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Sample records for organizations applied optics

  1. Organic nonlinear optical materials

    NASA Technical Reports Server (NTRS)

    Umegaki, S.

    1987-01-01

    Recently, it became clear that organic compounds with delocalized pi electrons show a great nonlinear optical response. Especially, secondary nonlinear optical constants of more than 2 digits were often seen in the molecular level compared to the existing inorganic crystals such as LiNbO3. The crystallization was continuously tried. Organic nonlinear optical crystals have a new future as materials for use in the applied physics such as photomodulation, optical frequency transformation, opto-bistabilization, and phase conjugation optics. Organic nonlinear optical materials, e.g., urea, O2NC6H4NH2, I, II, are reviewed with 50 references.

  2. Organic electro-optic materials

    NASA Astrophysics Data System (ADS)

    Dalton, Larry R.; Robinson, Bruce H.; Jen, Alex K.; Ried, Philip; Eichinger, Bruce; Jang, Sei-Hum; Luo, Jingdong; Liu, Sen; Liao, Yi; Firestone, Kimberly A.; Bhatambrekar, Nishant P.; Bale, Denise; Haller, Marnie A.; Bhattacharjee, Sanchali; Schendel, Jessica; Sullivan, Philip A.; Hammond, Scott; Buker, Nicholas; Cady, Field; Chen, Antao; Steier, William H.

    2004-12-01

    The potential of organic electro-optic materials for large electro-optic activity and fast response to applied electric fields (leading to 100 GHz device bandwidths) is important and increasingly well-recognized. In this communication, we demonstrate how quantum and statistical mechanical calculations can be used to guide the systematic improvement of both molecular first hyperpolarizability (β) and macroscopic electro-optic activity (r). Femtosecond time-resolved, wavelength-agile Hyper-Rayleigh Scattering (HRS) measurements have been used to measure β values relative to chloroform and to avoid confusion associated with two photon contributions. Electro-optic coefficients have been characterized by simple reflection (Teng-Man method), attenuated total reflection (ATR), and Mach Zehnder interferometry. "Constant bias" modifications of these techniques have been used to permit investigation of optimized poling conditions. Organic electro-optic materials also afford unique advantages for the fabrication of conformal and flexible devices, for the integration of disparate materials, and for exploitation of novel manufacturing technologies such as soft lithography. Both stripline and ring microresonator structures have been fabricated by soft lithography. The integration of organic electro-optic materials with silicon photonics (both split ring microresonators and photonic bandgap circuitry) has been demonstrated.

  3. Organic optical bistable switch

    NASA Astrophysics Data System (ADS)

    Xue, Jiangeng; Forrest, Stephen R.

    2003-01-01

    We demonstrate an organic optical bistable switch by integrating an efficient organic photodetector on top of a transparent electrophosphorescent organic light-emitting diode (TOLED). The bistability is achieved with an external field-effect transistor providing positive feedback. In the "LOW" state, the TOLED is off and the current in the photodetector is solely its dark current. In the "HIGH" state, the TOLED emits light that is directly coupled into the integrated photodetector through the transparent cathode. The photocurrent then is fed back to the TOLED, maintaining it in the HIGH state. The green electrophosphorescent material, fac tris(2-phenylpyridine) iridium [Ir(ppy)3] doped into a 4,4'-N,N'-dicarbazole-biphenyl host was used as the luminescent material in the TOLED, while alternating thin layers of copper phthalocyanine and 3,4,9,10-perylenetetracarboxylic bis-benzimidazole were used as the active region of the organic photodetector. The circuit has a 3 dB bandwidth of 25 kHz, and can be switched between HIGH and LOW using pulses as narrow as 60 ns. The bistable switch can be both electrically and optically reset, making it a candidate for image-retaining displays (e.g., electronic paper) and other photonic logic applications. The integrated organic device also has broad use as a linear circuit element in applications such as automatic brightness control.

  4. Applied optics in the automotive industry.

    PubMed

    Preston, B W

    1969-09-01

    A general discussion of the interrelated subjects of vision, illumination, marking systems, signaling devices, materials, and components as found in the automotive industry is included in this article. Optics as applied in supporting industries, such as the lighting, metal, glass, paint, plastics, and fabrics industries are also discussed. A few examples of optics in these industries as applied to product development and productioncontrol are presented and illustrated. PMID:20072517

  5. Velocity filtering applied to optical flow calculations

    NASA Technical Reports Server (NTRS)

    Barniv, Yair

    1990-01-01

    Optical flow is a method by which a stream of two-dimensional images obtained from a forward-looking passive sensor is used to map the three-dimensional volume in front of a moving vehicle. Passive ranging via optical flow is applied here to the helicopter obstacle-avoidance problem. Velocity filtering is used as a field-based method to determine range to all pixels in the initial image. The theoretical understanding and performance analysis of velocity filtering as applied to optical flow is expanded and experimental results are presented.

  6. Organic Materials For Optical Switching

    NASA Technical Reports Server (NTRS)

    Cardelino, Beatriz H.

    1993-01-01

    Equations predict properties of candidate materials. Report presents results of theoretical study of nonlinear optical properties of organic materials. Such materials used in optical switching devices for computers and telecommunications, replacing electronic switches. Optical switching potentially offers extremely high information throughout in compact hardware.

  7. Applications of optical holography to applied mechanics.

    NASA Technical Reports Server (NTRS)

    Aprahamian, R.

    1972-01-01

    This paper provides a brief summary of applications of optical holography and holographic interferometry to applied solid mechanics. Basic equations commonly used in fringe interpretation are described and used to reduce the data contained on holographic interferograms. A comparison of data obtained holographically with analytical prediction is given wherever possible. Applications contained herein include front surface physics, study of bomb breakup, transverse wave propagation, study of mode shapes of panels at elevated temperatures, nondestructive testing, and vibration analysis.

  8. Optical and optoelectronic properties of organic nanomaterials

    NASA Astrophysics Data System (ADS)

    Satapathi, Soumitra

    In this dissertation research, organic nanomaterials, such as semiconducting polymer nanoparticles, graphene nanosheets and organic small molecules were successfully utilized for fabrication of organic solar cells, optical sensors and for high contrast imaging of cancer cells. Semiconducting polymer nanoparticles were synthesized by a simple miniemulsion technique. These size controllable polymeric nanoparticles were proven to be able to optimize the morphologies of the bulk heterojunction solar cells and to provide fundamental insight into the evolution of the nanostructures. Highly sensitive optical sensors were fabricated using these polymeric nanoparticles for efficient detection of nitroaromatic explosives, such as 2,4 dinitrotoluene (DNT) and 2,4,6 trinitrotoluene (TNT) in aqueous medium as well as in vapor the phase. Moreover, these water dispersible and fluorescent polymer nanodots were two-photon active and could be internalized by tumor cells as demonstrated by two-photon confocal imaging. In addition to the polymer nanoparticles, the role of the graphene nanosheets in the performance enhancement of dye sensitized solar cells was also investigated. The use of organic small molecules for optical sensing of different nerve gas agents and their potential use in multiphoton imaging of cancer cells were discussed. Controlling material properties at nanoscale for optoelectronics and imaging application as discussed in this dissertation would provide new dimensions in the areas of applied physics and materials science researches.

  9. Applying the ABCs in provider organizations.

    PubMed

    Pandey, Seema

    2012-11-01

    Activity-based costing (ABC) is an accounting technique designed to guard against potentially serious financial problems that can arise when an organization's accounting costs deviate significantly from its actual costs. In general, an ABC analysis considers two factors: a cost element (a directly measurable unit of cost, such as the cost of an item) and a cost driver (a directly measurable feature of the service, such as how often the item is used). ABC is best applied to specific service areas, orservice packages, for which consumption of resources is largely predictable and atomic units of services can be accurately identified. PMID:23173369

  10. Polarization-sensitive optical coherence tomography applied to intervertebral disk

    NASA Astrophysics Data System (ADS)

    Matcher, Stephen J.; Winlove, Peter; Gangnus, Sergei V.

    2003-07-01

    Polarization-sensitive optical coherence tomography (PSOCT) is a powerful new optical imaging modality that is sensitive to the birefringence properties of tissues. It thus has potential applications in studying the large-scale ordering of collagen fibers within connective tisues and changes related to pathology. As a tissue for study by PSOCT, intervertebral disk respresents an interesting system as the collagen organization is believed to show pronounced variations with depth, on a spatial scale of about 100 μm. We have used a polarization-sensitive optical coherence tomography system to measure the birefringence properties of bovine caudal intervertebral disk and compared this with equine flexor tendon. The result for equine tendon, δ = (3.0 +/- 0.5)x10-3 at 1.3 μm, is in broad agreement with values reported for bovine tendon, while bovine intervertebral disk displays a birefringence of about half this, δ = 1.2 x 10-3 at 1.3 μm. While tendon appears to show a uniform fast-axis over 0.8 mm depth, intervertebral disk shows image contrast at all orientations relative to a linearly polarized input beam, suggesting a variation in fast-axis orientation with depth. These initial results suggest that PSOCT could be a useful tool to study collagen organization within this tissue and its variation with applied load and disease.

  11. Dielectric barrier discharges applied for optical spectrometry

    NASA Astrophysics Data System (ADS)

    Brandt, S.; Schütz, A.; Klute, F. D.; Kratzer, J.; Franzke, J.

    2016-09-01

    The present review reflects the importance of dielectric barrier discharges for optical spectrometric detection in analytical chemistry. In contrast to usual discharges with a direct current the electrodes are separated by at least one dielectric barrier. There are two main features of the dielectric barrier discharges: they can serve as dissociation and excitation devices as well as ionization sources, respectively. This article portrays various application fields of dielectric barrier discharges in analytical chemistry used for elemental and molecular detection with optical spectrometry.

  12. Superresolution technology applied to optical discs

    NASA Astrophysics Data System (ADS)

    Zhou, Changhe; Luo, Hongxin

    2005-09-01

    Smaller focal points are essential for the development of the next-generation optical disc. The size of focal point depends on the diffraction effect that is dependant on the numerical aperture of a lens and the wavelength of light. However, increase of the numerical aperture and decrease of the light wavelength will be ultimately limited due to the technical difficulty of fabricating a too-high NA lens and the too-short wavelength laser. In this paper, we report another approach of using the superresolution technology to compress the size of the so-called Airy spot for the next-generation optical disc, which is independent on the wavelength of laser. The superresolution phase plates are designed and fabricated with a microoptics technique. When such a phase plate is inserted into the optical system, the central spot at the focal plane of a lens is decreased to be 0.8 times of the Airy pattern, implying the possibility of reading higher storage density of optical discs. The most attractive feature is that the phase plate can be mass-produced at a very low cost, compared with the high cost of the high-numerical lens and/or the short wavelength laser. The disadvantages are that the inserted phase plate will induce the slight circular sidelobes around the central sport, so that it consumes a little more laser energy. The shortcoming could be overcome with suitable amendment. We have fabricated the phase plates with the surface-relief profile on a normal glass for phase modulation. Experimental results of superresolution effect with a low numerical aperture (NA=0.1) and a high-numerical lens (NA=0.8) are reported, which are in good agreement with the theoretical prediction. Superresolution technique should be highly interesting as a novel technique of the next-generation pickup head for reading the high storage of the optical discs.

  13. (Optical characterization techniques applied to ceramic oxides)

    SciTech Connect

    Abraham, M.M.

    1990-10-15

    The traveler collaborated with M.J.M. Leask, J.M. Baker, B. Bleaney, and others at the Clarendon Laboratory, Oxford University, Oxford, UK, to Study Tetragonal rare-earth phosphates and vanadates by optical and magnetic spectroscopy. This work is related to similar studies that have been performed at ORNL by the Synthesis and Properties of Novel Materials Group in the Solid State Division.

  14. Optical correlator techniques applied to robotic vision

    NASA Technical Reports Server (NTRS)

    Hine, Butler P., III; Reid, Max B.; Downie, John D.

    1991-01-01

    Vision processing is one of the most computationally intensive tasks required of an autonomous robot. The data flow from a single typical imaging sensor is roughly 60 Mbits/sec, which can easily overload current on-board processors. Optical correlator-based processing can be used to perform many of the functions required of a general robotic vision system, such as object recognition, tracking, and orientation determination, and can perform these functions fast enough to keep pace with the incoming sensor data. We describe a hybrid digital electronic/analog optical robotic vision processing system developed at Ames Research Center to test concepts and algorithms for autonomous construction, inspection, and maintenance of space-based habitats. We discuss the system architecture design and implementation, its performance characteristics, and our future plans. In particular, we compare the performance of the system to a more conventional all digital electronic system developed concurrently. The hybrid system consistently outperforms the digital electronic one in both speed and robustness.

  15. How optics and photonics is simply applied in agriculture?

    NASA Astrophysics Data System (ADS)

    Sumriddetchkajorn, Sarun

    2013-06-01

    This paper highlights based on author's experience how optics and photonics is applied in Thai agriculture. These include spectral imaging based systems and mobile applications that have been implemented in the last 5 years for rice, fishery, and sericulture. Brief review of optics and photonics in agriculture will also be introduced.

  16. Teaching applied optics at the Univ. of Minho

    NASA Astrophysics Data System (ADS)

    Costa, Manuel F. M.

    1995-10-01

    In this communication we make a brief presentation of the branch of Applied Optics of the University of Mihno's undergraduate course of Applied Physics. The course of Applied Physics began in the year 1988/89. Previously we had just a course devoted to the formation of future physics and chemistry teachers at high school level. The Applied Physics course specialized in Optics appeared due to the growth of the physics department and due to request from the industry. The Applied Physics course has two specialization's on the field of applied optics: Optometry; and Optics and Lasers. The topics covered in the two first years of the course ar common to the two branches. On the second semester of the third year the students must choose between either one. The number of students on the Optometry branch was usually almost four times the number of Applied Optics and Lasers students. Nevertheless this tendency is rapidly changing. A short analysis of the result obtained will be presented focusing on last couple of years' advances. Presented will also be the results of an inquest made on students's opinions about the quality of the course, and their own performance and expectations.

  17. Trends in optical coherence tomography applied to medical imaging

    NASA Astrophysics Data System (ADS)

    Podoleanu, Adrian G.

    2014-01-01

    The number of publications on optical coherence tomography (OCT) continues to double every three years. Traditionally applied to imaging the eye, OCT is now being extended to fields outside ophthalmology and optometry. Widening its applicability, progress in the core engine of the technology, and impact on development of novel optical sources, make OCT a very active and rapidly evolving field. Trends in the developments of different specific devices, such as optical sources, optical configurations and signal processing will be presented. Encompassing studies on both the configurations as well as on signal processing themes, current research in Kent looks at combining spectral domain with time domain imaging for long axial range and simultaneous imaging at several depths. Results of the collaborative work of the Applied Optics Group in Kent with organisers of this conference will be presented, with reference to 3D monitoring of abfraction.

  18. Applying Knowledge Management to an Organization's Transformation

    NASA Technical Reports Server (NTRS)

    Potter, Shannon; Gill, Tracy; Fritsche, Ralph

    2008-01-01

    Although workers in the information age have more information at their fingertips than ever before, the ability to effectively capture and reuse actual knowledge is still a surmounting challenge for many organizations. As high tech organizations transform from providing complex products and services in an established domain to providing them in new domains, knowledge remains an increasingly valuable commodity. This paper explores the supply and demand elements of the "knowledge market" within the International Space Station and Spacecraft Processing Directorate (ISSSPD) of NASA's Kennedy Space Center (KSC). It examines how knowledge supply and knowledge demand determine the success of an organization's knowledge management (KM) activities, and how the elements of a KM infrastructure (tools, culture, and training), can be used to create and sustain knowledge supply and demand

  19. Optical methods of stress analysis applied to cracked components

    NASA Technical Reports Server (NTRS)

    Smith, C. W.

    1991-01-01

    After briefly describing the principles of frozen stress photoelastic and moire interferometric analyses, and the corresponding algorithms for converting optical data from each method into stress intensity factors (SIF), the methods are applied to the determination of crack shapes, SIF determination, crack closure displacement fields, and pre-crack damage mechanisms in typical aircraft component configurations.

  20. Applied study of optical interconnection link in computer cluster

    NASA Astrophysics Data System (ADS)

    Zhou, Ge; Tian, Jindong; Zhang, Nan; Jing, Wencai; Li, Haifeng

    2000-10-01

    In this paper, some study results to apply fiber link to a computer cluster are presented. The research is based on a ring network topology for a cluster system, which is connected by gigabit/s virtual parallel optical fiber link (VPOFLink) and its driver is for Linux Operating System, the transmission protocol of VPOFLink is compliant with Ethernet standard. We have studied the effect of different types of motherboard on transmission rate of the VPOFLink, and have analyzed the influence of optical interconnection network topology and computer networks protocol on the performance of this optical interconnection computer cluster. The round-trip transmission bandwidth of the VPOFLink have been tested, and the factors that limit transmission bandwidth, such as modes of forwarding data packets in the optical interconnection ring networks, and the size of the link buffer etc., are investigated.

  1. Applying of digital signal processing to optical equisignal zone system

    NASA Astrophysics Data System (ADS)

    Maraev, Anton A.; Timofeev, Aleksandr N.; Gusarov, Vadim F.

    2015-05-01

    In this work we are trying to assess the application of array detectors and digital information processing to the system with the optical equisignal zone as a new method of evaluating of optical equisignal zone position. Peculiarities of optical equisignal zone formation are described. The algorithm of evaluation of optical equisignal zone position is applied to processing on the array detector. This algorithm enables to evaluate as lateral displacement as turning angles of the receiver relative to the projector. Interrelation of parameters of the projector and the receiver is considered. According to described principles an experimental set was made and then characterized. The accuracy of position evaluation of the equisignal zone is shown dependent of the size of the equivalent entrance pupil at processing.

  2. Ultrathin optical design for organic photovoltaic cells

    NASA Astrophysics Data System (ADS)

    Man, J. X.; Luo, D. Y.; Yu, L. M.; Wang, D. K.; Liu, Z.; Lu, Z. H.

    2015-05-01

    A trilayer ultrathin-film model concept had been adapted to maximize optical absorption of organic photovoltaic cells (OPVs) with a structure of transparent-electrode/highly-absorbing active material/metal. As demonstrated, device with the structure of ITO/Lead phthalocyanine (SubPc):Buckerminster fullerene (C60) (1:4 wt%)/Al had been studied. It is found that more than 90% optical absorption can be obtained in the device with a broaden wavelength range of 480-620 nm. The calculated optical electric fields shows that the unusually high optical absorption is due to the enhanced optical interference inside the OPVs device. This work paved a new way to design the OPVs device.

  3. Electro-optic properties of organic nanotubes.

    PubMed

    Stoylov, Stoyl P; Stoilova-McPhie, Svetla

    2011-08-10

    In this review article the theoretical and experimental possibilities of applying EO-methods for estimation of the physico-chemical properties of the organic nanotubes (ONTs) are studied. The ONTs are highly organized nanostructures of strongly elongated, anysometric, and hollow cylinders with a size range of 1 nm to 10,000 nm, e.g. in aqueous solutions they could behave as colloid (disperse) particles. They have high interaction ability due to their extremely large curved, rolled-up external surfaces (bilayers of membrane walls) and unique properties because of their specific electric charge distribution and dynamics that make possible the functionalization of their surfaces. Thus they could template guestsubstances such as membrane proteins and protein complexes on the exterior surfaces and in the membrane. We performed our investigations for the case of ONT aqueous colloid suspension. Following our earlier proposition of the general expression for the electro-optic (EO) effect we derived equations for the evaluation of the electric properties of ONT particles such as mechanism of electric polarization and identification of their most important electric Dipole Moments (DM), permanent (pDM) and induced (iDMs). Further we recommend ways for the calculation of their magnitude and direction. Also we evaluated some geometrical properties such as length of the ONT particles and their polydispersity. The knowledge that we provided about the ONT properties may enable us to elucidate and predict their biological activity. Templating biological active ligands (such as membrane proteins and protein complexes) on the inner and outer surfaces as well as in the surface membrane creates their potential usefulness as carrier and deliverer of biopharmaceuticals in bio-nanodevices. The theoretical equations were compared with the experimental data for ONTs such as (lipid) LNT, Tobacco Mosaic Virus (TMV) and microtubules (MT). Comparison of EO methods with other methods used till

  4. Applying simulation to optimize plastic molded optical parts

    NASA Astrophysics Data System (ADS)

    Jaworski, Matthew; Bakharev, Alexander; Costa, Franco; Friedl, Chris

    2012-10-01

    Optical injection molded parts are used in many different industries including electronics, consumer, medical and automotive due to their cost and performance advantages compared to alternative materials such as glass. The injection molding process, however, induces elastic (residual stress) and viscoelastic (flow orientation stress) deformation into the molded article which alters the material's refractive index to be anisotropic in different directions. Being able to predict and correct optical performance issues associated with birefringence early in the design phase is a huge competitive advantage. This paper reviews how to apply simulation analysis of the entire molding process to optimize manufacturability and part performance.

  5. Autofocus by Bayes Spectral Entropy Applied to Optical Microscopy.

    PubMed

    Podlech, Steffen

    2016-02-01

    This study introduces a passive autofocus method based on image analysis calculating the Bayes spectral entropy (BSE). The method is applied to optical microscopy and together with the specific construction of the opto-mechanical unit, it allows the analysis of large samples with complicated surfaces without subsampling. This paper will provide a short overview of the relevant theory of calculating the normalized discrete cosine transform when analyzing obtained images, in order to find the BSE measure. Furthermore, it will be shown that the BSE measure is a strong indicator, helping to determine the focal position of the optical microscope. To demonstrate the strength and robustness of the microscope system, tests have been performed using a 1951 USAF test pattern resolution chart determining the in focus position of the microscope. Finally, this method and the optical microscope system is applied to analyze an optical grating (100 lines/mm) demonstrating the detection of the focal position. The paper concludes with an outlook of potential applications of the presented system within quality control and surface analysis. PMID:26758956

  6. Nonlinear optical studies of organic monolayers

    SciTech Connect

    Shen, Y.R.

    1988-02-01

    Second-order nonlinear optical effects are forbidden in a medium with inversion symmetry, but are necessarily allowed at a surface where the inversion summary is broken. They are often sufficiently strong so that a submonolayer perturbation of the surface can be readily detected. They can therefore be used as effective tools to study monolayers adsorbed at various interfaces. We discuss here a number of recent experiments in which optical second harmonic generation (SHG) and sum-frequency generation (SFG) are employed to probe and characterize organic monolayers. 15 refs., 5 figs.

  7. Nonlinear optical properties and nonlinear optical probes of organic materials

    NASA Astrophysics Data System (ADS)

    Meredith, Gerald R.

    1992-02-01

    Nonlinear optical processes and electro-optical effects are expected to have increasing importance as the information age matures and photonics augment electronics in various high density and high bandwidth technologies. Whereas for electronics the emphasis is in construction of smaller device structures from a few parent materials, for organic materials the direction of materials research has been reversed. For some time it's been known that some molecular structures engender exceptionally large molecular nonlinear-polarization responses. If such molecules could be assembled in convenient, versatile, and reliable ways, the resulting materials would be very useful or even enabling in various photonics applications. The mature science and art of chemistry allows very good control over molecular composition and structure and, as will be illustrated in this talk, our knowledge of hyperpolarizability structure- property relationships is advancing rapidly. However, the science of fabrication and arrangement in molecular ensembles and polymers is rather primitive. Thus the goal to develop the appropriately structured materials for utilization in nonlinear and electro-optics has fostered the widespread use of nonlinear optical processes to probe the nature of supramolecular order and assembly. Examples of intrinsic and artificially assembled structures of crystals, molecular aggregates, polymeric orientational electrets and molecular mono- and multi-layer thin films will be shown. Nonlinear optical processes, primarily second-harmonic generation, provide unique probes of these structures, their assembly, and evolution.

  8. Highly Non-Linear Optical (NLO) organic crystals and films. Electrooptical organic materials

    NASA Technical Reports Server (NTRS)

    Mcmanus, Samuel P.; Rosenberger, Franz; Matthews, John

    1987-01-01

    Devices employing nonlinear optics (NLO) hold great promise for important applications in integrated optics, optical information processing and telecommunications. Properly designed organics possess outstanding optical and electrooptical properties which will substantially advance many technologies including electrooptical switching, optical amplification for communications, and parallel processing for hybrid optical computers. A brief comparison of organic and inorganic materials is given.

  9. Influencing organizations to promote health: applying stakeholder theory.

    PubMed

    Kok, Gerjo; Gurabardhi, Zamira; Gottlieb, Nell H; Zijlstra, Fred R H

    2015-04-01

    Stakeholder theory may help health promoters to make changes at the organizational and policy level to promote health. A stakeholder is any individual, group, or organization that can influence an organization. The organization that is the focus for influence attempts is called the focal organization. The more salient a stakeholder is and the more central in the network, the stronger the influence. As stakeholders, health promoters may use communicative, compromise, deinstitutionalization, or coercive methods through an ally or a coalition. A hypothetical case study, involving adolescent use of harmful legal products, illustrates the process of applying stakeholder theory to strategic decision making. PMID:25829111

  10. MERTIS: geometrical calibration of thermal infrared optical system by applying diffractive optical elements

    NASA Astrophysics Data System (ADS)

    Bauer, M.; Baumbach, D.; Buder, M.; Börner, A.; Grießbach, D.; Peter, G.; Santier, E.; Säuberlich, T.; Schischmanow, A.; Schrader, S.; Walter, I.

    2015-09-01

    Geometrical sensor calibration is essential for space applications based on high accuracy optical measurements, in this case for the thermal infrared push-broom imaging spectrometer MERTIS. The goal is the determination of the interior sensor orientation. A conventional method is to measure the line of sight for a subset of pixels by single pixel illumination with collimated light. To adjust angles, which define the line of sight of a pixel, a manipulator construction is used. A new method for geometrical sensor calibration is using Diffractive Optical Elements (DOE) in connection with laser beam equipment. Diffractive optical elements (DOE) are optical microstructures, which are used to split an incoming laser beam with a dedicated wavelength into a number of beams with well-known propagation directions. As the virtual sources of the diffracted beams are points at infinity, the resulting image is invariant against translation. This particular characteristic allows a complete geometrical sensor calibration with only one taken image avoiding complex adjustment procedures, resulting in a significant reduction of calibration effort. We present a new method for geometrical calibration of a thermal infrared optical system, including an thermal infrared test optics and the MERTIS spectrometer bolometer detector. The fundamentals of this new approach for geometrical infrared optical systems calibration by applying diffractive optical elements and the test equipment are shown.

  11. Teaching organization theory for healthcare management: three applied learning methods.

    PubMed

    Olden, Peter C

    2006-01-01

    Organization theory (OT) provides a way of seeing, describing, analyzing, understanding, and improving organizations based on patterns of organizational design and behavior (Daft 2004). It gives managers models, principles, and methods with which to diagnose and fix organization structure, design, and process problems. Health care organizations (HCOs) face serious problems such as fatal medical errors, harmful treatment delays, misuse of scarce nurses, costly inefficiency, and service failures. Some of health care managers' most critical work involves designing and structuring their organizations so their missions, visions, and goals can be achieved-and in some cases so their organizations can survive. Thus, it is imperative that graduate healthcare management programs develop effective approaches for teaching OT to students who will manage HCOs. Guided by principles of education, three applied teaching/learning activities/assignments were created to teach OT in a graduate healthcare management program. These educationalmethods develop students' competency with OT applied to HCOs. The teaching techniques in this article may be useful to faculty teaching graduate courses in organization theory and related subjects such as leadership, quality, and operation management. PMID:16566496

  12. Optical Trapping Techniques Applied to the Study of Cell Membranes

    NASA Astrophysics Data System (ADS)

    Morss, Andrew J.

    Optical tweezers allow for manipulating micron-sized objects using pN level optical forces. In this work, we use an optical trapping setup to aid in three separate experiments, all related to the physics of the cellular membrane. In the first experiment, in conjunction with Brian Henslee, we use optical tweezers to allow for precise positioning and control of cells in suspension to evaluate the cell size dependence of electroporation. Theory predicts that all cells porate at a transmembrane potential VTMof roughly 1 V. The Schwann equation predicts that the transmembrane potential depends linearly on the cell radius r, thus predicting that cells should porate at threshold electric fields that go as 1/r. The threshold field required to induce poration is determined by applying a low voltage pulse to the cell and then applying additional pulses of greater and greater magnitude, checking for poration at each step using propidium iodide dye. We find that, contrary to expectations, cells do not porate at a constant value of the transmembrane potential but at a constant value of the electric field which we find to be 692 V/cm for K562 cells. Delivering precise dosages of nanoparticles into cells is of importance for assessing toxicity of nanoparticles or for genetic research. In the second experiment, we conduct nano-electroporation—a novel method of applying precise doses of transfection agents to cells—by using optical tweezers in conjunction with a confocal microscope to manipulate cells into contact with 100 nm wide nanochannels. This work was done in collaboration with Pouyan Boukany of Dr. Lee's group. The small cross sectional area of these nano channels means that the electric field within them is extremely large, 60 MV/m, which allows them to electrophoretically drive transfection agents into the cell. We find that nano electroporation results in excellent dose control (to within 10% in our experiments) compared to bulk electroporation. We also find that

  13. Optical mirror coated with organic superconducting material

    NASA Astrophysics Data System (ADS)

    Lake, John A.; Heath, William B.

    1988-08-01

    An optical mirror has enhanced reflectivity and reduced thermal distortions when it is composed of a substrate coated with a reflective coating made of an organic superconducting material. The substrate is best constructed of materials which have the most favorable thermal expansion and thermal conduction characteristics at temperatures near 0 K. such as: silicon, diamond, copper, and sapphire. The reflective coating is only a few microns thick and composed of organometallic compounds and is cooled to superconducting or cryogenic temperatures of less than 100 K.

  14. Turbulence profiling methods applied to ESO's adaptive optics facility

    NASA Astrophysics Data System (ADS)

    Valenzuela, Javier; Béchet, Clémentine; Garcia-Rissmann, Aurea; Gonté, Frédéric; Kolb, Johann; Le Louarn, Miska; Neichel, Benoît; Madec, Pierre-Yves; Guesalaga, Andrés.

    2014-07-01

    Two algorithms were recently studied for C2n profiling from wide-field Adaptive Optics (AO) measurements on GeMS (Gemini Multi-Conjugate AO system). They both rely on the Slope Detection and Ranging (SLODAR) approach, using spatial covariances of the measurements issued from various wavefront sensors. The first algorithm estimates the C2n profile by applying the truncated least-squares inverse of a matrix modeling the response of slopes covariances to various turbulent layer heights. In the second method, the profile is estimated by deconvolution of these spatial cross-covariances of slopes. We compare these methods in the new configuration of ESO Adaptive Optics Facility (AOF), a high-order multiple laser system under integration. For this, we use measurements simulated by the AO cluster of ESO. The impact of the measurement noise and of the outer scale of the atmospheric turbulence is analyzed. The important influence of the outer scale on the results leads to the development of a new step for outer scale fitting included in each algorithm. This increases the reliability and robustness of the turbulence strength and profile estimations.

