must be a Cornerstone of any coherent program in high performance computing and communications.

  11. Optical Instruments

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Precision Lapping and Optical Co. has developed a wide variety of hollow retroreflector systems for applications involving the entire optical spectrum; they are, according to company literature, cheaper, more accurate, lighter and capable of greater size than solid prisms. Precision Lapping's major customers are aerospace and defense companies, government organizations, R&D and commercial instrument companies. For example, Precision Lapping supplies hollow retroreflectors for the laser fire control system of the Army's Abrams tank, and retroreflectors have been and are being used in a number of space tests relative to the Air Force's Strategic Defense Initiative research program. An example of a customer/user is Chesapeake Laser Systems, producer of the Laser Tracker System CMS-2000, which has applications in SDI research and industrial robotics. Another customer is MDA Scientific, Inc., manufacturer of a line of toxic gas detection systems used to monitor hazardous gases present in oil fields, refineries, offshore platforms, chemical plants, waste storage sites and other locations where gases are released into the environment.

  12. A new storage-ring light source

    SciTech Connect

    Chao, Alex

    2015-06-01

    A recently proposed technique in storage ring accelerators is applied to provide potential high-power sources of photon radiation. The technique is based on the steady-state microbunching (SSMB) mechanism. As examples of this application, one may consider a high-power DUV photon source for research in atomic and molecular physics or a high-power EUV radiation source for industrial lithography. A less challenging proof-of-principle test to produce IR radiation using an existing storage ring is also considered.

  13. Review of volume holographic data storage

    NASA Astrophysics Data System (ADS)

    Hinkle, William P.

    1997-07-01

    We present a review of volume holographic memory technology highlighting the most important issues for the development of commercially viable mass data storage systems. To record data using volume holographic storage, data is encoded on a laser beam with a spatial light modulator (SLM). The object beam is directed into an optically sensitive material, typically a photorefractive crystal, and superimposed with a coherent reference beam, forming interference gratings. The material reacts to the interference pattern by spatial modulation of its optical absorption or refractive index. During data retrieval the reference beam alone illuminates the modulated region, causing diffraction of a beam that is modulated as if it were generated by the original object beam incident on the SLM; that is a duplicate of the original object beam. This beam is imaged onto a photodetector array for capture and decoding. Because the data are stored and retrieved as a 2D matrix, a volume holographic storage system is inherently parallel. Consequently, data is read many bits (conceivably in the range of megabits) at a time, so that this approach offers the potential of high data retrieval rates, on the order of tens of gigabits per second and access times of much less than a millisecond. Data recording speeds are very dependent on the choice of storage material and energy of the laser. System capacity and capability are a consequence of three major interrelated factors: (1) the time-energy requirement of the storage material and the permanence of the stored data; (2) the capacity and efficiency of the spatial light modulator; and (3) the laser's power, physical size, and coherence properties. When compared with traditional flat surface magnetic or optical storage, volume holographic data storage has the potential of advantageous capacity, speed, weight, power, and physical size. While these are attractive attributes, they are particularly useful for space applications. This paper presents

  14. Cles: Etes-vous bon detective?; Enigmes grammaticales; Problemes policiers; Kidnapping (Keys: Are You a Good Detective?; Grammatical Puzzles; Detective Mysteries; Kidnapping).

    ERIC Educational Resources Information Center

    Debyser, Francis; And Others

    1984-01-01

    Four sets of French classroom activities are presented: a mystery whose clues include two postcard messages; three puzzles with grammar-related clues; a mystery contained in three comic strip frames; and the solving of a kidnapping mystery. (MSE)

  15. ERDA's Chemical Energy Storage Program

    NASA Technical Reports Server (NTRS)

    Swisher, J. H.; Kelley, J. H.

    1977-01-01

    The Chemical Energy Storage Program is described with emphasis on hydrogen storage. Storage techniques considered include pressurized hydrogen gas storage, cryogenic liquid hydrogen storage, storage in hydride compounds, and aromatic-alicyclic hydrogen storage. Some uses of energy storage are suggested. Information on hydrogen production and hydrogen use is also presented. Applications of hydrogen energy systems include storage of hydrogen for utilities load leveling, industrial marketing of hydrogen both as a chemical and as a fuel, natural gas supplementation, vehicular applications, and direct substitution for natural gas.

  16. Influence of technology on magnetic tape storage device characteristics

    NASA Technical Reports Server (NTRS)

    Gniewek, John J.; Vogel, Stephen M.

    1994-01-01

    There are available today many data storage devices that serve the diverse application requirements of the consumer, professional entertainment, and computer data processing industries. Storage technologies include semiconductors, several varieties of optical disk, optical tape, magnetic disk, and many varieties of magnetic tape. In some cases, devices are developed with specific characteristics to meet specification requirements. In other cases, an existing storage device is modified and adapted to a different application. For magnetic tape storage devices, examples of the former case are 3480/3490 and QIC device types developed for the high end and low end segments of the data processing industry respectively, VHS, Beta, and 8 mm formats developed for consumer video applications, and D-1, D-2, D-3 formats developed for professional video applications. Examples of modified and adapted devices include 4 mm, 8 mm, 12.7 mm and 19 mm computer data storage devices derived from consumer and professional audio and video applications. With the conversion of the consumer and professional entertainment industries from analog to digital storage and signal processing, there have been increasing references to the 'convergence' of the computer data processing and entertainment industry technologies. There has yet to be seen, however, any evidence of convergence of data storage device types. There are several reasons for this. The diversity of application requirements results in varying degrees of importance for each of the tape storage characteristics.

  17. Air-storage systems

    NASA Astrophysics Data System (ADS)

    Doherty, T. J.

    1981-10-01

    The air storage system, the critical component making compressed air energy storage technically economically feasible, is described in three of its forms. All have geological containments and reflect economics of scale requiring fairly large plant ratings and storage capacities. All three systems also are based on good precedent experience and there are a number of willing bidders in the engineering and construction field attesting to the readiness of the technology. The salient features of each storage system type are summarized. Hard rock caverns have the widest siting opportunity with a variety of geology, are well within construction capability in good quality rock with maximum control of system design through engineering, and have the highest cost of the storage system options study. They have the potential for longest time to startup and are difficult and expensive to expand for increased storage or plant rating. The salt-solutioned cavern has limited siting opportunities, is a very economical storage system, and storage increase is possible through cavern additions.

  18. Open systems storage platforms

    NASA Technical Reports Server (NTRS)

    Collins, Kirby

    1992-01-01

    The building blocks for an open storage system includes a system platform, a selection of storage devices and interfaces, system software, and storage applications CONVEX storage systems are based on the DS Series Data Server systems. These systems are a variant of the C3200 supercomputer with expanded I/O capabilities. These systems support a variety of medium and high speed interfaces to networks and peripherals. System software is provided in the form of ConvexOS, a POSIX compliant derivative of 4.3BSD UNIX. Storage applications include products such as UNITREE and EMASS. With the DS Series of storage systems, Convex has developed a set of products which provide open system solutions for storage management applications. The systems are highly modular, assembled from off the shelf components with industry standard interfaces. The C Series system architecture provides a stable base, with the performance and reliability of a general purpose platform. This combination of a proven system architecture with a variety of choices in peripherals and application software allows wide flexibility in configurations, and delivers the benefits of open systems to the mass storage world.

