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  1. Acknowledgement

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Acknowledgement. Financial support by Department of Atomic Energy, Government of India, under Young Scientist Research Award Scheme. IIT Kanpur Initiation Grant for a Young Faculty. Experimental work was carried out by: Mr. Ranjith Kumar Reddy G.

  2. Acknowledgements

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Acknowledgements. Graduate students-. Promita Ghosh Dastidar, Chandrama Mukherjee and Shubhra Majumder. Funds- Department of Biotechnology, Govt of India and FIRCA, NIH, USA. Kothari Centre for Gastroenterology, Kolkata for axenic cultures of E32 and ...

  3. ACKNOWLEDGEMENTS

    Indian Academy of Sciences (India)

    ACKNOWLEDGEMENTS. Journal of Earth System Science wishes to place on record the valuable assistance received from the ... Ravi Bhushan, Physical Research Laboratory, Ahmedabad. Dan Blumberg, Ben Gurion ... L Kannan, Centre of Advanced Study in Marine Biology, Parangipettai. Halil Karahan, Pamukkale ...

  4. Acknowledgments

    Directory of Open Access Journals (Sweden)

    Caty Ribas Segura

    2007-01-01

    Full Text Available ACKNOWLEDGMENTS FROM THE EDITOR Coolabah 1 is a dream come true. When Dr. Susan Ballyn invited me to be the guest editor of this volume, I accepted without hesitation: I felt honoured and wanted this issue to be special. Susan explained the editing process and we started to work. During the process I had Dr Ballyn’s and Dr. Morera de la Vall´s invaluable guidance and support, which I deeply appreciate: they read, commented and improved the final version of Coolabah 1: This Foreign Country and allowed me the freedom to decide, organise and edit this publication. I would also like to thank Dr. Helen Nickas for her works, which are a constant stimulation for me and have been an inspiration whilst editing this issue. I wish to thank all contributors to Coolabah 1, former exchange students to Australia from the Universitat de Barcelona, for their fabulous pieces of writing, generous time and enthusiasm in participating in this publication. The process of working with each one of you has been a pleasure. On a personal note, I thank my mother, Mª José, my father, Rafael, my sister, Bárbara, and my friends for their constant support and love throughout all the changes in my life: they give me the freedom to be myself and the space to grow. Needless to say, the mistakes in the editing process are my entire responsibility and the copyright of each contribution remains with its author, unless otherwise stated. I hope all the contributors and readers enjoy the final version of Coolabah 1: This Foreign Country and take pleasure in reading the different approaches to this “foreign country”. Thank you.

  5. Proper Acknowledgment?

    Science.gov (United States)

    East, Julianne

    2005-01-01

    The concern in Australian universities about the prevalence of plagiarism has led to the development of policies about academic integrity and in turn focused attention on the need to inform students about how to avoid plagiarism and how to properly acknowledge. Teaching students how to avoid plagiarism can appear to be straightforward if based on…

  6. Acknowledging the back patient

    DEFF Research Database (Denmark)

    Damsgaard, Janne Brammer; Bastrup, Lene; Norlyk, Annelise

    and reluctant to speak out. Therefore, telling about experiences and perceptions is important for back patients in order to feel accepted and acknowledged. The health professionals must incorporate the patients’ narratives as an integral part of the care and treatment. Conclusions: In order to acknowledge...

  7. Acknowledgment - Issue 61

    Directory of Open Access Journals (Sweden)

    Executive Editor

    2016-03-01

    • Regina Celia Baptista Belluzzo (Universidade Estadual Paulista - UNESP, Brasil In the same way our acknowledge to University Library System (University of Pittsburgh - PITTS, USA by constant technical support and advice for our journal.

  8. Acknowledgment - Issue 62

    Directory of Open Access Journals (Sweden)

    Executive Editor

    2016-03-01

    • Zapopan Martín Muela Meza (Universidad Autónoma de Nuevo León - UANL, México In the same way our acknowledge to University Library System (University of Pittsburgh - PITTS, USA by constant technical support and advice for our journal.

  9. Acknowledging the back patient

    DEFF Research Database (Denmark)

    Damsgaard, Janne Brammer; Bastrup Jørgensen, Lene; Norlyk, Annelise

    , Silkeborg Regional Hospital, Regional Hospital Central Jutland, Silkeborg, Denmark 2. Health, Section for Nursing, Aarhus University, Aarhus, Denmark 3. University of Southern Denmark & Vejle Sygehus, Vejle, Denmark keywords:Back Patient, Narrative, Biomedical, Marginalisation, Self-Identity, Ethical......#296 Acknowledging The Back Patient. A Thematic Synthesis Of Qualitative Research. A Systematic Literature Review. Janne Brammer Damsgaard1, Lene Bastrup Jørgensen1, Annelise Norlyk2, Regner Birkelund3 1. Health, Section for Nursing, Aarhus University & Research Unit, Elective Surgery Centre....... Therefore, telling about experiences and perceptions is important for back patients in order to feel accepted and acknowledged. But selfhood cannot be reduced to narrative identity since the identity of the self is only fully revealed the moment we include the ethical dimension including certain norms...

  10. Acknowledgment - Issue 60

    Directory of Open Access Journals (Sweden)

    Executive Editor

    2015-11-01

    Full Text Available Biblios wish to acknowledge the support of the following professionals who participated in the review process of submissions for our issue 60.ReviewersAndré Ancona Lopez (Universidade de Brasília - UnB, BrasilGildenir Carolino Santos (Universidade Estadual de Campinas - UNICAMP, BrasilJacira Gil Bernardes (Universidade Federal do Rio Grande do Sul - UFRGS, BrasilRodrigo Donoso Vegas (Universidad de Chile - UCHILE, ChileSaúl Hiram Souto Fuentes (Universidad de Monterrey - UDEM, MéxicoReviewers invitedAlejandro Uribe Tirado (Universidad de Antioquia - UDEA, ColombiaFernanda Passini Moreno (Universidade de Brasília - UnB, BrasilJosé Bernal Rivas Fernández (Universidad de Costa Rica - UCR, Costa RicaMarta Lígia Pomim Valentim (Universidade Estadual Paulista - UNESP, BrasilOrlando Corzo Cauracurí (Universidad Nacional Mayor de San Marcos - UNMSM, PerúTerezinha Elisabeth da Silva (Universidade Estadual de Londrina - UEL, BrasilZaira Regina Zafalon (Universidade Federal de São Carlos - UFSCAR, BrasilIn the same way our acknowledge to University Library System (University of Pittsburgh - PITTS, USA by constant technical support and advice for our journal.