  15. Applying the balanced scorecard in healthcare provider organizations.

    PubMed

    Inamdar, Noorein; Kaplan, Robert S; Bower, Marvin

    2002-01-01

    Several innovative healthcare executives have recently introduced a new business strategy implementation tool: the Balanced Scorecard. The scorecard's measurement and management system provides the following potential benefits to healthcare organizations: It aligns the organization around a more market-oriented, customer-focused strategy It facilitates, monitors, and assesses the implementation of the strategy It provides a communication and collaboration mechanism It assigns accountability for performance at all levels of the organization It provides continual feedback on the strategy and promotes adjustments to marketplace and regulatory changes. We surveyed executives in nine provider organizations that were implementing the Balanced Scorecard. We asked about the following issues relating to its implementation and effect: 1. The role of the Balanced Scorecard in relation to a well-defined vision, mission, and strategy 2. The motivation for adopting the Balanced Scorecard 3. The difference between the Balanced Scorecard and other measurement systems 4. The process followed to develop and implement the Balanced Scorecard 5. The challenges and barriers during the development and implementation process 6. The benefits gained by the organization from adoption and use. The executives reported that the Balanced Scorecard strategy implementation and performance management tool could be successfully applied in the healthcare sector, enabling organizations to improve their competitive market positioning, financial results, and customer satisfaction. This article concludes with guidelines for other healthcare provider organizations to capture the benefits of the Balanced Scorecard performance management system. PMID:12055900

  16. Growth and nonlinear optical characterization of organic single crystal films

    NASA Astrophysics Data System (ADS)

    Zhou, Ligui

    1997-12-01

    Organic single crystal films are important for various future applications in photonics and integrated optics. The conventional method for inorganic crystal growth is not suitable for organic materials, and the high temperature melting method is not good for most organic materials due to decomposition problems. We developed a new method-modified shear method-to grow large area organic single crystal thin films which have exceptional nonlinear optical properties and high quality surfaces. Several organic materials (NPP, PNP and DAST) were synthesized and purified before the thin film crystal growth. Organic single crystal thin films were grown from saturated organic solutions using modified shear method. The area of single crystal films were about 1.5 cm2 for PNP, 1 cm2 for NPP and 5 mm2 for DAST. The thickness of the thin films which could be controlled by the applied pressure ranged from 1μm to 10 μm. The single crystal thin films of organic materials were characterized by polarized microscopy, x-ray diffraction, polarized UV-Visible and polarized micro-FTIR spectroscopy. Polarized microscopy showed uniform birefringence and complete extinction with the rotation of the single crystal thin films under crossed- polarization, which indicated high quality single crystals with no scattering. The surface orientation of single crystal thin films was characterized by x-ray diffraction. The molecular orientation within the crystal was further studied by the polarized UV-Visible and Polarized micro-FTIR techniques combined with the x-ray and polarized microscopy results. A Nd:YAG laser with 35 picosecond pulses at 1064nm wavelength was employed to perform the nonlinear optical characterization of the organic single crystal thin films. Two measurement techniques were used to study the crystal films: second harmonic generation (SHG) and electro-optic (EO) effect. SHG results showed that the nonlinear optical coefficient of NPP was 18 times that of LiNbO3, a standard

  17. Multifunctional organic thin films and their electronic/optical properties

    NASA Astrophysics Data System (ADS)

    Shao, Yan

    The concept of multifunctional organic thin films and their electronic/optical properties has been applied to organic functional device design, fabrication, and characterization. The organic devices involve organic light-emitting diodes (OLEDs) and organic photovoltaic devices (OPV) in this dissertation. In the research of graded junction structure of OLEDs, two kinds of naturally-formed graded junction (NFGJ) structures, sharp and shallow graded junctions, can be formed using single thermal evaporation boat loaded with uniformly mixed charge transport and light-emitting materials. OLEDs with NFGJ have been demonstrated in Chapter 3; the performance is comparable to the heterojunction OLEDs, but with better device lifetime. A novel method to prepare highly uniform mixed organic solid solutions through a high temperature and high-pressure fusion process has been demonstrated in Chapter 4. A series of fused organic solid solution (FOSS) compounds with NPD doped with different organic emitting dopants were prepared and DSC technique was utilized to determine the thermal characteristics. For the first time, the schematic phase diagram for this binary system has been obtained. High performance OLEDs of single color and white emission were fabricated and the device properties were characterized. In Chapter 5, an efficient photovoltaic heterojunction of tetracene and fullerene has been investigated and high performance organic solar cells have been demonstrated by thermal deposition and successive heat treatment. The preliminary conclusion for this enhancement is discussed and supported by atomic force microscopy images, absorption spectra and x-ray diffraction analysis. Additionally, an effective organic photovoltaic heterojunction based on the typical triplet material PtOEP was demonstrated. It is believed that introducing appropriate organic materials with long exciton lifetime is a very promising way to improve photovoltaic performance.

  18. Non-Harmonic Analysis Applied to Optical Coherence Tomography Imaging

    NASA Astrophysics Data System (ADS)

    Cao, Xu; Uchida, Tetsuya; Hirobayashi, Shigeki; Chong, Changho; Morosawa, Atsushi; Totsuka, Koki; Suzuki, Takuya

    2012-02-01

    A new processing technique called non-harmonic analysis (NHA) is proposed for optical coherence tomography (OCT) imaging. Conventional Fourier-domain OCT employs the discrete Fourier transform (DFT), which depends on the window function and length. The axial resolution of the OCT image, calculated by using DFT, is inversely proportional to the full width at half maximum (FWHM) of the wavelength range. The FWHM of wavelength range is limited by the sweeping range of the source in swept-source OCT and it is limited by the number of CCD pixels in spectral-domain OCT. However, the NHA process does not have such constraints; NHA can resolve high frequencies irrespective of the window function and the frame length of the sampled data. In this study, the NHA process is described and it is applied to OCT imaging. It is compared with OCT images based on the DFT. To demonstrate the benefits of using NHA for OCT, we perform OCT imaging with NHA of an onion skin. The results reveal that NHA can achieve an image resolution equivalent that of a 100-nm sweep range using a significantly reduced wavelength range. They also reveal the potential of using this technique to achieve high-resolution imaging without using a broadband source. However, the long calculation times required for NHA must be addressed if it is to be used in clinical applications.

  19. Center for Applied Optics Studies: an investment in Indiana's future

    NASA Astrophysics Data System (ADS)

    Schuh, Delbert J., II; Khorana, Brij M.

    1992-05-01

    To understand the involvement of the State of Indiana with the Center for Applied Optics at Rose-Hulman Institute of Technology, it is best to start with an explanation of the Indiana Corporation for Science and Technology (CST), its basic charter and its programs. Established in 1982 as a private not-for-profit corporation, CST was formed to promote economic development within the State of Indiana. Two programs that were initially a part of CST's charter and supported with state dollars were a seed capital investment program, aimed at developing new products and processes, and the establishment of university centers of technology development. The former was conceived to create jobs and new, technologically advanced industries in Indiana. The latter was an attempt to encourage technology transfer from the research laboratories of the state universities to the production lines of Indiana industry. Recently, CST has undergone a name change to the Indiana Business Modernization and Technology Corporation (BMT) and adopted an added responsibility of proactive assistance to small- and medium-sized businesses in order to enhance the state's industrial competitiveness.

  20. Optical band gaps of organic semiconductor materials

    NASA Astrophysics Data System (ADS)

    Costa, José C. S.; Taveira, Ricardo J. S.; Lima, Carlos F. R. A. C.; Mendes, Adélio; Santos, Luís M. N. B. F.

    2016-08-01

    UV-Vis can be used as an easy and forthright technique to accurately estimate the band gap energy of organic π-conjugated materials, widely used as thin films/composites in organic and hybrid electronic devices such as OLEDs, OPVs and OFETs. The electronic and optical properties, including HOMO-LUMO energy gaps of π-conjugated systems were evaluated by UV-Vis spectroscopy in CHCl3 solution for a large number of relevant π-conjugated systems: tris-8-hydroxyquinolinatos (Alq3, Gaq3, Inq3, Al(qNO2)3, Al(qCl)3, Al(qBr)3, In(qNO2)3, In(qCl)3 and In(qBr)3); triphenylamine derivatives (DDP, p-TTP, TPB, TPD, TDAB, m-MTDAB, NPB, α-NPD); oligoacenes (naphthalene, anthracene, tetracene and rubrene); oligothiophenes (α-2T, β-2T, α-3T, β-3T, α-4T and α-5T). Additionally, some electronic properties were also explored by quantum chemical calculations. The experimental UV-Vis data are in accordance with the DFT predictions and indicate that the band gap energies of the OSCs dissolved in CHCl3 solution are consistent with the values presented for thin films.

  1. Organic Light-Sensitive Media For Holographic Optical Elements

    NASA Astrophysics Data System (ADS)

    Barachevsky, Valery A.

    1990-04-01

    The objective of this paper is to provide an overview of the art organic media for photofabrication of holographic optical elements. Perforce data are presented for a variety of relevant organic light-sensitive media manufactured by Soviet scientists.

  2. Optical fiber smart structures applied to secure containers

    SciTech Connect

    Sliva, P.; Gordon, N.R.; Stahl, K.A.; Simmon, K.L.; Anheier, N.C.

    1994-07-01

    A prototype secure container was prepared that uses continually monitored optical fiber as the smart structure. A small ({approx}7.6 cm {times} 10.2 cm {times} 12.7 cm), matchbox-shaped container consisting of an inner drawer within an outer shell was fabricated from polymer resin. The optical fiber was sandwiched between additional non-optical, strength-promoting fibers and embedded into the polymer. The additional non-optical fiber provides strength to the container, protects the optical fiber from damage, hides the fiber and acts as a decoy. The optical fiber was wound with a winding density such that a high probability of fiber damage would be expected if the container was penetrated.

  3. Applying Organ Clearance Concepts in a Clinical Setting

    PubMed Central

    2008-01-01

    Objective To teach doctor of pharmacy (PharmD) students how to apply organ clearance concepts in a clinical setting in order to optimize dose management, select the right drug product, and promote better patient-centered care practices. Design A student-focused 5-hour topic entitled "Organ Clearance Concepts: Modeling and Clinical Applications" was developed and delivered to second-year PharmD students. Active-learning techniques, such as reading assignments and thought-provoking questions, and collaborative learning techniques, such as small groups, were used. Student learning was assessed using application cards and a minute paper. Assessment Overall student responses to topic presentation were overwhelmingly positive. The teaching strategies here discussed allowed students to play an active role in their own learning process and provided the necessary connection to keep them motivated, as mentioned in the application cards and minute paper assessments. Students scored an average of 88% on the examination given at the end of the course. Conclusion By incorporating active-learning and collaborative-learning techniques in presenting material on organ clearance concept, students gained a more thorough knowledge of dose management and drug-drug interactions than if the concepts had been presented using a traditional lecture format. This knowledge will help students in solving critical patient situations in a real-world context. PMID:19214275

  4. Fast frequency hopping codes applied to SAC optical CDMA network

    NASA Astrophysics Data System (ADS)

    Tseng, Shin-Pin

    2015-06-01

    This study designed a fast frequency hopping (FFH) code family suitable for application in spectral-amplitude-coding (SAC) optical code-division multiple-access (CDMA) networks. The FFH code family can effectively suppress the effects of multiuser interference and had its origin in the frequency hopping code family. Additional codes were developed as secure codewords for enhancing the security of the network. In considering the system cost and flexibility, simple optical encoders/decoders using fiber Bragg gratings (FBGs) and a set of optical securers using two arrayed-waveguide grating (AWG) demultiplexers (DeMUXs) were also constructed. Based on a Gaussian approximation, expressions for evaluating the bit error rate (BER) and spectral efficiency (SE) of SAC optical CDMA networks are presented. The results indicated that the proposed SAC optical CDMA network exhibited favorable performance.

  5. Development of organic nonlinear optical materials

    NASA Astrophysics Data System (ADS)

    Sounik, J.; Norwood, R.; McCulloch, I.; Song, K.; Demartino, R.

    1992-10-01

    The design of organic polymers as active mediums for nonlinear optics has attracted much attention because their nature of versatility in synthetic chemistry and in fabrication. A series of new side chain polymers were synthesized and characterized for the second and third order NLO applications. Linear copolymers containing maleic anhydride as an active functional group on the main chain were prepared in this work. The maleic anhydride group reacts, by ring opening esterification with an appropriate alcohol containing an NLO functionality. These copolymers were also found to be suitable for branching or crosslinking reactions with alpha, omega-diols. A series of substituted silicon and aluminum phthalocyanines has been synthesized to study their third order nonlinear responses. A nitro/amino substituted aluminum phthalocyanine has been made along with mixtures of benzo-substituted silicon phthalocyanines. A synthetic route has been investigated to directly give donor acceptor phthalocyanines. To increase mechanical property of phthalocyanine compounds, copolymers with MMA have been synthesized and characterized. All of the copolymers show excellent film forming characteristics.

  6. Applying total quality management concepts to public health organizations.

    PubMed Central

    Kaluzny, A D; McLaughlin, C P; Simpson, K

    1992-01-01

    Total quality management (TQM) is a participative, systematic approach to planning and implementing a continuous organizational improvement process. Its approach is focused on satisfying customers' expectations, identifying problems, building commitment, and promoting open decision-making among workers. TQM applies analytical tools, such as flow and statistical charts and check sheets, to gather data about activities within an organization. TQM uses process techniques, such as nominal groups, brainstorming, and consensus forming to facilitate communication and decision making. TQM applications in the public sector and particularly in public health agencies have been limited. The process of integrating TQM into public health agencies complements and enhances the Model Standards Program and assessment methodologies, such as the Assessment Protocol for Excellence in Public Health (APEX-PH), which are mechanisms for establishing strategic directions for public health. The authors examine the potential for using TQM as a method to achieve and exceed standards quickly and efficiently. They discuss the relationship of performance standards and assessment methodologies with TQM and provide guidelines for achieving the full potential of TQM in public health organizations. The guidelines include redefining the role of management, defining a common corporate culture, refining the role of citizen oversight functions, and setting realistic estimates of the time needed to complete a task or project. PMID:1594734

  7. Optical design of low glare luminaire applied for tunnel light

    NASA Astrophysics Data System (ADS)

    Tsai, M. S.; Lee, X. H.; Lo, Y. C.; Sun, C. C.

    2014-09-01

    In this study, a low glare and high-efficient tunnel lighting design which consists of a cluster light-emitting diode and a free-form lens is presented. Most of the energy emitted from the proposed luminaire is transmitted onto the surface of the road in front of drivers, and the probability that the energy is emitted directly into drivers' eyes is low. Compared with traditional fluorescent lamps, the proposed luminaire, of which the optical utilization factor, optical efficiency, and uniformity are, respectively, 44%, 92.5%, and 0.72, performs favorably in traffic safety, energy saving, and glare reduction.

  8. Geometric and Applied Optics, Science (Experimental): 5318.04.

    ERIC Educational Resources Information Center

    Sanderson, Robert C.

    This unit of instruction presents a laboratory-oriented course which relates the sources and behaviors of light to man's control and uses of light. Successful completion of Algebra I and Plane Geometry is strongly recommended as indicators of success. The course is recommended if the student plans further studies in science, optical technology, or…

  9. Applied nonlinear optics in the journal 'Quantum Electronics'

    SciTech Connect

    Grechin, Sergei G; Dmitriev, Valentin G; Chirkin, Anatolii S

    2011-12-31

    A brief historical review of the experimental and theoretical works on nonlinear optical frequency conversion (generation of harmonics, up- and down-conversion, parametric oscillation), which have been published in the journal 'Quantum Electronics' for the last 40 years, is presented.

  10. Investigation of mechanical stress applied to the optical modular cables at low temperatures

    NASA Astrophysics Data System (ADS)

    Burdin, Vladimir A.; Voronkov, Andrey A.; Alekhin, Ivan N.

    2015-03-01

    This paper presents the investigate of mechanical loadings applied to the optical cables module structure at low temperatures. Mechanical loads experienced by the optical cable in the process of construction of fiber-optic communication lines, and in the course of their operation, are major factors affecting the reliability and service life optical cable. Over the past few years, optical cable modular design greatly supplanted other modifications, so in this article addresses the evaluation of mechanical loads applied to the modular design cables at low temperatures.

  11. Influencing Organizations to Promote Health: Applying Stakeholder Theory

    ERIC Educational Resources Information Center

    Kok, Gerjo; Gurabardhi, Zamira; Gottlieb, Nell H.; Zijlstra, Fred R. H.

    2015-01-01

    Stakeholder theory may help health promoters to make changes at the organizational and policy level to promote health. A stakeholder is any individual, group, or organization that can influence an organization. The organization that is the focus for influence attempts is called the focal organization. The more salient a stakeholder is and the more…

  12. Applying fiber optical methods for toxicological testing in vitro

    NASA Astrophysics Data System (ADS)

    Maerz, Holger K.; Buchholz, Rainer; Emmrich, Frank; Fink, Frank; Geddes, Clive L.; Pfeifer, Lutz; Raabe, Ferdinand; Scheper, Thomas-Helmut; Ulrich, Elizabeth; Marx, Uwe

    1999-04-01

    The new medical developments, e.g. immune therapy, patient oriented chemotherapy or even gene therapy, create a questionable doubt to the further requirement of animal test. Instead the call for humanitarian reproductive in vitro models becomes increasingly louder. Pharmaceutical usage of in vitro has a long proven history. In cancer research and therapy, the effect of chemostatica in vitro in the so-called oncobiogram is being tested; but the assays do not always correlate with in vivo-like drug resistance and sensitivity. We developed a drug test system in vitro, feasible for therapeutic drug monitoring by the combination of tissue cultivation in hollow fiber bioreactors and fiber optic sensors for monitoring the pharmaceutical effect. Using two fiber optic sensors - an optical oxygen sensor and a metabolism detecting Laserfluoroscope, we were able to successfully monitor the biological status of tissue culture and the drug or toxic effects of in vitro pharmaceutical testing. Furthermore, we developed and patented a system for monitoring the effect of minor toxic compounds which can induce Sick Building Syndrome.

  13. Organic transistors in optical displays and microelectronic applications.

    PubMed

    Gelinck, Gerwin; Heremans, Paul; Nomoto, Kazumasa; Anthopoulos, Thomas D

    2010-09-01

    Organic thin-film transistors (OTFTs) offer unprecedented opportunities for implementation in a broad range of technological applications spanning from large-volume microelectronics and optical displays to chemical and biological sensors. In this Progress Report, we review the application of organic transistors in the fields of flexible optical displays and microelectronics. The advantages associated with the use of OTFT technology are discussed with primary emphasis on the latest developments in the area of active-matrix electrophoretic and organic light-emitting diode displays based on OTFT backplanes and on the application of organic transistors in microelectronics including digital and analog circuits. PMID:20533415

  14. Graphic Organizers Applied to Higher-Level Secondary Mathematics.

    ERIC Educational Resources Information Center

    Ives, Bob; Hoy, Cheri

    2003-01-01

    This article provides a rationale for using graphic organizers based on the fact that students with language disorders often struggle with traditional instruction that places large demands on language skills. Effective features of graphic organizers are identified and examples of direct instruction in secondary algebra using graphic organizers are…

  15. Validation and qualification of surface-applied fibre optic strain sensors using application-independent optical techniques

    NASA Astrophysics Data System (ADS)

    Schukar, Vivien G.; Kadoke, Daniel; Kusche, Nadine; Münzenberger, Sven; Gründer, Klaus-Peter; Habel, Wolfgang R.

    2012-08-01

    Surface-applied fibre optic strain sensors were investigated using a unique validation facility equipped with application-independent optical reference systems. First, different adhesives for the sensor's application were analysed regarding their material properties. Measurements resulting from conventional measurement techniques, such as thermo-mechanical analysis and dynamic mechanical analysis, were compared with measurements resulting from digital image correlation, which has the advantage of being a non-contact technique. Second, fibre optic strain sensors were applied to test specimens with the selected adhesives. Their strain-transfer mechanism was analysed in comparison with conventional strain gauges. Relative movements between the applied sensor and the test specimen were visualized easily using optical reference methods, digital image correlation and electronic speckle pattern interferometry. Conventional strain gauges showed limited opportunities for an objective strain-transfer analysis because they are also affected by application conditions.

  16. Demonstration of completely organic, optically clear radioluminescent light

    NASA Astrophysics Data System (ADS)

    Renschler, C. L.; Clough, R. L.; Shepodd, T. J.

    1989-11-01

    A novel type of radioluminescent (RL) light source consisting of an all-organic optically clear system is described. In this device, tritium is covalently bound within a transparent polymeric matrix containing a set of soluble organic scintillant dyes. Applications of RL lighting include emergency exit lights in commercial aircraft and luminous instrumentation such as watch dials and gunsights.

  17. Apply lightweight recognition algorithms in optical music recognition

    NASA Astrophysics Data System (ADS)

    Pham, Viet-Khoi; Nguyen, Hai-Dang; Nguyen-Khac, Tung-Anh; Tran, Minh-Triet

    2015-02-01

    The problems of digitalization and transformation of musical scores into machine-readable format are necessary to be solved since they help people to enjoy music, to learn music, to conserve music sheets, and even to assist music composers. However, the results of existing methods still require improvements for higher accuracy. Therefore, the authors propose lightweight algorithms for Optical Music Recognition to help people to recognize and automatically play musical scores. In our proposal, after removing staff lines and extracting symbols, each music symbol is represented as a grid of identical M ∗ N cells, and the features are extracted and classified with multiple lightweight SVM classifiers. Through experiments, the authors find that the size of 10 ∗ 12 cells yields the highest precision value. Experimental results on the dataset consisting of 4929 music symbols taken from 18 modern music sheets in the Synthetic Score Database show that our proposed method is able to classify printed musical scores with accuracy up to 99.56%.

  18. Use of a fiber optic probe for organic species determination

    DOEpatents

    Ekechukwu, Amy A.

    1996-01-01

    A fiber optic probe for remotely detecting the presence and concentration organic species in aqueous solutions. The probe includes a cylindrical housing with an organic species indicator, preferably diaminonaphthyl sulfonic acid adsorbed in a silica gel (DANS-modified gel), contained in the probe's distal end. The probe admits aqueous solutions to the probe interior for mixing within the DANS-modified gel. An optical fiber transmits light through the DANS-modified gel while the indicator reacts with organic species present in the solution, thereby shifting the location of the fluorescent peak. The altered light is reflected to a receiving fiber that carries the light to a spectrophotometer or other analysis device.

  19. Optical and Transport Properties of Organic Molecules: Methods and Applications

    NASA Astrophysics Data System (ADS)

    Strubbe, David Alan

    Organic molecules are versatile and tunable building blocks for technology, in nanoscale and bulk devices. In this dissertation, I will consider some important applications for organic molecules involving optical and transport properties, and develop methods and software appropriate for theoretical calculations of these properties. Specifically, we will consider second-harmonic generation, a nonlinear optical process; photoisomerization, in which absorption of light leads to mechanical motion; charge transport in junctions formed of single molecules; and optical excitations in pentacene, an organic semiconductor with applications in photovoltaics, optoelectronics, and flexible electronics. In the Introduction (Chapter 1), I will give an overview of some phenomenology about organic molecules and these application areas, and discuss the basics of the theoretical methodology I will use: density-functional theory (DFT), time-dependent density-functional theory (TDDFT), and many-body perturbation theory based on the GW approximation. In the subsequent chapters, I will further discuss, develop, and apply this methodology. 2. I will give a pedagogical derivation of the methods for calculating response properties in TDDFT, with particular focus on the Sternheimer equation, as will be used in subsequent chapters. I will review the many different response properties that can be calculated (dynamic and static) and the appropriate perturbations used to calculate them. 3. Standard techniques for calculating response use either integer occupations (as appropriate for a system with an energy gap) or fractional occupations due to a smearing function, used to improve convergence for metallic systems. I will present a generalization which can be used to compute response for a system with arbitrary fractional occupations. 4. Chloroform (CHCl3) is a small molecule commonly used as a solvent in measurements of nonlinear optics. I computed its hyperpolarizability for second

  20. Optical spectroscopy of organic semiconductor monolayers

    NASA Astrophysics Data System (ADS)

    He, Rui; Tassi, Nancy G.; Blanchet, Graciela B.; Pinczuk, Aron

    2011-02-01

    Growing interest in organic molecular semiconductors is stimulated by their promising applications in flexible devices. Pentacene is a benchmark organic semiconductor material because of its potential applications in high mobility thin film transistors and optoelectronic devices. Highly uniform monolayers of pentacene grown on polymeric substrate of poly alpha-methylstyrene exhibit sharp and intense free exciton (FE) luminescence at low temperatures. The FE emission displays characteristic intensity that grows quadratically with the number of layers. Large enhancements of Raman scattering intensities at the FE resonance enable the first observations of low-lying lattice vibrational modes in films reaching the single monolayer level. The low-lying modes exhibit characteristic changes when going from a single monolayer to two layers, revealing that a phase akin to a thin film phase of pentacene already emerges in structures of only two monolayers. A simple analysis of mode splittings offers estimates of the strength of inter-layer interactions. The results demonstrate novel venues for ultra-thin film characterization and studies of interface effects in organic molecular semiconductor structures.

  1. Optical spectroscopy of organic semiconductor monolayers

    NASA Astrophysics Data System (ADS)

    He, Rui; Tassi, Nancy G.; Blanchet, Graciela B.; Pinczuk, Aron

    2010-10-01

    Growing interest in organic molecular semiconductors is stimulated by their promising applications in flexible devices. Pentacene is a benchmark organic semiconductor material because of its potential applications in high mobility thin film transistors and optoelectronic devices. Highly uniform monolayers of pentacene grown on polymeric substrate of poly alpha-methylstyrene exhibit sharp and intense free exciton (FE) luminescence at low temperatures. The FE emission displays characteristic intensity that grows quadratically with the number of layers. Large enhancements of Raman scattering intensities at the FE resonance enable the first observations of low-lying lattice vibrational modes in films reaching the single monolayer level. The low-lying modes exhibit characteristic changes when going from a single monolayer to two layers, revealing that a phase akin to a thin film phase of pentacene already emerges in structures of only two monolayers. A simple analysis of mode splittings offers estimates of the strength of inter-layer interactions. The results demonstrate novel venues for ultra-thin film characterization and studies of interface effects in organic molecular semiconductor structures.

  2. Optical Archive Organization And Strategies For The 1990S

    NASA Astrophysics Data System (ADS)

    Britt, Margaret O.; Ricca, Stephen P.; Rocca, Jeffrey J.; Sicherman, George L.

    1989-05-01

    The advent of second-generation optical storage technology and user experience with PACS dictate a new look at PACS long-term database organization and optical archive strategy. Optical disk drives are growing faster and more reliable, disks and jukeboxes will hold more data for their size, and the cost per byte of optical disk storage will fall. Users are becoming more sophisticated in their use of PACS. Field experience has increased our knowledge of user needs and refined our models of optical archive usage. COnsidering these advances, this paper addresses such topics as centralized archives, standards and equipment compatibility, flexible archival and de-archival criteria, data reliability, backup strategies, and improved archive performance.

  3. Organic materials with nonlinear optical properties

    DOEpatents

    Stupp, S.I.; Son, S.; Lin, H.C.

    1995-05-02

    The present invention is directed to organic materials that have the ability to double or triple the frequency of light that is directed through the materials. Particularly, the present invention is directed to the compound 4-[4-(2R)-2-cyano-7-(4{prime}-pentyloxy-4-biphenylcarbonyloxy)phenylheptylidenephenylcarbonyloxy]benzaldehyde, which can double the frequency of light that is directed through the compound. The invention is also directed to the compound (12-hydroxy-5,7-dodecadiynyl)-4{prime}-[(4{prime}-pentyloxy-4-biphenyl)carbonyloxy]-4-biphenylcarboxylate, and its polymeric form. The polymeric form can triple the frequency of light directed through it. 4 figs.

  4. Implementation of Optical Characterization for Flexible Organic Electronics Applications

    NASA Astrophysics Data System (ADS)

    Laskarakis, A.; Logothetidis, S.

    One of the most rapidly evolving sectors of the modern science and technology is the flexible organic electronic devices (FEDs) that are expected to significantly improve and revolutionize our everyday life. The FED application includes the generation of electricity by renewable sources (by organic photovoltaic cells - OPVs), power storage (thin film batteries), the visualization of information (by organic displays), the working and living environment (ambient lighting, sensors), safety, market (smart labels, radio frequency identification tags - RFID), textiles (smart fabrics with embedded display and sensor capabilities), as well as healthcare (smart sensors for vital sign monitoring), etc. Although there has been important progresses in inorganic-based Si devices, there are numerous advances in the organic (semiconducting, conducting), inorganic, and hybrid (organic-inorganic) materials that exhibit desirable properties and stability, and in the synthesis and preparation methods. The understanding of the organic material properties can lead to the fast progress of the functionality and performance of FEDs. The investigation of the optical properties of these materials can promote the understanding of the optical, electrical, structural properties of organic semiconductors and electrodes and can contribute to the optimization of the synthesis process and the tuning of their structure and morphology. In this chapter, we will describe briefly some of the advances toward the implementation of optical characterization methods, such as Spectroscopic Ellipsometry (SE) from the infrared to the visible and ultraviolet spectral region for the study of materials (flexible polymer substrates, barrier layers, transparent electrodes) to be used for application in the fabrication of FEDs.

  5. Antireflective coatings applied from metal-organic derived liquid precursors.

    PubMed

    Yoldas, B E; O'Keeffe, T W

    1979-09-15

    Antireflective (AR) coatings, which are produced from organometallic driven solutions containing oxide constituents in a chemically polymerized form, are presented. These solutions leave a film on substrates which, upon heat treatment, converts to a glasslike oxide film having the desired optical thickness and index of refraction. The index can be varied continuously from 1.4 to 2.4; thus the AR coatings can be fine-tuned for different substrates and for specific wavelengths of light. Silicon solar cells AR-coated by this technique showed as much as 49% improvement in efficiency over the uncoated state. The real advantage of the process, however, lies in the fact that it is simple, well-suited for automated mass production of photovoltaic cells, and reduces the cost of coating application from an estimated $0.20 per W-package to about $0.01 per W-package. PMID:20212817

  6. High precision zinc isotopic measurements applied to mouse organs.

    PubMed

    Moynier, Frédéric; Le Borgne, Marie

    2015-01-01

    We present a procedure to measure with high precision zinc isotope ratios in mouse organs. Zinc is composed of 5 stable isotopes ((64)Zn, (66)Zn, (67)Zn, (68)Zn and (70)Zn) which are naturally fractionated between mouse organs. We first show how to dissolve the different organs in order to free the Zn atoms; this step is realized by a mixture of HNO3 and H2O2. We then purify the zinc atoms from all the other elements, in particular from isobaric interferences (e.g., Ni), by anion-exchange chromatography in a dilute HBr/HNO3 medium. These first two steps are performed in a clean laboratory using high purity chemicals. Finally, the isotope ratios are measured by using a multi-collector inductively-coupled-plasma mass-spectrometer, in low resolution. The samples are injected using a spray chamber and the isotopic fractionation induced by the mass-spectrometer is corrected by comparing the ratio of the samples to the ratio of a standard (standard bracketing technique). This full typical procedure produces an isotope ratio with a 50 ppm (2 s.d.) reproducibility. PMID:26065372

  7. Organic non-linear optics and opto-electronics

    NASA Astrophysics Data System (ADS)

    Maldonado, J. L.; Ramos-Ortíz, G.; Rodríguez, M.; Meneses-Nava, M. A.; Barbosa-García, O.; Santillán, R.; Farfán, N.