  19. Wind-energy storage

    NASA Technical Reports Server (NTRS)

    Gordon, L. H.

    1980-01-01

    Program SIMWEST can model wind energy storage system using any combination of five types of storage: pumped hydro, battery, thermal, flywheel, and pneumatic. Program is tool to aid design of optional system for given application with realistic simulation for further evaluation and verification.

  20. Human Motives, Happiness, and the Puzzle of Parenthood: Commentary on Kenrick et al. (2010).

    PubMed

    Lyubomirsky, Sonja; Boehm, Julia K

    2010-05-01

    It is presumed that happiness, and its associated positive emotions, signal to the individual that an adaptive problem has been solved, thus allowing her to shift attention to other concerns, perhaps those "higher" on the revised motivational hierarchy proposed by Kenrick et al (2010, this issue). In this commentary, we present a sampling of longitudinal and experimental evidence supporting two predictions: (a) that people will feel happy after realizing fundamental human motives, and (b) that in turn, the experience of happiness will galvanize people to fulfill these very motives. However, one conspicuous exception to our argument that happiness is both a consequence and a stimulus of human motives is parenthood, which paradoxically is associated with decrements in well-being. Two broad sets of explanations to account for this puzzle are discussed. The first involves evolutionary accounts: that children interfere with lower level needs, that short-term costs of having children are outweighed by long-term benefits, and that the modern-day context of raising children is at odds with our ancestors' environments. The second possibility involves measurement: namely, problems with study designs and the difficulty of capturing on paper or computer screen what is precisely so wonderful and elusive that children grant their parents.

  1. Puzzles in modern biology. IV. Neurodegeneration, localized origin and widespread decay.

    PubMed

    Frank, Steven A

    2016-01-01

    The motor neuron disease amyotrophic lateral sclerosis (ALS) typically begins with localized muscle weakness. Progressive, widespread paralysis often follows over a few years. Does the disease begin with local changes in a small piece of neural tissue and then spread? Or does neural decay happen independently across diverse spatial locations? The distinction matters, because local initiation may arise by local changes in a tissue microenvironment, by somatic mutation, or by various epigenetic or regulatory fluctuations in a few cells. A local trigger must be coupled with a mechanism for spread. By contrast, independent decay across spatial locations cannot begin by a local change, but must depend on some global predisposition or spatially distributed change that leads to approximately synchronous decay. This article outlines the conceptual frame by which one contrasts local triggers and spread versus parallel spatially distributed decay. Various neurodegenerative diseases differ in their mechanistic details, but all can usefully be understood as falling along a continuum of interacting local and global processes. Cancer provides an example of disease progression by local triggers and spatial spread, setting a conceptual basis for clarifying puzzles in neurodegeneration. Heart disease also has crucial interactions between global processes, such as circulating lipid levels, and local processes in the development of atherosclerotic plaques. The distinction between local and global processes helps to understand these various age-related diseases.

  2. Unraveling the puzzling intermediate states in the Biham-Middleton-Levine traffic model.

    PubMed

    Olmos, L E; Muñoz, J D

    2015-05-01

    The Biham-Middleton-Levine (BML) traffic model, a cellular automaton with eastbound and northbound cars moving by turns on a square lattice, has been an underpinning model in the study of collective behavior by cars, pedestrians, and even internet packages. Contrary to initial beliefs that the model exhibits a sharp phase transition from freely flowing to fully jammed, it has been reported that it shows intermediate stable phases, where jams and freely flowing traffic coexist, but there is no clear understanding of their origin. Here, we analyze the model as an anisotropic system with a preferred fluid direction (northeast) and find that it exhibits two differentiated phase transitions: the system is either longer in the flow direction (longitudinal) or perpendicular to it (transversal). The critical densities where these transitions occur enclose the density interval of intermediate states and can be approximated by mean-field analysis, all derived from the anisotropic exponent relating the longitudinal and transversal correlation lengths. Thus, we arrive at the interesting result that the puzzling intermediate states in the original model are just a superposition of these two different behaviors of the phase transition, solving by the way most mysteries behind the BML model, which turns out to be a paradigmatic example of such anisotropic critical systems.

  3. Orbital Wall Reconstruction with Two-Piece Puzzle 3D Printed Implants: Technical Note

    PubMed Central

    Mommaerts, Maurice Y.; Büttner, Michael; Vercruysse, Herman; Wauters, Lauri; Beerens, Maikel

    2015-01-01

    The purpose of this article is to describe a technique for secondary reconstruction of traumatic orbital wall defects using titanium implants that act as three-dimensional (3D) puzzle pieces. We present three cases of large defect reconstruction using implants produced by Xilloc Medical B.V. (Maastricht, the Netherlands) with a 3D printer manufactured by LayerWise (3D Systems; Heverlee, Belgium), and designed using the biomedical engineering software programs ProPlan and 3-Matic (Materialise, Heverlee, Belgium). The smaller size of the implants allowed sequential implantation for the reconstruction of extensive two-wall defects via a limited transconjunctival incision. The precise fit of the implants with regard to the surrounding ledges and each other was confirmed by intraoperative 3D imaging (Mobile C-arm Systems B.V. Pulsera, Philips Medical Systems, Eindhoven, the Netherlands). The patients showed near-complete restoration of orbital volume and ocular motility. However, challenges remain, including traumatic fat atrophy and fibrosis. PMID:26889349

  4. The placebo puzzle: examining the discordant space between biomedical science and illness/healing.

    PubMed

    Pohlman, Shawn; Cibulka, Nancy J; Palmer, Janice L; Lorenz, Rebecca A; SmithBattle, Lee

    2013-03-01

    The placebo response presents an enigma to biomedical science: how can 'inert' or 'sham' procedures reduce symptoms and produce physiological changes that are comparable to prescribed treatments? In this study, we examine this puzzle by explicating the discordant space between the prevailing biomedical paradigm, which focuses on a technical understanding of diagnosis and treatment, and a broader understanding of illness and healing as relational and embodied. Although biomedical achievements are impressive, the knowledge resulting from this paradigm is limited by its ontological and epistemological assumptions. When the body and world are objectified, illness meanings, therapeutic relationships, and healing practices are dismissed or distorted. In spite of a robust critique of the tenets of biomedicine for guiding practice, the biomedical paradigm retains a tenacious hold on evidence-based medicine and nursing, downplaying our clinical understanding of the sentient body, patients' life-worlds, and illness and healing. In reality, skilled nurses rely on multiple forms of knowledge in providing high-quality care to particular patients. Clinically wise nurses integrate their experience and knowledge of patients' priorities, fears, and illness trajectories along with biomedical findings to make astute judgments and promote health and healing.