  11. Acknowledgment - Issue 64

    Directory of Open Access Journals (Sweden)

    Executive Editor

    2016-11-01

    • Saúl Hiram Souto Fuentes (Universidad de Monterrey - UDEM, México Reviewers invited • Deborah Ribeiro Carvalho (Universidade Federal do Paraná - UFPR, Brasil • Fabiano Ferreira de Castro (Universidade Federal de São Carlos - UFSCAR, Brasil • Isa Maria Freire (Universidade Federal de Paraiba - UFPB, Brasil • Luciano Antonio Digiampietri (Universidade de São Paulo - USP, Brasil • Maria Inês Tomaél (Universidade Estadual de Londrina - UEL, Brasil • Murilo Bastos da Cunha (Universidade de Brasília - UnB, Brasil • Orlando Corzo Cauracurí (Universidad Nacional Mayor de San Marcos - UNMSM, Perú • Thais Batista Zaninelli (Universidade Estadual de Londrina - UEL, Brasil In the same way our acknowledge to University Library System (University of Pittsburgh - PITTS, USA by constant technical support and advice for our journal.

  12. Acknowledgment - Issue 65

    Directory of Open Access Journals (Sweden)

    Executive Editor

    2016-12-01

    • Andrés Vuotto (Universidad Nacional de Mar del Plata - MDP, Argentina • Pedro Jorge Dimitri (Instituto Nacional de la Administración Pública, Argentina Reviewers invited • Adilson Luiz Pinto (Universidade Federal de Santa Catarina - UFSC, Brasil • Carlos Francisco Bitencourt Jorge (Universidade Estadual Paulista Júlio de Mesquita Filho - UNESP, Brasil • Jayme Leyro Vilan Filho (Universidade de Brasília - UnB, Brasil • Murilo Bastos da Cunha (Universidade de Brasília - UnB, Brasil • Silvana Vilodre Goellner (Universidade Federal do Rio Grande do Sul - UFRGS, Brasil In the same way our acknowledge to University Library System (University of Pittsburgh - PITTS, USA by constant technical support and advice for our journal.

  13. ACKNOWLEDGEMENTS

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    P K Gupta, Roorkee. Boris Gurevich, Australia. Simon Harley, Edinburgh, Scotland. Anand K Inamdar, California. A Jayaraman, Ahmedabad. K N Khattri, Dehradun. Ralf Kretz, Canada. S Krishnaswami, Ahmedabad. R K Lal, Varanasi. D C Mishra, Hyderabad. Asoke Mookherjee, Kolkata. Dhruba Mukhopadhyay, Kolkata.

  14. ACKNOWLEDGEMENTS

    Indian Academy of Sciences (India)

    Behera Mukunda, Indian Institute of Technology, Kharagpur. Bera M K, Indian Institutes ... Das Subrata, Indian Institute of Tropical Meteorology, Pune. Das Trupti ... Deb Sanjib Kumar, Space Applications Centre, Ahmedabad. Delire Christine ...

  15. Acknowledgements

    OpenAIRE

    2017-01-01

    This book is the product of a seminar series funded by the UK Economic and Social Research Council entitled ‘Security in Scotland, with or without constitutional change’, which ran from 2013–2015 at the University of Edinburgh (grant reference ES/L00139X/1). The Reports from this seminar series can be found on the title page on the Open Book Publishers website, http://www.openbookpublishers.com/product/524#resources The editor and principal investigator Andrew W. Neal would like to thank his ...

  16. ACKNOWLEDGEMENTS

    Indian Academy of Sciences (India)

    ... Raha, Soumen Basak , Amitava Majumder, Mousumi Basu, Smarajit Polley, Raja Bhattacharya, and all other lab members. OUR COLLABORATORS: Prof. S. Roy, Bose Institute, Kolkata. Prof.M.S.Shaila, IISC, Bangalore. GRANTING AGENCIES: Dept. of Science and Technology. All India Council for Technical Education.

  17. ACKNOWLEDGEMENTS

    Indian Academy of Sciences (India)

    Aavudai Anandhi, City University of New York, New York City, United States. Acharyya ... Collins Waylon, National Weather Service, Corpus Christi, United States ..... Smith Anne Mhairi, Agriculture and Agri-Food Canada, Lethdbridge, Canada.

  18. ACKNOWLEDGEMENTS

    Indian Academy of Sciences (India)

    0008471

    Journal of Earth System Science wishes to place on record the valuable assistance received from ... Abhijit Basu, Indiana University, Bloomington, United States .... Manoj Jaiswal, Indian Institute of Science Education and Research, Kolkata.

  19. Acknowledgements

    Science.gov (United States)

    2016-07-01

    The Meeting was sponsored by the Istituto Nazionale di Fisica Nucleare (INFN), the Società Italiana di Fisica (SIF), the European Physics Society (EPS), the University of Pisa and the University of Siena.

  20. ACKNOWLEDGEMENTS

    Indian Academy of Sciences (India)

    Chen Xingyuan Lorraine, University of California, Berkeley, United States ... Das Kaushik, Bengal Engineering and Science University, Kolkata de Boyer ..... Samborska Katarzyna, Institute for Ecology of Industrial Areas, Katowice, Poland.

  1. ACKNOWLEDGEMENTS

    African Journals Online (AJOL)

    fishes whose members appear to fill very similar ecological roles in ... ways and also provided us with a great deal of interesting information. .... lakes. Verh. into Verein. Iheor. angew. Limnol. 17: 303 - 322. FRYER, G. 1972. ... Evolulion 23:.

  2. ACKNOWLEDGEMENTS

    Indian Academy of Sciences (India)

    Khayat Saied. Hsu Shu-Lu. Huang Chenn-Jung. Huang Baoshan. Hussain R. Jahir. Ibrahim A ... Lin Tao. Liu W.K.. Liu Jiming. Liu J. Lohani Bharat. Lucey Anthony. M Venkataramana. Madhu Kumar S D. Madria Sanjay. Mahadevappa Manjunatha.

  3. Acknowledgements

    Indian Academy of Sciences (India)

    Dr. B. Rajakumar, D. Anandaraj, Janardan Kundu, Harish Chakravarty (Ph.D. students). D.S.S. Hembram, Mukesh Agrawal, Vijayanand Chandrasekharan, Naga Boopathy, Sharath (Project Assistants). Dr. Dinesh Bilehal and Dr. Amit Pathak (Postdocs). Knowledge and Wisdom (Yellow is color of wisdom: Google). Profs.

  4. ACKNOWLEDGEMENTS

    Indian Academy of Sciences (India)

    covers1

    . Dipankar Nandi, Bangalore. Vidyanand Nanjundiah, Bangalore. Sankar Narayanan, Hyderabad. Laxmi Charan Padhy, Mumbai. Gopal Pande, Hyderabad. H N Pandey, Nirjuli. Ashwani Pareek, New Delhi. Veena K Parnaik, Hyderabad.

  5. Acknowledgements

    CERN Multimedia

    2004-01-01

    All the team of the Théodora Foundation and the members of its Board warmly thank everyone who contributed to the collection organized after the death of our colleague and friend Hubert Muller Created 11 years ago, the Théodora Foundation's goal was to relieve the suffering of hospitalized children through laughter. Thanks to your gift of 850 CHF, hospitalized children will receive a tender and funny visit from one of the Théodora Foundation's Dream Doctors. The Foundation dedicates to everyone who participated the magic moments of joy and happiness lived by each small patient during one of these visits. We express here our deep gratitude to Hubert's family for this gesture and hope that they find comfort in knowing that Hubert's memory will live through these children, for whom this sum will help to relieve the difficulty of their every day lives. In the name of the Safety Commission

  6. ACKNOWLEDGEMENTS

    Indian Academy of Sciences (India)

    C T Achutankutty, National Institute of Oceanography, Goa. Rajesh Agnihotri, Max Planck Institute For Chemistry, Germany. S Ahmed, National Geophysical Research Institute, Hyderabad. B R Arora, Wadia Institute of Himalayan Geology, Dehradun. K Balakrishna, National Institute of Technology Karnataka, Surathkal.