    2010-12-01

    π-conjugated organic molecules and polymers are of great importance in physics, chemistry, material science and engineering. It is expected that, in the near future, organic materials will find widespread use in many technological applications. In the case of organic opto-electronic systems, the list of devices includes light emitting diodes (OLEDs), photovoltaic cells (OPVs), field-effect transistors (OFET), photorefractive materials for light manipulation, among others. These materials are also used for photonic applications: all-optical switching, modulators, optical correlators, plastic waveguides, all polymeric integrated circuits, solid-state lasers, and for biophotonic applications as in the case of the development of organic labels for multiphoton microscopy and photodynamic therapy. The advances in the developing of organic compounds with better mechanical, electrical, and optical (linear and non-linear) characteristics are of a great importance for this field. Here, we present the research on this area carried out at the Centro de Investigaciones en Óp-tica (CIO), in collaboration with Chemistry Departments of different institutions. This work focuses on the optical characterization of materials through several techniques such as TOF, FWM, TBC, THG Maker Fringes, HRS, Z-scan, and TPEF. Additionally, some applications, such as dynamic holography by using photorefractive polymers, and OPVs cells will be discussed.

  8. Crystal growth of organics for nonlinear optical applications

    NASA Technical Reports Server (NTRS)

    Singh, N. B.; Mazelsky, R.

    1993-01-01

    The crystal growth and characterization of organic and inorganic nonlinear optical materials were extensively studied. For example, inorganic crystals such as thallium arsenic selenide were studied in our laboratory for several years and crystals in sizes over 2.5 cm in diameter are available. Organic crystals are suitable for the ultraviolet and near infrared region, but are relatively less developed than their inorganic counterparts. Very high values of the second harmonic conversion efficiency and the electro-optic coefficient were reported for organic compounds. Single crystals of a binary organic alloy based on m.NA and CNA were grown and higher second harmonic conversion efficiency than the values reported for m.NA were observed.

  9. [White organic light-emitting diodes applied for lighting technology].

    PubMed

    Huang, Qing-Yu; Zhao, Su-Ling; Xu, Zheng; Fan, Xing; Wang, Jian; Yang, Qian-Qian

    2014-01-01

    Lighting accounts for approximately 22 percent of the electricity consumed in buildings in the United States, with 40 percent of that amount consumed by inefficient incandescent lamps. This has generated increased interest in the use of white electroluminescent organic light-emitting devices (WOLEDS) as the next generation solid-state lighting source, owing to their potential for significantly improved efficiency over incandescent sources, combined with low-cost, high-throughput manufacturability. The research and application of the devices have witnessed great progress. WOLEDS have incomparable advantages for its special characteristics. This progress report sketched the principle of WOLEDS and provided some common structures, and further investigation of the mechanism of different structures was made. Meanwhile, the key technologies of WOLEDS were summarized. Finally, the latest research progress of WOLEDS was reviewed. PMID:24783527

  10. Experimental scrambling and noise reduction applied to the optical encryption of QR codes.

    PubMed

    Barrera, John Fredy; Vélez, Alejandro; Torroba, Roberto

    2014-08-25

    In this contribution, we implement two techniques to reinforce optical encryption, which we restrict in particular to the QR codes, but could be applied in a general encoding situation. To our knowledge, we present the first experimental-positional optical scrambling merged with an optical encryption procedure. The inclusion of an experimental scrambling technique in an optical encryption protocol, in particular dealing with a QR code "container", adds more protection to the encoding proposal. Additionally, a nonlinear normalization technique is applied to reduce the noise over the recovered images besides increasing the security against attacks. The opto-digital techniques employ an interferometric arrangement and a joint transform correlator encrypting architecture. The experimental results demonstrate the capability of the methods to accomplish the task. PMID:25321236

  11. Use of a fiber optic probe for organic species determination

    DOEpatents

    Ekechukwu, A.A.

    1996-12-10

    A fiber optic probe is described for remotely detecting the presence and concentration organic species in aqueous solutions. The probe includes a cylindrical housing with an organic species indicator, preferably diaminonaphthyl sulfonic acid adsorbed in a silica gel (DANS-modified gel), contained in the probe`s distal end. The probe admits aqueous solutions to the probe interior for mixing within the DANS-modified gel. An optical fiber transmits light through the DANS-modified gel while the indicator reacts with organic species present in the solution, thereby shifting the location of the fluorescent peak. The altered light is reflected to a receiving fiber that carries the light to a spectrophotometer or other analysis device. 5 figs.

  12. Optical clearing for luminal organ imaging with ultrahigh-resolution optical coherence tomography.

    PubMed

    Liang, Yanmei; Yuan, Wu; Mavadia-Shukla, Jessica; Li, Xingde

    2016-08-01

    The imaging depth of optical coherence tomography (OCT) in highly scattering biological tissues (such as luminal organs) is limited, particularly for OCT operating at shorter wavelength regions (such as around 800 nm). For the first time, the optical clearing effect of the mixture of liquid paraffin and glycerol on luminal organs was explored with ultrahigh-resolution spectral domain OCT at 800 nm. Ex vivo studies were performed on pig esophagus and bronchus, and guinea pig esophagus with different volume ratios of the mixture. We found that the mixture of 40% liquid paraffin had the best optical clearing effect on esophageal tissues with a short effective time of ∼ 10 min, which means the clearing effect occurs about 10 min after the application of the clearing agent. In contrast, no obvious optical clearing effect was identified on bronchus tissues. PMID:27335154

  13. Dynamics of a low-threshold optically pumped organic vertical-cavity surface-emitting laser

    NASA Astrophysics Data System (ADS)

    Shayesteh, Mohammad Reza; Darvish, Ghafar

    2016-06-01

    We propose a low-threshold optically pumped organic vertical-cavity surface-emitting laser (OVCSEL). This device has the capability to apply both electrical and optical excitation. The microcavity structure consists of an organic light emitting diode with field-effect electron transport inserted in a high-quality factor double distributed Bragg reflector. The simulated quality factor of the microcavity is shown to be as high as 16,000. Also, we investigate threshold behaviour and the dynamics of the optically pumped OVCSEL with sub-picosecond pulses. Results from numerical simulation show that lasing threshold is 12.8 pJ/0.64 µJ cm-2 when pumped by sub-picosecond pulses of λ = 400 nm wavelength light.

  14. Experiment definition phase shuttle laboratory LDRL-10.6 experiment. [applying optical communication

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The 10.6 microns laser data relay link (LDRL 10.6) program was directed to applying optical communications to NASA's wideband data transmission requirements through the 1980's. The LDRL consists of a transmitter on one or more low earth orbit satellites with an elliptical orbit satellite receivers. Topics discussed include: update of the LDRL design control table to detail the transmitter optical chain losses and to incorporate the change to a reflective beam pre-expander; continued examination of the link establishment sequence, including its dependence upon spacecraft stability; design of the transmitter pointing and tracking control system; and finalization of the transmitter brassboard optical and mechanical design.

  15. Optical Detection of Organic Chemical Biosignatures at Hydrothermal Vents

    NASA Technical Reports Server (NTRS)

    Conrad, P. G.; Lane, A. L.; Bhartia, R.; Hug, W. H.

    2004-01-01

    We have developed a non-contact, optical life detection instrument that can detect organic chemical biosignatures in a number of different environments, including dry land, shallow aqueous, deep marine or in ice. Hence, the instrument is appropriate as a biosignature survey tool both for Mars exploration or in situ experiments in an ice-covered ocean such as one might wish to explore on Europa. Here, we report the results we obtained on an expedition aboard the Russian oceanographic vessel Akademik Mstislav Keldysh to hydrothermal vent sites in the Pacific Ocean using our life detection instrument MCDUVE, a multichannel, deep ultraviolet excitation fluorescence detector. MCDUVE detected organic material distribution on rocks near the vent, as well as direct detection of organisms, both microbial and microscopic. We also were able to detect organic material issuing directly from vent chimneys, measure the organic signature of the water column as we ascended, and passively observe the emission of light directly from some vents.

  16. Applying Western Organization Development in China: Lessons from a Case of Success

    ERIC Educational Resources Information Center

    Wang, Jia

    2010-01-01

    Purpose: The purpose of this paper is to explore a successful case of a Chinese state-owned enterprise (SOE) as it applied western organization development (OD) approaches. Specifically, this study seeks to answer two questions: How has western organization development and change (OD/C) been applied in one Chinese SOE? and What lessons can be…

  17. Organic Single-Crystal Light-Emitting Transistor Coupling with Optical Feedback Resonators

    PubMed Central

    Bisri, Satria Zulkarnaen; Sawabe, Kosuke; Imakawa, Masaki; Maruyama, Kenichi; Yamao, Takeshi; Hotta, Shu; Iwasa, Yoshihiro; Takenobu, Taishi

    2012-01-01

    Organic light-emitting transistors (OLETs) are of great research interest because they combine the advantage of the active channel of a transistor that can control the luminescence of an in-situ light-emitting diode in the same device. Here we report a novel single-crystal OLET (SCLET) that is coupled with single crystal optical feedback resonators. The combination of single-crystal waveguides with native Fabry-Perot cavities, formed by parallel crystal edges, drastically lowers the threshold energy for spectral narrowing and non-linear intensity enhancement. We apply this structure to SCLETs and demonstrate the first fabrication of a SCLET with the optical feedback resonators. PMID:23248748

  18. Comparative, transcriptome analysis of self-organizing optic tissues

    PubMed Central

    Andrabi, Munazah; Kuraku, Shigehiro; Takata, Nozomu; Sasai, Yoshiki; Love, Nick R.

    2015-01-01

    Embryonic stem (ES) cells have a remarkable capacity to self-organize complex, multi-layered optic cups in vitro via a culture technique called SFEBq. During both SFEBq and in vivo optic cup development, Rax (Rx) expressing neural retina epithelial (NRE) tissues utilize Fgf and Wnt/β-catenin signalling pathways to differentiate into neural retina (NR) and retinal-pigmented epithelial (RPE) tissues, respectively. How these signaling pathways affect gene expression during optic tissue formation has remained largely unknown, especially at the transcriptome scale. Here, we address this question using RNA-Seq. We generated Rx+ optic tissue using SFEBq, exposed these tissues to either Fgf or Wnt/β-catenin stimulation, and assayed their gene expression across multiple time points using RNA-Seq. This comparative dataset will help elucidate how Fgf and Wnt/β-catenin signaling affect gene expression during optic tissue differentiation and will help inform future efforts to optimize in vitro optic tissue culture technology. PMID:26110066

  19. Education in applied and instrumental optics at the University of Helsinki

    NASA Astrophysics Data System (ADS)

    Stenman, Folke

    1997-12-01

    The teaching of applied and instrumental optics at the University of Helsinki Department of Physics originally grew out of the needs of the research group of molecular physics as a basis for the experimental work in the group. The training program starts with a one-year course for senior undergraduates and graduates comprising geometrical optics, eikonal theory, image forming components, matrix methods, optical instruments, the optics of laser beams, radiometry and photometry, ray tracing methods, optics of anisotropic media, diffraction theory, general image formation theory and Fourier optics. The course starts from fundamentals, but the mathematical level is kept adequate for serious work. Further applications are treated in courses on molecular spectroscopy, where ruled and holographic diffraction gratings (both plane and spherical), interferometric spectroscopy and imaging properties of spectral equipment are treated. Aspects of image analysis, information in optics, signal-to-noise ratio, etc. are treated in separate courses on Fourier method and digital spectral analysis. The applicability of optical techniques to various fields of physics and engineering and the analogies with them are especially brought out. Experimental and calculational and skills are stressed throughout. Computer programming is introduced as an indispensable tool for the optics practitioner, and the students are required to write programs of their own. The students gain practical experience, e.g., by working in the molecular physics group. Close cooperation is maintained with other research groups in laser physics, ultrasonics and physical chemistry. The training in optics has proved very useful, with students frequently ending up working in the industry on optics and spectroscopy problems. Parts of these courses have also been given at other universities and to engineers and scientists working in the industry.

  20. 26 CFR 1.1381-1 - Organizations to which part applies.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... subchapter T does not apply to: (1) Any organization which is exempt from income taxes under chapter 1 of the Code (other than an exempt farmers' cooperative described in section 521); (2) Any organization which... Code (relating to mutual savings banks, etc.); (3) Any organization which is subject to the...

  1. Volatile Organic Compound Optical Fiber Sensors: A Review

    PubMed Central

    Elosua, Cesar; Matias, Ignacio R.; Bariain, Candido; Arregui, Francisco J.

    2006-01-01

    Volatile organic compound (VOC) detection is a topic of growing interest with applications in diverse fields, ranging from environmental uses to the food or chemical industries. Optical fiber VOC sensors offering new and interesting properties which overcame some of the inconveniences found on traditional gas sensors appeared over two decades ago. Thanks to its minimum invasive nature and the advantages that optical fiber offers such as light weight, passive nature, low attenuation and the possibility of multiplexing, among others, these sensors are a real alternative to electronic ones in electrically noisy environments where electronic sensors cannot operate correctly. In the present work, a classification of these devices has been made according to the sensing mechanism and taking also into account the sensing materials or the different methods of fabrication. In addition, some solutions already implemented for the detection of VOCs using optical fiber sensors will be described with detail.

  2. Characterization of Optical Fiber Strength Under Applied Tensile Stress and Bending Stress

    SciTech Connect

    P.E. Klingsporn

    2011-08-01

    Various types of tensile testing and bend radius tests were conducted on silica core/silica cladding optical fiber of different diameters with different protective buffer coatings, fabricated by different fiber manufacturers. The tensile tests were conducted to determine not only the average fiber strengths at failure, but also the distribution in fracture strengths, as well as the influence of buffer coating on fracture strength. The times-to-failure of fiber subjected to constant applied bending stresses of various magnitudes were measured to provide a database from which failure times of 20 years or more, and the corresponding minimum bend radius, could be extrapolated in a statistically meaningful way. The overall study was done to provide an understanding of optical fiber strength in tensile loading and in applied bending stress as related to applications of optical fiber in various potential coizfgurations for weapons and enhanced surveillance campaigns.

  3. Field Test of Fiber-Optic Voltage and Current Sensors Applied to Gas Insulated Substation

    NASA Astrophysics Data System (ADS)

    Kuroda, Y.; Abe, Y.; Kuwahara, H.; Yoshinaga, K.

    1986-08-01

    The fiber-optic voltage and current sensors applied for 84kV three phase type gas insulated substation (GIS) were tested in order to see the advantages of these sensors practically in adverse field condition. The application technologies and field endurance test results of the sensors are described in this paper.

  4. Highly Non-Linear Optical (NLO) organic crystals

    NASA Technical Reports Server (NTRS)

    Harris, J. Milton

    1987-01-01

    This research project involves the synthesis and characterization of organic materials having powerful nonlinear optical (NLO) properties and the growth of highly ordered crystals and monomolecular films of these materials. Research in four areas is discussed: theoretical design of new materials, characterization of NLO materials, synthesis of new materials and development of coupling procedures for forming layered films, and improvement of the techniques for vapor phase and solution phase growth of high quality organic crystals. Knowledge gained from these experiments will form the basis for experiments in the growth of these crystals.

  5. A complete digital optics applied to digital holographic microscopy: application to chromatic aberration compensation

    NASA Astrophysics Data System (ADS)

    Colomb, Tristan; Charrière, Florian; Kühn, Jonas; Montfort, Frédéric; Depeursinge, Christian

    2007-06-01

    In optics, optical elements are used to transform, to filter or to process physical wavefronts in order to magnify images, compensate for aberration or to suppress unwanted diffracted order for example. Because digital holography provides numerical wavefronts, we developed a digital optics, involving numerical elements such as numerical lenses and pinholes, to mimic numerically what is usually done physically, with the advantage to be able to define any shape for these elements and to place them everywhere without obstruction problems. We demonstrate that automatic and non-automatic procedures allow diffracted order or parasitic interferences filtering, compensation for aberration and image distortion, and control of position and magnification of reconstructed wavefront. We apply this digital optics to compensate for chromatic aberration in multi-wavelength holography in order to have perfect superposition between wavefronts reconstructed from digital hologram recorded with different wavelengths. This has a great importance for synthetic wavelength digital holography or tomographic digital holography that use multiple wavelengths.

  6. Two-photon absorption and optical-limiting properties of a novel organic compound

    NASA Astrophysics Data System (ADS)

    Ye, Lihua; Zhang, Junxiang; Cui, Yiping; Li, Zhenhua; He, Anzhi

    2002-09-01

    The two-photon absorption and applications become the hot points in the recent photoelectronic material research field. The two-photon absorption materials can be applied to many fields such as up-conversion lasing, optical limiting, optical stabilization, three-dimension optical storage, three-dimension micro-machining, et al. Especially studies of optical power limiting have become more interesting to the research community because of the need for automatic protection of optical sensors against intense laser radiation. Here we report the observation of the TPA and optical power limiting property of a novel double conjugated molecule DSBDR1 in solution. The linear absorption spectral is observed using a scanning spectrophotometer. Using Nd:YAG laser pulse as exciting laser, the incident pulse energy and the transmitted pulse energy are respectively recorded by an energy meter. Then we obtain the nonlinear absorption coefficient of the novel double conjugated molecule in THF. Figures show that the molecule exhibts the large TPA cross-section and excellent optical limiting at 1064 nm. The nonlinear absorption mechanism of the novel organic compound is finally analyzed.

  7. Electrical and Optical Properties of Organic Thin Films

    NASA Astrophysics Data System (ADS)

    Buckner, Spencer Lewis

    The purpose of this research was to examine the applicability of organic thin films as electrical insulators in metal-insulator-semiconductor (MIS) and metal-insulator -metal (MIM) devices and an anti-reflective (A-R) coatings for solar cells. Films of anthracene, stearic acid and diacetylene alcohol were examined for their electrical and optical properties. Two techniques were used to deposit the films for these studies. Thermal evaporation in vacuum was used to deposit aluminum as electrodes and contacts in MIS and MIM devices. The organic films were deposited by either thermal evaporation or the Langmuir-Blodgett (L-B) dipping technique. Several vacuum systems and an L-B trough were fabricated for these studies and their design and construction are outlined. Several types of measurements were used to examine the properties of the organic films. Optical reflectance measurements of the diacetylene alcohol and stearic acid, both deposited by the L-B technique, on commercial silicon solar cells were used to study the potential use of these types of films as A-R and protective coatings. Electrical breakdown studies of the MIM devices were conducted to determine the maximum electric fields the insulators could withstand without destruction. Capacitance versus voltage (C-V) measurements of the organic films in MIS devices were used to determine surface defect densities at the semicondcutor/insulator interface. For each type of measurements made on the devices, theories are outlined to analyze the data obtained. The optical reflectance data are analyzed using standard electromagnetic theory. The electrical breakdown data are examined using the theories of Forlani and Minnaja (F-M) and Klein. The C-V data are examined using several different theories to determine charge and defect densities and to analyze the effects of thermal stressing and annealing. Finally, conclusions are drawn as to the applicability of these types of organic materials as insulators and coatings

  8. 13 CFR 119.9 - How will a qualified organization apply for PRIME grant awards?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 13 Business Credit and Assistance 1 2014-01-01 2014-01-01 false How will a qualified organization apply for PRIME grant awards? 119.9 Section 119.9 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION PROGRAM FOR INVESTMENT IN MICROENTREPRENEURS (âPRIMEâ OR âTHE ACTâ) § 119.9 How will a qualified organization apply for PRIME grant...

  9. A novel organic nonlinear optical crystal: Creatininium succinate

    NASA Astrophysics Data System (ADS)

    Thirumurugan, R.; Anitha, K.

    2015-06-01

    A novel organic material complex of creatininium succinate (CS) has been synthesized and single crystals were grown by the reaction of creatinine and succinic acid from aqueous solution by employing the technique of slow evaporation at room temperature. The structure of the grown crystal has been elucidated using single crystal X-ray diffraction analysis and the structure was refined by least-squares method to R = 0.027 for 1840 reflections. FT-IR spectral investigation has been carried out to identify the various functional groups in the title compound. UV-Vis transmission was carried out which shows the crystal has a good optical transmittance in the visible region with lower cutoff wavelength around 220 nm. Nonlinear optical property of the crystal was confirmed by Kurtz-Perry powder technique.

  10. A novel organic nonlinear optical crystal: Creatininium succinate

    SciTech Connect

    Thirumurugan, R.; Anitha, K.

    2015-06-24

    A novel organic material complex of creatininium succinate (CS) has been synthesized and single crystals were grown by the reaction of creatinine and succinic acid from aqueous solution by employing the technique of slow evaporation at room temperature. The structure of the grown crystal has been elucidated using single crystal X-ray diffraction analysis and the structure was refined by least-squares method to R = 0.027 for 1840 reflections. FT-IR spectral investigation has been carried out to identify the various functional groups in the title compound. UV–Vis transmission was carried out which shows the crystal has a good optical transmittance in the visible region with lower cutoff wavelength around 220 nm. Nonlinear optical property of the crystal was confirmed by Kurtz-Perry powder technique.

  11. Self-organized plasmonic metasurfaces for all-optical modulation

    NASA Astrophysics Data System (ADS)

    Della Valle, G.; Polli, D.; Biagioni, P.; Martella, C.; Giordano, M. C.; Finazzi, M.; Longhi, S.; Duò, L.; Cerullo, G.; Buatier de Mongeot, F.

    2015-06-01

    We experimentally demonstrate a self-organized metasurface with a polarization dependent transmittance that can be dynamically controlled by optical means. The configuration consists of tightly packed plasmonic nanowires with a large dispersion of width and height produced by the defocused ion-beam sputtering of a thin gold film supported on a silica glass. Our results are quantitatively interpreted according to a theoretical model based on the thermomodulational nonlinearity of gold and a finite-element numerical analysis of the absorption and scattering cross-sections of the nanowires. We found that the polarization sensitivity of the metasurface can be strongly enhanced by pumping with ultrashort laser pulses, leading to potential applications in ultrafast all-optical modulation and switching of light.

  12. How Settings Change People: Applying Behavior Setting Theory to Consumer-Run Organizations

    ERIC Educational Resources Information Center

    Brown, Louis D.; Shepherd, Matthew D.; Wituk, Scott A.; Meissen, Greg

    2007-01-01

    Self-help initiatives stand as a classic context for organizational studies in community psychology. Behavior setting theory stands as a classic conception of organizations and the environment. This study explores both, applying behavior setting theory to consumer-run organizations (CROs). Analysis of multiple data sets from all CROs in Kansas…

  13. Applying LED in full-field optical coherence tomography for gastrointestinal endoscopy

    NASA Astrophysics Data System (ADS)

    Yang, Bor-Wen; Wang, Yu-Yen; Juan, Yu-Shan; Hsu, Sheng-Jie

    2015-08-01

    Optical coherence tomography (OCT) has become an important medical imaging technology due to its non-invasiveness and high resolution. Full-field optical coherence tomography (FF-OCT) is a scanning scheme especially suitable for en face imaging as it employs a CMOS/CCD device for parallel pixels processing. FF-OCT can also be applied to high-speed endoscopic imaging. Applying cylindrical scanning and a right-angle prism, we successfully obtained a 360° tomography of the inner wall of an intestinal cavity through an FF-OCT system with an LED source. The 10-μm scale resolution enables the early detection of gastrointestinal lesions, which can increase detection rates for esophageal, stomach, or vaginal cancer. All devices used in this system can be integrated by MOEMS technology to contribute to the studies of gastrointestinal medicine and advanced endoscopy technology.

  14. Nonlinear optical properties of organic materials: A theoretical study

    NASA Technical Reports Server (NTRS)

    Cardelino, Beatriz H.

    1991-01-01

    Replacement of electronic switching circuits in computing and telecommunication systems with purely optical devices offers the potential for extremely high throughput and compact information processing systems. The potential application of organic materials containing molecules with large nonresonant nonlinear effects in this area have triggered intensive research during the last decade. Interest on this area was due to two facts: (1) that many organic materials show nonlinearities that are orders of magnitude larger than those of conventional inorganic materials such as lithium niobate and potassium dihydrogen phosphate; and (2) that organic materials show much flexibility in terms of molecular designs. Some of the desirable characteristics that these materials should have are that they be transparent to the frequency of the incident laser and its second or third harmonic, that they have a high damage threshold, and, in the case of second-order effects, that their crystal structure or molecular orientation be accentric. Since polymeric assemblages can enhance the nonlinear response of organic molecules severalfold, efforts have been directed toward the synthesis of thin films with interpenetrating lattices of electroactive molecules. The goal of this theoretical investigation is to predict the magnitude of the molecular polarizabilities of organic molecules that could be incorporated into films. These calculations are intended to become a powerful tool to assist material scientists in screening for the best candidates for optical applications. The procedure that was developed for the present calculations is based on the static-field approach, and is a modification to the method developed by Dewar and Stewart, 1984 for calculating molecular linear polarizabilities.

  15. 13 CFR 119.9 - How will a qualified organization apply for PRIME grant awards?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... apply for PRIME grant awards? 119.9 Section 119.9 Business Credit and Assistance SMALL BUSINESS... organization apply for PRIME grant awards? (a) SBA will issue Program Announcements specifying the terms... application for a grant in accordance with this part and the applicable Program Announcement. (c) SBA...

  16. 13 CFR 119.9 - How will a qualified organization apply for PRIME grant awards?

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... apply for PRIME grant awards? 119.9 Section 119.9 Business Credit and Assistance SMALL BUSINESS... organization apply for PRIME grant awards? (a) SBA will issue Program Announcements specifying the terms... application for a grant in accordance with this part and the applicable Program Announcement. (c) SBA...

  17. 13 CFR 119.9 - How will a qualified organization apply for PRIME grant awards?

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... apply for PRIME grant awards? 119.9 Section 119.9 Business Credit and Assistance SMALL BUSINESS... organization apply for PRIME grant awards? (a) SBA will issue Program Announcements specifying the terms... application for a grant in accordance with this part and the applicable Program Announcement. (c) SBA...

  18. 13 CFR 119.9 - How will a qualified organization apply for PRIME grant awards?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... apply for PRIME grant awards? 119.9 Section 119.9 Business Credit and Assistance SMALL BUSINESS... organization apply for PRIME grant awards? (a) SBA will issue Program Announcements specifying the terms... application for a grant in accordance with this part and the applicable Program Announcement. (c) SBA...

  19. Two-dimensional null subspace algorithm applied for blind optical images deconvolution

    NASA Astrophysics Data System (ADS)

    Berezovskiy, Andrey; Goriachkin, Oleg

    2016-03-01

    The article deals with the image blind identification algorithm applied for optical images restoration. The proposed solution is based on the polynomial transform of the signals and allows to reduce multichannel blind image identification to the linear equation solving with the number of equations, equal to the number of the unknown PSF samples. The outcome of the simulation for different SNR is examined during the simulation; the real images, restored by the proposed algorithm are shown.

  20. Optical Properties of Photovoltaic Organic-Inorganic Lead Halide Perovskites.

    PubMed

    Green, Martin A; Jiang, Yajie; Soufiani, Arman Mahboubi; Ho-Baillie, Anita

    2015-12-01

    Over the last several years, organic-inorganic lead halide perovskites have rapidly emerged as a new photovoltaic contender. Although energy conversion efficiency above 20% has now been certified, improved understanding of the material properties contributing to these high performance levels may allow the progression to even higher efficiency, stable cells. The optical properties of these new materials are important not only to device design but also because of the insight they provide into less directly accessible properties, including energy-band structures, binding energies, and likely impact of excitons, as well as into absorption and inverse radiative recombination processes. PMID:26560862

  1. OPTICAL correlation identification technology applied in underwater laser imaging target identification

    NASA Astrophysics Data System (ADS)

    Yao, Guang-Tao; Zhang, Xiao-Hui; Ge, Wei-Long

    2011-11-01

    The underwater laser imaging detection is an effective method of detecting short distance target underwater as an important complement of sonar detection. With the development of underwater laser imaging technology and underwater vehicle technology, the underwater automatic target identification has gotten more and more attention, and is a research difficulty in the area of underwater optical imaging information processing. Today, underwater automatic target identification based on optical imaging is usually realized with the method of digital circuit software programming. The algorithm realization and control of this method is very flexible. However, the optical imaging information is 2D image even 3D image, the amount of imaging processing information is abundant, so the electronic hardware with pure digital algorithm will need long identification time and is hard to meet the demands of real-time identification. If adopt computer parallel processing, the identification speed can be improved, but it will increase complexity, size and power consumption. This paper attempts to apply optical correlation identification technology to realize underwater automatic target identification. The optics correlation identification technology utilizes the Fourier transform characteristic of Fourier lens which can accomplish Fourier transform of image information in the level of nanosecond, and optical space interconnection calculation has the features of parallel, high speed, large capacity and high resolution, combines the flexibility of calculation and control of digital circuit method to realize optoelectronic hybrid identification mode. We reduce theoretical formulation of correlation identification and analyze the principle of optical correlation identification, and write MATLAB simulation program. We adopt single frame image obtained in underwater range gating laser imaging to identify, and through identifying and locating the different positions of target, we can improve

  2. OPTICAL correlation identification technology applied in underwater laser imaging target identification

    NASA Astrophysics Data System (ADS)

    Yao, Guang-tao; Zhang, Xiao-hui; Ge, Wei-long

    2012-01-01

    The underwater laser imaging detection is an effective method of detecting short distance target underwater as an important complement of sonar detection. With the development of underwater laser imaging technology and underwater vehicle technology, the underwater automatic target identification has gotten more and more attention, and is a research difficulty in the area of underwater optical imaging information processing. Today, underwater automatic target identification based on optical imaging is usually realized with the method of digital circuit software programming. The algorithm realization and control of this method is very flexible. However, the optical imaging information is 2D image even 3D image, the amount of imaging processing information is abundant, so the electronic hardware with pure digital algorithm will need long identification time and is hard to meet the demands of real-time identification. If adopt computer parallel processing, the identification speed can be improved, but it will increase complexity, size and power consumption. This paper attempts to apply optical correlation identification technology to realize underwater automatic target identification. The optics correlation identification technology utilizes the Fourier transform characteristic of Fourier lens which can accomplish Fourier transform of image information in the level of nanosecond, and optical space interconnection calculation has the features of parallel, high speed, large capacity and high resolution, combines the flexibility of calculation and control of digital circuit method to realize optoelectronic hybrid identification mode. We reduce theoretical formulation of correlation identification and analyze the principle of optical correlation identification, and write MATLAB simulation program. We adopt single frame image obtained in underwater range gating laser imaging to identify, and through identifying and locating the different positions of target, we can improve

  3. Optical diagnostic test of stress conditions of aquatic organisms.

    PubMed

    Axenov-Gribanov, Denis V; Gurkov, Anton N; Shakhtanova, Nadezhda S; Bedulina, Daria S; Timofeyev, Maxim A; Meglinski, Igor

    2011-09-01

    Global climate change has become a dire reality and its impact is expected to rise dramatically in the near future. Combined with the day-to-day human activities the climatic changes heavily affect the environment. In particular, a global temperature increase accompanied by a number of anthropogenic chemicals falling within the freshwater ecosystem results in a dramatic enhancement of the overall stress for most aquatic organisms. This leads to a significant shift in the species inventory and potential breakdown of the water ecosystem with severe consequences for local economies and water supply. In order to understand and predict the influence of climatic changes on the physiological and biochemical processes that take place in living aquatic organisms we explore the application of optical spectroscopy for monitoring and quantitative assessment of antioxidant enzymes activity in benthic amphipods of Lake Baikal. We demonstrate that the changes of the enzymes activity in Baikal amphipods undergoing thermal and/or hypoxia stress can be observed and documented by UV and optical spectroscopy both in vivo and in vitro. PMID:21548104

  4. Tailoring the optical and electronic properties of nanomaterials for organic optoelectronics

    NASA Astrophysics Data System (ADS)

    Dewald, James L.