  5. [What type of welfare policy promotes health?: the puzzling interrelation of economic and health inequality].

    PubMed

    Hurrelmann, K; Richter, M; Rathmann, K

    2011-06-01

    In all highly developed countries, the overall health status of the population has significantly improved within the past 30 years. The most important reason for this is the increase in economic prosperity. Economic wealth, however, today is much more unequally distributed than it was 3 decades ago. Countries with relatively small disparities in the availability of material resources between socioeconomic groups, such as the Scandinavian countries, have better health outcomes on the population level. Health inequalities, however, have also reached a higher level than 30 years ago. As of today, we do not have convincing explanations for the interrelation of economic and health inequality. This paper gives an overview of existing research on a comparative basis. The research results are ambivalent. They show the puzzling result that the Scandinavian countries with their highly distributive welfare policy manage to achieve the comparatively highest level of economic, but not health, equity. Based on these results, we develop proposals for future research approaches. A central assumption is that in rich societies no longer only material, but more and more immaterial determinants are crucial for the formation of health inequality. The promotion of "salutogenic" self-management capabilities in socially disadvantaged groups is considered to be the central element in effective intervention strategies.

  6. Unraveling the puzzling intermediate states in the Biham-Middleton-Levine traffic model

    NASA Astrophysics Data System (ADS)

    Olmos, L. E.; Muñoz, J. D.

    2015-05-01

    The Biham-Middleton-Levine (BML) traffic model, a cellular automaton with eastbound and northbound cars moving by turns on a square lattice, has been an underpinning model in the study of collective behavior by cars, pedestrians, and even internet packages. Contrary to initial beliefs that the model exhibits a sharp phase transition from freely flowing to fully jammed, it has been reported that it shows intermediate stable phases, where jams and freely flowing traffic coexist, but there is no clear understanding of their origin. Here, we analyze the model as an anisotropic system with a preferred fluid direction (northeast) and find that it exhibits two differentiated phase transitions: the system is either longer in the flow direction (longitudinal) or perpendicular to it (transversal). The critical densities where these transitions occur enclose the density interval of intermediate states and can be approximated by mean-field analysis, all derived from the anisotropic exponent relating the longitudinal and transversal correlation lengths. Thus, we arrive at the interesting result that the puzzling intermediate states in the original model are just a superposition of these two different behaviors of the phase transition, solving by the way most mysteries behind the BML model, which turns out to be a paradigmatic example of such anisotropic critical systems.

  7. A New Piece in the High Tc Superconductivity Puzzle: Fe based Superconductors

    NASA Astrophysics Data System (ADS)

    Moreo, Adriana

    2011-10-01

    An overview of the historic and current developments in superconductivity will be be presented. The phenomenon of superconductivity was discovered almost 100 hundred years ago and it is still one of the hottest research topics providing fascinating puzzles and challenges to both theoreticians and experimentalists. There was a lag of almost 50 years between the experimental discovery of (low Tc) superconductivity and the development of the BCS theory which explained the phenomenon in terms of pairs of electrons held together by the interaction with the phonons in the material. The quest to discover superconducting materials with higher Tc's continued quietly for many years until huge progress occurred in the 1980' when Tc's higher than 77K were observed in copper-oxide based materials. The study of these new materials generated tremendous advances in both experimental and theoretical methods and much is now known about their properties; but the mechanism, i.e., the ``glue,'' that binds the electrons together is still unknown; it appears that phonons are unable to do the job and there is controversy on whether the magnetism present in these materials helps or hurts. Very recently, in 2008, high Tc was discovered in a new family of iron based materials. While they are similar to the cuprates in some ways, i.e., magnetism is present, there are many differences as well. This discovery provides a new chance to unveil the high-Tc mystery and the condensed matter community is intensely working on the subject.

  8. Interactive Puzzles for the mean climate dyanmics and climate change with the Monash Simple Climate Model

    NASA Astrophysics Data System (ADS)

    Dommenget, D.

    2014-12-01

    The Monash university interactive simple climate model is a web-based interface that allows students and the general public to explore the physical simulation of the climate system with a real global climate model. It is based on the Globally Resolved Energy Balance (GREB) model that simulates most of the main physical processes in the climate system in a very simplistic way and therefore allows very fast and simple climate model simulations. Despite its simplicity the model simulates the mean climate and its response to external forcings, such as doubling of the CO2 concentrations very realistically.The Monash simple climate model web-interface allows you to do some entertaining and educational puzzles about the interaction of climate dynamics. By turning switches OFF and ON you control physical processes in the climate system, but you do not know what these processes. By testing a number of experiments you learn about the interactions in the climate system and thereby figure out which switch controls what process in the climate system. The presentation will illustrate how this web-base tool works and what are the possibilities in teaching students with this tool are.

  9. Physics and financial economics (1776-2014): puzzles, Ising and agent-based models

    NASA Astrophysics Data System (ADS)

    Sornette, Didier

    2014-06-01

    This short review presents a selected history of the mutual fertilization between physics and economics—from Isaac Newton and Adam Smith to the present. The fundamentally different perspectives embraced in theories developed in financial economics compared with physics are dissected with the examples of the volatility smile and of the excess volatility puzzle. The role of the Ising model of phase transitions to model social and financial systems is reviewed, with the concepts of random utilities and the logit model as the analog of the Boltzmann factor in statistical physics. Recent extensions in terms of quantum decision theory are also covered. A wealth of models are discussed briefly that build on the Ising model and generalize it to account for the many stylized facts of financial markets. A summary of the relevance of the Ising model and its extensions is provided to account for financial bubbles and crashes. The review would be incomplete if it did not cover the dynamical field of agent-based models (ABMs), also known as computational economic models, of which the Ising-type models are just special ABM implementations. We formulate the ‘Emerging Intelligence Market Hypothesis’ to reconcile the pervasive presence of ‘noise traders’ with the near efficiency of financial markets. Finally, we note that evolutionary biology, more than physics, is now playing a growing role to inspire models of financial markets.

  10. Theory of mind: a new perspective on the puzzle of belief ascription.

    PubMed

    Airenti, Gabriella

    2015-01-01

    The concept of theory of mind (ToM) has considerably changed since its first proposal. The aim of first human studies was to understand how young children acquire the representation of others' mental states, in particular beliefs, and how they distinguish them from their own and from reality. The False Belief Task was designed to prove the acquisition of this capacity. According to children's performance in this test the acquisition of ToM has been attested at around 4 years of age. In last years it has been shown that using spontaneous response tasks also 15-month-old-children could attribute to an agent a false belief about the location of an object. These results have generated the puzzle of belief-ascription: Why do 3-year-old children fail the classical false belief tasks whereas much younger children show the correct expectation in the spontaneous response tasks? In this paper I shall argue that (i) infants and young children, when confronted with the two forms of false belief tasks do not face the same problem and (ii) behind the two testing situations there are different ways to understand theory of mind. I shall propose that what appears in infants is the natural human disposition to intersubjectivity.