  7. ACKNOWLEDGEMENTS

    Indian Academy of Sciences (India)

    Parkash B, Indian Institute of Technology, Roorkee. Parthasarathy G, National Geophysical Research Institute, Hyderabad. Parvez Imtiyaz, CSIR Centre for ... Raman Sethu, North Carolina State University, Raleigh, USA. Ramana M V, National Institute of Oceanography, Dona Paula, Goa. Ramana Muvva, Scripps Institution ...

  8. ACKNOWLEDGEMENTS

    Indian Academy of Sciences (India)

    Azamathulla Hazi Mohammad, Universiti Sains Malaysia, Nibong Tebal, Pulau Pinang, ... Bai Chao-Ying, Chang'an University, Chang'an, Xi'an, China ..... Sikdar Pradip, Indian Institute of Social Welfare and Business Management, Kolkata.

  9. ACKNOWLEDGEMENTS

    Indian Academy of Sciences (India)

    R.Narasimhan(krishtel emaging)1461 1996 Oct 15 13:05:22

    J M Bull, Southampton, UK. Chaofang Zhao, China. D Chandrasekharan, Mumbai, India. R Cullers, Kansas, USA. Danling Tang, Japan. A C Das, Ahmedabad, India. S K Dash, Delhi, India. Don Olson, USA, India. Dev Niyogi, Raleigh, NC, USA. Edward Monahan, USA. G Ekstrom, Cambridge, USA. Elgar Desa, Goa, India.

  10. Fiber Optic Bragg Gratings

    National Research Council Canada - National Science Library

    Battiato, James

    1998-01-01

    Coupled mode theory was used to model reflection fiber gratings. The effects of experimental parameters on grating characteristics were modeled for both uniform and non-uniform grating profiles using this approach...

  11. Do Orthopaedic Surgeons Acknowledge Uncertainty?

    Science.gov (United States)

    Teunis, Teun; Janssen, Stein; Guitton, Thierry G; Ring, David; Parisien, Robert

    2016-06-01

    R(2), 0.29). The relatively low levels of uncertainty among orthopaedic surgeons and confidence bias seem inconsistent with the paucity of definitive evidence. If patients want to be informed of the areas of uncertainty and surgeon-to-surgeon variation relevant to their care, it seems possible that a low recognition of uncertainty and surgeon confidence bias might hinder adequately informing patients, informed decisions, and consent. Moreover, limited recognition of uncertainty is associated with modifiable factors such as confidence bias, trust in orthopaedic evidence base, and statistical understanding. Perhaps improved statistical teaching in residency, journal clubs to improve the critique of evidence and awareness of bias, and acknowledgment of knowledge gaps at courses and conferences might create awareness about existing uncertainties. Level 1, prognostic study.

  12. Gravitational Grating

    Science.gov (United States)

    Rahvar, Sohrab

    2018-05-01

    In this work, we study the interaction of the electromagnetic wave (EW) from a distant quasar with the gravitational wave (GW) sourced by the binary stars. While in the regime of geometric optics, the light bending due to this interaction is negligible, we show that the phase shifting on the wavefront of an EW can produce the diffraction pattern on the observer plane. The diffraction of the light (with the wavelength of λe) by the gravitational wave playing the role of gravitational grating (with the wavelength of λg) has the diffraction angle of Δβ ˜ λe/λg. The relative motion of the observer, the source of gravitational wave and the quasar results in a relative motion of the observer through the interference pattern on the observer plane. The consequence of this fringe crossing is the modulation in the light curve of a quasar with the period of few hours in the microwave wavelength. The optical depth for the observation of this phenomenon for a Quasar with the multiple images strongly lensed by a galaxy where the light trajectory of some of the images crosses the lensing galaxy is τ ≃ 0.2. By shifting the time-delay of the light curves of the multiple images in a strong lensed quasar and removing the intrinsic variations of a quasar, our desired signals, as a new method for detection of GWs can be detected.

  13. Acknowledging the dilemmas of intrusive media

    DEFF Research Database (Denmark)

    Mathieu, David; Finger, Juliane; Dias, Patrcia

    2017-01-01

    Part of the stakeholder consultation addressed strategies that media audiences are developing to cope with pressures and intrusions in a changing media environment, characterised by digitalisation and interactive possibilities. We interviewed ten stakeholders representing interests such as content...... production, media literacy, media regulation, and activism. Consulting with these stakeholders left the impression that pressures and intrusions from media lack widespread acknowledgement, and that little is known about audiences’ strategies to cope with media. Even when intrusions are acknowledged, we find...... no consensual motivation, nor any clear avenue for action. Therefore, we have analysed different discursive positions that prevent acknowledging or taking action upon the pressures and intrusions that we presented to these stakeholders. The discursive positions are outlined below....

  14. Acknowledging the patient with back pain

    DEFF Research Database (Denmark)

    Damsgaard, Janne Brammer; Jørgensen, Lene Bastrup; Norlyk, Annelise

    2015-01-01

    Rationale and aims: Research shows that back patients’ illness experiences affect their interaction with the healthcare system. It is important to examine the exact nature of these experiences in order to shed valuable light on how back patients perceive their illness and hospitalisation. The aim...... and translates into a certain way of perceiving and explaining illnesses and symptoms. Results: The thematic analysis shows that it is through experiences and memories that we create our identity and consciousness. Ignoring the illness experiences can therefore be seen as disregarding, the patient as a human...... of the included studies demonstrates the need for healthcare professionals to pay attention to back patients’ narratives in order to acknowledge them as human beings. This acknowledgement involves an ethical dimension and a sense of responsibility, manifested as respectful inclusion of the patient’s experiences...

  15. Acknowledgement of manuscript reviewers, the underappreciated contributors

    Directory of Open Access Journals (Sweden)

    Abel Lucy

    2013-02-01

    Full Text Available Contributing reviewers We and the Editorial Board acknowledge and thank all reviewers for their active participation and contribution during 2012. We greatly appreciate their dedication and behind the scenes contribution. It is largely due to their support and expertise that we have been able to publish high-standard manuscripts. We would also like to thank authors for choosing Nutrition & Metabolism and contributing their cherished work.

  16. An elastomeric grating coupler

    NARCIS (Netherlands)

    Kocabas, A.; Ay, F.; Dana, A.; Aydinli, A.

    We report on a novel nondestructive and reversible method for coupling free space light to planar optical waveguides. In this method, an elastomeric grating is used to produce an effective refractive index modulation on the surface of the optical waveguide. The external elastomeric grating binds to

  17. Bragg gratings in Topas

    DEFF Research Database (Denmark)

    Zhang, C.; Webb, D.J.; Kalli, K.