    The purpose of this research was to gain a fundamental understanding of the optical, morphological, and optoelectronic properties of conjugated organic nanomaterials and polymer composites with the aim to tailor their properties for new electronic and optoelectronic devices. The organic nanomaterials studied were the conjugated polymers poly(3-hexyl-thiophene-2,5-diyl) (P3HT), poly(m-phenylenevinylene-co-2,5-dioctoxy- p-phenlenevinylene) (PmPV), and the functionalized Fullerene [1-(3-methoxycarbonyl) propyl-1-phenyl-(6,6) C61], when blended with P3HT. The other nanocomposite studied was a blend of PmPV and gold nanoparticles, in order to study inorganic nanofillers as alternatives to fullerenes. Bulk optical characterization of materials was performed via UV-Visible absorption, photoluminescence, and Raman spectroscopy. Morphological and nanoscale optical characterization were performed using Atomic Force Microscopy (AFM) and Near-Field Optical Microscopy (NSOM). Flat-panel Schottky diode sandwich cells were fabricated using both pure PmPV and PmPV-gold nanoparticle composites, and characterized via current density versus voltage (J-V) measurements. Incorporation of gold nanoparticles into PmPV significantly enhanced the performance of the diodes, reducing the diode ideality factor from 14.55 to 1.32. Flat-panel organic photovoltaic devices were fabricated using a P 3HT:PCBM nanocomposite active layer, and characterized via J-V measurements (both dark and illuminated). Various annealing conditions applied to the nanocomposite active layer were studied, resulting in an optimum annealing condition; bringing the power conversion efficiency of these devices to 5.2%. This power conversion efficiency was a record for organic photovoltaics. NSOM analysis revealed that the enhanced efficiency of these devices was due to better dispersion of the fullerenes within the P3HT matrix upon annealing. In addition, a brand new architecture was created for organic photovoltaics

  5. Leaching of Particulate and Dissolved Organic Carbon from Compost Applied to Bioretention Systems

    NASA Astrophysics Data System (ADS)

    Iqbal, Hamid; Flury, Markus; Mullane, Jessica; Baig, Muhammad

    2015-04-01

    Compost is used in bioretention systems to improve soil quality, to promote plant growth, and to remove metal contaminants from stormwater. However, compost itself, particularly when applied freshly, can be a source of contamination of the stormwater. To test the potential contamination caused by compost when applied to bioretention systems, we continuously leached a compost column with water under unsaturated conditions and characterized dissolved and particulate organic matter in the leachate. Freshly applied, mature compost leached up to 400 mg/L of dissolved organic carbon and 2,000 mg/L of suspended particulate organic carbon. It required a cumulative water flux of 4,000 mm until concentrations of dissolved and particulate organic carbon declined to levels typical for surface waters. Although, dissolved and particulate organic carbon are not contaminants per se, they can facilitate the movement of metals, thereby enhancing the mobility of toxic metals present in stormwater. Therefore, we recommended that compost is washed before it is applied to bioretention systems. Keywords compost; leachate; alkali extract; dissolved organic carbon; flux

  6. Multifocus microscopy with precise color multi-phase diffractive optics applied in functional neuronal imaging.

    PubMed

    Abrahamsson, Sara; Ilic, Rob; Wisniewski, Jan; Mehl, Brian; Yu, Liya; Chen, Lei; Davanco, Marcelo; Oudjedi, Laura; Fiche, Jean-Bernard; Hajj, Bassam; Jin, Xin; Pulupa, Joan; Cho, Christine; Mir, Mustafa; El Beheiry, Mohamed; Darzacq, Xavier; Nollmann, Marcelo; Dahan, Maxime; Wu, Carl; Lionnet, Timothée; Liddle, J Alexander; Bargmann, Cornelia I

    2016-03-01

    Multifocus microscopy (MFM) allows high-resolution instantaneous three-dimensional (3D) imaging and has been applied to study biological specimens ranging from single molecules inside cells nuclei to entire embryos. We here describe pattern designs and nanofabrication methods for diffractive optics that optimize the light-efficiency of the central optical component of MFM: the diffractive multifocus grating (MFG). We also implement a "precise color" MFM layout with MFGs tailored to individual fluorophores in separate optical arms. The reported advancements enable faster and brighter volumetric time-lapse imaging of biological samples. In live microscopy applications, photon budget is a critical parameter and light-efficiency must be optimized to obtain the fastest possible frame rate while minimizing photodamage. We provide comprehensive descriptions and code for designing diffractive optical devices, and a detailed methods description for nanofabrication of devices. Theoretical efficiencies of reported designs is ≈90% and we have obtained efficiencies of > 80% in MFGs of our own manufacture. We demonstrate the performance of a multi-phase MFG in 3D functional neuronal imaging in living C. elegans. PMID:27231594

  7. Threshold thickness for applying diffusion equation in thin tissue optical imaging

    NASA Astrophysics Data System (ADS)

    Zhang, Yunyao; Zhu, Jingping; Cui, Weiwen; Nie, Wei; Li, Jie; Xu, Zhenghong

    2014-08-01

    We investigated the suitability of the semi-infinite model of the diffusion equation when using diffuse optical imaging (DOI) to image thin tissues with double boundaries. Both diffuse approximation and Monte Carlo methods were applied to simulate light propagation in the thin tissue model with variable optical parameters and tissue thicknesses. A threshold value of the tissue thickness was defined as the minimum thickness in which the semi-infinite model exhibits the same reflected intensity as that from the double-boundary model and was generated as the final result. In contrast to our initial hypothesis that all optical properties would affect the threshold thickness, our results show that only absorption coefficient is the dominant parameter and the others are negligible. The threshold thickness decreases from 1 cm to 4 mm as the absorption coefficient grows from 0.01 mm-1 to 0.2 mm-1. A look-up curve was derived to guide the selection of the appropriate model during the optical diagnosis of thin tissue cancers. These results are useful in guiding the development of the endoscopic DOI for esophageal, cervical and colorectal cancers, among others.

  8. Multifocus microscopy with precise color multi-phase diffractive optics applied in functional neuronal imaging

    PubMed Central

    Abrahamsson, Sara; Ilic, Rob; Wisniewski, Jan; Mehl, Brian; Yu, Liya; Chen, Lei; Davanco, Marcelo; Oudjedi, Laura; Fiche, Jean-Bernard; Hajj, Bassam; Jin, Xin; Pulupa, Joan; Cho, Christine; Mir, Mustafa; El Beheiry, Mohamed; Darzacq, Xavier; Nollmann, Marcelo; Dahan, Maxime; Wu, Carl; Lionnet, Timothée; Liddle, J. Alexander; Bargmann, Cornelia I.

    2016-01-01

    Multifocus microscopy (MFM) allows high-resolution instantaneous three-dimensional (3D) imaging and has been applied to study biological specimens ranging from single molecules inside cells nuclei to entire embryos. We here describe pattern designs and nanofabrication methods for diffractive optics that optimize the light-efficiency of the central optical component of MFM: the diffractive multifocus grating (MFG). We also implement a “precise color” MFM layout with MFGs tailored to individual fluorophores in separate optical arms. The reported advancements enable faster and brighter volumetric time-lapse imaging of biological samples. In live microscopy applications, photon budget is a critical parameter and light-efficiency must be optimized to obtain the fastest possible frame rate while minimizing photodamage. We provide comprehensive descriptions and code for designing diffractive optical devices, and a detailed methods description for nanofabrication of devices. Theoretical efficiencies of reported designs is ≈90% and we have obtained efficiencies of > 80% in MFGs of our own manufacture. We demonstrate the performance of a multi-phase MFG in 3D functional neuronal imaging in living C. elegans. PMID:27231594

  9. Temperature and pressure fiber-optic sensors applied to minimally invasive diagnostics and therapies

    NASA Astrophysics Data System (ADS)

    Hamel, Caroline; Pinet, Éric

    2006-02-01

    We present how fiber-optic temperature or pressure sensors could be applied to minimally invasive diagnostics and therapies. For instance a miniature pressure sensor based on micro-optical mechanical systems (MOMS) could solve most of the problems associated with fluidic pressure transduction presently used for triggering purposes. These include intra-aortic balloon pumping (IABP) therapy and other applications requiring detection of fast and/or subtle fluid pressure variations such as for intracranial pressure monitoring or for urology diagnostics. As well, miniature temperature sensors permit minimally invasive direct temperature measurement in diagnostics or therapies requiring energy transfer to living tissues. The extremely small size of fiber-optic sensors that we have developed allows quick and precise in situ measurements exactly where the physical parameters need to be known. Furthermore, their intrinsic immunity to electromagnetic interference (EMI) allows for the safe use of EMI-generating therapeutic or diagnostic equipments without compromising the signal quality. With the trend of ambulatory health care and the increasing EMI noise found in modern hospitals, the use of multi-parameter fiber-optic sensors will improve constant patient monitoring without any concern about the effects of EMI disturbances. The advantages of miniature fiberoptic sensors will offer clinicians new monitoring tools that open the way for improved diagnostic accuracy and new therapeutic technologies.

  10. Layer-Resolved Evolution of Organic Thin Films Monitored by Photoelectron Emission Microscopy and Optical Reflectance Spectroscopy

    PubMed Central

    2015-01-01

    Photoelectron emission microscopy (PEEM) and differential (optical) reflectance spectroscopy (DRS) have proven independently to be versatile analytical tools for monitoring the evolution of organic thin films during growth. In this paper, we present the first experiment in which both techniques have been applied simultaneously and synchronously. We illustrate how the combined PEEM and DRS results can be correlated to obtain an extended perspective on the electronic and optical properties of a molecular film dependent on the film thickness and morphology. As an example, we studied the deposition of the organic molecule α-sexithiophene on Ag(111) in the thickness range from submonolayers up to several monolayers. PMID:26523159

  11. Acenes and acenequinones for optics and organic electronics

    NASA Astrophysics Data System (ADS)

    Bruzek, Matthew J.

    Acenes have been explored by a number of research groups in the field of organic electronics with a particular emphasis on transistor materials. This group has been actively studying acene-based organic semiconductors for more than a decade using a crystal engineering approach and has developed acene derivatives for applications in field-effect transistors, light-emitting diodes, and photovoltaics. In addition to organic electronics, crystal engineering has important applications in a number of other fields, quite notably in the design of metal-organic frameworks. Chapters 2 and 3 of this dissertation focus on applying crystal engineering to the synthesis of acene derivatives for use as solid-state, long-wavelength fluorescent organic dyes in the field of biomedical imaging. More specifically, this work studied the synthesis and properties of dioxolane-functionalized pentacenes and hexacenes. One of these pentacene derivatives has already been demonstrated in biomedical imaging which may lead to improved treatment of tuberculosis. The dioxolane-functionalized hexacene is still under evaluation for bioimaging applications. Chapters 4 and 5 focus on crystal engineering in relation to organic electronics. Chapter 4 deals with fine-tuning of crystal packing and demonstrated that small differences in molecular structure can result in significant changes to the solid-state structure which affects semiconductor properties. Finally, chapter 5 studies the use of singlet fission in photovoltaics and demonstrated that this process does occur in a solar cell incorporating a hexacene derivative. Pentadithiophenes were also synthesized for singlet fission photovoltaics, but they have yet to be studied further. KEYWORDS: Crystal Engineering, Biomedical Imaging, Acenes, Singlet Fission, Organic Semiconductors.

  12. Luminescence Sensors Applied to Water Analysis of Organic Pollutants—An Update

    PubMed Central

    Ibañez, Gabriela A.; Escandar, Graciela M.

    2011-01-01

    The development of chemical sensors for environmental analysis based on fluorescence, phosphorescence and chemiluminescence signals continues to be a dynamic topic within the sensor field. This review covers the fundamentals of this type of sensors, and an update on recent works devoted to quantifying organic pollutants in environmental waters, focusing on advances since about 2005. Among the wide variety of these contaminants, special attention has been paid polycyclic aromatic hydrocarbons, pesticides, explosives and emerging organic pollutants. The potential of coupling optical sensors with multivariate calibration methods in order to improve the selectivity is also discussed. PMID:22247654

  13. Applied electro-optics educational and training program with multiple entrance and exit pathways

    NASA Astrophysics Data System (ADS)

    Scott, Patricia; Zhou, Feng; Zilic, Dorothy

    2007-06-01

    This paper presents an innovative hands-on training program designed to create a pipeline of highly-skilled technical workers for today's workforce economy. The 2+2+2 Pennsylvania Integrated Workforce Leadership Program in Electro-Optics prepares students for a career in this new high-tech field. With seamless transition from high school into college, the program offers the versatility of multiple entrance and exit pathways. After completion of each educational level, students can exit the program with various skill levels, including certificates, an associate's degree, or a bachelor's degree. Launched by Indiana University of Pennsylvania (IUP) in partnership with Lenape Vocational School (Lenape), the 2+2+2 educational pathway program was implemented to promote early training of high-school students. During the first level, students in their junior and/or senior year enroll in four Electro-Optics courses at Lenape. Upon completion of these courses and an Advanced Placement Equivalency course with an appropriate exam score, students can earn a certificate from Lenape for the 15+ credits, which also can be articulated into IUP's associate degree program in Electro-Optics. During the second level, students can earn an associate's degree in Electro-Optics, offered only at the IUP Northpointe Campus. After completion of the Associate in Applied Science (A.A.S.), students are prepared to enter the workforce as senior technicians. During the third level, students who have completed the Associate of Science (A.S.) in Electro-Optics have the opportunity to matriculate at IUP's Indiana Campus to earn a Bachelor of Science (B.S.) degree in Applied Physics with a track in Electro-Optics. Hence, the name 2+2+2 refers to getting started in high school, continuing the educational experience with an associate's degree program, and optionally moving on to a bachelor's degree. Consequently, students move from one educational level to the next with advanced credits toward the next

  14. Applying UV cameras for SO2 detection to distant or optically thick volcanic plumes

    USGS Publications Warehouse

    Kern, Christoph; Werner, Cynthia; Elias, Tamar; Sutton, A. Jeff; Lübcke, Peter

    2013-01-01

    Ultraviolet (UV) camera systems represent an exciting new technology for measuring two dimensional sulfur dioxide (SO2) distributions in volcanic plumes. The high frame rate of the cameras allows the retrieval of SO2 emission rates at time scales of 1 Hz or higher, thus allowing the investigation of high-frequency signals and making integrated and comparative studies with other high-data-rate volcano monitoring techniques possible. One drawback of the technique, however, is the limited spectral information recorded by the imaging systems. Here, a framework for simulating the sensitivity of UV cameras to various SO2 distributions is introduced. Both the wavelength-dependent transmittance of the optical imaging system and the radiative transfer in the atmosphere are modeled. The framework is then applied to study the behavior of different optical setups and used to simulate the response of these instruments to volcanic plumes containing varying SO2 and aerosol abundances located at various distances from the sensor. Results show that UV radiative transfer in and around distant and/or optically thick plumes typically leads to a lower sensitivity to SO2 than expected when assuming a standard Beer–Lambert absorption model. Furthermore, camera response is often non-linear in SO2 and dependent on distance to the plume and plume aerosol optical thickness and single scatter albedo. The model results are compared with camera measurements made at Kilauea Volcano (Hawaii) and a method for integrating moderate resolution differential optical absorption spectroscopy data with UV imagery to retrieve improved SO2 column densities is discussed.

  15. Single crystal films and waveguides of organic materials: Preparation and nonlinear optical properties

    NASA Astrophysics Data System (ADS)

    Thakur, Mrinal

    1994-03-01

    The objective of this program is to establish a generic method for the growth of thin single crystal films of important organic nonlinear optical materials and measurement of their nonlinear optical properties. Through the last year's effort we have successfully prepared single crystal films of three organic materials which are: (1) (N-(4-Nitrophenyl)-L-prolinol) abbreviated as NPP, (2) 2-cyclooctylamino- 5-nitropyridine, abbreviated as COANP, and (3) 4'-N, N-dimethylamino- 4-N-methylstilbazolium toluene-p-sulfonate, abbreviated as DAST. These materials have very large second order susceptibilities. Both NPP and COANP have an amphiphillic molecular structure, while DAST is an organic molecular salt. The single crystal films were prepared by a method called the shear method, with appropriate choice of the growth conditions. The shear method involves crystal growth at an interface and was originally applied to the growth of polydiacetylene films. Our results show that using the principles involved in the shear method, if the growth conditions are properly optimized for each compound, then molecules other than diacetylene are possible to organize as single crystal films. The only major condition that needs to be satisfied for this method to be applicable is that the molecule must be of an elongated shape with polar chemical groups at one or both ends.

  16. Superior characteristics of organic chalcone single crystals as efficient nonlinear optical material

    NASA Astrophysics Data System (ADS)

    Kiran, A. John; Kim, H. C.; Kim, K.; Rotermund, F.; Ravindra, H. J.; Dharmaprakash, S. M.; Lim, H.

    2008-03-01

    High-quality biaxial single crystals of chalcone derivatives were grown by solution growth technique. Their molecular structures were designed to possess large second-order nonlinearities by choosing proper donor/acceptor groups while retaining a high transparency in the visible and infrared spectral regions. The second-order nonlinear optical coefficients, determined by applying the Maker fringe technique, were found to be much larger than those of LiB3O5, KTiOPO4, KH2PO4, and urea. The advantages, such as easy synthesis and crystal growth, low cutoff wavelength (<450nm ), large optical nonlinearity, and high damage threshold (>7.2GW/cm2), make these organic crystals promising for efficient frequency doubling.

  17. [Techniques of on-line monitoring volatile organic compounds in ambient air with optical spectroscopy].

    PubMed

    Du, Zhen-Hui; Zhai, Ya-Qiong; Li, Jin-Yi; Hu, Bo

    2009-12-01

    Volatile organic compounds (VOCs) are harmful gaseous pollutants in the ambient air. The techniques of on-line monitoring VOCs are very significant for environment protection. Until now, there is no single technology that can meet all the needs of monitoring various VOCs. The characteristics and present situation of several optical methods, which can be applied to on-line monitoring VOCs, including non dispersive infrared (NDIR), Fourier transform infrared (FTIR) spectroscopy, differential optical absorption spectroscopy (DOAS), and laser spectroscopy were reviewed. Comparison was completed between the national standard methods and spectroscopic method for measuring VOCs. The main analysis was focused on the status and trends of tuning diode laser absorption spectroscopy (TDLAS) technology. PMID:20210131

  18. A general method for manipulating DNA sequences from any organism with optical tweezers

    NASA Astrophysics Data System (ADS)

    Fuller, Derek N.; Gemmen, Gregory J.; Rickgauer, John Peter; DuPont, Aurelie; Millin, Rachel; Recouvreux, Pierre; Schweitzer, Allen L.; Smith, Douglas E.

    2005-08-01

    Here we describe and characterize a method for manipulating desired DNA sequences from any organism with optical tweezers. Molecules are produced from either genomic or cloned DNA by PCR using labeled primers and are tethered between two optically trapped microspheres. We demonstrate that human, insect, plant, bacterial, and viral sequences ranging from ~10 to 40 kbp can be manipulated. Force-extension measurements show that these constructs exhibit uniform elastic properties in accord with the expected contour lengths for the targeted sequences. Detailed protocols for preparing and manipulating these molecules are presented, and tethering efficiency is characterized as a function of DNA concentration, ionic strength, and pH. Attachment strength is characterized by measuring the unbinding time distribution as a function of applied force.

  19. Crystal stability and optical properties of organic chain compounds

    NASA Astrophysics Data System (ADS)

    Zupanovic, P.; Bjelis, A.; Barisic, S.

    1999-01-01

    The solution to the long-standing problem of the cohesion of organic chain compounds is proposed. We consider the tight-binding dielectric matrix with two electronic bands per chain, determine the corresponding hybridized collective modes, and show that three among them are considerably softened due to strong dipole-dipole and monopole-dipole interactions. By this we explain the unusual low-frequency optical activity of TTF-TCNQ, including the observed 10 meV anomaly. The softening of the modes also explains the cohesion of the mixed-stack lattice, the fractional charge transfer almost independent of the material, and the formation of the charged sheets in some compounds.

  20. Third- and fifth-order optical nonlinearities in organic materials

    NASA Astrophysics Data System (ADS)

    Said, A. A.; Wamsley, C.; Hagan, D. J.; Van Stryland, E. W.; Reinhardt, Bruce A.; Roderer, Paul; Dillard, Ann G.

    1994-10-01

    We measure the nonlinear optical properties of solutions of a bisbenzethiozole-substituted thiophene compound (BBTDOT) and didecyloxy substituted polyphenyl (DDOS) using the Z-scan technique with 532 nm picosecond pulses. Both compounds exhibit two-photon absorption (2PA) and excited-state absorption (ESA) from the 2PA generated excited states. We measure the magnitude and sign of the real (refractive) and imaginary (2PA) parts of the third-order hyperpolarizability, and the excited-state absorptive and refractive cross sections. We observe third-order self-focusing in BBTDOT and self-defocusing in DDOS while both show excited-state defocusing. All these effects were previously observed and modeled in semiconductors giving insight into the nonlinearities occurring in these organic materials.

  1. Self-organized optical device driven by motor proteins

    PubMed Central

    Aoyama, Susumu; Shimoike, Masahiko; Hiratsuka, Yuichi

    2013-01-01

    Protein molecules produce diverse functions according to their combination and arrangement as is evident in a living cell. Therefore, they have a great potential for application in future devices. However, it is currently very difficult to construct systems in which a large number of different protein molecules work cooperatively. As an approach to this challenge, we arranged protein molecules in artificial microstructures and assembled an optical device inspired by a molecular system of a fish melanophore. We prepared arrays of cell-like microchambers, each of which contained a scaffold of microtubule seeds at the center. By polymerizing tubulin from the fixed microtubule seeds, we obtained radially arranged microtubules in the chambers. We subsequently prepared pigment granules associated with dynein motors and attached them to the radial microtubule arrays, which made a melanophore-like system. When ATP was added to the system, the color patterns of the chamber successfully changed, due to active transportation of pigments. Furthermore, as an application of the system, image formation on the array of the optical units was performed. This study demonstrates that a properly designed microstructure facilitates arrangement and self-organization of molecules and enables assembly of functional molecular systems. PMID:24065817

  2. Organic vapor detection with fiber optic bead arrays

    NASA Astrophysics Data System (ADS)

    Stitzel, Shannon E.; Albert, Keith J.; Walt, David R.

    1999-12-01

    The need for small, fast responding detection systems is growing and fiber-optic bead arrays offer a different approach to small sensor design. Sensor arrays are fabricated by inserting self-encoded microspheres into microwells etched into the distal face of an imaging fiber. Each imaging fiber is 0.5 - 1 mm in outer diameter and consists of 5,000 - 10,000 individually clad, 3 - 4 micrometers diameter optical fibers bundled together. The bundles are coherent, allowing each microsphere in a well to be addressed as an individual sensor. Microsphere sensors are silica or polymer beads (approximately 3 micrometers in diameter) impregnated with solvatochromic dyes. These dyes alter their fluorescence emission spectra in response to changes in vapor polarity, allowing analytes to be discriminated based on their signature fluorescence response over time. A computational network is trained to recognize these response patterns for each sensor type, allowing for identification of specific organic vapors. Each sensor type is cross- reactive, and has unique fluorescence response patterns to different analytes. The sensor types can be identified based on their unique responses, allowing their position to be registered by observing the identity of the response pattern toward a known standard. Such encoding enables array fabrication to be simplified since sensors can be randomly dispersed throughout the array, instead of specifically patterned within the array. Possible applications for bead array detectors include environmental and industrial monitoring, land mine detection, and medical diagnostics.

  3. Self-organized optical device driven by motor proteins.

    PubMed

    Aoyama, Susumu; Shimoike, Masahiko; Hiratsuka, Yuichi

    2013-10-01

    Protein molecules produce diverse functions according to their combination and arrangement as is evident in a living cell. Therefore, they have a great potential for application in future devices. However, it is currently very difficult to construct systems in which a large number of different protein molecules work cooperatively. As an approach to this challenge, we arranged protein molecules in artificial microstructures and assembled an optical device inspired by a molecular system of a fish melanophore. We prepared arrays of cell-like microchambers, each of which contained a scaffold of microtubule seeds at the center. By polymerizing tubulin from the fixed microtubule seeds, we obtained radially arranged microtubules in the chambers. We subsequently prepared pigment granules associated with dynein motors and attached them to the radial microtubule arrays, which made a melanophore-like system. When ATP was added to the system, the color patterns of the chamber successfully changed, due to active transportation of pigments. Furthermore, as an application of the system, image formation on the array of the optical units was performed. This study demonstrates that a properly designed microstructure facilitates arrangement and self-organization of molecules and enables assembly of functional molecular systems. PMID:24065817

  4. Optical spintronics in organic-inorganic perovskite photovoltaics

    NASA Astrophysics Data System (ADS)

    Li, Junwen; Haney, Paul M.

    2016-04-01

    Organic-inorganic halide CH3NH3PbI3 solar cells have attracted enormous attention in recent years due to their remarkable power conversion efficiency. When inversion symmetry is broken, these materials should exhibit interesting spin-dependent properties as well, owing to their strong spin-orbit coupling. In this work, we consider the spin-dependent optical response of CH3NH3PbI3 . We first use density functional theory to compute the ballistic spin current generated by absorption of unpolarized light. We then consider diffusive transport of photogenerated charge and spin for a thin CH3NH3PbI3 layer with a passivated surface and an Ohmic, nonselective contact. The spin density and spin current are evaluated by solving the drift-diffusion equations for a simplified three-dimensional Rashba model of the electronic structure of the valence and conduction bands. We provide analytic expressions for the photon flux required to induce measurable spin densities, and propose that these spin densities can provide useful information about the role of grain boundaries in the photovoltaic behavior of these materials. We also discuss the prospects for measuring the optically generated spin current with the inverse spin Hall effect.

  5. Multiconjugate adaptive optics applied to an anatomically accurate human eye model.

    PubMed

    Bedggood, P A; Ashman, R; Smith, G; Metha, A B

    2006-09-01

    Aberrations of both astronomical telescopes and the human eye can be successfully corrected with conventional adaptive optics. This produces diffraction-limited imagery over a limited field of view called the isoplanatic patch. A new technique, known as multiconjugate adaptive optics, has been developed recently in astronomy to increase the size of this patch. The key is to model atmospheric turbulence as several flat, discrete layers. A human eye, however, has several curved, aspheric surfaces and a gradient index lens, complicating the task of correcting aberrations over a wide field of view. Here we utilize a computer model to determine the degree to which this technology may be applied to generate high resolution, wide-field retinal images, and discuss the considerations necessary for optimal use with the eye. The Liou and Brennan schematic eye simulates the aspheric surfaces and gradient index lens of real human eyes. We show that the size of the isoplanatic patch of the human eye is significantly increased through multiconjugate adaptive optics. PMID:19529172

  6. Applying Hofstede's Cross-Cultural Theory of Organizations to School Governance: A French Case Study.

    ERIC Educational Resources Information Center

    Fowler, Frances C.

    This paper applies Geert Hofstede's cross-cultural theory of organizational structure and behavior to school administration, examining the governance structure of the French public school system to determine how accurately it predicts the form of that educational organization. The first section of the paper presents Hofstede's theory and his…

  7. Graphic Organizers Applied to Secondary Algebra Instruction for Students with Learning Disorders

    ERIC Educational Resources Information Center

    Ives, Bob

    2007-01-01

    Students who have particular difficulty in mathematics are a growing concern for educators. Graphic organizers have been shown to improve reading comprehension and may be applied to upper level secondary mathematics content. In two systematic replications, one randomly assigned group was taught to solve systems of linear equations through direct…

  8. 24 CFR 5.1003 - Use of a universal identifier for organizations applying for HUD grants.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 1 2013-04-01 2013-04-01 false Use of a universal identifier for organizations applying for HUD grants. 5.1003 Section 5.1003 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development GENERAL HUD PROGRAM REQUIREMENTS; WAIVERS...

  9. 24 CFR 5.1003 - Use of a universal identifier for organizations applying for HUD grants.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Use of a universal identifier for organizations applying for HUD grants. 5.1003 Section 5.1003 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development GENERAL HUD PROGRAM REQUIREMENTS; WAIVERS...

  10. 24 CFR 5.1003 - Use of a universal identifier for organizations applying for HUD grants.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 1 2012-04-01 2012-04-01 false Use of a universal identifier for organizations applying for HUD grants. 5.1003 Section 5.1003 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development GENERAL HUD PROGRAM REQUIREMENTS; WAIVERS...

  11. 24 CFR 5.1003 - Use of a universal identifier for organizations applying for HUD grants.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 1 2011-04-01 2011-04-01 false Use of a universal identifier for organizations applying for HUD grants. 5.1003 Section 5.1003 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development GENERAL HUD PROGRAM REQUIREMENTS; WAIVERS...

  12. 24 CFR 5.1003 - Use of a universal identifier for organizations applying for HUD grants.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 1 2014-04-01 2014-04-01 false Use of a universal identifier for organizations applying for HUD grants. 5.1003 Section 5.1003 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development GENERAL HUD PROGRAM REQUIREMENTS; WAIVERS...

  13. 40 CFR 262.100 - To what organizations does this subpart apply?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 27 2012-07-01 2012-07-01 false To what organizations does this subpart apply? 262.100 Section 262.100 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS APPLICABLE TO GENERATORS OF HAZARDOUS WASTE...

  14. 40 CFR 262.100 - To what organizations does this subpart apply?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 27 2013-07-01 2013-07-01 false To what organizations does this subpart apply? 262.100 Section 262.100 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS APPLICABLE TO GENERATORS OF HAZARDOUS WASTE...

  15. 40 CFR 262.100 - To what organizations does this subpart apply?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 26 2011-07-01 2011-07-01 false To what organizations does this subpart apply? 262.100 Section 262.100 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS APPLICABLE TO GENERATORS OF HAZARDOUS WASTE...

  16. 40 CFR 262.100 - To what organizations does this subpart apply?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false To what organizations does this subpart apply? 262.100 Section 262.100 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS APPLICABLE TO GENERATORS OF HAZARDOUS WASTE...

  17. 20 CFR 641.620 - How may an organization apply for section 502(e) funding?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false How may an organization apply for section 502(e) funding? 641.620 Section 641.620 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR PROVISIONS GOVERNING THE SENIOR COMMUNITY SERVICE EMPLOYMENT PROGRAM Private...

  18. Multi-spectral optical simulation system applied in hardware-in-the-loop

    NASA Astrophysics Data System (ADS)

    Yu, Hong; Lei, Jie; Gao, Yang; Liu, Yang

    2009-07-01

    The Multi-spectral simulation system has been constructed at Beijing Simulation Center (BSC) for hardware-in-the-loop (HWIL) testing of optical and infrared seekers, in single-band and dual-band, or even multi-band. This multi-spectral simulation facility consists primarily of several projectors and a wide-angular simulation mechanism, the projector technologies utilized at BSC include a broadband point source collimator, a laser echo simulator and a visible scene projection system. These projectors can be used individually with the wide-angular simulation mechanism, or any combination of both or all of three can be used according to different needs. The configuration and performance of each technology are reviewed in the paper. Future plans include two IR imaging projectors which run at high frame frequency. The multi-spectral optical simulation system has been successfully applied for visible and IR imaging seekers testing in HWIL simulation. The laser echo simulator hardware will be applied soon.

  19. Marine organism repellent covering for protection of underwater objects and method of applying same

    SciTech Connect

    Fischer, K.J.

    1993-07-13

    A method is described of protecting the surface of underwater objects from fouling by growth of marine organisms thereon comprising the steps of: (A) applying a layer of waterproof adhesive to the surface to be protected; (B) applying to the waterproof adhesive layer, a deposit of cayenne pepper material; (C) applying a permeable layer of copper containing material to the adhesive layer in such a configuration as to leave certain areas of the outer surface of the adhesive layer exposed, through open portions of the permeable layer, to the ambient environment of the surface to be protected when such surface is submerged in water; (D) the permeable layer having the property of being a repellent to marine organisms.