  11. The Variance of Solar Wind Magnetic Fluctuations: Solutions and Further Puzzles

    NASA Technical Reports Server (NTRS)

    Roberts, D. A.; Goldstein, M. L.

    2006-01-01

    We study the dependence of the variance directions of the magnetic field in the solar wind as a function of scale, radial distance, and Alfvenicity. The study resolves the question of why different studies have arrived at widely differing values for the maximum to minimum power (approximately equal to 3:1 up to approximately equal to 20:1). This is due to the decreasing anisotropy with increasing time interval chosen for the variance, and is a direct result of the "spherical polarization" of the waves which follows from the near constancy of |B|. The reason for the magnitude preserving evolution is still unresolved. Moreover, while the long-known tendency for the minimum variance to lie along the mean field also follows from this view (as shown by Barnes many years ago), there is no theory for why the minimum variance follows the field direction as the Parker angle changes. We show that this turning is quite generally true in Alfvenic regions over a wide range of heliocentric distances. The fact that nonAlfvenic regions, while still showing strong power anisotropies, tend to have a much broader range of angles between the minimum variance and the mean field makes it unlikely that the cause of the variance turning is to be found in a turbulence mechanism. There are no obvious alternative mechanisms, leaving us with another intriguing puzzle.

  12. Neural bases for basic processes in heuristic problem solving: Take solving Sudoku puzzles as an example.

    PubMed

    Qin, Yulin; Xiang, Jie; Wang, Rifeng; Zhou, Haiyan; Li, Kuncheng; Zhong, Ning

    2012-12-01

    Newell and Simon postulated that the basic steps in human problem-solving involve iteratively applying operators to transform the state of the problem to eventually achieve a goal. To check the neural basis of this framework, the present study focused on the basic processes in human heuristic problem-solving that the participants identified the current problem state and then recalled and applied the corresponding heuristic rules to change the problem state. A new paradigm, solving simplified Sudoku puzzles, was developed for an event-related functional magnetic resonance imaging (fMRI) study in problem solving. Regions of interest (ROIs), including the left prefrontal cortex, the bilateral posterior parietal cortex, the anterior cingulated cortex, the bilateral caudate nuclei, the bilateral fusiform, as well as the bilateral frontal eye fields, were found to be involved in the task. To obtain convergent evidence, in addition to traditional statistical analysis, we used the multivariate voxel classification method to check the accuracy of the predictions for the condition of the task from the blood oxygen level dependent (BOLD) response of the ROIs, using a new classifier developed in this study for fMRI data. To reveal the roles that the ROIs play in problem solving, we developed an ACT-R computational model of the information-processing processes in human problem solving, and tried to predict the BOLD response of the ROIs from the task. Advances in human problem-solving research after Newell and Simon are then briefly discussed.

  13. Learning and Memory Processes Following Cochlear Implantation: The Missing Piece of the Puzzle

    PubMed Central

    Pisoni, David B.; Kronenberger, William G.; Chandramouli, Suyog H.; Conway, Christopher M.

    2016-01-01

    At the present time, there is no question that cochlear implants (CIs) work and often work very well in quiet listening conditions for many profoundly deaf children and adults. The speech and language outcomes data published over the last two decades document quite extensively the clinically significant benefits of CIs. Although there now is a large body of evidence supporting the “efficacy” of CIs as a medical intervention for profound hearing loss in both children and adults, there still remain a number of challenging unresolved clinical and theoretical issues that deal with the “effectiveness” of CIs in individual patients that have not yet been successfully resolved. In this paper, we review recent findings on learning and memory, two central topics in the field of cognition that have been seriously neglected in research on CIs. Our research findings on sequence learning, memory and organization processes, and retrieval strategies used in verbal learning and memory of categorized word lists suggests that basic domain-general learning abilities may be the missing piece of the puzzle in terms of understanding the cognitive factors that underlie the enormous individual differences and variability routinely observed in speech and language outcomes following cochlear implantation. PMID:27092098

  14. Structure-Promiscuity Relationship Puzzles-Extensively Assayed Analogs with Large Differences in Target Annotations.

    PubMed

    Hu, Ye; Jasial, Swarit; Gilberg, Erik; Bajorath, Jürgen

    2017-03-06

    Publicly available screening data were systematically searched for extensively assayed structural analogs with large differences in the number of targets they were active against. Screening compounds with potential chemical liabilities that may give rise to assay artifacts were identified and excluded from the analysis. "Promiscuity cliffs" were frequently identified, defined here as pairs of structural analogs with a difference of at least 20 target annotations across all assays they were tested in. New assay indices were introduced to prioritize cliffs formed by screening compounds that were extensively tested in comparably large numbers of assays including many shared assays. In these cases, large differences in promiscuity degrees were not attributable to differences in assay frequency and/or lack of assay overlap. Such analog pairs have high priority for further exploring molecular origins of multi-target activities. Therefore, these promiscuity cliffs and associated target annotations are made freely available. The corresponding analogs often represent equally puzzling and interesting examples of structure-promiscuity relationships.

  15. Physics and financial economics (1776-2014): puzzles, Ising and agent-based models.

    PubMed

    Sornette, Didier

    2014-06-01

    This short review presents a selected history of the mutual fertilization between physics and economics--from Isaac Newton and Adam Smith to the present. The fundamentally different perspectives embraced in theories developed in financial economics compared with physics are dissected with the examples of the volatility smile and of the excess volatility puzzle. The role of the Ising model of phase transitions to model social and financial systems is reviewed, with the concepts of random utilities and the logit model as the analog of the Boltzmann factor in statistical physics. Recent extensions in terms of quantum decision theory are also covered. A wealth of models are discussed briefly that build on the Ising model and generalize it to account for the many stylized facts of financial markets. A summary of the relevance of the Ising model and its extensions is provided to account for financial bubbles and crashes. The review would be incomplete if it did not cover the dynamical field of agent-based models (ABMs), also known as computational economic models, of which the Ising-type models are just special ABM implementations. We formulate the 'Emerging Intelligence Market Hypothesis' to reconcile the pervasive presence of 'noise traders' with the near efficiency of financial markets. Finally, we note that evolutionary biology, more than physics, is now playing a growing role to inspire models of financial markets.

  16. 12. NORTHWEST CORNER OF STORAGE MAGAZINE (BUILDING 342) IN STORAGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. NORTHWEST CORNER OF STORAGE MAGAZINE (BUILDING 342) IN STORAGE AREA. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

  17. Plutonium storage criteria

    SciTech Connect

    Chung, D.; Ascanio, X.