    We report for the first time fibre Bragg grating inscription in microstructured optical fibre fabricated from Topas® cyclic olefin copolymer. The temperature sensitivity of the grating was studied revealing a positive Bragg wavelength shift of approximately 0.8 nmK-1,the largest sensitivity yet...

  18. Acknowledging the results of blood tests

    DEFF Research Database (Denmark)

    Torkilsheyggi, Arnvør Martinsdottir á; Hertzum, Morten

    At the studied hospital, physicians from the Medical and Surgical Departments work some of their shifts in the Emergency Department (ED). Though icons showing the blood-test process were introduced on electronic whiteboards in the ED, these icons did not lead to increased attention to test acknow...... acknowledgement. Rather, the physicians, trans-ferred work practices from their own departments, which did not have electronic white-boards, to the ED. This finding suggests a challenge to the cross-disciplinary work and norms for how to follow up on blood-test results in the ED....

  19. Defect grating modes as superimposed grating states

    NARCIS (Netherlands)

    van Groesen, Embrecht W.C.; Sopaheluwakan, A.; Andonowati, A.; de Ridder, R.M; de Ridder, R.M.; Altena, G; Altena, G.; Geuzebroek, D.H.; Geuzenboek, D.; Dekker, R.; Dekker, R

    2003-01-01

    For a symmetric grating structure with a defect, we show that a fully transmitted defect mode in the band gap can be obtained as a superposition of two steady states: an amplified and an attenuated defect state. Without scanning the whole band gap by transmission calculations, this simplifies the

  20. 5 CFR 1601.33 - Acknowledgment of risk.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Acknowledgment of risk. 1601.33 Section... TSP FUNDS Contribution Allocations and Interfund Transfer Requests § 1601.33 Acknowledgment of risk... acknowledgment of risk for that fund. If a required acknowledgment of risk has not been executed, no transactions...

  1. Examining the Psychological Effect of Rape Acknowledgment: The Interaction of Acknowledgment Status and Ambivalent Sexism.

    Science.gov (United States)

    Wilson, Laura C; Miller, Katherine E; Leheney, Emma K; Ballman, Alesha D; Scarpa, Angela

    2017-07-01

    Although the majority of rape survivors do not label their experiences as rape (i.e., unacknowledged rape), the literature is mixed in terms of how this affects survivors' psychological functioning. To elucidate the discrepancies, the present study examined the interaction between rape acknowledgement and ambivalent sexism in relation to depression and posttraumatic stress disorder (PTSD) symptoms. The analyzed sample included 128 female rape survivors who were drawn from a larger college sample of 1,595 participants. The participants completed measures of sexual assault experiences, ambivalent sexism, and depression and PTSD symptoms. The results supported a significant interaction between acknowledgement status and benevolent sexism in relation to both depression and PTSD symptoms. Conversely, the present study failed to find support for an interaction between acknowledgment status and hostile sexism. The clinical implications suggest that rather than seeing acknowledging rape as essential to the recovery process, clinicians should assess for and take into account other factors that may contribute to psychological functioning. Additionally, the findings support that more complex models of trauma recovery should be investigated with the goal of working toward a more comprehensive understanding of the longitudinal process of rape acknowledgment. © 2016 Wiley Periodicals, Inc.

  2. Spherical grating spectrometers

    Science.gov (United States)

    O'Donoghue, Darragh; Clemens, J. Christopher

    2014-07-01

    We describe designs for spectrometers employing convex dispersers. The Offner spectrometer was the first such instrument; it has almost exclusively been employed on satellite platforms, and has had little impact on ground-based instruments. We have learned how to fabricate curved Volume Phase Holographic (VPH) gratings and, in contrast to the planar gratings of traditional spectrometers, describe how such devices can be used in optical/infrared spectrometers designed specifically for curved diffraction gratings. Volume Phase Holographic gratings are highly efficient compared to conventional surface relief gratings; they have become the disperser of choice in optical / NIR spectrometers. The advantage of spectrometers with curved VPH dispersers is the very small number of optical elements used (the simplest comprising a grating and a spherical mirror), as well as illumination of mirrors off axis, resulting in greater efficiency and reduction in size. We describe a "Half Offner" spectrometer, an even simpler version of the Offner spectrometer. We present an entirely novel design, the Spherical Transmission Grating Spectrometer (STGS), and discuss exemplary applications, including a design for a double-beam spectrometer without any requirement for a dichroic. This paradigm change in spectrometer design offers an alternative to all-refractive astronomical spectrometer designs, using expensive, fragile lens elements fabricated from CaF2 or even more exotic materials. The unobscured mirror layout avoids a major drawback of the previous generation of catadioptric spectrometer designs. We describe laboratory measurements of the efficiency and image quality of a curved VPH grating in a STGS design, demonstrating, simultaneously, efficiency comparable to planar VPH gratings along with good image quality. The stage is now set for construction of a prototype instrument with impressive performance.

  3. Acknowledging and Accounting for Employee Benefits

    Directory of Open Access Journals (Sweden)

    Florentina MOISESCU

    2009-01-01

    Full Text Available Employee benefits are all forms of counter services granted by anentity in return to services given by the employees. This category includes onlythe benefits covered by the entity, not those from the state or the employee onthe payroll. The employer counting and presenting all the benefits of theemployees, including those provided on the basis of official programs or otherofficial contracts between the entity and the individual employees, groups ofemployees or their representatives, those established on the basis of legalprovisions or by contracts at the level of activity sector, through which theentities are required to contribute to national programs, as well as thoseresulting from unofficial practices give rise to an implicit obligation.Acknowledging and especially assessing these benefits are issues demandingspecial attention.

  4. Switchable Bragg gratings

    DEFF Research Database (Denmark)

    Marckmann, Carl Johan

    2003-01-01

    Research Center (MIC) at the Technical University of Denmark. The Bragg gratings were fabricated at COM using UV irradiation of the planar waveguides using the phase mask method. The induction of a frozen-in DC electric field into the samples was performed by thermal poling of the Bragg gratings...... layers, it becam possible to investigate the symmetry properties of the third-order nonlinearities. Contrary to the expectations for an amorphous material, the measurements indicated an almost polarization independent third-order nonlinearity - the most probable explanation being electrostriction......The subject of this ph.d. thesis was the development of an electrically switchable Bragg grating made in an optical waveguide using thermal poling to be applied within optical telecommunication systems. The planar waveguides used in this thesis were fabricated at the Micro- and Nanotechnology...

  5. Grateful Med: getting started.

    Science.gov (United States)

    Shearer, B; McCann, L; Crump, W J

    1990-01-01

    When a local medical library is not available, it is often necessary for physicians to discover alternate ways to receive medical information. Rural physicians, particularly, can make use of a computer program called Grateful Med that provides access to the same literature available to physicians in large cities. This program permits the user to perform database searches on the National Library of Medicine database (MEDLINE), corresponding to the primary index to medical literature, Index Medicus. In this article, we give the procedure for procuring a National Library of Medicine password and for making efficient use of the Grateful Med program.