  20. Characterization of optically stimulated luminescence dosemeters to measure organ doses in diagnostic radiology

    PubMed Central

    Endo, A; Katoh, T; Kobayashi, I; Joshi, R; Sur, J; Okano, T

    2012-01-01

    Objective The aim of this study was to assess the characteristics of an optically stimulated luminescence dosemeter (OSLD) for use in diagnostic radiology and to apply the OSLD in measuring the organ doses by panoramic radiography. Methods The dose linearity, energy dependency and angular dependency of aluminium oxide-based OSLDs were examined using an X-ray generator to simulate various exposure settings in diagnostic radiology. The organ doses were then measured by inserting the dosemeters into an anthropomorphic phantom while using three panoramic machines. Results The dosemeters demonstrated consistent dose linearity (coefficient of variation<1.5%) and no significant energy dependency (coefficient of variation<1.5%) under the applied exposure conditions. They also exhibited negligible angular dependency (≤10%). The organ doses of the X-ray as a result of panoramic imaging by three machines were calculated using the dosemeters. Conclusion OSLDs can be utilized to measure the organ doses in diagnostic radiology. The availability of these dosemeters in strip form proves to be reliably advantageous. PMID:22116136

  1. 3D Fluorescence Quenching of Dissolved Organic Matter Applying PARAFAC Treatment

    NASA Astrophysics Data System (ADS)

    Zhao, H. A.; Garnier, C.; Redon, R.; Mounier, S.

    2009-12-01

    Dissolved Organic Matter (DOM) exists everywhere in the environment. The studies of DOM in aquatic ecosystems enable us to obtain some information on its coming future and the importance of its role in the bio-geochemical processes. The fluorescence technique makes analyzes possible on the basis of the optical propriety of the DOM including its fluorophores composition and its complexation propriety face to face to certain metal (3). Recently for luminescence spectrum it is possible to determine the fluorescent component composition by the statistical analysis of parallel factor analysis (PARAFAC) with excitation-emission matrix (EEM) (1). The complexation propriety between DOM and metals is accessible by measuring the fluorescence quenching (FQ) functional to the metal additions. The EEMs in the FQ experiments contain maximal information as a whole of fluorescent DOM (FDOM). This work presents a quenching experience brought from copper ions titration onto a tropical river water sample (Rio Negro à Sao Gabriel Brésil) of 5mgC/L carbon concentration and 1.68 nano-molaire initial copper ions concentration (pH=4.5). A titration of copper ions (Cu(NO3)2) has been applied at total analytical concentration of copper-ions from 10-9M jusqu’à 10-3M. Fifty (50) EEM were obtained and gathered in order to analyze the FQ by PARAFAC. This statistic treatment permits us to extract 2 fluorescent components with the whole EEM: C1 (λex=225-235nm/λem=420-425nm) and C2 (λex=250-260nm and 345-355nm/λem=470-480nm) corresponding to the peaks already descript in the literature. Using the participation to the total fluorescence of these peaks, we have observed clearly that the fluorescence diminution was not uniform. The measurement of complexation propriety by this new approach gives the values following: K1=10E4.6; L1=10E-7.8 et K2=10E4.46; L2=10E-9 respectively the components C1 et C2. These results conform that determined in the literature by FQ. The utilisation of PARAFAC has

  2. Optical tools for high-throughput screening of abrasion resistance of combinatorial libraries of organic coatings

    NASA Astrophysics Data System (ADS)

    Potyrailo, Radislav A.; Chisholm, Bret J.; Olson, Daniel R.; Brennan, Michael J.; Molaison, Chris A.

    2002-02-01

    Design, validation, and implementation of an optical spectroscopic system for high-throughput analysis of combinatorially developed protective organic coatings are reported. Our approach replaces labor-intensive coating evaluation steps with an automated system that rapidly analyzes 8x6 arrays of coating elements that are deposited on a plastic substrate. Each coating element of the library is 10 mm in diameter and 2 to 5 micrometers thick. Performance of coatings is evaluated with respect to their resistance to wear abrasion because this parameter is one of the primary considerations in end-use applications. Upon testing, the organic coatings undergo changes that are impossible to quantitatively predict using existing knowledge. Coatings are abraded using industry-accepted abrasion test methods at single-or multiple-abrasion conditions, followed by high- throughput analysis of abrasion-induced light scatter. The developed automated system is optimized for the analysis of diffusively scattered light that corresponds to 0 to 30% haze. System precision of 0.1 to 2.5% relative standard deviation provides capability for the reliable ranking of coatings performance. While the system was implemented for high-throughput screening of combinatorially developed organic protective coatings for automotive applications, it can be applied to a variety of other applications where materials ranking can be achieved using optical spectroscopic tools.

  3. Colored polydimethylsiloxane micropillar arrays for high throughput measurements of forces applied by genetic model organisms.

    PubMed

    Khare, Siddharth M; Awasthi, Anjali; Venkataraman, V; Koushika, Sandhya P

    2015-01-01

    Measuring forces applied by multi-cellular organisms is valuable in investigating biomechanics of their locomotion. Several technologies have been developed to measure such forces, for example, strain gauges, micro-machined sensors, and calibrated cantilevers. We introduce an innovative combination of techniques as a high throughput screening tool to assess forces applied by multiple genetic model organisms. First, we fabricated colored Polydimethylsiloxane (PDMS) micropillars where the color enhances contrast making it easier to detect and track pillar displacement driven by the organism. Second, we developed a semi-automated graphical user interface to analyze the images for pillar displacement, thus reducing the analysis time for each animal to minutes. The addition of color reduced the Young's modulus of PDMS. Therefore, the dye-PDMS composite was characterized using Yeoh's hyperelastic model and the pillars were calibrated using a silicon based force sensor. We used our device to measure forces exerted by wild type and mutant Caenorhabditis elegans moving on an agarose surface. Wild type C. elegans exert an average force of ∼1 μN on an individual pillar and a total average force of ∼7.68 μN. We show that the middle of C. elegans exerts more force than its extremities. We find that C. elegans mutants with defective body wall muscles apply significantly lower force on individual pillars, while mutants defective in sensing externally applied mechanical forces still apply the same average force per pillar compared to wild type animals. Average forces applied per pillar are independent of the length, diameter, or cuticle stiffness of the animal. We also used the device to measure, for the first time, forces applied by Drosophila melanogaster larvae. Peristaltic waves occurred at 0.4 Hz applying an average force of ∼1.58 μN on a single pillar. Our colored microfluidic device along with its displacement tracking software allows us to measure forces

  4. Colored polydimethylsiloxane micropillar arrays for high throughput measurements of forces applied by genetic model organisms

    PubMed Central

    Khare, Siddharth M.; Awasthi, Anjali; Venkataraman, V.; Koushika, Sandhya P.

    2015-01-01

    Measuring forces applied by multi-cellular organisms is valuable in investigating biomechanics of their locomotion. Several technologies have been developed to measure such forces, for example, strain gauges, micro-machined sensors, and calibrated cantilevers. We introduce an innovative combination of techniques as a high throughput screening tool to assess forces applied by multiple genetic model organisms. First, we fabricated colored Polydimethylsiloxane (PDMS) micropillars where the color enhances contrast making it easier to detect and track pillar displacement driven by the organism. Second, we developed a semi-automated graphical user interface to analyze the images for pillar displacement, thus reducing the analysis time for each animal to minutes. The addition of color reduced the Young's modulus of PDMS. Therefore, the dye-PDMS composite was characterized using Yeoh's hyperelastic model and the pillars were calibrated using a silicon based force sensor. We used our device to measure forces exerted by wild type and mutant Caenorhabditis elegans moving on an agarose surface. Wild type C. elegans exert an average force of ∼1 μN on an individual pillar and a total average force of ∼7.68 μN. We show that the middle of C. elegans exerts more force than its extremities. We find that C. elegans mutants with defective body wall muscles apply significantly lower force on individual pillars, while mutants defective in sensing externally applied mechanical forces still apply the same average force per pillar compared to wild type animals. Average forces applied per pillar are independent of the length, diameter, or cuticle stiffness of the animal. We also used the device to measure, for the first time, forces applied by Drosophila melanogaster larvae. Peristaltic waves occurred at 0.4 Hz applying an average force of ∼1.58 μN on a single pillar. Our colored microfluidic device along with its displacement tracking software allows us to measure forces

  5. Racemization and the origin of optically active organic compounds in living organisms

    NASA Technical Reports Server (NTRS)

    Bada, J. L.; Miller, S. L.

    1987-01-01

    The organic compounds synthesized in prebiotic experiments are racemic mixtures. A number of proposals have been offered to explain how asymmetric organic compounds formed on the Earth before life arose, with the influence of chiral weak nuclear interactions being the most frequent proposal. This and other proposed asymmetric syntheses give only sight enantiomeric excess and any slight excess will be degraded by racemization. This applies particularly to amino acids where half-lives of 10(5)-10(6) years are to be expected at temperatures characteristic of the Earth's surface. Since the generation of chiral molecules could not have been a significant process under geological conditions, the origins of this asymmetry must have occurred at the time of the origin of life or shortly thereafter. It is possible that the compounds in the first living organisms were prochiral rather than chiral; this is unlikely for amino acids, but it is possible for the monomers of RNA-like molecules.

  6. Optical scatterometry with analytic approaches applied to periodic nano-arrays including anisotropic layers

    NASA Astrophysics Data System (ADS)

    Abdulhalim, I.

    2007-06-01

    Optical scatterometry is being used as a powerful technique for measurement of sub-wavelength periodic structures. It is based on measuring the scattered signal and solving the inverse scattering problem. For periodic nano-arrays with feature size less than 100nm, it is possible to simplify the electromagnetic simulations using the Rytov near quasi-static approximation valid for feature periods only few times less than the wavelength. This is shown to be adequate for the determination of the structure parameters from the zero order reflected or transmitted waves and their polarization or ellipsometric properties. The validity of this approach is applied to lamellar nano-scale grating photo-resist lines on Si substrate. Formulation for structures containing anisotropic multilayers is presented using the 4x4 matrix approach.

  7. Optical Properties of Mixed Black Carbon, Inorganic and Secondary Organic Aerosols

    SciTech Connect

    Paulson, S E

    2012-05-30

    Summarizes the achievements of the project, which are divided into four areas: 1) Optical properties of secondary organic aerosols; 2) Development and of a polar nephelometer to measure aerosol optical properties and theoretical approaches to several optical analysis problems, 3) Studies on the accuracy of measurements of absorbing carbon by several methods, and 4) Environmental impacts of biodiesel.

  8. Applying an optical space-time coding method to enhance light scattering signals in microfluidic devices.

    PubMed

    Mei, Zhe; Wu, Tsung-Feng; Pion-Tonachini, Luca; Qiao, Wen; Zhao, Chao; Liu, Zhiwen; Lo, Yu-Hwa

    2011-09-01

    An "optical space-time coding method" was applied to microfluidic devices to detect the forward and large angle light scattering signals for unlabelled bead and cell detection. Because of the enhanced sensitivity by this method, silicon pin photoreceivers can be used to detect both forward scattering (FS) and large angle (45-60°) scattering (LAS) signals, the latter of which has been traditionally detected by a photomultiplier tube. This method yields significant improvements in coefficients of variation (CV), producing CVs of 3.95% to 10.05% for FS and 7.97% to 26.12% for LAS with 15 μm, 10 μm, and 5 μm beads. These are among the best values ever demonstrated with microfluidic devices. The optical space-time coding method also enables us to measure the speed and position of each particle, producing valuable information for the design and assessment of microfluidic lab-on-a-chip devices such as flow cytometers and complete blood count devices. PMID:21915241

  9. Optical Image Analysis Applied to Pore Network Quantification of Sandstones Under Experimental CO2 Injection

    NASA Astrophysics Data System (ADS)

    Berrezueta, E.; González, L.; Ordóñez, B.; Luquot, L.; Quintana, L.; Gallastegui, G.; Martínez, R.; Olaya, P.; Breitner, D.

    2015-12-01

    This research aims to propose a protocol for pore network quantification in sandstones applying the Optical Image Analysis (OIA) procedure, which guarantees the measurement reproducibility and its reliability. Two geological formations of sandstone, located in Spain and potentially suitable for CO2 sequestration, were selected for this study: a) the Cretaceous Utrillas unit, at the base of the Cenozoic Duero Basin and b) a Triassic unit at the base of the Cenozoic Guadalquivir Basin. Sandstone samples were studied before and after the CO2 experimental injection using Optical and scanning electronic microscopy (SEM), while the quantification of petrographic changes was done with OIA. The first phase of the rersearch consisted on a detailed mineralogical and petrographic study of the sandstones (before and after CO2-injection), for which we observed thin sections. Later, the methodological and experimental processes of the investigation were focused on i) adjustment and calibration of OIA tools; ii) data acquisition protocol based on image capture with different polarization conditions (synchronized movement of polarizers), using 7 images of the same mineral scene (6 in crossed polarizer and 1 in parallel polarizer); and iii) automated identification and segmentation of pore in 2D mineral images, generating applications by executable macros. Finally, once the procedure protocols had been, the compiled data was interpreted through an automated approach and the qualitative petrography was carried out. The quantification of changes in the pore network through OIA (porosity increase ≈ 2.5%) has allowed corroborate the descriptions obtained by SEM and microscopic techniques, which consisted in an increase in the porosity when CO2 treatment occurs. Automated-image identification and quantification of minerals, pores and textures together with petrographic analysis can be applied to improve pore system characterization in sedimentary rocks. This research offers numerical

  10. A 10-year global gridded Aerosol Optical Thickness Reanalysis for climate and applied applications

    NASA Astrophysics Data System (ADS)

    Lynch, P.; Reid, J. S.; Zhang, J.; Westphal, D. L.; Campbell, J. R.; Curtis, C. A.; Hegg, D.; Hyer, E. J.; Sessions, W.; Shi, Y.; Turk, J.

    2013-12-01

    While standalone satellite and model aerosol products see wide utilization, there is a significant need of a best-available fused product on a regular grid for numerous climate and applied applications. Remote sensing and modeling technologies have now advanced to a point where aerosol data assimilation is an operational reality at numerous centers. It is inevitable that, like meteorological reanalyses, aerosol reanalyses will see heavy use in the near future. A first long term, 2003-2012 global 1x1 degree and 6-hourly aerosol optical thickness (AOT) reanalysis product has been generated. The goal of this effort is not only for climate applications, but to generate a dataset that can be used by the US Navy to understand operationally hindering aerosol events, aerosol impacts on numerical weather prediction, and application of electro-optical technologies. The reanalysis utilizes Navy Aerosol Analysis and Prediction System (NAAPS) at its core and assimilates quality controlled collection 5 Moderate Resolution Imaging Spectroradiometer (MODIS) AOD with minor corrections from Multi-angle Imaging SpectroRaditometer (MISR). A subset of this product includes Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) lidar assimilation since its launch in mid-2006. Surface aerosol sources, including dust and smoke, in the aerosol model have been regionally tuned so that fine and coarse mode AOTs best match those resolve by ground-based Aerosol Robotic Network (AERONET). The AOT difference between the model and satellite AOT is then used to adjust other aerosol processes, eg., sources, dry deposition, etc. Aerosol wet deposition is constrained with satellite-retrieved precipitation. The final AOT reanalysis is shown to exhibit good agreement with AERONET. Here we review the development of the reanalysis and consider issues particular to aerosol reanalyses that make them distinct from standard meteorological reanalyses. Considerations are also made for extending such work

  11. Toward Investigating Optically Trapped Organic Aerosols with CARS Microspectroscopy

    NASA Astrophysics Data System (ADS)

    Voss, L. F.

    2009-12-01

    The Intergovernmental Panel on Climate Change notes the huge uncertainty in the effect that atmospheric aerosols play in determining overall global temperature, specifically in their ability to nucleate clouds. To better understand aerosol chemistry, the novel coupling of gradient force optical trapping with broad bandwidth coherent anti-Stokes Raman scattering (CARS) spectroscopy is being developed to study single particles suspended in air. Building on successful designs employed separately for the techniques, this hybrid technology will be used to explain how the oxidation of organic compounds changes the chemical and physical properties of aerosols. By trapping the particles, an individual aerosol can be studied for up to several days. Using a broad bandwidth pulse for one of the incident beams will result in a Raman vibrational spectrum from every laser pulse. Combined with signal enhancement due to resonance and coherence of nonlinear CARS spectroscopy, this technique will allow for acquisition of data on the millisecond time scale, facilitating the study of dynamic processes. This will provide insights on how aerosols react with and absorb species from the gas phase. These experiments will increase understanding of aerosol oxidation and growth mechanisms and the effects that aerosols have on our atmosphere and climate. Progress in efforts developing this novel technique to study model systems is presented.

  12. The Relationship Between Dissolved Organic Matter Composition and Organic Matter Optical Properties in Freshwaters

    NASA Astrophysics Data System (ADS)

    Aiken, G.; Spencer, R. G.; Butler, K.

    2010-12-01

    Dissolved organic matter (DOM) chemistry and flux are potentially useful, albeit, underutilized, indicators of watershed characteristics, climate influences on watershed hydrology and soils, and changes associated with resource management. Source materials, watershed geochemistry, oxidative processes and hydrology exert strong influences on the nature and reactivity of DOM in aquatic systems. The molecules that comprise DOM, in turn, control a number of environmental processes important for ecosystem function including light penetration and photochemistry, microbial activity, mineral dissolution/precipitation, and the transport and reactivity of hydrophobic compounds and metals (e.g. Hg). In particular, aromatic molecules derived from higher plants exert strong controls on aquatic photochemistry, and on the transport and biogeochemistry of metals. Assessment of DOM composition and transport, therefore, can provide a basis for understanding watershed processes and biogeochemistry of rivers and streams. Here we present results of multi-year studies designed to assess the seasonal and spatial variability of DOM quantity and quality for 57 North American Rivers. DOM concentrations and composition, based on DOM fractionation on XAD resins, ultraviolet (UV)/visible absorption and fluorescence spectroscopic analyses, and specific compound analyses, varied greatly both between sites and seasonally within a given site. DOM in these rivers exhibited a wide range of concentration (<80 to >4000 µM C* L-1) and specific ultra-violet absorbance at 254 nm (SUVA254) (0.6 to 5 L *mg C-1 *m-1), an optical measurement that is an indicator of aromatic carbon content. In almost all systems, UV absorbance measured at specific wavelengths (e.g. 254 nm) correlated strongly with DOM and hydrophobic organic acid (HPOA) content (aquatic humic substances). The relationships between dissolved organic carbon (DOC) concentration and absorbance for the range of systems were quite variable due to

  13. Low consumption power variable optical attenuator with sol-gel derived organic/inorganic hybrid materials

    NASA Astrophysics Data System (ADS)

    Li, Dongxiao; Zhang, Yanwu; Liu, Liying; Xu, Lei

    2006-06-01

    An integrated optical waveguide variable optical attenuator (VOA) made of organic/inorganic hybrid materials was fabricated. At 1550 nm, the VOA showed a very low activation power of about 13 mW, due to the large thermo-optic coefficients of the hybrid materials. The optical power attenuations achieved were more than 25 dB for both TE and TM polarization. The response time of the device was less than 4.7 ms.

  14. Device applications and structural and optical properties of Indigo - A biodegradable, low-cost organic semiconductor

    NASA Astrophysics Data System (ADS)

    Wang, Zhengjun; Pisane, Kelly L.; Sierros, Konstantinos; Seehra, Mohindar S.; Korakakis, Dimitris

    2015-03-01

    Currently, memory devices based on organic materials are attracting great attention due to their simplicity in device structure, mechanical flexibility, potential for scalability, low-cost potential, low-power operation, and large capacity for data storage. In a recent paper from our group, Indigo-based nonvolatile organic write-once-read-many-times (WORM) memory device, consisting of a 100nm layer of indigo sandwiched between an indium tin oxide (ITO) cathode and an Al anode, has been reported. This device is found to be at its low resistance state (ON state) and can be switched to high resistance state (OFF state) by applying a positive bias with ON/OFF current ratio of the device being up to 1.02 × e6. A summary of these results along with the structural and optical properties of indigo powder will be reported. Analysis of x-ray diffraction shows a monoclinic structure with lattice parameters a(b)[c] = 0.924(0.577)[0.1222]nm and β =117° . Optical absorption shows a band edge at 1.70 eV with peak of absorption occurring at 1.90 eV. These results will be interpreted in terms of the HOMO-LUMO bands of Indigo.

  15. Applying new data-entropy and data-scatter methods for optical digital signal analysis

    NASA Astrophysics Data System (ADS)

    McMillan, N. D.; Egan, J.; Denieffe, D.; Riedel, S.; Tiernan, K.; McGowan, G.; Farrell, G.

    2005-06-01

    This paper introduces for the first time a numerical example of the data-entropy 'quality-budget' method. The paper builds on an earlier theoretical investigation into the application of this information theory approach for opto-electronic system engineering. Currently the most widely used way of analysing such a system is with the power budget. This established method cannot however integrate noise of different generic types. The traditional power budget approach is not capable of allowing analysis of a system with different noise types and specifically providing a measure of signal quality. The data-entropy budget first introduced by McMillan and Reidel on the other hand is able to handle diverse forms of noise. This is achieved by applying the dimensionless 'bit measure' in a quality-budget to integrate the analysis of all types of losses. This new approach therefore facilitates the assessment of both signal quality and power issues in a unified way. The software implementation of data-entropy has been utilised for testing on a fiber optic network. The results of various new quantitative data-entropy measures on the digital system are given and their utility discussed. A new data mining technique known as data-scatter also introduced by McMillan and Reidel provides a useful visualisation of the relationships between data sets and is discussed. The paper ends by giving some perspective on future work in which the data-entropy technique, providing the objective difference measure on the signals, and data-scatter technique, providing qualitative information on the signals, are integrated together for optical communication applications.

  16. Performance evaluation of gratings applied by genetic algorithm for the real-time optical interconnection

    NASA Astrophysics Data System (ADS)

    Yoon, Jin-Seon; Kim, Nam; Suh, HoHyung; Jeon, Seok Hee

    2000-03-01

    In this paper, gratings to apply for the optical interconnection are designed using a genetic algorithm (GA) for a robust and efficient schema. The real-time optical interconnection system architecture is composed with LC-SLM, CCD array detector, IBM-PC, He-Ne laser, and Fourier transform lens. A pixelated binary phase grating is displayed on LC-SLM and could interconnect incoming beams to desired output spots freely by real-time. So as to adapt a GA for finding near globally-cost solutions, a chromosome is coded as a binary integer of length 32 X 32, the stochastic tournament method for decreasing the stochastic sampling error is performed, and a single-point crossover having 16 X 16 block size is used. The characteristics on the several parameters are analyzed in the desired grating design. Firstly, as the analysis of the effect on the probability of crossover, a designed grating when the probability of crossover is 0.75 has a 74.7[%] high diffraction efficiency and a 1.73 X 10-1 uniformity quantitatively, where the probability of mutation is 0.001 and the population size is 300. Secondly, on the probability of mutation, a designed grating when the probability of mutation is 0.001 has a 74.4[%] high efficiency and a 1.61 X 10-1 uniformity quantitatively, where the probability of crossover is 1.0 and the population size is 300. Thirdly, on the population size, a designed grating when the population size is 300 and the generation is 400 has above 74[%] diffraction efficiency, where the probability of mutation is 0.001 and the probability of crossover is 1.0.

  17. Double-fiber electric current measurements applying thermal-lens-coupled magneto-optical effect in ferrofluid

    NASA Astrophysics Data System (ADS)

    Li, Hongjie; Chen, Xiaowei; Yuan, Suihua

    1998-08-01

    The optical current transformer (OCT) reported in the past decades is mainly based on the traditional principle of Faraday rotation effect. Presented is a new type of OCT based on a new physical effect, the thermal lens coupled magneto-optical effect in ferrofluid. The use of optical array in the measuring system made the instrument complicated and expensive. This paper proposes applying double fibers to detect the current-corresponding variation of light intensity of the diffraction rings to simplify the instrumental structure. The fluctuations of the laser beam were eliminated by differential optical paths. Results obtained showed a DC measurement accuracy of 1 percent with a dynamic range of 0-500 angstrom, extendible to 2000 angstrom. All experiments were computerized. The set-up can also be applied to measure AC currents with similar qualities to the DC case.

  18. Evaluation of topically applied copper(II) oxide nanoparticle cytotoxicity in human skin organ culture.

    PubMed

    Cohen, Dror; Soroka, Yoram; Ma'or, Zeev; Oron, Miriam; Portugal-Cohen, Meital; Brégégère, François Menahem; Berhanu, Deborah; Valsami-Jones, Eugenia; Hai, Noam; Milner, Yoram

    2013-02-01

    The increasing use of nano-sized materials in our environment, and in many consumer products, dictates new safety concerns. In particular, adequate experimental models are needed to evaluate skin toxicity of metal oxide ions, commonly found in cosmetic and dermatologic preparations. We have addressed the biological effects of topically applied copper oxide (CuO) nanoparticles in human skin organ cultures, using light and electron microscopy, and biochemical tests. Nanoparticles were more toxic than micro-sized particles, and their effects were stronger when supplied in growth medium than in topical application. Still topically applied CuO nanoparticles induced inflammatory cytokine secretion and necrosis, especially in epidermis deprived of its protective cornea. Since nanoparticle penetration was not seen, we propose that they may adhere to skin surface, react with the local acidic environment, and generate soluble ions that make their way to inner sites. This work illustrates the abilities of skin organ culture to evaluate the biological effects of topically-applied materials on skin in vitro. PMID:22954531

  19. Intense laser effects on the optical properties of asymmetric GaAs double quantum dots under applied electric field

    NASA Astrophysics Data System (ADS)

    Bejan, Doina; Niculescu, Ecaterina Cornelia

    2016-06-01

    We investigated the combined effects of a non-resonant intense laser field and a static electric field on the electronic structure and the nonlinear optical properties (absorption, optical rectification) of a GaAs asymmetric double quantum dot under a strong probe field excitation. The calculations were performed within the compact density-matrix formalism under steady state conditions using the effective mass approximation. Our results show that: (i) the electronic structure and optical properties are sensitive to the dressed potential; (ii) under applied electric fields, an increase of the laser intensity induces a redshift of the optical absorption and rectification spectra; (iii) the augment of the electric field strength leads to a blueshift of the spectra; (iv) for high electric fields the optical spectra show a shoulder-like feature, related with the occurrence of an anti-crossing between the two first excited levels.

  20. Optical detection of charge carriers in multilayer organic light-emitting diodes: Experiment and theory

    NASA Astrophysics Data System (ADS)

    Book, K.; Nikitenko, V. R.; Bässler, H.; Elschner, A.

    2001-03-01

    We have investigated a multilayer organic light-emitting diode with 1,3,5-tris (N,N-bis-(4-methoxyphenyl)aminophenyl)-benzene acting as the hole transporting layer (HTL) and tris (8-hydroxy-quinolinolato) aluminum (Alq3) as the electron transporting layer. Positive charge carriers in the HTL were detected optically as a function of the applied bias. It was found that a hole injecting layer, consisting of 3,4 polyethylene-dioxy-thiophene doped with polystyrenesulfonate, forms an ohmic contact to the HTL by inducing a thin layer of holes in the interfacial region. An analytical model is developed to describe the observed carrier concentrations as well as the current-brightness-voltage characteristics quantitatively.

  1. Accelerated Optical Projection Tomography Applied to In Vivo Imaging of Zebrafish

    PubMed Central

    Correia, Teresa; Yin, Jun; Ramel, Marie-Christine; Andrews, Natalie; Katan, Matilda; Bugeon, Laurence; Dallman, Margaret J.; McGinty, James; Frankel, Paul; French, Paul M. W.; Arridge, Simon

    2015-01-01

    Optical projection tomography (OPT) provides a non-invasive 3-D imaging modality that can be applied to longitudinal studies of live disease models, including in zebrafish. Current limitations include the requirement of a minimum number of angular projections for reconstruction of reasonable OPT images using filtered back projection (FBP), which is typically several hundred, leading to acquisition times of several minutes. It is highly desirable to decrease the number of required angular projections to decrease both the total acquisition time and the light dose to the sample. This is particularly important to enable longitudinal studies, which involve measurements of the same fish at different time points. In this work, we demonstrate that the use of an iterative algorithm to reconstruct sparsely sampled OPT data sets can provide useful 3-D images with 50 or fewer projections, thereby significantly decreasing the minimum acquisition time and light dose while maintaining image quality. A transgenic zebrafish embryo with fluorescent labelling of the vasculature was imaged to acquire densely sampled (800 projections) and under-sampled data sets of transmitted and fluorescence projection images. The under-sampled OPT data sets were reconstructed using an iterative total variation-based image reconstruction algorithm and compared against FBP reconstructions of the densely sampled data sets. To illustrate the potential for quantitative analysis following rapid OPT data acquisition, a Hessian-based method was applied to automatically segment the reconstructed images to select the vasculature network. Results showed that 3-D images of the zebrafish embryo and its vasculature of sufficient visual quality for quantitative analysis can be reconstructed using the iterative algorithm from only 32 projections—achieving up to 28 times improvement in imaging speed and leading to total acquisition times of a few seconds. PMID:26308086

  2. Accelerated Optical Projection Tomography Applied to In Vivo Imaging of Zebrafish.

    PubMed

    Correia, Teresa; Lockwood, Nicola; Kumar, Sunil; Yin, Jun; Ramel, Marie-Christine; Andrews, Natalie; Katan, Matilda; Bugeon, Laurence; Dallman, Margaret J; McGinty, James; Frankel, Paul; French, Paul M W; Arridge, Simon

    2015-01-01

    Optical projection tomography (OPT) provides a non-invasive 3-D imaging modality that can be applied to longitudinal studies of live disease models, including in zebrafish. Current limitations include the requirement of a minimum number of angular projections for reconstruction of reasonable OPT images using filtered back projection (FBP), which is typically several hundred, leading to acquisition times of several minutes. It is highly desirable to decrease the number of required angular projections to decrease both the total acquisition time and the light dose to the sample. This is particularly important to enable longitudinal studies, which involve measurements of the same fish at different time points. In this work, we demonstrate that the use of an iterative algorithm to reconstruct sparsely sampled OPT data sets can provide useful 3-D images with 50 or fewer projections, thereby significantly decreasing the minimum acquisition time and light dose while maintaining image quality. A transgenic zebrafish embryo with fluorescent labelling of the vasculature was imaged to acquire densely sampled (800 projections) and under-sampled data sets of transmitted and fluorescence projection images. The under-sampled OPT data sets were reconstructed using an iterative total variation-based image reconstruction algorithm and compared against FBP reconstructions of the densely sampled data sets. To illustrate the potential for quantitative analysis following rapid OPT data acquisition, a Hessian-based method was applied to automatically segment the reconstructed images to select the vasculature network. Results showed that 3-D images of the zebrafish embryo and its vasculature of sufficient visual quality for quantitative analysis can be reconstructed using the iterative algorithm from only 32 projections-achieving up to 28 times improvement in imaging speed and leading to total acquisition times of a few seconds. PMID:26308086

  3. Biosafety assessment protocols for new organisms in New Zealand: Can they apply internationally to emerging technologies?

    SciTech Connect

    Barratt, B.I.P. . E-mail: barbara.barratt@agresearch.co.nz; Moeed, A.; Malone, L.A.