    1996-05-01

    The Department of Energy has issued a technical standard for long-term (>50 years) storage and will soon issue a criteria document for interim (<20 years) storage of plutonium materials. The long-term technical standard, {open_quotes}Criteria for Safe Storage of Plutonium Metals and Oxides,{close_quotes} addresses the requirements for storing metals and oxides with greater than 50 wt % plutonium. It calls for a standardized package that meets both off-site transportation requirements, as well as remote handling requirements from future storage facilities. The interim criteria document, {open_quotes}Criteria for Interim Safe Storage of Plutonium-Bearing Solid Materials{close_quotes}, addresses requirements for storing materials with less than 50 wt% plutonium. The interim criteria document assumes the materials will be stored on existing sites, and existing facilities and equipment will be used for repackaging to improve the margin of safety.

  18. Electricity storage using a thermal storage scheme

    NASA Astrophysics Data System (ADS)

    White, Alexander

    2015-01-01

    The increasing use of renewable energy technologies for electricity generation, many of which have an unpredictably intermittent nature, will inevitably lead to a greater demand for large-scale electricity storage schemes. For example, the expanding fraction of electricity produced by wind turbines will require either backup or storage capacity to cover extended periods of wind lull. This paper describes a recently proposed storage scheme, referred to here as Pumped Thermal Storage (PTS), and which is based on "sensible heat" storage in large thermal reservoirs. During the charging phase, the system effectively operates as a high temperature-ratio heat pump, extracting heat from a cold reservoir and delivering heat to a hot one. In the discharge phase the processes are reversed and it operates as a heat engine. The round-trip efficiency is limited only by process irreversibilities (as opposed to Second Law limitations on the coefficient of performance and the thermal efficiency of the heat pump and heat engine respectively). PTS is currently being developed in both France and England. In both cases, the schemes operate on the Joule-Brayton (gas turbine) cycle, using argon as the working fluid. However, the French scheme proposes the use of turbomachinery for compression and expansion, whereas for that being developed in England reciprocating devices are proposed. The current paper focuses on the impact of the various process irreversibilities on the thermodynamic round-trip efficiency of the scheme. Consideration is given to compression and expansion losses and pressure losses (in pipe-work, valves and thermal reservoirs); heat transfer related irreversibility in the thermal reservoirs is discussed but not included in the analysis. Results are presented demonstrating how the various loss parameters and operating conditions influence the overall performance.

  19. Electricity storage using a thermal storage scheme

    SciTech Connect

    White, Alexander

    2015-01-22

    The increasing use of renewable energy technologies for electricity generation, many of which have an unpredictably intermittent nature, will inevitably lead to a greater demand for large-scale electricity storage schemes. For example, the expanding fraction of electricity produced by wind turbines will require either backup or storage capacity to cover extended periods of wind lull. This paper describes a recently proposed storage scheme, referred to here as Pumped Thermal Storage (PTS), and which is based on “sensible heat” storage in large thermal reservoirs. During the charging phase, the system effectively operates as a high temperature-ratio heat pump, extracting heat from a cold reservoir and delivering heat to a hot one. In the discharge phase the processes are reversed and it operates as a heat engine. The round-trip efficiency is limited only by process irreversibilities (as opposed to Second Law limitations on the coefficient of performance and the thermal efficiency of the heat pump and heat engine respectively). PTS is currently being developed in both France and England. In both cases, the schemes operate on the Joule-Brayton (gas turbine) cycle, using argon as the working fluid. However, the French scheme proposes the use of turbomachinery for compression and expansion, whereas for that being developed in England reciprocating devices are proposed. The current paper focuses on the impact of the various process irreversibilities on the thermodynamic round-trip efficiency of the scheme. Consideration is given to compression and expansion losses and pressure losses (in pipe-work, valves and thermal reservoirs); heat transfer related irreversibility in the thermal reservoirs is discussed but not included in the analysis. Results are presented demonstrating how the various loss parameters and operating conditions influence the overall performance.

  20. The cryogenic storage ring CSR

    NASA Astrophysics Data System (ADS)

    von Hahn, R.; Becker, A.; Berg, F.; Blaum, K.; Breitenfeldt, C.; Fadil, H.; Fellenberger, F.; Froese, M.; George, S.; Göck, J.; Grieser, M.; Grussie, F.; Guerin, E. A.; Heber, O.; Herwig, P.; Karthein, J.; Krantz, C.; Kreckel, H.; Lange, M.; Laux, F.; Lohmann, S.; Menk, S.; Meyer, C.; Mishra, P. M.; Novotný, O.; O'Connor, A. P.; Orlov, D. A.; Rappaport, M. L.; Repnow, R.; Saurabh, S.; Schippers, S.; Schröter, C. D.; Schwalm, D.; Schweikhard, L.; Sieber, T.; Shornikov, A.; Spruck, K.; Sunil Kumar, S.; Ullrich, J.; Urbain, X.; Vogel, S.; Wilhelm, P.; Wolf, A.; Zajfman, D.

    2016-06-01

    An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed, and put into operation. With a circumference of 35 m, the ion-beam vacuum chambers and all beam optics are in a cryostat and cooled by a closed-cycle liquid helium system. At temperatures as low as (5.5 ± 1) K inside the ring, storage time constants of several minutes up to almost an hour were observed for atomic and molecular, anion and cation beams at an energy of 60 keV. The ion-beam intensity, energy-dependent closed-orbit shifts (dispersion), and the focusing properties of the machine were studied by a system of capacitive pickups. The Schottky-noise spectrum of the stored ions revealed a broadening of the momentum distribution on a time scale of 1000 s. Photodetachment of stored anions was used in the beam lifetime measurements. The detachment rate by anion collisions with residual-gas molecules was found to be extremely low. A residual-gas density below 140 cm-3 is derived, equivalent to a room-temperature pressure below 10-14 mbar. Fast atomic, molecular, and cluster ion beams stored for long periods of time in a cryogenic environment will allow experiments on collision- and radiation-induced fragmentation processes of ions in known internal quantum states with merged and crossed photon and particle beams.

  1. The cryogenic storage ring CSR.

    PubMed

    von Hahn, R; Becker, A; Berg, F; Blaum, K; Breitenfeldt, C; Fadil, H; Fellenberger, F; Froese, M; George, S; Göck, J; Grieser, M; Grussie, F; Guerin, E A; Heber, O; Herwig, P; Karthein, J; Krantz, C; Kreckel, H; Lange, M; Laux, F; Lohmann, S; Menk, S; Meyer, C; Mishra, P M; Novotný, O; O'Connor, A P; Orlov, D A; Rappaport, M L; Repnow, R; Saurabh, S; Schippers, S; Schröter, C D; Schwalm, D; Schweikhard, L; Sieber, T; Shornikov, A; Spruck, K; Sunil Kumar, S; Ullrich, J; Urbain, X; Vogel, S; Wilhelm, P; Wolf, A; Zajfman, D

    2016-06-01

    An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed, and put into operation. With a circumference of 35 m, the ion-beam vacuum chambers and all beam optics are in a cryostat and cooled by a closed-cycle liquid helium system. At temperatures as low as (5.5 ± 1) K inside the ring, storage time constants of several minutes up to almost an hour were observed for atomic and molecular, anion and cation beams at an energy of 60 keV. The ion-beam intensity, energy-dependent closed-orbit shifts (dispersion), and the focusing properties of the machine were studied by a system of capacitive pickups. The Schottky-noise spectrum of the stored ions revealed a broadening of the momentum distribution on a time scale of 1000 s. Photodetachment of stored anions was used in the beam lifetime measurements. The detachment rate by anion collisions with residual-gas molecules was found to be extremely low. A residual-gas density below 140 cm(-3) is derived, equivalent to a room-temperature pressure below 10(-14) mbar. Fast atomic, molecular, and cluster ion beams stored for long periods of time in a cryogenic environment will allow experiments on collision- and radiation-induced fragmentation processes of ions in known internal quantum states with merged and crossed photon and particle beams.