  6. Birefringence Bragg Binary (3B) grating, quasi-Bragg grating and immersion gratings

    Science.gov (United States)

    Ebizuka, Noboru; Morita, Shin-ya; Yamagata, Yutaka; Sasaki, Minoru; Bianco, Andorea; Tanabe, Ayano; Hashimoto, Nobuyuki; Hirahara, Yasuhiro; Aoki, Wako

    2014-07-01

    A volume phase holographic (VPH) grating achieves high angular dispersion and very high diffraction efficiency for the first diffraction order and for S or P polarization. However the VPH grating could not achieve high diffraction efficiency for non-polarized light at a large diffraction angle because properties of diffraction efficiencies for S and P polarizations are different. Furthermore diffraction efficiency of the VPH grating extinguishes toward a higher diffraction order. A birefringence binary Bragg (3B) grating is a thick transmission grating with optically anisotropic material such as lithium niobate or liquid crystal. The 3B grating achieves diffraction efficiency up to 100% for non-polarized light by tuning of refractive indices for S and P polarizations, even in higher diffraction orders. We fabricated 3B grating with liquid crystal and evaluated the performance of the liquid crystal grating. A quasi-Bragg (QB) grating, which consists long rectangle mirrors aligned in parallel precisely such as a window shade, also achieves high diffraction efficiency toward higher orders. We fabricated QB grating by laminating of silica glass substrates and glued by pressure fusion of gold films. A quasi-Bragg immersion (QBI) grating has smooth mirror hypotenuse and reflector array inside the hypotenuse, instead of step-like grooves of a conventional immersion grating. An incident beam of the QBI grating reflects obliquely at a reflector, then reflects vertically at the mirror surface and reflects again at the same reflector. We are going to fabricate QBI gratings by laminating of mirror plates as similar to fabrication of the QB grating. We will also fabricate silicon and germanium immersion gratings with conventional step-like grooves by means of the latest diamond machining methods. We introduce characteristics and performance of these gratings.

  7. Electro-optic diffraction grating tuned laser

    International Nuclear Information System (INIS)

    Hughes, R.S.

    1975-01-01

    An electro-optic diffraction grating tuned laser comprising a laser medium, output mirror, retro-reflective grating and an electro-optic diffraction grating beam deflector positioned between the laser medium and the reflective diffraction grating is described. An optional angle multiplier may be used between the electro-optic diffraction grating and the reflective grating. (auth)

  8. Bragg grating rogue wave

    Energy Technology Data Exchange (ETDEWEB)

    Degasperis, Antonio [Dipartimento di Fisica, “Sapienza” Università di Roma, P.le A. Moro 2, 00185 Roma (Italy); Wabnitz, Stefan, E-mail: stefan.wabnitz@unibs.it [Dipartimento di Ingegneria dell' Informazione, Università degli Studi di Brescia and INO-CNR, via Branze 38, 25123 Brescia (Italy); Aceves, Alejandro B. [Southern Methodist University, Dallas (United States)

    2015-06-12

    We derive the rogue wave solution of the classical massive Thirring model, that describes nonlinear optical pulse propagation in Bragg gratings. Combining electromagnetically induced transparency with Bragg scattering four-wave mixing may lead to extreme waves at extremely low powers.

  9. Silicon graphene Bragg gratings.

    Science.gov (United States)

    Capmany, José; Domenech, David; Muñoz, Pascual

    2014-03-10

    We propose the use of interleaved graphene sections on top of a silicon waveguide to implement tunable Bragg gratings. The filter central wavelength and bandwidth can be controlled changing the chemical potential of the graphene sections. Apodization techniques are also presented.

  10. Legal provisions governing the acknowledgment of test results

    International Nuclear Information System (INIS)

    Strecker, A.

    1982-01-01

    The legal provisions governing the acknowledgment of test results are most frequently applied by administrative orders (design and qualification approvals or specimen testing and approval) and are thus claimable and voidable in accordance with general administrative law. The acknowledgment of test certificates requires a legal basis. Test results, however, can be acknowledged also by administrative bodies. Recently, the Federal Government began to delegate more of its legal authority in this field to private institutions, allowing test results to be acknowledged and test certificates to be issued by government controlled private institutions. (orig.) [de

  11. Optical fiber Bragg gratings. Part II. Modeling of finite-length gratings and grating arrays.

    Science.gov (United States)

    Passaro, Vittorio M N; Diana, Roberto; Armenise, Mario N

    2002-09-01

    A model of both uniform finite-length optical fiber Bragg gratings and grating arrays is presented. The model is based on the Floquet-Bloch formalism and allows rigorous investigation of all the physical aspects in either single- or multiple-periodic structures realized on the core of a monomodal fiber. Analytical expressions of reflectivity and transmittivity for both single gratings and grating arrays are derived. The influence of the grating length and the index modulation amplitude on the reflected and transmitted optical power for both sinusoidal and rectangular profiles is evaluated. Good agreement between our method and the well-known coupled-mode theory (CMT) approach has been observed for both single gratings and grating arrays only in the case of weak index perturbation. Significant discrepancies exist there in cases of strong index contrast because of the increasing approximation of the CMT approach. The effects of intragrating phase shift are also shown and discussed.

  12. Grating stimulated echo

    International Nuclear Information System (INIS)

    Dubetsky, B.; Berman, P.R.; Sleator, T.

    1992-01-01

    A theory of a grating simulated echo (GTE) is developed. The GSE involves the sequential excitation of atoms by two counterpropagating traveling waves, a standing wave, and a third traveling wave. It is shown that the echo signal is very sensitive to small changes in atomic velocity, much more sensitive than the normal stimulated echo. Use of the GSE as a collisional probe or accelerometer is discussed

  13. Immersion Gratings for Infrared High-resolution Spectroscopy

    Science.gov (United States)

    Sarugaku, Yuki; Ikeda, Yuji; Kobayashi, Naoto; Kaji, Sayumi; Sukegawa, Takashi; Sugiyama, Shigeru; Nakagawa, Takao; Arasaki, Takayuki; Kondo, Sohei; Nakanishi, Kenshi; Yasui, Chikako; Kawakita, Hideyo

    2016-10-01

    High-resolution spectroscopy in the infrared wavelength range is essential for observations of minor isotopologues, such as HDO for water, and prebiotic organic molecules like hydrocarbons/P-bearing molecules because numerous vibrational molecular bands (including non-polar molecules) are located in this wavelength range. High spectral resolution enables us to detect weak lines without spectral line confusion. This technique has been widely used in planetary sciences, e.g., cometary coma (H2O, CO, and organic molecules), the martian atmosphere (CH4, CO2, H2O and HDO), and the upper atmosphere of gas giants (H3+ and organic molecules such as C2H6). Spectrographs with higher resolution (and higher sensitivity) still have a potential to provide a plenty of findings. However, because the size of spectrographs scales with the spectral resolution, it is difficult to realize it.Immersion grating (IG), which is a diffraction grating wherein the diffraction surface is immersed in a material with a high refractive index (n > 2), provides n times higher spectral resolution compared to a reflective grating of the same size. Because IG reduces the size of spectrograph to 1/n compared to the spectrograph with the same spectral resolution using a conventional reflective grating, it is widely acknowledged as a key optical device to realize compact spectrographs with high spectral resolution.Recently, we succeeded in fabricating a CdZnTe immersion grating with the theoretically predicted diffraction efficiency by machining process using an ultrahigh-precision five-axis processing machine developed by Canon Inc. Using the same technique, we completed a practical germanium (Ge) immersion grating with both a reflection coating on the grating surface and the an AR coating on the entrance surface. It is noteworthy that the wide wavelength range from 2 to 20 um can be covered by the two immersion gratings.In this paper, we present the performances and the applications of the immersion