    2006-05-15

    An analysis of established biosafety protocols for release into the environment of exotic plants and biological control agents for weeds and arthropod pests has been carried out to determine whether such protocols can be applied to relatively new and emerging technologies intended for the primary production industries, such as transgenic plants. Example case studies are described to indicate the scope of issues considered by regulators who make decisions on new organism releases. No transgenic plants have been released to date in New Zealand, but two field test approvals are described as examples. An analysis of the biosafety protocols has shown that, while many of the risk criteria considered for decision-making by regulators are similar for all new organisms, a case-by-case examination of risks and potential impacts is required in order to fully assess risk. The value of post-release monitoring and validation of decisions made by regulators is emphasised.

  4. Pu-239 organ specific dosimetric model applied to non-human biota

    NASA Astrophysics Data System (ADS)

    Kaspar, Matthew Jason

    There are few locations throughout the world, like the Maralinga nuclear test site located in south western Australia, where sufficient plutonium contaminate concentration levels exist that they can be utilized for studies of the long-term radionuclide accumulation in non-human biota. The information obtained will be useful for the potential human users of the site while also keeping with international efforts to better understand doses to non-human biota. In particular, this study focuses primarily on a rabbit sample set collected from the population located within the site. Our approach is intended to employ the same dose and dose rate methods selected by the International Commission on Radiological Protection and adapted by the scientific community for similar research questions. These models rely on a series of simplifying assumptions on biota and their geometry; in particular; organisms are treated as spherical and ellipsoidal representations displaying the animal mass and volume. These simplifications assume homogeneity of all animal tissues. In collaborative efforts between Colorado State University and the Australian Nuclear Science and Technology Organisation (ANSTO), we are expanding current knowledge on radionuclide accumulation in specific organs causing organ-specific dose rates, such as Pu-239 accumulating in bone, liver, and lungs. Organ-specific dose models have been developed for humans; however, little has been developed for the dose assessment to biota, in particular rabbits. This study will determine if it is scientifically valid to use standard software, in particular ERICA Tool, as a means to determine organ-specific dosimetry due to Pu-239 accumulation in organs. ERICA Tool is normally applied to whole organisms as a means to determine radiological risk to whole ecosystems. We will focus on the aquatic model within ERICA Tool, as animal organs, like aquatic organisms, can be assumed to lie within an infinite uniform medium. This model would

  5. Optical properties of organic films, multilayers and plasmonic metal-organic waveguides fabricated by organic molecular beam deposition

    NASA Astrophysics Data System (ADS)

    Wickremasinghe, Niranjala D.

    In this thesis, the optical properties of tris (8-hydroxyquinoline) aluminum (Alq3) and 3,5,9,10-perylentetracarboxylic dianhydride (PTCDA) organic films, PTCDA/ Alq3 multilayers and plasmonic Alq3 -metal waveguides are investigated. The organic films and heterostructures used for this work were fabricated by organic molecular beam deposition (OMBD). We investigated the quenching of the light emission in Alq3 films grown on a Si substrate as a function of cw laser excitation intensity at varying temperatures from 15 to 300 K. The saturation of the singlet-singlet annihilation coefficient was measured with spectrally-integrated (SI) photoluminescence (PL) using a photodiode. The bimolecular quenching coefficient was further studied with time-resolved (TR) PL as a function of 100 fs pulse fluences. The PL quenching is attributed to the annihilation of trapped excitons at Alq3 nanocrystal grain boundaries. The saturation is explained by the limited density of available trapping states at the grain boundaries. Our interpretation is supported by structural investigations of ultrathin Alq3 films with atomic force microscopy (AFM), scanning electron microscopy (SEM) and by comparing the experimental data with calculations using a coupled rate equation model. The wavelength dispersion of the refractive indices of PTCDA and Alq 3 layers and of PTCDA/Alq3 multilayer waveguides grown on Pyrex substrates was investigated. The m-line technique, an evanescent prism coupling technique, was used to determine the layers' thickness and the in-plane (TE modes) and normal (TM modes) refractive indices. The potential for controlling the refractive index dispersion and anisotropy by tailored organic multilayer waveguides is discussed.

  6. Statistical Track-Before-Detect Methods Applied to Faint Optical Observations of Resident Space Objects

    NASA Astrophysics Data System (ADS)

    Fujimoto, K.; Yanagisawa, T.; Uetsuhara, M.

    Automated detection and tracking of faint objects in optical, or bearing-only, sensor imagery is a topic of immense interest in space surveillance. Robust methods in this realm will lead to better space situational awareness (SSA) while reducing the cost of sensors and optics. They are especially relevant in the search for high area-to-mass ratio (HAMR) objects, as their apparent brightness can change significantly over time. A track-before-detect (TBD) approach has been shown to be suitable for faint, low signal-to-noise ratio (SNR) images of resident space objects (RSOs). TBD does not rely upon the extraction of feature points within the image based on some thresholding criteria, but rather directly takes as input the intensity information from the image file. Not only is all of the available information from the image used, TBD avoids the computational intractability of the conventional feature-based line detection (i.e., "string of pearls") approach to track detection for low SNR data. Implementation of TBD rooted in finite set statistics (FISST) theory has been proposed recently by Vo, et al. Compared to other TBD methods applied so far to SSA, such as the stacking method or multi-pass multi-period denoising, the FISST approach is statistically rigorous and has been shown to be more computationally efficient, thus paving the path toward on-line processing. In this paper, we intend to apply a multi-Bernoulli filter to actual CCD imagery of RSOs. The multi-Bernoulli filter can explicitly account for the birth and death of multiple targets in a measurement arc. TBD is achieved via a sequential Monte Carlo implementation. Preliminary results with simulated single-target data indicate that a Bernoulli filter can successfully track and detect objects with measurement SNR as low as 2.4. Although the advent of fast-cadence scientific CMOS sensors have made the automation of faint object detection a realistic goal, it is nonetheless a difficult goal, as measurements

  7. Self-aligned optical couplings by self-organized waveguides toward luminescent targets in organic/inorganic hybrid materials.

    PubMed

    Yoshimura, Tetsuzo; Iida, Makoto; Nawata, Hideyuki

    2014-06-15

    Self-organization of optical waveguides is observed between two opposed optical fibers placed in a photosensitive organic/inorganic hybrid material, Sunconnect. A luminescent target containing coumarin 481 was deposited onto the edge of one of the two fibers at the core. When a 448-nm write beam was introduced from the other fiber, the write beam and the luminescence from the photoexcited target increased the refractive index of Sunconnect to induce self-focusing. Traces of waveguides were seen to grow from the cores of both fibers and merged into a single self-aligned optical coupling between the fibers. This optical solder functionality enabled increases in both coupling efficiency and tolerance to lateral misalignment of the fibers. PMID:24978520

  8. The Electric and Optical Properties of Doped Small Molecular Organic Light-Emitting Devices

    SciTech Connect

    Kwang-Ohk Cheon

    2003-08-05

    Organic light-emitting devices (OLEDs) constitute a new and exciting emissive display technology. In general, the basic OLED structure consists of a stack of fluorescent organic layers sandwiched between a transparent conducting-anode and metallic cathode. When an appropriate bias is applied to the device, holes are injected from the anode and electrons from the cathode; some of the recombination events between the holes and electrons result in electroluminescence (EL). Until now, most of the efforts in developing OLEDs have focused on display applications, hence on devices within the visible range. However some organic devices have been developed for ultraviolet or infrared emission. Various aspects of the device physics of doped small molecular OLEDs were described and discussed. The doping layer thickness and concentration were varied systematically to study their effects on device performances, energy transfer, and turn-off dynamics. Low-energy-gap DCM2 guest molecules, in either {alpha}-NPD or DPVBi host layers, are optically efficient fluorophores but also generate deep carrier trap-sites. Since their traps reduce the carrier mobility, the current density decreases with increased doping concentration. At the same time, due to efficient energy transfer, the quantum efficiency of the devices is improved by light doping or thin doping thickness, in comparison with the undoped neat devices. However, heavy doping induces concentration quenching effects. Thus, the doping concentration and doping thickness may be optimized for best performance.

  9. Synthesis and evaluation of sensitizer drug photorelease chemistry: Micro-optic method applied to singlet oxygen generation and drug delivery

    NASA Astrophysics Data System (ADS)

    Ghosh, Goutam

    This thesis summarizes a new micro-optic method for singlet oxygen generation and sensitizer drug delivery, which include i) synthesis and evaluation of a first generation device for drug delivery from native and fluorinated silica probe tips, ii) synthesis of PEG conjugated sensitizers to study phototoxicity in ovarian cancer cells, and iii) synthesis and evaluation of tris-PEGylated chlorin conjugated fluorinated silica for its future integration into the device to use as a 2nd generation device. A first generation micro-optic device was developed that works by sparging O2 gas and light generating cytotoxic singlet oxygen that cleaves the covalently attached drug (sensitizer) from the probe tip at the distal end of the fiber. The aim is to develop a 1st and 2nd generation device for site specific delivery of photosensitizer and singlet oxygen to overcome the challenges involved in systemic administration of the sensitizer. Synthesis and evaluation of drug (pheophorbide-a) delivery applying micro-optic method from native and fluorinated silica probe tip was achieved. The amount of sensitizer photocleavage depends on the loading level of sensitizer onto the probe tips. We also found that photorelease efficiency depends on the nature of the solvents where sensitizer is photocleaved. For example, no photorelease was observed in an aqueous solvent where sensitizer remained adsorbed to the native silica probe-tip. But, 90% photocleavage was obtained in octanol. A significant amount of photosensitizer (formate ester of pyropheophorbide- a) diffused into the liposome when photocleavage study was carried out in liposome. Substantial increase of photorelease was observed in organic solvent when pyropheophorbide-a (PPa) sensitizer was attached to the partially fluorinated porous Vycor glass. We also explored sensitizer photorelease from the fluorinated silica surface at various temperatures and we found that autocatalytic photorelease happened at room temperature and above

  10. Growth of bulk single crystals of organic materials for nonlinear optical devices - An overview

    NASA Technical Reports Server (NTRS)

    Penn, Benjamin G.; Cardelino, Beatriz H.; Moore, Craig E.; Shields, Angela W.; Frazier, D. O.

    1991-01-01

    Highly perfect single crystals of nonlinear optical organic materials are required for use in optical devices. An overview of the bulk crystal growth of these materials by melt, vapor, and solution processes is presented. Additionally, methods that may be used to purify starting materials, detect impurities at low levels, screen materials for crystal growth, and process grown crystals are discussed.

  11. Physico-chemical properties of organically modified silicates' sol-gel layers for optical fibre sensors

    NASA Astrophysics Data System (ADS)

    Chodkowska, Eliza; Rayss, Jan

    2006-10-01

    The paper concerns the investigation of modified silica gel materials applied in optical fibre sensors. These materials are products of a sol-gel process in which three kinds of alkoxysilanes undergo hydrolysis and condensation and may play a role of the matrices containing transducer's molecules in the active layer of the sensor. In the experiment presented below three different compositions comprising tetraethoxysilane (TEOS), methyltriethoxysilane (MTES) and phenyltriethoxysilane (PhTES) were used. The alkoxysilanes underwent hydrolysis and condensation and the obtained gels were investigated in order to determine their texture, strucuture, composition and chemical properties as far as the dependence of those characteristics on the hydrolysis time and the molar ratio of the ingredients in the initial sols. The methods employed in the experiment were: Atomic Force Microscopy (AFM) which delivered vital information about the gels' textures, contact angles' and surface charge's measurements serving to estimate chemical properties of the gels' surfaces, Nuclear Magnetic Resonance (NMR) which helped to evaluate the hydrolysis' rate and porosimetric measurements enabling a determination of BET surface area and average diametres of the pores. The results may occur important for improving the construction of optical fibre sensors in which organically modified silicates (ORMOSILs)-TEOS layes are used.

  12. Electro-Optical Effects in Thin Organic Films

    NASA Technical Reports Server (NTRS)

    Leyderman, Alexander; Penn, Benjamin G.

    1998-01-01

    Meta-nitroaniline (mNA) and 2-cyclo-octylamino-5-nitropyridine (COANP) single crystals were grown between two transparent fused quartz plates on which indium-tin-oxide layers were deposited. Both linear and quadratic electro-optic effects of the crystals were examined by an ac modulation method. The figures of merit for mNA and COANP are estimated to be 3.2(10-12 m/V and 4.2(10-12 m/V, respectively. It was found that the crystals were under good protection of the cells and the figure of merits of the crystals did not decrease with time. It is believed that the method adopted in the paper is applicable to electro-optic cell fabrication with other compounds if those crystals growth from melt is feasible. It is suggested that the electro-optic cells have potential fortune because of their durability and relative easy manipulation processes of crystal growth.

  13. Prediction of nonlinear optical properties of large organic molecules

    NASA Technical Reports Server (NTRS)

    Cardelino, Beatriz H.

    1992-01-01

    The preparation of materials with large nonlinear responses usually requires involved synthetic processes. Thus, it is very advantageous for materials scientists to have a means of predicting nonlinear optical properties. The prediction of nonlinear optical properties has to be addressed first at the molecular level and then as bulk material. For relatively large molecules, two types of calculations may be used, which are the sum-over-states and the finite-field approach. The finite-field method was selected for this research, because this approach is better suited for larger molecules.

  14. Wavelet image processing applied to optical and digital holography: past achievements and future challenges

    NASA Astrophysics Data System (ADS)

    Jones, Katharine J.

    2005-08-01

    The link between wavelets and optics goes back to the work of Dennis Gabor who both invented holography and developed Gabor decompositions. Holography involves 3-D images. Gabor decompositions involves 1-D signals. Gabor decompositions are the predecessors of wavelets. Wavelet image processing of holography, both optical holography and digital holography, will be examined with respect to past achievements and future challenges.

  15. Aberration modeling of thermo-optical effects applied to wavefront fine-tuning and thermal compensation of Sodern UV and LWIR optical systems

    NASA Astrophysics Data System (ADS)

    Battarel, D.; Fuss, P.; Durieux, A.; Martaud, E.

    2015-09-01

    As a manufacturer of optical systems for space applications, Sodern is faced with the necessity to design optical systems which image quality remains stable while the environment temperature changes. Two functions can be implemented: either a wavefront control or the athermalization of the optical system. In both cases, the mechanical deformations and thermal gradients are calculated by finite-element modeling with the IDEAS NX7 software. The data is then used in CODE V models for wavefront and image quality evaluation purposes. Two cases are presented: one is a UV beam expander in which a wavefront control is implemented and the other is an athermalized IR camera. The beam expander has a wavefront-tuning capability by thermal control. In order to perform the thermo-optical analysis in parallel with the opto-mechanical development, the thermo-optical modeling is done step by step in order to start before the mechanical design is completed. Each step then includes a new modeling stage leading to progressive improvements in accuracy. The IR camera athermalization is achieved through interaction between the mechanical CAD software and the optical design software to simulate the axial thermal gradients, radial gradients and all other thermal variations. The purpose of this paper is to present the steps that have led to the final STOP (Structural, Thermal Optical) analysis. Using incremental accuracy in modeling the thermo-optical effects enables to take them into account very early in the development process to devise all adjustment and test procedures to apply when assembling and testing the optical system.

  16. Net transformation of phosphorus forms applied as inorganic and organic amendments to a calcareous soil

    NASA Astrophysics Data System (ADS)

    Audette, Yuki; O'Halloran, Ivan; Voroney, Paul

    2016-04-01

    The forms of phosphorus (P) in animal manure composts are different from that of synthetic P fertilizers, and this could affect how soil P chemistry will be altered when they are used as P amendments. The objective of this study was to analyze the net changes in the nature and dynamics of plant available P forms applied either as inorganic P (KH2PO4) or turkey litter compost (TLC) in calcareous soil with and without plant growth. Forms of TLC-P were characterized by x-ray diffraction and solution 31P NMR spectroscopy techniques. The amounts of various P forms in soils were measured by a sequential fractionation method after 4, 8, 12 and 16 weeks incubation. Brushite (Ca-P) and newberyite (Mg-P) were the major forms of inorganic P, and phosphate monoester was the major form of organic P present in TLC. The addition of inorganic P fertilizer increased the labile/moderately labile P, whereas the compost increased the moderately labile P extractable with weak acid (pH 4.2). Even though the amount of the labile P fraction in the compost-treated soil was smaller than that in the fertilizer-treated soils, ryegrass growth and plant P uptake were greater. The net transformation of the labile/moderately labile P was slower in the compost-treated soil without plant growth, however it was faster with plant growth. This study showed that P applied either as an inorganic or an organic amendment was recovered in different P fractions in a calcareous soil, and therefore it is expected that the P source would affect soil P chemistry. A weak acid extractable inorganic P fraction should be considered as plant available P especially in the compost-treated soil, that is converted into plant available P through direct and/or indirect root-induced acidification in the rhizosphere.

  17. Synthesis and Characterization of Electroresponsive Materials with Applications In: Part I. Second Harmonic Generation. Part II. Organic-Lanthanide Ion Complexes for Electroluminescence and Optical Amplifiers.

    NASA Astrophysics Data System (ADS)

    Claude, Charles

    1995-01-01

    Materials for optical waveguides were developed from two different approaches, inorganic-organic composites and soft gel polymers. Inorganic-organic composites were developed from alkoxysilane and organically modified silanes based on nonlinear optical chromophores. Organically modified silanes based on N-((3^' -trialkoxysilyl)propyl)-4-nitroaniline were synthesized and sol-gelled with trimethoxysilane. After a densification process at 190^circC with a corona discharge, the second harmonic of the film was measured with a Nd:YAG laser with a fundamental wavelength of 1064nm, d_{33} = 13pm/V. The decay of the second harmonic was expressed by a stretched bi-exponential equation. The decay time (tau _2) was equal to 3374 hours, and was comparable to nonlinear optical systems based on epoxy/Disperse Orange 1. The processing temperature of the organically modified silane was limited to 200^circC due to the decomposition of the organic chromophore. Soft gel polymers were synthesized and characterized for the development of optical waveguides with dc-electrical field assisted phase-matching. Polymers based on 4-nitroaniline terminated poly(ethylene oxide-co-propylene oxide) were shown to exhibit second harmonic generation that were optically phase-matched in an electrical field. The optical signals were stable and reproducible. Siloxane polymers modified with 1-mercapto-4-nitrobenzene and 1-mercapto-4-methylsulfonylstilbene nonlinear optical chromophores were synthesized. The physical and the linear and nonlinear optical properties of the polymers were characterized. Waveguides were developed from the polymers which were optically phase -matched and had an efficiency of 8.1%. The siloxane polymers exhibited optical phase-matching in an applied electrical field and can be used with a semiconductor laser. Organic lanthanide ion complexes for electroluminescence and optical amplifiers were synthesized and characterized. The complexes were characterized for their thermal and

  18. Optical properties of thin gold films applied to Schottky barrier solar cells

    NASA Technical Reports Server (NTRS)

    YEH Y. M.

    1974-01-01

    The Schottky barrier solar cell is considered a possible candidate for converting solar to electrical energy both for space and terrestrial applications. Knowledge of the optical constants of the ultrathin metal film used in the cell is essential for analyzing and designing higher efficiency Schottky barrier cells. The optical constants of 7.5 -nm (75-A) gold films on gallium arsenide have been obtained. In addition, the absolute collection efficiency of Schottky barrier solar cells has been determined from measured spectral response and optical constants of the gold film.

  19. Comparing geometrical and wave-optical algorithms of a novel propagation code applied to the VLTI

    NASA Astrophysics Data System (ADS)

    Wilhelm, Rainer

    2001-12-01

    Time-dependent modeling of controlled opto-mechanical systems (e.g. astronomical telescopes) is part of the VLTI system engineering work at ESO. For creation of optical models to be integrated within a dynamic Matlab/ Simulink simulation, a novel optical modeling tool has been developed. It offers a versatile set of geometrical and wave optical propagation algorithms each with its specific strengths. The article describes the algorithms -both from a theoretical and practical point of view. The VLTI as a "real world" application example is presented.

  20. Photographic-Based Optical Evaluation of Tissues and Biomaterials Used for Corneal Surface Repair: A New Easy-Applied Method

    PubMed Central

    Gonzalez-Andrades, Miguel; Cardona, Juan de la Cruz; Ionescu, Ana Maria; Mosse, Charles A.; Brown, Robert A.

    2015-01-01

    Purpose Tissues and biomaterials used for corneal surface repair require fulfilling specific optical standards prior to implantation in the patient. However, there is not a feasible evaluation method to be applied in clinical or Good Manufacturing Practice settings. In this study, we describe and assess an innovative easy-applied photographic-based method (PBM) for measuring functional optical blurring and transparency in corneal surface grafts. Methods Plastic compressed collagen scaffolds (PCCS) and multilayered amniotic membranes (AM) samples were optically and histologically evaluated. Transparency and image blurring measures were obtained by PBM, analyzing photographic images of a standardized band pattern taken through the samples. These measures were compared and correlated to those obtained applying the Inverse Adding-Doubling (IAD) technique, which is the gold standard method. Results All the samples used for optical evaluation by PBM or IAD were histological suitable. PCCS samples presented transmittance values higher than 60%, values that increased with increasing wavelength as determined by IAD. The PBM indicated that PCCS had a transparency ratio (TR) value of 80.3±2.8%, with a blurring index (BI) of 50.6±4.2%. TR and BI obtained from the PBM showed a high correlation (ρ>|0.6|) with the diffuse transmittance and the diffuse reflectance, both determined using the IAD (p<0.005). The AM optical properties showed that there was a largely linear relationship between the blurring and the number of amnion layers, with more layers producing greater blurring. Conclusions This innovative proposed method represents an easy-applied technique for evaluating transparency and blurriness of tissues and biomaterials used for corneal surface repair. PMID:26566050

  1. Image processing techniques applied to the detection of optic disk: a comparison

    NASA Astrophysics Data System (ADS)

    Kumari, Vijaya V.; Narayanan, Suriya N.

    2010-02-01

    In retinal image analysis, the detection of optic disk is of paramount importance. It facilitates the tracking of various anatomical features and also in the extraction of exudates, drusens etc., present in the retina of human eye. The health of retina crumbles with age in some people during the presence of exudates causing Diabetic Retinopathy. The existence of exudates increases the risk for age related macular Degeneration (AMRD) and it is the leading cause for blindness in people above the age of 50.A prompt diagnosis when the disease is at the early stage can help to prevent irreversible damages to the diabetic eye. Screening to detect diabetic retinopathy helps to prevent the visual loss. The optic disk detection is the rudimentary requirement for the screening. In this paper few methods for optic disk detection were compared which uses both the properties of optic disk and model based approaches. They are uniquely used to give accurate results in the retinal images.

  2. Gerchberg-Saxton algorithm applied to a translational-variant optical setup.

    PubMed

    Amézquita-Orozco, Ricardo; Mejía-Barbosa, Yobani

    2013-08-12

    The standard Gerchberg-Saxton (GS) algorithm is normally used to find the phase (measured on two different parallel planes) of a propagating optical field (usually far-field propagation), given that the irradiance information on those planes is known. This is mostly used to calculate the modulation function of a phase mask so that when illuminated by a plane wave, it produces a known far-field irradiance distribution, or the equivalent, to calculate the phase mask to be used in a Fourier optical system so the desired pattern is obtained on the image plane. There are some extensions of the GS algorithm that can be used when the transformations that describe the optical setup are non-unitary, for example the Yang-Gu algorithm, but these are usually demonstrated using nonunitary translational-invariant optical systems. In this work a practical approach to use the GS algorithm is presented, where raytracing together with the Huygens-Fresnel principle are used to obtain the transformations that describe the optical system, so the calculation can be made when the field is propagated through a translational-variant optical system (TVOS) of arbitrary complexity. Some numerical results are shown for a system where a microscope objective composed by 5 lenses is used. PMID:23938827

  3. Influence of dissolved organic materials on turbid water optical properties and remote-sensing reflectance

    NASA Technical Reports Server (NTRS)

    Witte, W. G.; Whitlock, C. H.; Harriss, R. C.; Usry, J. W.; Poole, L. R.; Houghton, W. M.; Morris, W. D.; Gurganus, E. A.

    1982-01-01

    The effects of dissolved organic materials on turbid-water optical properties are assessed, by means of field measurements and laboratory simulations in which upwelled reflectance, attenuation, absorption, and backscatter spectral properties at wavelengths from 450 to 800 nm are examined in relation to water chemistry. The data show that dissolved organic materials decrease upwelled reflectance from turbid waters, and that the decrease in reflectance is a nonlinear function of concentration with the largest gradients at low carbon concentrations, depending on wavelength. Upwelled reflectance is found to be highly correlated with two backscatter-absorption parameters used in some optical models, which are nonlinear with dissolved organic material concentration change.

  4. 25 CFR 900.44 - What minimum general standards apply to all Indian tribe or tribal organization financial...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... or tribal organization financial management systems when carrying out a self-determination contract... Financial Management Systems § 900.44 What minimum general standards apply to all Indian tribe or tribal organization financial management systems when carrying out a self-determination contract? The fiscal...

  5. 25 CFR 900.44 - What minimum general standards apply to all Indian tribe or tribal organization financial...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... or tribal organization financial management systems when carrying out a self-determination contract... Financial Management Systems § 900.44 What minimum general standards apply to all Indian tribe or tribal organization financial management systems when carrying out a self-determination contract? The fiscal...

  6. 25 CFR 900.44 - What minimum general standards apply to all Indian tribe or tribal organization financial...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... or tribal organization financial management systems when carrying out a self-determination contract... Financial Management Systems § 900.44 What minimum general standards apply to all Indian tribe or tribal organization financial management systems when carrying out a self-determination contract? The fiscal...

  7. 25 CFR 900.44 - What minimum general standards apply to all Indian tribe or tribal organization financial...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... or tribal organization financial management systems when carrying out a self-determination contract... Financial Management Systems § 900.44 What minimum general standards apply to all Indian tribe or tribal organization financial management systems when carrying out a self-determination contract? The fiscal...

  8. 25 CFR 900.44 - What minimum general standards apply to all Indian tribe or tribal organization financial...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... or tribal organization financial management systems when carrying out a self-determination contract... Financial Management Systems § 900.44 What minimum general standards apply to all Indian tribe or tribal organization financial management systems when carrying out a self-determination contract? The fiscal...

  9. Integrated optical and electrical modeling of plasmon-enhanced thin film photovoltaics: A case-study on organic devices

    NASA Astrophysics Data System (ADS)

    Rourke, Devin; Ahn, Sungmo; Nardes, Alexandre M.; van de Lagemaat, Jao; Kopidakis, Nikos; Park, Wounjhang

    2014-09-01

    The nanoscale light control for absorption enhancement of organic photovoltaic (OPV) devices inevitably produces strongly non-uniform optical fields. These non-uniformities due to the localized optical modes are a primary route toward absorption enhancement in OPV devices. Therefore, a rigorous modeling tool taking into account the spatial distribution of optical field and carrier generation is necessary. Presented here is a comprehensive numerical model to describe the coupled optical and electrical behavior of plasmon-enhanced polymer:fullerene bulk heterojunction (BHJ) solar cells. In this model, a position-dependent electron-hole pair generation rate that could become highly non-uniform due to photonic nanostructures is directly calculated from the optical simulations. By considering the absorption and plasmonic properties of nanophotonic gratings included in two different popular device architectures, and applying the Poisson, current continuity, and drift/diffusion equations, the model predicts quantum efficiency, short-circuit current density, and desired carrier mobility ratios for bulk heterojunction devices incorporating nanostructures for light management. In particular, the model predicts a significant degradation of device performance when the carrier species with lower mobility are generated far from the collecting electrode. Consequently, an inverted device architecture is preferred for materials with low hole mobility. This is especially true for devices that include plasmonic nanostructures. Additionally, due to the incorporation of a plasmonic nanostructure, we use simulations to theoretically predict absorption band broadening of a BHJ into energies below the band gap, resulting in a 4.8% increase in generated photocurrent.

  10. Doppler optical coherence microscopy and tomography applied to inner ear mechanics

    NASA Astrophysics Data System (ADS)

    Page, Scott; Ghaffari, Roozbeh; Freeman, Dennis M.

    2015-12-01

    While it is clear that cochlear traveling waves underlie the extraordinary sensitivity, frequency selectivity, and dynamic range of mammalian hearing, the underlying micromechanical mechanisms remain unresolved. Recent advances in low coherence measurement techniques show promise over traditional laser Doppler vibrometry and video microscopy, which are limited by low reflectivities of cochlear structures and restricted optical access. Doppler optical coherence tomography (DOCT) and Doppler optical coherence microscopy (DOCM) both utilize a broadband source to limit constructive interference of scattered light to a small axial depth called a coherence gate. The coherence gate can be swept axially to image and measure sub-nanometer motions of cochlear structures throughout the cochlear partition. The coherence gate of DOCT is generally narrower than the confocal gate of the focusing optics, enabling increased axial resolution (typically 15 μm) within optical sections of the cochlear partition. DOCM, frequently implemented in the time domain, centers the coherence gate on the focal plane, achieving enhanced lateral and axial resolution when the confocal gate is narrower than the coherence gate. We compare these two complementary systems and demonstrate their utility in studying cellular and micromechanical mechanisms involved in mammalian hearing.

  11. Doppler optical coherence microscopy and tomography applied to inner ear mechanics

    SciTech Connect

    Page, Scott; Freeman, Dennis M.; Ghaffari, Roozbeh

    2015-12-31

    While it is clear that cochlear traveling waves underlie the extraordinary sensitivity, frequency selectivity, and dynamic range of mammalian hearing, the underlying micromechanical mechanisms remain unresolved. Recent advances in low coherence measurement techniques show promise over traditional laser Doppler vibrometry and video microscopy, which are limited by low reflectivities of cochlear structures and restricted optical access. Doppler optical coherence tomography (DOCT) and Doppler optical coherence microscopy (DOCM) both utilize a broadband source to limit constructive interference of scattered light to a small axial depth called a coherence gate. The coherence gate can be swept axially to image and measure sub-nanometer motions of cochlear structures throughout the cochlear partition. The coherence gate of DOCT is generally narrower than the confocal gate of the focusing optics, enabling increased axial resolution (typically 15 μm) within optical sections of the cochlear partition. DOCM, frequently implemented in the time domain, centers the coherence gate on the focal plane, achieving enhanced lateral and axial resolution when the confocal gate is narrower than the coherence gate. We compare these two complementary systems and demonstrate their utility in studying cellular and micromechanical mechanisms involved in mammalian hearing.