  2. Telemetry data storage systems technology for the Space Station Freedom era

    NASA Technical Reports Server (NTRS)

    Dalton, John T.

    1989-01-01

    This paper examines the requirements and functions of the telemetry-data recording and storage systems, and the data-storage-system technology projected for the Space Station, with particular attention given to the Space Optical Disk Recorder, an on-board storage subsystem based on 160 gigabit erasable optical disk units each capable of operating at 300 M bits per second. Consideration is also given to storage systems for ground transport recording, which include systems for data capture, buffering, processing, and delivery on the ground. These can be categorized as the first in-first out storage, the fast random-access storage, and the slow access with staging. Based on projected mission manifests and data rates, the worst case requirements were developed for these three storage architecture functions. The results of the analysis are presented.

  3. Aflatoxins and safe storage

    PubMed Central

    Villers, Philippe

    2014-01-01

    The paper examines both field experience and research on the prevention of the exponential growth of aflatoxins during multi-month post-harvest storage in hot, humid countries. The approach described is the application of modern safe storage methods using flexible, Ultra Hermetic™ structures that create an unbreatheable atmosphere through insect and microorganism respiration alone, without use of chemicals, fumigants, or pumps. Laboratory and field data are cited and specific examples are given describing the uses of Ultra Hermetic storage to prevent the growth of aflatoxins with their significant public health consequences. Also discussed is the presently limited quantitative information on the relative occurrence of excessive levels of aflatoxin (>20 ppb) before vs. after multi-month storage of such crops as maize, rice, and peanuts when under high humidity, high temperature conditions and, consequently, the need for further research to determine the frequency at which excessive aflatoxin levels are reached in the field vs. after months of post-harvest storage. The significant work being done to reduce aflatoxin levels in the field is mentioned, as well as its probable implications on post-harvest storage. Also described is why, with some crops such as peanuts, using Ultra Hermetic storage may require injection of carbon dioxide, or use of an oxygen absorber as an accelerant. The case of peanuts is discussed and experimental data is described. PMID:24782846

  4. Aflatoxins and safe storage.

    PubMed

    Villers, Philippe

    2014-01-01

    The paper examines both field experience and research on the prevention of the exponential growth of aflatoxins during multi-month post-harvest storage in hot, humid countries. The approach described is the application of modern safe storage methods using flexible, Ultra Hermetic™ structures that create an unbreatheable atmosphere through insect and microorganism respiration alone, without use of chemicals, fumigants, or pumps. Laboratory and field data are cited and specific examples are given describing the uses of Ultra Hermetic storage to prevent the growth of aflatoxins with their significant public health consequences. Also discussed is the presently limited quantitative information on the relative occurrence of excessive levels of aflatoxin (>20 ppb) before vs. after multi-month storage of such crops as maize, rice, and peanuts when under high humidity, high temperature conditions and, consequently, the need for further research to determine the frequency at which excessive aflatoxin levels are reached in the field vs. after months of post-harvest storage. The significant work being done to reduce aflatoxin levels in the field is mentioned, as well as its probable implications on post-harvest storage. Also described is why, with some crops such as peanuts, using Ultra Hermetic storage may require injection of carbon dioxide, or use of an oxygen absorber as an accelerant. The case of peanuts is discussed and experimental data is described.

  5. Ultrafine hydrogen storage powders

    DOEpatents

    Anderson, Iver E.; Ellis, Timothy W.; Pecharsky, Vitalij K.; Ting, Jason; Terpstra, Robert; Bowman, Robert C.; Witham, Charles K.; Fultz, Brent T.; Bugga, Ratnakumar V.

    2000-06-13

    A method of making hydrogen storage powder resistant to fracture in service involves forming a melt having the appropriate composition for the hydrogen storage material, such, for example, LaNi.sub.5 and other AB.sub.5 type materials and AB.sub.5+x materials, where x is from about -2.5 to about +2.5, including x=0, and the melt is gas atomized under conditions of melt temperature and atomizing gas pressure to form generally spherical powder particles. The hydrogen storage powder exhibits improved chemcial homogeneity as a result of rapid solidfication from the melt and small particle size that is more resistant to microcracking during hydrogen absorption/desorption cycling. A hydrogen storage component, such as an electrode for a battery or electrochemical fuel cell, made from the gas atomized hydrogen storage material is resistant to hydrogen degradation upon hydrogen absorption/desorption that occurs for example, during charging/discharging of a battery. Such hydrogen storage components can be made by consolidating and optionally sintering the gas atomized hydrogen storage powder or alternately by shaping the gas atomized powder and a suitable binder to a desired configuration in a mold or die.

  6. SERI solar energy storage program

    NASA Astrophysics Data System (ADS)

    Copeland, R. J.; Wright, J. D.; Wyman, C. E.

    1980-02-01

    Research on advanced technologies, system analyses, and assessments of thermal energy storage for solar applications in support of the Thermal and Chemical Energy Storage program are presented. Currently, research is in progress on direct contact latent heat storage and thermochemical energy storage and transport. Systems analyses are being performed of thermal energy storage for solar thermal applications, and surveys and assessments are being prepared of thermal energy storage in solar applications.

  7. SERI solar energy storage program

    NASA Astrophysics Data System (ADS)

    Baylin, F.; Copeland, R. J.; Kotch, A.; Kriz, T.; Luft, W.; Nix, R. G.; Wright, J. O.

    1982-05-01

    Thermal energy storage technologies are identified for specific solar thermal applications. The capabilities and limitations of direct-contact thermal storage and thermochemical energy storage and transport are examined. Storage of energy from active solar thermal systems for industrial process heat and the heating of buildings is analyzed and seasonal energy storage is covered. The coordination of numerous thermal energy storage research and development activities is described.