  14. An Investigation of Generic Structures of Pakistani Doctoral Thesis Acknowledgements

    Science.gov (United States)

    Rofess, Sakander; Mahmood, Muhammad Asim

    2015-01-01

    This paper investigates Pakistani doctoral thesis acknowledgements from genre analysis perspective. A corpus of 235 PhD thesis acknowledgements written in English was taken from Pakistani doctoral theses collected from eight different disciplines. HEC Research Repository of Pakistan was used as a data sources. The theses written by Pakistani…

  15. International Adoption: Issues of Acknowledgement of Adoption and Birth Culture.

    Science.gov (United States)

    Trolley, Barbara C.; And Others

    1995-01-01

    Families who adopt children internationally are faced with not only the acknowledgement of the adoption but also the recognition of the child's birth culture. Thirty-four families were surveyed to assess issues regarding the relevance, frequency, and means of acknowledgement of the adoption and of the birth culture. Findings suggest ways adoption…

  16. Low crosstalk Arrayed Waveguide Grating with Cascaded Waveguide Grating Filter

    International Nuclear Information System (INIS)

    Deng Yang; Liu Yuan; Gao Dingshan

    2011-01-01

    We propose a highly compact and low crosstalk arrayed waveguide grating (AWG) with cascaded waveguide grating (CWGF). The side lobes of the silicon nanowire AWG, which are normally introduced by fabrication errors, can be effectively suppressed by the CWGF. And the crosstalk can be improved about 15dB.

  17. 14 CFR 91.1013 - Operational control briefing and acknowledgment.

    Science.gov (United States)

    2010-01-01

    ... Ownership Operations Operational Control § 91.1013 Operational control briefing and acknowledgment. (a) Upon...) Liability risk in the event of a flight-related occurrence that causes personal injury or property damage...

  18. Optical Fiber Grating based Sensors

    DEFF Research Database (Denmark)

    Michelsen, Susanne

    2003-01-01

    In this thesis differenct optical fiber gratings are used for sensor purposes. If a fiber with a core concentricity error (CCE) is used, a directional dependent bend sensor can be produced. The CCE direction can be determined by means of diffraction. This makes it possible to produce long......-period gratings in a fiber with a CCE direction parallel or perpendicular to the writing direction. The maximal bending sensitivity is independent on the writing direction, but the detailed bending response is different in the two cases. A temperature and strain sensor, based on a long-period grating and two...... sampled gratings, was produced and investigated. It is based on the different temperature and strain response of these gratings. Both a transfer matrix method and an overlap calculation is performed to explain the sensor response. Another type of sensor is based on tuning and modulation of a laser...

  19. Bragg gratings: Optical microchip sensors

    Science.gov (United States)

    Watts, Sam

    2010-07-01

    A direct UV writing technique that can create multiple Bragg gratings and waveguides in a planar silica-on-silicon chip is enabling sensing applications ranging from individual disposable sensors for biotechnology through to multiplexed sensor networks in pharmaceutical manufacturing.

  20. Waveguide silicon nitride grating coupler

    Science.gov (United States)

    Litvik, Jan; Dolnak, Ivan; Dado, Milan

    2016-12-01

    Grating couplers are one of the most used elements for coupling of light between optical fibers and photonic integrated components. Silicon-on-insulator platform provides strong confinement of light and allows high integration. In this work, using simulations we have designed a broadband silicon nitride surface grating coupler. The Fourier-eigenmode expansion and finite difference time domain methods are utilized in design optimization of grating coupler structure. The fully, single etch step grating coupler is based on a standard silicon-on-insulator wafer with 0.55 μm waveguide Si3N4 layer. The optimized structure at 1550 nm wavelength yields a peak coupling efficiency -2.6635 dB (54.16%) with a 1-dB bandwidth up to 80 nm. It is promising way for low-cost fabrication using complementary metal-oxide- semiconductor fabrication process.

  1. Encapsulation process for diffraction gratings.

    Science.gov (United States)

    Ratzsch, Stephan; Kley, Ernst-Bernhard; Tünnermann, Andreas; Szeghalmi, Adriana

    2015-07-13

    Encapsulation of grating structures facilitates an improvement of the optical functionality and/or adds mechanical stability to the fragile structure. Here, we introduce novel encapsulation process of nanoscale patterns based on atomic layer deposition and micro structuring. The overall size of the encapsulated structured surface area is only restricted by the size of the available microstructuring and coating devices; thus, overcoming inherent limitations of existing bonding processes concerning cleanliness, roughness, and curvature of the components. Finally, the process is demonstrated for a transmission grating. The encapsulated grating has 97.5% transmission efficiency in the -1st diffraction order for TM-polarized light, and is being limited by the experimental grating parameters as confirmed by rigorous coupled wave analysis.

  2. MEMS Bragg grating force sensor

    DEFF Research Database (Denmark)

    Reck, Kasper; Thomsen, Erik Vilain; Hansen, Ole

    2011-01-01

    We present modeling, design, fabrication and characterization of a new type of all-optical frequency modulated MEMS force sensor based on a mechanically amplified double clamped waveguide beam structure with integrated Bragg grating. The sensor is ideally suited for force measurements in harsh...... environments and for remote and distributed sensing and has a measured sensitivity of -14 nm/N, which is several times higher than what is obtained in conventional fiber Bragg grating force sensors. © 2011 Optical Society of America....

  3. Capturing Qualitative Data: Northwestern University Special Libraries' Acknowledgments Database

    Science.gov (United States)

    Stigberg, Sara; Guittar, Michelle; Morse, Geoffrey

    2015-01-01

    Assessment and supporting data have become of increasing interest in librarianship. In this paper, we describe the development and implementation of the Northwestern University Library Acknowledgments Database tool, which gathers and documents qualitative data, as well as its component reporting function. This collaborative project and resulting…

  4. Listener Responses According to Stuttering Self-Acknowledgment and Modification

    Science.gov (United States)

    Lee, Kyungjae; Manning, Walter H.

    2010-01-01

    Given the well-documented understanding that stuttering behavior elicits stereotypically negative responses from listeners, two experiments explored the equivocal results of earlier investigations concerning the potential for self-acknowledgment and modification of stuttering to elicit positive responses from naive (unfamiliar with stuttering)…

  5. The praxis of acknowledgement: from bibliometrics to influmetrics

    Directory of Open Access Journals (Sweden)

    Cronin, B.