  12. Manipulating Magneto-Optic Properties of a Chiral Polymer by Doping with Stable Organic Biradicals.

    PubMed

    Lim, Chang-Keun; Cho, Min Ju; Singh, Ajay; Li, Qi; Kim, Won Jin; Jee, Hong Sub; Fillman, Kathlyn L; Carpenter, Stephanie H; Neidig, Michael L; Baev, Alexander; Swihart, Mark T; Prasad, Paras N

    2016-09-14

    We report the first example of tuning the large magneto-optic activity of a chiral polymer by addition of stable organic biradicals. The spectral dispersion of Verdet constant, which quantifies magneto-optic response, differs substantially between the base polymer and the nanocomposite. We employed a microscopic model, supported by atomistic calculations, to rationalize the behavior of this nanocomposite system. The suggested mechanism involves magnetic coupling between helical conjugated polymer fibrils, with spatially delocalized helical π-electron density, and the high density of spin states provided by the biradical dopants, which leads to synergistic enhancement of magneto-optic response. Our combined experimental and theoretical studies reveal that the manipulation of magnetic coupling in this new class of magneto-optic materials offers an opportunity to tailor the magnitude, sign, and spectral dispersion of the Verdet constant over a broad range of wavelengths, from the UV to the near-IR. This provides a new strategy for creating conformable materials with extraordinary magneto-optic activity, which can ultimately enable new applications requiring spatially and temporally resolved measurement of extremely weak magnetic fields. In particular, magneto-optic materials, presently employed in technologies like optical isolators and optical circulators, could be used in ultrasensitive optical magnetometers. This, in turn, could open a path toward mapping of brain activity via optical magnetoencephalography. PMID:27518762

  13. Optical Engines, Organic Spintronics & Ice-Cube/Astranomcs Notions

    NASA Astrophysics Data System (ADS)

    Hidajatullah-Maksoed, Fatahillah; Faizal-Imaduddin, Fauzan

    2015-09-01

    Refers to ``Optical engines for light energy detection,'' PhysicsToday,June 2012, h 60 denotes NewPortCorp's OptoFlash is a miniature multichannel spectrometer engine that detects lght energy at multiple wavelengths. According to NewPort, the demultiplexing optical engine is easy to customize. Involves the Computational Fluid Dynamics/ContractForDifferences, there were sought for ``LaserDopplerVelocimetry/LDV, we intended to comprises the lVDT include in Sensor technology as well as to PVDF/polyvynilidine fluoride who comprises giant flexoelectric in alpha-phase-Xiaoning Jiang et al.``Flexoelectric Nanogenerator:Materials, structures & devices,'' 2013 paved with good intentions, the ``jellium model'' [Overhauser, 1963a] maybe can be interrelated to reflex action & primary process used by Id to avoids pain in painstakingly to wieghs spin relaxation & dephasing process that guides ``EQILIBRATION.'' Also offered the spintronics using PID-controller, from Microbisl Cells to ``The Motor Response inPlasma Heating.'' Further, the Aug 1985 FAA Certification for IAI 1125 ASTRA Jet Corp inherently existed between Julian C. Blecker's dissertation to ``realistic mathematics'' from Prof. R.K. Sembiring/MA-ITB. Great acknowledgment devotes to HE. Mr. Drs. P. SWANTORO through the Jakarta-based BCA Bank.

  14. Integrated optical components using hybrid organic-inorganic materials prepared by sol-gel technology

    NASA Astrophysics Data System (ADS)

    Mishechkin, Oleg Viktorovich

    2003-10-01

    A technological platform based on low-temperature hybrid sol-gel method for fabrication of optical waveguides and integrated optical components has been developed. The developed chemistry for doping incorporation in the host network provides a range of refractive indexes (1.444--1.51) critical for device optimization. A passivation method for improving long-term stability of organic-inorganic sol-gel material is reported. The degradation of waveguide loss over time due to moisture adsorption from the atmosphere is drastically suppressed by coating the material with a protective thin SiO2 film. The results indicate a long-term optical loss below 0.3 dB/cm for protected waveguides. The theory of multimode interference couplers employing self-imaging effect is described. A novel approach for design of high-performance MMI devices in low-contrast material is proposed. The design method is based on optimization of refractive index contrast and width of a multimode waveguide (the body of MMI couplers) to achieve a maximum number of constructively interfering modes resulting to the best self-imaging. This optimization is carried out using 3D BPM simulations. This method was applied to design 1 x 4, 1 x 12, and 4 x 4 MMI couplers and led to a superior performance in excess loss, power imbalance in output ports, and polarization sensitivity. Taking advantage of the inherent input-output phase relations in a 4 x 4 MMI coupler, an optical 90° hybrid is realized by incorporation a Y-junction to coherently excite two ports of the coupler. A series of MMI couplers were fabricated and characterized. The experimental results are in good agreement with the design. Measured performance of the sol-gel derived MMI components was compared to analogues fabricated by other technologies. The comparison demonstrates the superior performance of the sol-gel devices. The polarization sensitivity of all fabricated couplers is below 0.05 dB.

  15. MaizeGDB: The Maize Model Organism Database for Basic, Translational, and Applied Research

    PubMed Central

    Lawrence, Carolyn J.; Harper, Lisa C.; Schaeffer, Mary L.; Sen, Taner Z.; Seigfried, Trent E.; Campbell, Darwin A.

    2008-01-01

    In 2001 maize became the number one production crop in the world with the Food and Agriculture Organization of the United Nations reporting over 614 million tonnes produced. Its success is due to the high productivity per acre in tandem with a wide variety of commercial uses. Not only is maize an excellent source of food, feed, and fuel, but also its by-products are used in the production of various commercial products. Maize's unparalleled success in agriculture stems from basic research, the outcomes of which drive breeding and product development. In order for basic, translational, and applied researchers to benefit from others' investigations, newly generated data must be made freely and easily accessible. MaizeGDB is the maize research community's central repository for genetics and genomics information. The overall goals of MaizeGDB are to facilitate access to the outcomes of maize research by integrating new maize data into the database and to support the maize research community by coordinating group activities. PMID:18769488

  16. Quantifying singlet fission in novel organic materials using nonlinear optics

    NASA Astrophysics Data System (ADS)

    Busby, Erik; Xia, Jianlong; Yaffe, Omer; Kumar, Bharat; Berkelbach, Timothy; Wu, Qin; Miller, John; Nuckolls, Colin; Zhu, Xiaoyang; Reichman, David; Campos, Luis; Sfeir, Matthew Y.

    2014-10-01

    Singlet fission is a form of multiple exciton generation in which two triplet excitons are produced from the decay of a photoexcited singlet exciton. In a small number of organic materials, most notably pentacene, this conversion process has been shown to occur with unity quantum yield on sub-ps timescales. However, a poorly understood mechanism for fission along with strict energy and geometry requirements have so far limited the observation of this process to a few classes of organic materials, with only a subset of these (most notably the polyacenes) showing both efficient fission and long-lived triplets. Here, we utilize novel organic materials to investigate how the efficiency of the fission process depends on the coupling and the energetic driving force between chromophores in both intra- and intermolecular singlet fission materials. We demonstrate how the triplet yield can be accurately quantified using a combination of traditional transient spectroscopies and recently developed excited state saturable absorption techniques. These results allow us to gain mechanistic insight into the fission process and suggest general strategies for generating new materials that can undergo efficient fission.

  17. Molecular engineering of nanoscale order in organic electro-optic glasses

    SciTech Connect

    Hammond, Scott R.; Sinness, Jessica; Dubbury, Sara; Firestone, Kimberly A.; Benedict, Jason B.; Wawrzak, Zdzislaw; Clot, Olivier; Reid, Philip J.; Dalton, Larry R.

    2012-06-28

    The rational design of bulk nanoscale order in organic electro-optic materials, where the strong dipole-dipole interactions tend to dominate over the weaker forces exploited for self-assembly processes, remains an attractive yet elusive goal. Towards this end, a series of pseudo-discotic dipolar nonlinear optical chromophores have been synthesized and fully characterized. Theoretical guidance and an iterative molecular design process have succeeded in engineering long-range nanoscale order in organic electro-optic glasses. Small-angle thin-film X-ray diffraction experiments demonstrate a self-assembled lamellar morphology in a majority of these materials. Cryogenic crystallography, using a synchrotron X-ray source, afforded the structure of a representative system. This structure, in concert with thin-film X-ray diffraction, atomic force microscopy, UV-vis-NIR absorption spectroscopy, and refractive index experiments elucidated the nanoscale order in the films. Application of these materials in electro-optics is discussed.

  18. Hybrid Organic-Inorganic Coordination Complexes as Tunable Optical Response Materials.

    PubMed

    Travis, Will; Knapp, Caroline E; Savory, Christopher N; Ganose, Alex M; Kafourou, Panagiota; Song, Xingchi; Sharif, Zainab; Cockcroft, Jeremy K; Scanlon, David O; Bronstein, Hugo; Palgrave, Robert G

    2016-04-01

    Novel lead and bismuth dipyrido complexes have been synthesized and characterized by single-crystal X-ray diffraction, which shows their structures to be directed by highly oriented π-stacking of planar fully conjugated organic ligands. Optical band gaps are influenced by the identity of both the organic and inorganic component. Density functional theory calculations show optical excitation leads to exciton separation between inorganic and organic components. Using UV-vis, photoluminescence, and X-ray photoemission spectroscopies, we have determined the materials' frontier energy levels and show their suitability for photovoltaic device fabrication by use of electron- and hole-transport materials such as TiO2 and spiro-OMeTAD respectively. Such organic/inorganic hybrid materials promise greater electronic tunability than the inflexible methylammonium lead iodide structure through variation of both the metal and organic components. PMID:26974692

  19. Organic crystalline films for optical applications and related methods of fabrication

    NASA Technical Reports Server (NTRS)

    Leyderman, Alexander (Inventor); Cui, Yunlong (Inventor)

    2003-01-01

    The present invention provides organic single crystal films of less than 20 .mu.m, and devices and methods of making such films. The crystal films are useful in electro-optical applications and can be provided as part of an electro-optical device which provides strength, durability, and relative ease of manipulation of the mono-crystalline films during and after crystal growth.

  20. Growth and spectroscopic characterization of a new organic nonlinear optical crystal—8-hydroxyquinoline

    NASA Astrophysics Data System (ADS)

    Krishnakumar, V.; Nagalakshmi, R.; Janaki, P.

    2005-04-01

    A novel organic nonlinear optical crystal 8-hydroxyquinoline having good optical quality has been grown by slow evaporation solution technique using methanol as solvent. The morphology of the grown crystals were identified by X-ray diffraction method. Solubility studies were made under various solvents and solvent mixtures at different temperatures. Functional groups present in the grown material have been identified using FTIR and FT Raman spectra. Transparency was tested using UV-vis spectrophotometer and the second harmonic generation was also verified.

  1. Optical spacing effect in organic photovoltaic cells incorporating a dilute acceptor layer

    SciTech Connect

    Menke, S. Matthew; Lindsay, Christopher D.; Holmes, Russell J.

    2014-06-16

    The addition of spacing layers in organic photovoltaic cells (OPVs) can enhance light absorption by optimizing the spatial distribution of the incident optical field in the multilayer structure. We explore the optical spacing effect in OPVs achieved using a diluted electron acceptor layer of C{sub 60}. While optical spacing is often realized by optimizing buffer layer thickness, we find that optical spacing via dilution leads to cells with similar or enhanced photocurrent. This is observed despite a smaller quantity of absorbing molecules, suggesting a more efficient use of absorbed photons. In fact, dilution is found to concentrate optical absorption near the electron donor-acceptor interface, resulting in a marked increase in the exciton diffusion efficiency. Contrasting the use of changes in thickness to engineer optical absorption, the use of dilution does not significantly alter the overall thickness of the OPV. Optical spacing via dilution is shown to be a viable alternative to more traditional optical spacing techniques and may be especially useful in the continued optimization of next-generation, tandem OPVs where it is important to minimize competition for optical absorption between individual sub-cells.

  2. Optical limiter with an organic solution sandwiched between a polymer slab and a polymer grating

    SciTech Connect

    Chen Ming; Li Chunfei; Zhang Yundong; Xu Mai; Ma Shaojie; Wang Weibiao; Xia Yuxue

    2005-08-10

    An optical limiter was designed and fabricated. The device consists of an organic solution sandwiched between a polymer slab and a transparent relief polymer grating with a triangular groove. At low power the device has a high transmittance because the refractive index of the solution is matched with those of the slab and the grating materials and because the grating does not diffract. However, high power makes the organic solution thermally vaporize and makes the indices of the solution, slab, and grating materials become mismatched, which causes the grating to appear. The incident light is strongly absorbed, scattered, and self-defocused by the organic solution, and the grating suppresses the zero-order diffraction. Thus the transmitted light energy becomes lower than the damage threshold of human eyes or optical sensors. The device is an effective protection for human eyes or optical sensors against broadband pulsed-laser damage.

  3. Direct optical excitation of singlet oxygen in organic solvents

    NASA Astrophysics Data System (ADS)

    Bagrov, I. V.; Kiselev, V. M.; Kislyakov, I. M.; Sosnov, E. N.

    2014-04-01

    Efficient excitation of singlet oxygen is demonstrated for several organic solvents (CS2, CCl4, and C6F14) that are irradiated using LED in the visible spectral range in the absorption bands of the O2-O2 collision complexes at the corresponding cooperative transitions. It is shown that the two-photon interaction of the pumping radiation in the Herzberg I band of molecular oxygen with its excitation to the 3Σ{/u +} state and the subsequent collisional relaxation to the 1Σ g and 1Δ g singlet states contributes to the excitation of singlet oxygen.

  4. Optical tomograph optimized for tumor detection inside highly absorbent organs

    NASA Astrophysics Data System (ADS)

    Boutet, Jérôme; Koenig, Anne; Hervé, Lionel; Berger, Michel; Dinten, Jean-Marc; Josserand, Véronique; Coll, Jean-Luc

    2011-05-01

    This paper presents a tomograph for small animal fluorescence imaging. The compact and cost-effective system described in this article was designed to address the problem of tumor detection inside highly absorbent heterogeneous organs, such as lungs. To validate the tomograph's ability to detect cancerous nodules inside lungs, in vivo tumor growth was studied on seven cancerous mice bearing murine mammary tumors marked with Alexa Fluor 700. They were successively imaged 10, 12, and 14 days after the primary tumor implantation. The fluorescence maps were compared over this time period. As expected, the reconstructed fluorescence increases with the tumor growth stage.

  5. Fiber-optic technologies for advanced thermo-therapy applied ex vivo to liver tumors

    NASA Astrophysics Data System (ADS)

    Tosi, D.; Perrone, G.; Vallan, A.; Braglia, A.; Liu, Y.; Macchi, E. G.; Braschi, G.; Gallati, M.; Cigada, A.; Poeggel, S.; Duraibabu, D. B.; Leen, G.; Lewis, E.

    2015-07-01

    Thermal ablation, using radiofrequency, microwave, and laser sources, is a common treatment for hepatic tumors. Sensors allow monitoring, at the point of treatment, the evolution of thermal ablation procedures. We present optical fiber sensors that allow advanced capabilities for recording the biophysical phenomena occurring in the tissue in real time. Distributed or quasi-distributed thermal sensors allow recording temperature with spatial resolution ranging from 0.1 mm to 5 mm. In addition, a thermally insensitive pressure sensor allows recording pressure rise, supporting advanced treatment of encapsulated tumors. Our investigation is focused on two case studies: (1) radiofrequency ablation of hepatic tissue, performed on a phantom with a stem-shaped applicator; (2) laser ablation of a liver phantom, performed with a fiber laser. The main measurement results are discussed, comparing the technologies used for the investigation, and drawing the potential for using optical fiber sensors for "smart"-ablation.

  6. Proven high-reliability assembly methods applied to avionics fiber-optics high-speed transceivers

    NASA Astrophysics Data System (ADS)

    Lauzon, Jocelyn; Leduc, Lorrain; Bessette, Daniel; Bélanger, Nicolas; Larose, Robert; Dion, Bruno

    2012-06-01

    Harsh environment avionics applications require operating temperature ranges that can extend to, and exceed -50 to 115°C. For obvious maintenance, management and cost arguments, product lifetimes as long as 20 years are also sought. This leads to mandatory long-term hermeticity that cannot be obtained with epoxy or silicone sealing; but only with glass seal or metal solder or brazing. A hermetic design can indirectly result in the required RF shielding of the component. For fiber-optics products, these specifications need to be compatible with the smallest possible size, weight and power consumption. The products also need to offer the best possible high-speed performances added to the known EMI immunity in the transmission lines. Fiber-optics transceivers with data rates per fiber channel up to 10Gbps are now starting to be offered on the market for avionics applications. Some of them are being developed by companies involved in the "normal environment" telecommunications market that are trying to ruggedize their products packaging in order to diversify their customer base. Another approach, for which we will present detailed results, is to go back to the drawing boards and design a new product that is adapted to proven MIL-PRF-38534 high-reliability packaging assembly methods. These methods will lead to the introduction of additional requirements at the components level; such as long-term high-temperature resistance for the fiber-optic cables. We will compare both approaches and demonstrate the latter, associated with the redesign, is the preferable one. The performance of the fiber-optic transceiver we have developed, in terms of qualification tests such as temperature cycling, constant acceleration, hermeticity, residual gaz analysis, operation under random vibration and mechanical shocks and accelerated lifetime tests will be presented. The tests are still under way, but so far, we have observed no performance degradation of such a product after more than

  7. Detection of volatile organic compounds using optical fibre long period grating modified with metal organic framework thin films

    NASA Astrophysics Data System (ADS)

    Hromadka, Jiri; Tokay, Begum; Korposh, Sergiy; James, Stephen; Tatam, Ralph P.

    2015-09-01

    An optical fibre long period grating (LPG) modified with a thin film of ZIF-8, a zeolitic immidazol framework (ZIF) material, a subgroup of the metal organic framework (MOF) family, was employed for the detection of organic vapours. ZIF-8 film was deposited onto the surface of the LPG using an in-situ crystallization technique. The sensing mechanism is based on the measurement of the refractive index (RI) change induced by the penetration of the chemical molecules into the ZIF-8 pores. An LPG modified with 5 growth cycles of ZIF-8 responded to exposure to methanol and ethanol vapours.

  8. Optical polarimetry applied to the development of a noninvasive in-vivo glucose monitor

    NASA Astrophysics Data System (ADS)

    Cameron, Brent D.; Baba, Justin S.; Cote, Gerard L.

    2000-05-01

    The application of optical polarimetry, using the anterior chamber of the eye as the sensing site, is being investigated as a potential method to develop a noninvasive physiological glucose monitor. First, we present results characterizing the optical rotatory dispersion of the main optically active analytes found within the aqueous humor of the eye including, glucose, albumin, and ascorbic acid. This information is used in conjunction with multiple linear regression to demonstrate how multispectral polarimetry can be used to minimize glucose prediction error in samples containing varying physiological concentrations of glucose and albumin. For this multispectral study, a novel dual wavelength (532 nm and 635 nm) polarimeter was designed and constructed. This sensor is novel in that it provides simultaneous measurements using a 532 nm laser in an open- loop configuration and a 635 nm laser in a closed-loop configuration. In addition, we present in vivo results using New Zealand White rabbits that indicate the time delay between blood and aqueous human glucose levels is below ten minutes. Lastly, we provide preliminary in vivo polarimetric results and discuss the main issues currently hindering the measurement of glucose.

  9. Optical absorption in transparent PDMS materials applied for multimode waveguides fabrication

    NASA Astrophysics Data System (ADS)

    Cai, D. K.; Neyer, A.; Kuckuk, R.; Heise, H. M.

    2008-03-01

    The optical properties of transparent PDMS polymer materials, which can be integrated into general printed circuit board (PCB) for data communication, are of great interest due to the substantial market expectations for the near future. For the present paper, it was found that the absorption loss in polydimethylsiloxane (PDMS) is mainly caused by the vibrational overtone and combination bands of the CH 3-groups of the polymer in the spectral datacom region of 600-900 nm. Based on observed positions of fundamental, overtone and combination bands of the methyl-group, as recorded within the mid- and near-infrared spectra, anharmonicity constants and normal vibration frequencies were determined. Thus, an empirical equation for estimating the wavelengths with the most significant intrinsic absorption loss due to the corresponding band positions was formulated, which was found to agree well with the experimental data. In addition, PDMS multimode waveguides were fabricated and the respective optical insertion loss was measured at 850 nm, which is commercially used for optical datacom transmission and finally the thermal stability of PDMS multimode waveguides was verified as well.

  10. Mustiscaling Analysis applied to field Water Content through Distributed Fiber Optic Temperature sensing measurements

    NASA Astrophysics Data System (ADS)

    Benitez Buelga, Javier; Rodriguez-Sinobas, Leonor; Sanchez, Raul; Gil, Maria; Tarquis, Ana M.

    2014-05-01

    signal variation, or to see at which scales signals are most correlated. This can give us an insight into the dominant processes An alternative to both of the above methods has been described recently. Relative entropy and increments in relative entropy has been applied in soil images (Bird et al., 2006) and in soil transect data (Tarquis et al., 2008) to study scale effects localized in scale and provide the information that is complementary to the information about scale dependencies found across a range of scales. We will use them in this work to describe the spatial scaling properties of a set of field water content data measured in an extension of a corn field, in a plot of 500 m2 and an spatial resolution of 25 cm. These measurements are based on an optics cable (BruggSteal) buried on a ziz-zag deployment at 30cm depth. References Bird, N., M.C. Díaz, A. Saa, and A.M. Tarquis. 2006. A review of fractal and multifractal analysis of soil pore-scale images. J. Hydrol. 322:211-219. Kravchenko, A.N., R. Omonode, G.A. Bollero, and D.G. Bullock. 2002. Quantitative mapping of soil drainage classes using topographical data and soil electrical conductivity. Soil Sci. Soc. Am. J. 66:235-243. Lark, R.M., A.E. Milne, T.M. Addiscott, K.W.T. Goulding, C.P. Webster, and S. O'Flaherty. 2004. Scale- and location-dependent correlation of nitrous oxide emissions with soil properties: An analysis using wavelets. Eur. J. Soil Sci. 55:611-627. Lark, R.M., S.R. Kaffka, and D.L. Corwin. 2003. Multiresolution analysis of data on electrical conductivity of soil using wavelets. J. Hydrol. 272:276-290. Lark, R. M. and Webster, R. 1999. Analysis and elucidation of soil variation using wavelets. European J. of Soil Science, 50(2): 185-206. Mandelbrot, B.B. 1982. The fractal geometry of nature. W.H. Freeman, New York. Percival, D.B., and A.T. Walden. 2000. Wavelet methods for time series analysis. Cambridge Univ. Press, Cambridge, UK. Tarquis, A.M., N.R. Bird, A.P. Whitmore, M.C. Cartagena, and

  11. Mustiscaling Analysis applied to field Water Content through Distributed Fiber Optic Temperature sensing measurements

    NASA Astrophysics Data System (ADS)

    Benitez Buelga, Javier; Rodriguez-Sinobas, Leonor; Sanchez, Raul; Gil, Maria; Tarquis, Ana M.

    2014-05-01

    signal variation, or to see at which scales signals are most correlated. This can give us an insight into the dominant processes An alternative to both of the above methods has been described recently. Relative entropy and increments in relative entropy has been applied in soil images (Bird et al., 2006) and in soil transect data (Tarquis et al., 2008) to study scale effects localized in scale and provide the information that is complementary to the information about scale dependencies found across a range of scales. We will use them in this work to describe the spatial scaling properties of a set of field water content data measured in an extension of a corn field, in a plot of 500 m2 and an spatial resolution of 25 cm. These measurements are based on an optics cable (BruggSteal) buried on a ziz-zag deployment at 30cm depth. References Bird, N., M.C. Díaz, A. Saa, and A.M. Tarquis. 2006. A review of fractal and multifractal analysis of soil pore-scale images. J. Hydrol. 322:211-219. Kravchenko, A.N., R. Omonode, G.A. Bollero, and D.G. Bullock. 2002. Quantitative mapping of soil drainage classes using topographical data and soil electrical conductivity. Soil Sci. Soc. Am. J. 66:235-243. Lark, R.M., A.E. Milne, T.M. Addiscott, K.W.T. Goulding, C.P. Webster, and S. O'Flaherty. 2004. Scale- and location-dependent correlation of nitrous oxide emissions with soil properties: An analysis using wavelets. Eur. J. Soil Sci. 55:611-627. Lark, R.M., S.R. Kaffka, and D.L. Corwin. 2003. Multiresolution analysis of data on electrical conductivity of soil using wavelets. J. Hydrol. 272:276-290. Lark, R. M. and Webster, R. 1999. Analysis and elucidation of soil variation using wavelets. European J. of Soil Science, 50(2): 185-206. Mandelbrot, B.B. 1982. The fractal geometry of nature. W.H. Freeman, New York. Percival, D.B., and A.T. Walden. 2000. Wavelet methods for time series analysis. Cambridge Univ. Press, Cambridge, UK. Tarquis, A.M., N.R. Bird, A.P. Whitmore, M.C. Cartagena, and

  12. Computational Study of Linear and Nonlinear Optical Properties of Single Molecules and Clusters of Organic Electro-Optic Chromophores

    NASA Astrophysics Data System (ADS)

    Garrett, Kerry

    Organic electro-optic (OEO) materials integrated into silicon-organic hybrid (SOH) devices afford significant improvements in size, weight, power, and bandwidth (SWAP) performance of integrated electronic/photonic systems critical for current and next generation telecommunication, computer, sensor, transportation, and defense technologies. Improvement in molecular first hyperpolarizability, and in turn electro-optic activity, is crucial to further improvement in the performance of SOH devices. The timely preparation of new chromophores with improved molecular first hyperpolarizability requires theoretical guidance; however, common density functional theory (DFT) methods often perform poorly for optical properties in systems with substantial intramolecular charge transfer character. The first part of this dissertation describes the careful evaluation of popular long-range correction (LC) and range-separated hybrid (RSH) density functional theory (DFT) for definition of structure/function relationships crucial for the optimization of molecular first hyperpolarizability, beta. In particular, a benchmark set of well-characterized OEO chromophores is used to compare calculated results with the corresponding experimentally measured linear and nonlinear optical properties; respectively, the wavelength of the peak one-photon absorption energy, lambdamax, and beta. A goal of this work is to systematically determine the amount of exact exchange in LC/RSH-DFT methods required for accurately computing these properties for a variety OEO chromophores. High-level electron correlation (post-Hartree-Fock) methods are also investigated and compared with DFT. Included are results for the computation of beta using second-order Moller-Plesset perturbation theory (MP2) and the double-hybrid method, B2PLYP. The second part of this work transitions from single-molecule studies to computing bulk electronic and nonlinear optical properties of molecular crystals and isotropic ensembles of a

  13. Measuring the effects of topically applied skin optical clearing agents and modeling the effects and consequences for laser therapies

    NASA Astrophysics Data System (ADS)

    Verkruysse, Wim; Khan, Misbah; Choi, Bernard; Svaasand, Lars O.; Nelson, J. Stuart

    2005-04-01

    Human skin prepared with an optical clearing agent manifests reduced scattering as a result of de-hydration and refractive index matching. This has potentially large effects for laser therapies of several skin lesions such as port wine stain, hair removal and tattoo removal. With most topically applied clearing agents the clearing effect is limited because they penetrate poorly through the intact superficial skin layer (stratum corneum). Agent application modi other than topical are impractical and have limited the success of optical clearing in laser dermatology. In recent reports, however, a mixture of lipofylic and hydrofylic agents was shown to successfully penetrate through the intact stratum corneum layer which has raised new interest in this field. Immediately after application, the optical clearing effect is superficial and, as the agent diffuses through the skin, reduced scattering is manifested in deeper skin layers. For practical purposes as well as to maximize therapeutic success, it is important to quantify the reduced scattering as well as the trans-cutaneous transport dynamics of the agent. We determined the time and tissue depth resolved effects of optically cleared skin by inserting a microscopic reflector array in the skin. Depth dependent light intensity was measured by quantifying the signal of the reflector array with optical coherence tomography. A 1-dimensional mass diffusion model was used to estimate a trans-cutaneous transport diffusion constant for the clearing agent mixture. The results are used in Monte Carlo modeling to determine the optimal time of laser treatment after topical application of the optical clearing agent.

  14. Optical and electrical properties of bi-layers organic devices

    NASA Astrophysics Data System (ADS)

    Trad, Hager; Rouis, Ahlem; Davenas, Jöel; Majdoub, Mustapha

    2014-10-01

    The influence of interfacial charges on the device characteristics of bi-layers structure LEDs with poly[5-methoxy-2-octyloxy-1,4-phenylenevinylene] (MO-PPV) as active polymer layer is investigated. The concept to improve device performance is presented using: a diacetate cellulose (DAC) and a new synthetized 5-{2-(2-chloroethoxy)ethoxy}-2-{(E)-(2-pyridyl)azo}phenol (PDEG) components. The DAC and mixed (DAC+PDEG) layers were inserted between indium tin oxide (ITO) and MO-PPV polymer. The optical properties (UV-Vis) of MO-PPV, PDEG and mixed (DAC+PDEG) in solutions were studied and compared to those on thin films. Detailed current-voltage measurements of the bi-layers devices showed improvements of the threshold voltage (Vth) of the ITO/(DAC+PDEG)/MO-PPV/Al device attributed to the enhancement of carriers injection and transport resulted from the modified electrode structures. Conduction mechanisms of structure LEDs were matched with space-charge-limited current (SCLC) one. The impedance spectra for all devices can be discussed in terms of an equivalent circuit model designed as a parallel resistor Rp and capacitor Cp network in series with resistor Rs. The ITO/(DAC+PDEG)/MO-PPV/Al device showed the lowest impedance attributed to the removal of contaminants and to changes in the work function of ITO. The frequency-dependent electrical properties of the ITO/(DAC+PDEG)/MO-PPV/Al structure is analyzed by impedance spectroscopy as function of bias. We have extracted numerical values of the equivalent circuit model parameters by fitting experimental data. Their evolution with bias voltages has shown that the SCLC mechanism is characterized by an exponential trap distribution.

  15. Applying hafnia mixtures to enhance the laser-induced damage threshold of coatings for third-harmonic generation optics

    NASA Astrophysics Data System (ADS)

    Mende, Mathias; Jensen, Lars O.; Ehlers, Henrik; Bruns, Stefan; Vergöhl, Michael; Burdack, Peer; Ristau, Detlev

    2012-11-01

    The generation of third harmonic radiation (THG) is required for many pulsed solid-state laser applications in industry and science. In this contribution, the coatings for two necessary optical components, dichroic mirrors and nonlinear optical (NLO) crystals are in the focus of investigation. Because of the high bulk damage threshold lithium triborate (LBO) crystals are applied for this study. HfO2/SiO2 mixtures are employed as high refractive index material to improve the power handling capability of the multilayers. All coatings are produced by ion beam sputtering (IBS) using a zone target assembly for the deposition of material mixtures. The atomic composition and the oxidation ratio of different HfO2/SiO2 mixtures are analyzed by X-ray photoelectron spectroscopy (XPS). The influence of different deposition temperatures and post annealing on the optical properties and the amorphous micro structure of the films is investigated by UV/Vis/NIR spectroscopy and X-ray diffraction (XRD). The laser induced damage thresholds at 355 nm wavelength for nanosecond pulse durations are measured in a 10,000on1 experiment according with the standard ISO21254. Furthermore, the optical components are tested under real application conditions.

  16. Optical macro-tweezers: trapping of highly motile micro-organisms

    NASA Astrophysics Data System (ADS)

    Thalhammer, G.; Steiger, R.; Bernet, S.; Ritsch-Marte, M.

    2011-04-01

    Optical micromanipulation stands for contact-free handling of microscopic particles by light. Optical forces can manipulate non-absorbing objects in a large range of sizes, e.g., from biological cells down to cold atoms. Recently much progress has been made going from the micro- down to the nanoscale. Less attention has been paid to going the other way, trapping increasingly large particles. Optical tweezers typically employ a single laser beam tightly focused by a microscope objective of high numerical aperture to stably trap a particle in three dimensions (3D). As the particle size increases, stable 3D trapping in a single-beam trap requires scaling up the optical power, which eventually induces adverse biological effects. Moreover, the restricted field of view of standard optical tweezers, dictated by the use of high NA objectives, is particularly unfavorable for catching actively moving specimens. Both problems can be overcome by traps with counter-propagating beams. Our 'macro-tweezers' are especially designed to trap highly motile organisms, as they enable three-dimensional all-optical trapping and guiding in a volume of 2 × 1 × 2 mm3. Here we report for the first time the optical trapping of large actively swimming organisms, such as for instance Euglena protists and dinoflagellates of up to 70 µm length. Adverse bio-effects are kept low since trapping occurs outside high intensity regions, e.g., focal spots. We expect our approach to open various possibilities in the contact-free handling of 50-100 µm sized objects that could hitherto not be envisaged, for instance all-optical holding of individual micro-organisms for taxonomic identification, selective collecting or tagging.