  8. Exciton storage in a nanoscale Aharonov-Bohm ring with electric field tuning.

    PubMed

    Fischer, Andrea M; Campo, Vivaldo L; Portnoi, Mikhail E; Römer, Rudolf A

    2009-03-06

    We study analytically the optical properties of a simple model for an electron-hole pair on a ring subjected to perpendicular magnetic flux and in-plane electric field. We show how to tune this excitonic system from optically active to optically dark as a function of these external fields. Our results offer a simple mechanism for exciton storage and readout.

  9. Exciton Storage in a Nanoscale Aharonov-Bohm Ring with Electric Field Tuning

    SciTech Connect

    Fischer, Andrea M.; Roemer, Rudolf A.; Campo, Vivaldo L. Jr.; Portnoi, Mikhail E.

    2009-03-06

    We study analytically the optical properties of a simple model for an electron-hole pair on a ring subjected to perpendicular magnetic flux and in-plane electric field. We show how to tune this excitonic system from optically active to optically dark as a function of these external fields. Our results offer a simple mechanism for exciton storage and readout.

  10. Gas Storage Technology Consortium

    SciTech Connect

    Joel L. Morrison; Sharon L. Elder

    2007-06-30

    Gas storage is a critical element in the natural gas industry. Producers, transmission and distribution companies, marketers, and end users all benefit directly from the load balancing function of storage. The unbundling process has fundamentally changed the way storage is used and valued. As an unbundled service, the value of storage is being recovered at rates that reflect its value. Moreover, the marketplace has differentiated between various types of storage services and has increasingly rewarded flexibility, safety, and reliability. The size of the natural gas market has increased and is projected to continue to increase towards 30 trillion cubic feet over the next 10 to 15 years. Much of this increase is projected to come from electric generation, particularly peaking units. Gas storage, particularly the flexible services that are most suited to electric loads, is crucial in meeting the needs of these new markets. To address the gas storage needs of the natural gas industry, an industry-driven consortium was created--the Gas Storage Technology Consortium (GSTC). The objective of the GSTC is to provide a means to accomplish industry-driven research and development designed to enhance the operational flexibility and deliverability of the nation's gas storage system, and provide a cost-effective, safe, and reliable supply of natural gas to meet domestic demand. This report addresses the activities for the quarterly period of April 1, 2007 through June 30, 2007. Key activities during this time period included: (1) Organizing and hosting the 2007 GSTC Spring Meeting; (2) Identifying the 2007 GSTC projects, issuing award or declination letters, and begin drafting subcontracts; (3) 2007 project mentoring teams identified; (4) New NETL Project Manager; (5) Preliminary planning for the 2007 GSTC Fall Meeting; (6) Collecting and compiling the 2005 GSTC project final reports; and (7) Outreach and communications.

  11. Gas Storage Technology Consortium

    SciTech Connect

    Joel Morrison

    2005-09-14

    Gas storage is a critical element in the natural gas industry. Producers, transmission and distribution companies, marketers, and end users all benefit directly from the load balancing function of storage. The unbundling process has fundamentally changed the way storage is used and valued. As an unbundled service, the value of storage is being recovered at rates that reflect its value. Moreover, the marketplace has differentiated between various types of storage services, and has increasingly rewarded flexibility, safety, and reliability. The size of the natural gas market has increased and is projected to continue to increase towards 30 trillion cubic feet (TCF) over the next 10 to 15 years. Much of this increase is projected to come from electric generation, particularly peaking units. Gas storage, particularly the flexible services that are most suited to electric loads, is critical in meeting the needs of these new markets. In order to address the gas storage needs of the natural gas industry, an industry driven consortium was created--the Gas Storage Technology Consortium (GSTC). The objective of the GSTC is to provide a means to accomplish industry-driven research and development designed to enhance operational flexibility and deliverability of the Nation's gas storage system, and provide a cost effective, safe, and reliable supply of natural gas to meet domestic demand. This report addresses the activities for the quarterly period of April 1, 2005 through June 30, 2005. During this time period efforts were directed toward (1) GSTC administration changes, (2) participating in the American Gas Association Operations Conference and Biennial Exhibition, (3) issuing a Request for Proposals (RFP) for proposal solicitation for funding, and (4) organizing the proposal selection meeting.

  12. Gas Storage Technology Consortium

    SciTech Connect

    Joel L. Morrison; Sharon L. Elder

    2006-05-10

    Gas storage is a critical element in the natural gas industry. Producers, transmission and distribution companies, marketers, and end users all benefit directly from the load balancing function of storage. The unbundling process has fundamentally changed the way storage is used and valued. As an unbundled service, the value of storage is being recovered at rates that reflect its value. Moreover, the marketplace has differentiated between various types of storage services, and has increasingly rewarded flexibility, safety, and reliability. The size of the natural gas market has increased and is projected to continue to increase towards 30 trillion cubic feet (TCF) over the next 10 to 15 years. Much of this increase is projected to come from electric generation, particularly peaking units. Gas storage, particularly the flexible services that are most suited to electric loads, is critical in meeting the needs of these new markets. In order to address the gas storage needs of the natural gas industry, an industry-driven consortium was created--the Gas Storage Technology Consortium (GSTC). The objective of the GSTC is to provide a means to accomplish industry-driven research and development designed to enhance operational flexibility and deliverability of the Nation's gas storage system, and provide a cost effective, safe, and reliable supply of natural gas to meet domestic demand. This report addresses the activities for the quarterly period of January 1, 2006 through March 31, 2006. Activities during this time period were: (1) Organize and host the 2006 Spring Meeting in San Diego, CA on February 21-22, 2006; (2) Award 8 projects for co-funding by GSTC for 2006; (3) New members recruitment; and (4) Improving communications.

  13. Gas Storage Technology Consortium

    SciTech Connect

    Joel L. Morrison; Sharon L. Elder

    2007-03-31

    Gas storage is a critical element in the natural gas industry. Producers, transmission and distribution companies, marketers, and end users all benefit directly from the load balancing function of storage. The unbundling process has fundamentally changed the way storage is used and valued. As an unbundled service, the value of storage is being recovered at rates that reflect its value. Moreover, the marketplace has differentiated between various types of storage services and has increasingly rewarded flexibility, safety, and reliability. The size of the natural gas market has increased and is projected to continue to increase towards 30 trillion cubic feet (TCF) over the next 10 to 15 years. Much of this increase is projected to come from electric generation, particularly peaking units. Gas storage, particularly the flexible services that are most suited to electric loads, is crucial in meeting the needs of these new markets. To address the gas storage needs of the natural gas industry, an industry-driven consortium was created - the Gas Storage Technology Consortium (GSTC). The objective of the GSTC is to provide a means to accomplish industry-driven research and development designed to enhance the operational flexibility and deliverability of the nation's gas storage system, and provide a cost-effective, safe, and reliable supply of natural gas to meet domestic demand. This report addresses the activities for the quarterly period of January1, 2007 through March 31, 2007. Key activities during this time period included: {lg_bullet} Drafting and distributing the 2007 RFP; {lg_bullet} Identifying and securing a meeting site for the GSTC 2007 Spring Proposal Meeting; {lg_bullet} Scheduling and participating in two (2) project mentoring conference calls; {lg_bullet} Conducting elections for four Executive Council seats; {lg_bullet} Collecting and compiling the 2005 GSTC Final Project Reports; and {lg_bullet} Outreach and communications.