    1995-06-01

    Full Text Available The practice of acknowledgement in scholarly communication is widespread and growing. Acknowledgements define a variety of cognitive and social relationships between researchers within and across disciplines, and could thus be used to map networks of influence. We explore the relationship between authorship, acknowledgement and citation -the «Reward Triangle»- in the context of the academic audit process. We also consider the case for using acknowledgement data conjointly with established bibliometric indicators, such as citations, in performance assessment.

    El uso del agradecimiento está muy extendido en la comunicación académica y tiende a aumentar. El agradecimiento sirve para definir una serie de relaciones sociales y de conocimiento entre investigadores de una disciplina, así como vinculación con otras áreas del saber y, por eso, puede utilizarse para hacer un diseño de redes de influencia. En este artículo se explora la relación entre autores, agradecimientos y citas -el «triángulo del reconocimiento»- en el contexto de la evaluación académica. Los autores también consideran la posible utilización de datos procedentes del agradecimiento conjuntamente con otros indicadores bibliométricos, tales como las citas, en las evaluaciones.

  6. Reframing Assessment: Reconceptualising Relationships and Acknowledging Emotional Labour

    Science.gov (United States)

    Cooper, Maria

    2017-01-01

    Implementing relationships-based pedagogies in infant and toddler settings might assume that teachers' experiences of emotional labour will be acknowledged. This assumption may be complicated by assessment practices that both rely on and detract from relationship-building opportunities with infants and toddlers. Assessment also relies on…

  7. Acknowledging patient heterogeneity in economic evaluation : a systematic literature review.

    Science.gov (United States)

    Grutters, Janneke P C; Sculpher, Mark; Briggs, Andrew H; Severens, Johan L; Candel, Math J; Stahl, James E; De Ruysscher, Dirk; Boer, Albert; Ramaekers, Bram L T; Joore, Manuela A

    2013-02-01

    Patient heterogeneity is the part of variability that can be explained by certain patient characteristics (e.g. age, disease stage). Population reimbursement decisions that acknowledge patient heterogeneity could potentially save money and increase population health. To date, however, economic evaluations pay only limited attention to patient heterogeneity. The objective of the present paper is to provide a comprehensive overview of the current knowledge regarding patient heterogeneity within economic evaluation of healthcare programmes. A systematic literature review was performed to identify methodological papers on the topic of patient heterogeneity in economic evaluation. Data were obtained using a keyword search of the PubMed database and manual searches. Handbooks were also included. Relevant data were extracted regarding potential sources of patient heterogeneity, in which of the input parameters of an economic evaluation these occur, methods to acknowledge patient heterogeneity and specific concerns associated with this acknowledgement. A total of 20 articles and five handbooks were included. The relevant sources of patient heterogeneity (demographics, preferences and clinical characteristics) and the input parameters where they occurred (baseline risk, treatment effect, health state utility and resource utilization) were combined in a framework. Methods were derived for the design, analysis and presentation phases of an economic evaluation. Concerns related mainly to the danger of false-positive results and equity issues. By systematically reviewing current knowledge regarding patient heterogeneity within economic evaluations of healthcare programmes, we provide guidance for future economic evaluations. Guidance is provided on which sources of patient heterogeneity to consider, how to acknowledge them in economic evaluation and potential concerns. The improved acknowledgement of patient heterogeneity in future economic evaluations may well improve the

  8. Canadian University Acknowledgment of Indigenous Lands, Treaties, and Peoples.

    Science.gov (United States)

    Wilkes, Rima; Duong, Aaron; Kesler, Linc; Ramos, Howard

    2017-02-01

    At many Canadian universities it is now common to publicly acknowledge Indigenous lands, treaties, and peoples. Yet, this practice has yet to be considered as a subject of scholarly inquiry. How does this practice vary and why? In this paper we describe the content and practice of acknowledgment, linking this content to treaty relationships (or lack thereof). We show that acknowledgment tends to be one of five general types: of land and title (British Columbia), of specific treaties and political relationships (Prairies), of multiculturalism and heterogeneity (Ontario), of no practice (most of Quebec), and of people, territory, and openness to doing more (Atlantic). Based on these results, we conclude that the fluidity of acknowledgment as a practice, including changing meanings depending on the positionality of the acknowledger, need to be taken into account. Plusieurs universités Canadien pratique une reconnaissance des territoires, des traités, et des peoples autochtone en publique. Cette pratique, cependant, n'a jamais été considérée comme une enquête savante. Dans ce projet nous regardons comment les reconnaissances varie par institution et pourquoi. Nous trouvons qu'il y a un lien entre le contenu des reconnaissances et les relations traité. On démontre cinq forme des reconnaissances: territoire et titre (Colombie britannique); traité spécifique and les relations politiques (Prairies); multiculturalisme et hétérogénéité (Ontario); l'absence (la majorité du Québec); et des peoples, territoire et volonté a plus faire (Atlantique). Nous concluons que la fluidité de la reconnaissance, comme pratique, est fluide et doit prendre en considération la position de la personne qui le fait. © 2017 Canadian Sociological Association/La Société canadienne de sociologie.

  9. Financialization and financial profit

    Directory of Open Access Journals (Sweden)

    Arturo Guillén

    2014-09-01

    Full Text Available This article starts from the critical review of the concept of financial capital. I consider it is necessary not to confuse this category with of financialization, which has acquired a certificate of naturalization from the rise of neoliberalism. Although financial monopoly-financial capital is the hegemonic segment of the bourgeoisie in the major capitalist countries, their dominance does not imply, a fortiori, financialization of economic activity, since it depends of the conditions of the process reproduction of capital. The emergence of joint stock companies modified the formation of the average rate of profit. The "promoter profit" becomes one of the main forms of income of monopoly-financial capital. It is postulated that financial profit is a kind of "extraordinary surplus-value" which is appropriated by monopoly-financial capital by means of the monopolistic control it exerts on the issue and circulation of fictitious capital.

  10. Thermal and Structural Analysis of FIMS Grating

    Directory of Open Access Journals (Sweden)

    K.-I. Seon

    2001-06-01

    Full Text Available Far ultraviolet IMaging Spectrograph (FIMS should be designed to maintain its structural stability and to minimize optical performance degradation in launch and in operation enviroments. The structural and thermal analyzes of grating and grating mount system, which are directly related to FIMS optical performance, was performed using finite element method. The grating mount was made to keep the grating stress down, while keeping the natural frequency of the grating mount higher than 100 Hz. Transient and static thermal analyzes were also performed and the results shows that the thermal stress on the grating can be attenuated sufficiently The optical performance variation due to temperature variation was within the allowed range.

  11. Improving the satellite communication efficiency of the accumulative acknowledgement strategies

    Science.gov (United States)

    Duarte, Otto Carlos M. B.; de Lima, Heliomar Medeiros

    The performances of two finite buffer error recovery strategies are analyzed. In both strategies the retransmission request decision between selective repeat and continuous retransmission is based on an imminent buffer overflow condition. These are accumulative acknowledgment schemes, but in the second strategy the selective-repeat control frame is uniquely an individual negative acknowledgment. The two strategies take advantage of the availability of a greater buffer capacity, making the most of the selective repeat, postponing the sending of a continuous retransmission request. Numerical results show a better performance very close to the ideal, but it does not integrally conform to the high-level data link control (HDLC) procedures. It is shown that these strategies are well suited for high-speed data transfer in the high-error-rate satellite environment.