  17. The removal kinetics of dissolved organic matter and the optical clarity of groundwater

    NASA Astrophysics Data System (ADS)

    Chapelle, Francis H.; Shen, Yuan; Strom, Eric W.; Benner, Ronald

    2016-04-01

    Concentrations of dissolved organic matter (DOM) and ultraviolet/visible light absorbance decrease systematically as groundwater moves through the unsaturated zones overlying aquifers and along flowpaths within aquifers. These changes occur over distances of tens of meters (m) implying rapid removal kinetics of the chromophoric DOM that imparts color to groundwater. A one-compartment input-output model was used to derive a differential equation describing the removal of DOM from the dissolved phase due to the combined effects of biodegradation and sorption. The general solution to the equation was parameterized using a 2-year record of dissolved organic carbon (DOC) concentration changes in groundwater at a long-term observation well. Estimated rates of DOC loss were rapid and ranged from 0.093 to 0.21 micromoles per liter per day (μM d-1), and rate constants for DOC removal ranged from 0.0021 to 0.011 per day (d-1). Applying these removal rate constants to an advective-dispersion model illustrates substantial depletion of DOC over flow-path distances of 200 m or less and in timeframes of 2 years or less. These results explain the low to moderate DOC concentrations (20-75 μM; 0.26-1 mg L-1) and ultraviolet absorption coefficient values (a 254 < 5 m-1) observed in groundwater produced from 59 wells tapping eight different aquifer systems of the United States. The nearly uniform optical clarity of groundwater, therefore, results from similarly rapid DOM-removal kinetics exhibited by geologically and hydrologically dissimilar aquifers.

  18. Quantum ground state of self-organized atomic crystals in optical resonators

    SciTech Connect

    Fernandez-Vidal, Sonia; De Chiara, Gabriele; Larson, Jonas; Morigi, Giovanna

    2010-04-15

    Cold atoms, driven by a laser and simultaneously coupled to the quantum field of an optical resonator, may self-organize in periodic structures. These structures are supported by the optical lattice, which emerges from the laser light they scatter into the cavity mode and form when the laser intensity exceeds a threshold value. We study theoretically the quantum ground state of these structures above the pump threshold of self-organization by mapping the atomic dynamics of the self-organized crystal to a Bose-Hubbard model. We find that the quantum ground state of the self-organized structure can be the one of a Mott insulator, depending on the pump strength of the driving laser. For very large pump strengths, where the intracavity-field intensity is maximum and one would expect a Mott-insulator state, we find intervals of parameters where the phase is compressible. These states could be realized in existing experimental setups.

  19. Anisotropic optical distribution of powder phosphor materials applied in medical imaging instrumentation

    NASA Astrophysics Data System (ADS)

    Liaparinos, P. F.

    2016-02-01

    Image quality for medical purposes is related to the useful diagnostic information that can be extracted from an image. The performance of indirect X-ray detectors, which in turn affects the quality of the medical image, can be significantly influenced by the characteristics of the phosphor, employed to convert incident radiation into emitted light. Given the technological and medical importance of phosphor materials, understanding the fundamental effects of optical anisotropy is crucial. The purpose of the present paper was to examine the influence of optical anisotropy in optical diffusion within the powder phosphor-based X-ray detectors. The present investigation was based on Mie scattering theory and Monte Carlo simulation techniques. The variation of the anisotropy factor was examined for: (1) light wavelengths in the range 400-700 nm, (2) particle refractive index between 1.5 and 2 and (3) three regions of particle sizes: nanoscale (from 10 up to 100 nm), submicron scale (from 100 nm up to 1 μm), and microscale (from 1 up to 10 μm). In addition, optical diffusion performance was carried out considering: (a) anisotropy factor values 0.2, 0.5, 0.8 which represent different aspects of light propagation after scattering and (b) phosphors of different layer thickness, 100 (thin layer) and 300 μm (thick layer), respectively. Results showed that the highest variation on the anisotropy factor was observed in the submicron scale, and, in particular, for grain diameters between 100 and 600 nm (increase from 0.1 up to 0.8). In addition, Monte Carlo simulations showed that the spread of light photons decreases (i.e., high spatial resolution) with the decrease in the anisotropy factor. In particular, the FWHM was found to decrease with the anisotropy factor: (1) 11.4 % at 100 μm and 4.2 %, at 300 μm layer thickness, for light extinction coefficient 0.217 μm-1 and (2) 1.9 % at 100 μm and 2.0 %, at 300 μm layer thickness, for light extinction coefficient 3 μm-1

  20. Optical fiber imaging for high speed plasma motion diagnostics: applied to low voltage circuit breakers.

    PubMed

    McBride, J W; Balestrero, A; Ghezzi, L; Tribulato, G; Cross, K J

    2010-05-01

    An integrated portable measurement system is described for the study of high speed and high temperature unsteady plasma flows such as those found in the vicinity of high current switching arcs. An array of optical fibers allows the formation of low spatial resolution images, with a maximum capture rate of 1 x 10(6) images per second (1 MHz), with 8 bit intensity resolution. Novel software techniques are reported to allow imaging of the arc; and to measure arc trajectories. Results are presented on high current (2 kA) discharge events in a model test fixture and on the application to a commercial low voltage circuit breaker. PMID:20515174

  1. A statistical model for road surface friction forecasting applying optical road weather measurements

    NASA Astrophysics Data System (ADS)

    Hippi, M.; Juga, I.; Nurmi, P.

    2009-09-01

    Road surface friction is defined as the grip between car tyre and underlying surface. Poor friction often plays a crucial role in wintertime car accidents. Friction can decrease dramatically during snowfall or when wet road surface temperature falls below zero. Even a thin layer of ice or snow can decrease friction substantially increasing the risk of accidents. Many studies have shown that road surface temperature, road conditions and friction can fluctuate dramatically within short distances under specific weather situations. Friction or grip can be improved with road maintenance activities like salting and gritting. Salting will melt the ice or snow layer, whereas gritting will improve the grip. Salting is effective only above -5C temperatures. Light snowfall together with low temperatures can result in very slippery driving conditions. Finnish Road Administration's observing network covers c. 500 road weather stations in Finland. Almost 100 of them are equipped with optical sensors (in winter 2008-2009). The number of optical sensors has increased remarkably during past few years. The optical measuring devices are Vaisala DSC111 sensors which measure the depth of water, snow and ice on the road surface and also produce an estimate of the state of road and prevailing friction. Observation data from road weather stations with optical sensors were collected from winter 2007/08, and a couple of representative (from a weather perspective) stations were selected for detailed statistical analysis. The purpose of the study was to find a statistical relationship between the observed values and, especially, the correlation between friction and other road weather parameters. Consequently, a model based on linear regression was developed. With the model friction being the dependent variable, the independent variables having highest correlations were the composite of ice and snow (water content) on the road, and the road surface temperature. In the case of a wet road

  2. Etendue-preserving mixing and projection optics for high-luminance LEDs, applied to automotive headlamps.

    PubMed

    Cvetkovic, Aleksandra; Dross, Oliver; Chaves, Julio; Benitez, Pablo; Miñano, Juan C; Mohedano, Rubén

    2006-12-25

    By having a single optical element combine the light of several high luminance LEDs, a high luminance light source can be formed, with shape and emission characteristics adaptable to nearly all illumination problems. The illuminance distribution of this virtual source facilitates the generation of the desired intensity pattern via its imaging-stye projection into the far field. This projection is achieved by one refractive and one reflective freeform surface, both calculated simultaneously by the 3D SMS method, which is herein demonstrated for an LED automotive headlamp. PMID:19532196

  3. The early-stage diagnosis of albinic embryos by applying optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Yang, Bor-Wen; Wang, Shih-Yuan; Wang, Yu-Yen; Cai, Jyun-Jhang; Chang, Chung-Hao

    2013-09-01

    Albinism is a kind of congenital disease of abnormal metabolism. Poecilia reticulata (guppy fish) is chosen as the model to study the development of albinic embryos as it is albinic, ovoviviparous and with short life period. This study proposed an imaging method for penetrative embryo investigation using optical coherence tomography. By imaging through guppy mother’s reproduction purse, we found the embryo’s eyes were the early-developed albinism features. As human’s ocular albinism typically appear at about four weeks old, it is the time to determine if an embryo will grow into an albino.

  4. From hyperons to applied optics: {open_quotes}Winston Cones{close_quotes} during and after ZGS era

    SciTech Connect

    Swallow, E.C. |

    1994-12-31

    This paper discusses developments in light collection which had their origin in efforts to construct high performance gas Cerenkov detectors for precision studies of hyperon beta decays at the ZGS. The resulting devices, know generally as {open_quotes}compound parabolic concentrators,{close_quotes} have found applications ranging from nuclear and particle physics experiments to solar energy concentration, instrument illumination, and understanding the optics of visual receptors. Interest in these devices and the ideas underlying them stimulated the development of a substantial new subfield of physics: nonimaging optics. This progression provides an excellent example of some ways in which unanticipated - and often unanticipatable - applied science and {open_quotes}practical{close_quotes} devices naturally emerge from first-rate basic science. The characteristics of this process suggest that the term {open_quotes}spinoff{close_quotes} commonly used to denote it is misleading and in need of replacement.

  5. Crystal structure, growth and nonlinear optical studies of isonicotinamide p-nitrophenol: A new organic crystal for optical limiting applications

    NASA Astrophysics Data System (ADS)

    Vijayalakshmi, A.; Vidyavathy, B.; Vinitha, G.

    2016-08-01

    Isonicotinamide p-nitrophenol (ICPNP), a new organic material, was synthesized using methanol solvent. Single crystals of ICPNP were grown using a slow evaporation solution growth technique. Crystal structure of ICPNP is elucidated by single crystal X-ray diffraction analysis. It belongs to monoclinic crystal system with space group of P21/c. It forms two dimensional networks by O-H…O, N-H…O and C-H…O hydrogen bonds. The molecular structure of ICPNP was further confirmed by Fourier transform infrared (FTIR) spectral analysis. The optical transmittance range and the lower cut-off wavelength (421 nm) with the optical band gap (2.90 eV) of the ICPNP crystal were determined by UV-vis-NIR spectral study. Thermal behavior of ICPNP was studied by thermo gravimetric and differential thermal analyses (TG/DTA). The relative dielectric permittivity was calculated for various temperature ranges. Laser damage threshold of ICPNP crystal was found to be 1.9 GW/cm2 using an Nd:YAG laser. A Z-scan technique was employed to measure the nonlinear absorption coefficient, nonlinear refractive index and nonlinear optical susceptibility. Optical limiting behavior of ICPNP was observed at 35 mW input power.

  6. Calibration of laser tomography as a new optical diagnostic tool applied to dosimetric polymer gels

    NASA Astrophysics Data System (ADS)

    Alwan, R.; Guermeur, F.; Bailly, Y.; Simonin, L.; Svoboda, J.; Makovicka, L.; Martin, E.

    2008-03-01

    Numerous medical applications, as radiotherapy for example, require accurate and reproducible three-dimensional dose measurements with high spatial resolution. A solution of great interest and which has been exploited for many years is the use of dosimetric gels based on different physico-chemical principles, as Fricke's gels or polymer gels. Fricke's gels take advantage of the oxidation of ferrous ions in ferric while polymer gels are the result of the synthesis of polyacrylamide hydrogel from monomer and cross-linking agent. Fricke's gels have particular limitations not encountered with polymer gel dosimeters: the time delay between irradiation and measurement must be reduced in order to limit the diffusion of ferric ions which may remove the spatial dose information. That's why, during the past decade, many compositions of polymer gels have been studied (PAG, MAGIC, …), elaborated and even commercialized (BANG gels). However the gel composition remains of great interest regarding its physical properties. In this work, the authors propose a new optical diagnostic tool more flexible and less expensive in comparison with existing techniques like magnetic resonance imaging (MRI) and Optical-CT. This technique is based on light scattering behaviour occurring in an irradiated polymer gel (note that light scattering in Fricke's gels is very feeble, the latter being essentially absorbant).

  7. Determination of Hurst exponent by optical signal processing applied on surface roughness measurements

    NASA Astrophysics Data System (ADS)

    Marbán Salgado, José Antonio; Sarmiento Martínez, Oscar; Mayorga Cruz, Darwin; Uruchurtu Chavarín, Jorge

    2009-09-01

    In this work a surface roughness measurement performed by Hurst exponent determination, calculated at the same time from data processing of an optical reflected signal is presented. An industrial plate roller rod covered with a polymeric coating is illuminated using a laser source. A lens is used for casting the scattered light reflected from several sectors of the plate roller, and also to focus it into a power meter connected to a computer where corresponding data series are stored. Information related to specific points of the considered object is contained into the optical reflected signal and post-processing of related data signal series allows calculation of the Hurst exponent, also known as roughness exponent. A wear analysis on considered surface sectors of the roller is performed and as a result a relation between Hurst exponent and the coating thickness for each surface sector is clearly established. The simplicity of the opto-mechanical setup among other evident advantages may suggest the application of this non-destructive technique on surface metrology.

  8. Control analysis applied to the whole body: control by body organs over plasma concentrations and organ fluxes of substances in the blood.

    PubMed

    Brown, G C

    1994-01-01

    Metabolic control analysis is adapted as a method for describing and analysing the control by organs in the body over the fluxes and concentrations of substances carried in the blood. This physiological control analysis can most usefully be applied to substances with fluxes into and out of organs that are uniquely dependent only on their plasma concentrations. The organ flux of a substance is defined as the steady-state net flux of a substance into a particular organ. The organ flux control coefficients quantify the extent to which a particular organ controls the flux of a substance into the same or another particular organ. Organ concentration control coefficients quantify the extent to which an organ controls the steady-state concentration of a substance in the blood. The control coefficients are additive and obey summation, connectivity and branching theorems. Thus the control coefficients can be determined experimentally by measuring the sensitivities (elasticities) of organ fluxes to the plasma concentration of the substance. As an example of the application of these concepts, the control of ketone-body metabolism in vivo is analysed using data from the literature. PMID:8280089

  9. Organic semiconductor lasers as integrated light sources for optical sensor systems

    NASA Astrophysics Data System (ADS)

    Punke, Martin; Woggon, Thomas; Stroisch, Marc; Ebenhoch, Bernd; Geyer, Ulf; Karnutsch, Christian; Gerken, Martina; Lemmer, Uli; Bruendel, Mathias; Wang, Jing; Weimann, Thomas

    2007-09-01

    We demonstrate the feasibility of organic semiconductor lasers as light sources for lab-on-a-chip systems. These lasers are based on a 1D- or 2D-photonic crystal resonator structure providing optical feedback in the active laser material that is deposited on top, e.g. aluminum tris(8-hydroxyquinoline) (Alq 3) doped with the laser dye 4-dicyanomethylene-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM). We investigated different fabrication methods for the resonator structures, like thermal nanoimprint, UV nanoimprint, and laser interference lithography. Different substrate materials commonly used in lab-on-a-chip systems, e.g. PMMA, Topas, and Ormocer were deployed. By changing the distributed feedback grating periodicity, we demonstrate a tuning range for a single material system of more than 120 nm. The investigated organic semiconductor lasers are optically pumped. External optical pumping provides a feasible way for one-time-use chips. Our recent success of pumping organic lasers with a low-cost laser diode also renders hand-held systems possible. As a further step towards the integration of organic lasers in sensor systems, we demonstrate the coupling of an organic laser into polymeric waveguides which can be combined with microfluidic channels. The integrated organic lasers and the waveguides are both fabricated on the same polished PMMA substrate using thermal nanoimprint lithography and deep-UV modification, respectively. We could demonstrate the guiding of the laser light in single-mode waveguides.

  10. APPLYING OPEN-PATH OPTICAL SPECTROSCOPY TO HEAVY-DUTY DIESEL EMISSIONS

    EPA Science Inventory

    Non-dispersive infrared absorption has been used to measure gaseous emissions for both stationary and mobile sources. Fourier transform infrared spectroscopy has been used for stationary sources as both extractive and open-path methods. We have applied the open-path method for bo...

  11. New light-trapping concept by means of several optical components applied to compact holographic 3D concentration solar module

    NASA Astrophysics Data System (ADS)

    Villamarín Villegas, Ayalid M.; Pérez López, Francisco J.; Calo López, Antonio; Rodríguez San Segundo, Hugo-José

    2014-05-01

    A new light-trapping concept is presented, which joins broad bandwidth volume phase reflection holograms (VPRH) working together with three other optical components: specifically designed three-dimensional (3D) cavities, Total Internal Reflection (TIR) within an optical medium, and specular reflection by means of a highly reflective surface. This concept is applied to the design and development of both low concentration photovoltaic (LCPV) and solar thermal modules reaching a concentration factor of up to 3X. Higher concentrations are feasible for use in concentrated solar power (CSP) devices. The whole system is entirely made of polymeric materials (except for the solar cells or fluid carrying pipes), thus reducing cost by up to 40%. The module concentrates solar light onto solar cells - or fluid carrying pipes - with no need for active tracking of the sun, covering the whole seasonal and daily incident angle spectrum while it also minimizes optical losses. In this work we analyze the first experimentally measured optical characteristics and performance of VPRH in dichromated gelatin film (DCG) in our concept. The VPRH can reach high diffraction efficiencies (˜98%, ignoring Fresnel reflection losses). Thanks to specifically designed raw material, coating and developing process specifications, also very broad selective spectral (higher than 300 nm) and angular bandwidths (˜+20º) per grating are achieved. The VPRH was optimized to use silicon solar cells, but designs for other semiconductor devices or for fluid heating are feasible. The 3D shape, the hologram's and reflective surface's optical quality, the TIR effect and the correct coupling of all the components are key to high performance of the concentration solar module.

  12. Optical devices combining an organic semiconductor crystal with a two-dimensional inorganic diffraction grating

    NASA Astrophysics Data System (ADS)

    Kitazawa, Takenori; Yamao, Takeshi; Hotta, Shu

    2016-02-01

    We have fabricated optical devices using an organic semiconductor crystal as an emission layer in combination with a two-dimensional (2D) inorganic diffraction grating used as an optical cavity. We formed the inorganic diffraction grating by wet etching of aluminum-doped zinc oxide (AZO) under a 2D cyclic olefin copolymer (COC) diffraction grating used as a mask. The COC diffraction grating was fabricated by nanoimprint lithography. The AZO diffraction grating was composed of convex prominences arranged in a triangular lattice. The organic crystal placed on the AZO diffraction grating indicated narrowed peaks in its emission spectrum under ultraviolet light excitation. These are detected parallel to the crystal plane. The peaks were shifted by rotating the optical devices around the normal to the crystal plane, which reflected the rotational symmetries of the triangular lattice through 60°.

  13. Silver nanoparticles grown in organic solvent PGMEA by pulsed laser ablation and their nonlinear optical properties.

    PubMed

    Shi, Hongfei; Wang, Can; Zhou, Yueliang; Jin, Kuijuan; Yang, Guozhen

    2012-10-01

    Well dispersed silver nanoparticles (AgNPs) with narrow size distribution have been grown in organic solvent propylene glycol monomethyl ether acetate (PGMEA) by pulsed laser ablation techniques. The presence of AgNPs in PGMEA solvent gives rise to an enhancement of the absorption and nonlinear optical properties due to the surface plasmon resonance induced by AgNPs. The shape and density of the AgNPs have been estimated by fitting the absorption spectra with a given model, and the results also show that an additional laser irradiation treatment can improve the monodispersity of the AgNPs and their nonlinear optical properties. The synthesis of AgNPs in PGMEA will facilitate adding AgNPs into organic functional materials especially for photoresist to modify their optical properties. PMID:23421153

  14. Optical Properties of Fluorescent Mixtures: Comparing Quantum Dots to Organic Dyes

    ERIC Educational Resources Information Center

    Hutchins, Benjamin M.; Morgan, Thomas T.; Ucak-Astarlioglu, Mine G.; Wlilliams, Mary Elizabeth

    2007-01-01

    The study describes and compares the size-dependent optical properties of organic dyes with those of semiconductor nanocrystals or quantum dots (QDs). The analysis shows that mixtures of QDs contain emission colors that are sum of the individual QD components.

  15. Wigner distribution function applied to twisted Gaussian light propagating in first-order optical systems.

    PubMed

    Bastiaans, M J

    2000-12-01

    A measure for the twist of Gaussian light is expressed in terms of the second-order moments of the Wigner distribution function. The propagation law for these second-order moments between the input plane and the output plane of a first-order optical system is used to express the twist in one plane in terms of moments in the other plane. Although in general the twist in one plane is determined not only by the twist in the other plane but also by other combinations of the moments, several special cases exist for which a direct relationship between the twists can be formulated. Three such cases, for which zero twist is preserved, are considered: (i) propagation between conjugate planes, (ii) adaptation of the signal to the system, and (iii) the case of symplectic Gaussian light. PMID:11140506

  16. CORDIC algorithm based digital detection technique applied in resonator fiber optic gyroscope

    NASA Astrophysics Data System (ADS)

    Yang, Zhihuai; Jin, Xiaojun; Ma, Huilian; Jin, Zhonghe

    2009-06-01

    A digital detection technique based on the coordinate rotation digital computer (CORDIC) algorithm is proposed for a resonator fiber optic gyroscope (R-FOG). It makes the generation of modulation signal, synchronous demodulation and signal processing in R-FOG to be realized in a single field programmable gate array (FPGA). The frequency synthesis and synchronous detection techniques based on the CORDIC algorithm have been analyzed and designed firstly. The experimental results indicate that the precision of the detection circuit satisfies the requirements for the closed-loop feedback in R-FOG system. The frequency of the laser is locked to the resonance frequency of the fiber ring resonator stably and the open-loop gyro output signal is observed successfully. The dynamic range and the bias drift of the R-FOG are ±1.91 rad/s and 0.005 rad/s over 10 s, respectively.

  17. Ultrafast Rotation of Light Fields Applied to Highly Non-Linear Optics

    NASA Astrophysics Data System (ADS)

    Quéré, Fabien

    2014-05-01

    Femtosecond laser beams can exhibit spatio-temporal couplings (STC), i.e. a temporal dependence of their spatial properties, or vice versa. Although these couplings have long been considered as detrimental for high-intensity and ultrafast experiments, moderate and controlled STC provide a powerful means of controlling high-intensity laser-matter interactions. This talk will first explain the basics of a particular STC, where the propagation direction of laser light rotates in time on the femtosecond time scale. Laser pulses with such ultrafast wavefront rotation can be used to generate attosecond pulses of light through non-linear optical processes. We show that these pulses, periodically generated in each laser cycle, can then be emitted in spatially separated beamlets. This effects provides a new type of light sources called attosecond lighthouses, and can be exploited for ultrafast measurements with femtosecond resolution, in a scheme called photonic streaking.

  18. Optical fiber direct-sensing biosensor applied in detecting biolayer thickness of nanometer grade

    NASA Astrophysics Data System (ADS)

    Sun, Yan; Li, Mingming; Zhao, Hong; Yang, Yu Xiao; Zhang, Lu

    2006-02-01

    An optical fiber biosensor is introduced herein, which could directly detect biological interaction such as immunoreactions of antigens and antibodies without destroy the biolayer. The test is based on the theory of multilayer-reflection principle in white-light interferometry. When immunoreactions occur, the reflected spectrum phase shifts. Immunoreactions could be detected by means of reflected spectrum phase shifting, or by biolayer thickness changing. Continuously detecting of thickness changing on a fractional nanometer scale with subsecond repetition times is allowed in this system. The detecting system has high sensitivity, high precision, high speed, cost effective and working on a high reliability. The bioprobe is easy integrated as a BlAcore. The system and the experimental results on the reaction of rabbit-IgG with anti-rabbit-IgG are described in this paper. A sandwich method was adopted in the experiments.

  19. Laser-electron beam interaction applied to optical amplifiers and oscillators

    NASA Technical Reports Server (NTRS)

    Pantell, R. H.; Piestrup, M. A.

    1976-01-01

    Momentum modulation of a relativistic electron beam by a Nd:YAG laser is demonstrated. The electrons, at 100 MeV energy, interact with the laser light in helium gas at standard temperature and pressure. At an angle of 6.55 mrad between the two wavevectors, corresponding to the Cerenkov angle, a given electron remains in a field of constant phase as it passes through the light beam. The experimental arrangement is illustrated showing the trajectories of the electron and light. The particle momentum is measured by a mass spectrometer, and the angle between the wavevectors is controlled by a rotatable mirror. Experimental results indicate that momentum modulation of an electron beam may be used for amplification. A possible configuration for an optical klystron is illustrated.

  20. Monochromatic aberrations in resonant optical elements applied to a focusing multilevel reflectarray.

    PubMed

    Ginn, James; Alda, Javier; Gómez-Pedrero, José Antonio; Boreman, Glenn

    2010-05-24

    The monochromatic aberrations produced by the phase distribution reflected by resonant sub-wavelength metallic structures are studied both analytically and numerically. Even for normal incidence, the angular dependence of the re-radiated wavefront disturbs the overall performance of the reflectarray. This effect is modelled as combination of a linear and a cubic dependence. A complete numerical simulation of a multilevel focusing reflectarray is performed using computational-electromagnetic and physical-optics-propagation methods. A modified Strehl ratio is defined to show the dependence of the focused spot behavior on aperture. The irradiance distribution is dependent on the polarization state. A small-aperture focusing reflectarray has been designed, fabricated, and tested. The irradiance distribution at the focusing plane is compared with the simulated one, showing a good agreement when residual wavefront aberrations are included. PMID:20588948

  1. Stable inverted small molecular organic solar cells using a p-doped optical spacer.

    PubMed

    Lee, Sang-Hoon; Seo, Ji-Won; Lee, Jung-Yong

    2015-01-01

    We report inverted small molecular organic solar cells using a doped window layer as an optical spacer. The optical spacer was used to shift the optical field distribution inside the active layers, generating more charge carriers from sunlight. In this report, N,N,N',N'-tetrakis(4-methoxyphenyl)-benzidine (MeO-TPD) was doped with 2,2-(perfluoronaphthalene-2,6-diylidene)dimalononitrile (F6-TCNNQ), a p-type dopant material. P-doped MeO-TPD was adopted as an optical spacer because it has a large energy band gap, and its conductivity can be increased by several orders of magnitude through a doping process. As a result, a power conversion efficiency of 4.15% was achieved with the doped window layer of optimized thickness. Lastly, we present significantly improved stability of the inverted devices with the MeO-TPD layer. PMID:25407588

  2. Noncrystalline Condensation of Densely Dissolved Optically Nonlinear Organic Compound in Polymer Matrices

    NASA Astrophysics Data System (ADS)

    Hiraga, Takashi; Tanaka, Norio; Hayamizu, Kikuko; Mito, Akihiro; Takarada, Shigeru; Yamasaki, Yuuichi; Nakamura, Michie; Hoshino, Nobuo; Moriya, Tetsuo

    1993-04-01

    Optical properties and condensed states of the densely dissolved optically nonlinear organic compound in polymer matrices were investigated by means of optical measurements, structural analysis and pressure tuning spectroscopy. In the investigation of the absorption peak wavelength, 2-methyl-4-nitroaniline (MNA) in poly(methyl methacrylate) (PMMA) exhibited characteristics intermediate between the crystal and the MNA dissolved in solvents, i.e., noncrystalline condensation. This result was consistent with those of X-ray diffraction analysis, second- and third-harmonics generation, IR absorption and 13C-NMR spectroscopies. It has also been revealed that such a system provides the most suitable measuring method of the third optical nonlinear constant for a variety of compounds.

  3. 7 CFR 322.14 - Documentation; applying for a permit to import a restricted organism.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., subspecies or strain, and author (if known). (5) Type of organism. Select or write “Bees and/or bee germ... host material accompanying the organism (e.g., pollen, honey, wax, nesting material). (13) Source of...) of approval. Is your facility approved for the species of bees or bee germ plasm for which you...

  4. 7 CFR 322.14 - Documentation; applying for a permit to import a restricted organism.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., subspecies or strain, and author (if known). (5) Type of organism. Select or write “Bees and/or bee germ... host material accompanying the organism (e.g., pollen, honey, wax, nesting material). (13) Source of...) of approval. Is your facility approved for the species of bees or bee germ plasm for which you...

  5. 7 CFR 322.14 - Documentation; applying for a permit to import a restricted organism.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., subspecies or strain, and author (if known). (5) Type of organism. Select or write “Bees and/or bee germ... host material accompanying the organism (e.g., pollen, honey, wax, nesting material). (13) Source of...) of approval. Is your facility approved for the species of bees or bee germ plasm for which you...

  6. 7 CFR 322.14 - Documentation; applying for a permit to import a restricted organism.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., subspecies or strain, and author (if known). (5) Type of organism. Select or write “Bees and/or bee germ... host material accompanying the organism (e.g., pollen, honey, wax, nesting material). (13) Source of...) of approval. Is your facility approved for the species of bees or bee germ plasm for which you...

  7. 7 CFR 322.14 - Documentation; applying for a permit to import a restricted organism.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., subspecies or strain, and author (if known). (5) Type of organism. Select or write “Bees and/or bee germ... host material accompanying the organism (e.g., pollen, honey, wax, nesting material). (13) Source of...) of approval. Is your facility approved for the species of bees or bee germ plasm for which you...

  8. Menzerath-Altmann Law: Statistical Mechanical Interpretation as Applied to a Linguistic Organization

    NASA Astrophysics Data System (ADS)

    Eroglu, Sertac

    2014-10-01

    The distribution behavior described by the empirical Menzerath-Altmann law is frequently encountered during the self-organization of linguistic and non-linguistic natural organizations at various structural levels. This study presents a statistical mechanical derivation of the law based on the analogy between the classical particles of a statistical mechanical organization and the distinct words of a textual organization. The derived model, a transformed (generalized) form of the Menzerath-Altmann model, was termed as the statistical mechanical Menzerath-Altmann model. The derived model allows interpreting the model parameters in terms of physical concepts. We also propose that many organizations presenting the Menzerath-Altmann law behavior, whether linguistic or not, can be methodically examined by the transformed distribution model through the properly defined structure-dependent parameter and the energy associated states.

  9. Optical properties of dissolved organic matter (DOM): Effects of biological and photolytic degradation

    USGS Publications Warehouse

    Hansen, Angela; Kraus, Tamara; Pellerin, Brian; Fleck, Jacob; Downing, Bryan D.; Bergamaschi, Brian

    2016-01-01

    Advances in spectroscopic techniques have led to an increase in the use of optical properties (absorbance and fluorescence) to assess dissolved organic matter (DOM) composition and infer sources and processing. However, little information is available to assess the impact of biological and photolytic processing on the optical properties of original DOM source materials. We measured changes in commonly used optical properties and indices in DOM leached from peat soil, plants, and algae following biological and photochemical degradation to determine whether they provide unique signatures that can be linked to original DOM source. Changes in individual optical parameters varied by source material and process, with biodegradation and photodegradation often causing values to shift in opposite directions. Although values for different source materials overlapped at the end of the 111-day lab experiment, multivariate statistical analyses showed that unique optical signatures could be linked to original DOM source material even after degradation, with 17 optical properties determined by discriminant analysis to be significant (p<0.05) in distinguishing between DOM source and environmental processing. These results demonstrate that inferring the source material from optical properties is possible when parameters are evaluated in combination even after extensive biological and photochemical alteration.

  10. 25 CFR 900.43 - What are the general financial management system standards that apply to a tribal organization...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false What are the general financial management system... ASSISTANCE ACT Standards for Tribal or Tribal Organization Management Systems Standards for Financial Management Systems § 900.43 What are the general financial management system standards that apply to a...