  14. Amplified light storage with high fidelity based on electromagnetically induced transparency in rubidium atomic vapor

    NASA Astrophysics Data System (ADS)

    Zhou, Wei; Wang, Gang; Tang, Guoyu; Xue, Yan

    2016-06-01

    By using slow and stored light based on electromagnetically induced transparency (EIT), we theoretically realize the storage of optical pulses with enhanced efficiency and high fidelity in ensembles of warm atoms in 85Rb vapor cells. The enhancement of storage efficiency is achieved by introducing a pump field beyond three-level configuration to form a N-type scheme, which simultaneously inhibits the undesirable four-wave mixing effect while preserves its fidelity. It is shown that the typical storage efficiency can be improved from 29% to 53% with the application of pump field. Furthermore, we demonstrate that this efficiency decreases with storage time and increases over unity with optical depth.

  15. Thermal energy storage

    NASA Technical Reports Server (NTRS)

    Grodzka, P. G.; Picklesimer, E. A.

    1978-01-01

    The general scope of study on thermal energy storage development includes: (1) survey and review possible concepts for storing thermal energy; (2) evaluate the potentials of the surveyed concepts for practical applications in the low and high temperature ranges for thermal control and storage, with particular emphasis on the low temperature range, and designate the most promising concepts; and (3) determine the nature of further studies required to expeditiously convert the most promising concept(s) to practical applications. Cryogenic temperature control by means of energy storage materials was also included.

  16. Ultrafast nanomagnets: seeing data storage in a new light.

    PubMed

    Hicken, R J

    2003-12-15

    Magnetic materials provide the most important form of erasable data storage for information technology today. The demand for increased storage capacity has caused bit sizes and features of the read-write transducers to be reduced to the nanoscale. However, increased storage capacity is only useful if there is a commensurate reduction in the time taken to read and write the data. In this article, the basic principles that determine the behaviour of nanomagnetic materials are introduced and their use in data-storage systems is described. Particular attention is paid to processes that limit the speed of operation of the data-storage system. It is shown that optical pump-probe experiments may be used to characterize dynamic magnetic processes with femtosecond temporal resolution. The macroscopic magnetization of a ferromagnet can be made to precess in response to an optically triggered magnetic field pulse, leading to reduced switching times. Alternatively, an ultrashort laser pulse may be used to manipulate the magnitude of the magnetization on femtosecond time-scales, leading to an ultrafast demagnetization in certain ferromagnets, and providing new insight into magnetotransport phenomena. Finally, the outlook for increased record and replay rates is assessed and the prospect of further use of optical techniques within magnetic data-storage technology is discussed.

  17. Multiplexed Holographic Data Storage in Bacteriorhodopsin

    NASA Technical Reports Server (NTRS)

    Mehrl, David J.; Krile, Thomas F.

    1999-01-01

    Biochrome photosensitive films in particular Bacteriorhodopsin exhibit features which make these materials an attractive recording medium for optical data storage and processing. Bacteriorhodopsin films find numerous applications in a wide range of optical data processing applications; however the short-term memory characteristics of BR limits their applications for holographic data storage. The life-time of the BR can be extended using cryogenic temperatures [1], although this method makes the system overly complicated and unstable. Longer life-times can be provided in one modification of BR - the "blue" membrane BR [2], however currently available films are characterized by both low diffraction efficiency and difficulties in providing photoreversible recording. In addition, as a dynamic recording material, the BR requires different wavelengths for recording and reconstructing of optical data in order to prevent the information erasure during its readout. This fact also put constraints on a BR-based Optical Memory, due to information loss in holographic memory systems employing the two-lambda technique for reading-writing thick multiplexed holograms.

  18. New, puzzling insights from comparative myological studies on the old and unsolved forelimb/hindlimb enigma.

    PubMed

    Diogo, Rui; Linde-Medina, Marta; Abdala, Virginia; Ashley-Ross, Miriam A

    2013-02-01

    Most textbooks and research reports state that the structures of the tetrapod forelimbs and hindlimbs are serial homologues. From this view, the main challenge of evolutionary biologists is not to explain the similarity between tetrapod limbs, but instead to explain why and how they have diverged. However, these statements seem to be related to a confusion between the serial homology of the vertebrate pelvic and pectoral appendages as a whole, and the serial homology of the specific soft- and hard-tissue structures of the tetrapod forelimbs and hindlimbs, leading to an even more crucial and puzzling question being overlooked: why are the skeletal and particularly the muscle structures of the forelimb and hindlimb actually so strikingly similar to each other? Herein we provide an updated discussion of these questions and test two main hypotheses: (i) that the similarity of the limb muscles is due to serial homology; and (ii) that tetrapods that use hindlimbs for a largely exclusive function (e.g. bipedalism in humans) exhibit fewer cases of similarity between forelimbs and hindlimbs than do quadrupedal species. Our review shows that of the 23 arm, forearm and hand muscles/muscle groups of salamanders, 18 (78%) have clear 'topological equivalents' in the hindlimb; in lizards, 14/24 (58%); in rats, 14/35 (40%); and in modern humans, 19/37 (51%). These numbers seem to support the idea that there is a plesiomorphic similarity and subsequent evolutionary divergence, but this tendency actually only applies to the three former quadrupedal taxa. Moreover, if one takes into account the total number of 'correspondences', one comes to a surprising and puzzling conclusion: in modern humans the number of forelimb muscles/muscle groups with clear 'equivalents' in the hindlimb (19) is substantially higher than in quadrupedal mammals such as rats (14), lizards (14) and even salamanders (18). These data contradict the hypothesis that divergent functions lead to divergent

  19. Wavelength Independent Optical Lithography.

    DTIC Science & Technology

    1986-06-06

    lamp because it has a smooth, broadband output in the visible and near UV. High Density Optical Intormation Storage The NSOM concept can be combined...stringent control can be maintained over the temperature of the entire apparatus. Ideally, both of these methods should be used. - . * S P. .~ V: -:V- TwT ...DNA helixes : enantiomers of tris(4, 7-diphenylpheanthroline)ruthenium (II). Proc. Natl. Acad. Sci. U.S.A. 81, 7 (1984). 27. J.M. Fernandez, E. Neher

  20. Optical Hidden Layer Networks

    DTIC Science & Technology

    1991-07-01

    List of Figures 1. Schematic for holographic Adaline learning. 2 2. Fiber optic acoustic transducer. 4 3. The storage of the Fourier transform of...modulator. The object of this experiment was to perform what is known as Adaline learning on a set of input vectors. In this task, one has a desired...ll ll! I Computer Figure I Schematic for holographic Adaline learning. In the course of our experiments we found that in practice our system