  12. Exploiting a Transmission Grating Spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Ronald E. Bell

    2004-12-08

    The availability of compact transmission grating spectrometers now allows an attractive and economical alternative to the more familiar Czerny-Turner configuration for many high-temperature plasma applications. Higher throughput is obtained with short focal length refractive optics and stigmatic imaging. Many more spectra can be obtained with a single spectrometer since smaller, more densely packed optical input fibers can be used. Multiple input slits, along with a bandpass filter, can be used to maximize the number of spectra per detector, providing further economy. Curved slits can correct for the strong image curvature of the short focal length optics. Presented here are the governing grating equations for both standard and high-dispersion transmission gratings, defining dispersion, image curvature, and desired slit curvature, that can be used in the design of improved plasma diagnostics.

  13. Exploiting a Transmission Grating Spectrometer

    International Nuclear Information System (INIS)

    Bell, Ronald E.

    2004-01-01

    The availability of compact transmission grating spectrometers now allows an attractive and economical alternative to the more familiar Czerny-Turner configuration for many high-temperature plasma applications. Higher throughput is obtained with short focal length refractive optics and stigmatic imaging. Many more spectra can be obtained with a single spectrometer since smaller, more densely packed optical input fibers can be used. Multiple input slits, along with a bandpass filter, can be used to maximize the number of spectra per detector, providing further economy. Curved slits can correct for the strong image curvature of the short focal length optics. Presented here are the governing grating equations for both standard and high-dispersion transmission gratings, defining dispersion, image curvature, and desired slit curvature, that can be used in the design of improved plasma diagnostics

  14. Polymer optical fiber bragg grating sensors

    DEFF Research Database (Denmark)

    Stefani, Alessio; Yuan, Scott Wu; Andresen, Søren

    2010-01-01

    Fiber-optical accelerometers based on polymer optical fiber Bragg gratings are reported. We have written fiber Bragg gratings for 1550 nm and 850 nm operations, characterized their temperature and strain response, and tested their performance in a prototype accelerometer....

  15. Enhanced Raman scattering in porous silicon grating.

    Science.gov (United States)

    Wang, Jiajia; Jia, Zhenhong; Lv, Changwu

    2018-03-19

    The enhancement of Raman signal on monocrystalline silicon gratings with varying groove depths and on porous silicon grating were studied for a highly sensitive surface enhanced Raman scattering (SERS) response. In the experiment conducted, porous silicon gratings were fabricated. Silver nanoparticles (Ag NPs) were then deposited on the porous silicon grating to enhance the Raman signal of the detective objects. Results show that the enhancement of Raman signal on silicon grating improved when groove depth increased. The enhanced performance of Raman signal on porous silicon grating was also further improved. The Rhodamine SERS response based on Ag NPs/ porous silicon grating substrates was enhanced relative to the SERS response on Ag NPs/ porous silicon substrates. Ag NPs / porous silicon grating SERS substrate system achieved a highly sensitive SERS response due to the coupling of various Raman enhancement factors.

  16. Grating-Coupled Waveguide Cloaking

    International Nuclear Information System (INIS)

    Wang Jia-Fu; Qu Shao-Bo; Ma Hua; Wang Cong-Min; Wang Xin-Hua; Zhou Hang; Xu Zhuo; Xia Song

    2012-01-01

    Based on the concept of a grating-coupled waveguide (GCW), a new strategy for realizing EM cloaking is presented. Using metallic grating, incident waves are firstly coupled into the effective waveguide and then decoupled into free space behind, enabling EM waves to pass around the obstacle. Phase compensation in the waveguide keeps the wave-front shape behind the obstacle unchanged. Circular, rectangular and triangular cloaks are presented to verify the robustness of the GCW cloaking. Electric field animations and radar cross section (RCS) comparisons convincingly demonstrate the cloaking effect

  17. Fabrication of Polymer Optical Fibre (POF Gratings

    Directory of Open Access Journals (Sweden)

    Yanhua Luo

    2017-03-01

    Full Text Available Gratings inscribed in polymer optical fibre (POF have attracted remarkable interest for many potential applications due to their distinctive properties. This paper overviews the current state of fabrication of POF gratings since their first demonstration in 1999. In particular we summarize and discuss POF materials, POF photosensitivity, techniques and issues of fabricating POF gratings, as well as various types of POF gratings.

  18. Embedded high-contrast distributed grating structures

    Science.gov (United States)

    Zubrzycki, Walter J.; Vawter, Gregory A.; Allerman, Andrew A.

    2002-01-01

    A new class of fabrication methods for embedded distributed grating structures is claimed, together with optical devices which include such structures. These new methods are the only known approach to making defect-free high-dielectric contrast grating structures, which are smaller and more efficient than are conventional grating structures.

  19. Hybrid grating reflectors: Origin of ultrabroad stopband

    DEFF Research Database (Denmark)

    Park, Gyeong Cheol; Taghizadeh, Alireza; Chung, Il-Sug

    2016-01-01

    Hybrid grating (HG) reflectors with a high-refractive-index cap layer added onto a high contrast grating (HCG) provide a high reflectance close to 100% over a broader wavelength range than HCGs. The combination of a cap layer and a grating layer brings a strong Fabry-Perot (FP) resonance as well ...

  20. [The birth of acknowledgement: Michel Foucault and Werner Leibbrand].

    Science.gov (United States)

    Mildenberger, Florian

    2006-01-01

    In 1964, Werner Leibbrand (1896-1974) was the first German medical historian to present, in Sudhoffs Archiv, a review of the work of Michel Foucault (1926-1984). This paper examines some of the reasons leading to the fact that Leibbrand's own generation refused to acknowledge the importance of Foucault's ideas, while, later on, younger German medical historians, although impressed with Foucault's writings, failed to acknowledge, first, the close relationship between Leibbrand's and Foucault's world views, and, second, Leibbrand's attempts at introducing Foucault to German medical historians. Leibbrand with his Jewish wife had survived the Nazi period partly in hiding. His attempts at clearing post-war German psychiatry and medical historiography of NS-sympathizers isolated him among his colleagues, many of whom had begun their career during the Third Reich. Leibbrand enjoyed the support by the Swiss medical historian and avowed Communist Erwin Ackerknecht (1906-1988), but later turned against him, possibly because Acknerknecht had called Leibbrand's writings "unscientific". Leibbrand was unable to overcome his antagonisms with his contemporaries. At the same time, opposition to Ackerknecht made him appear a respresentative of the past in the eyes of the younger generation. Thus, when Foucault was accepted by the latter, they were not prepared to examine the work of Leibbrand and realize how close some of the ideas developed by Leibbrand and Foucault had been.

  1. Acknowledging sexual bereavement: a path out of disenfranchised grief.

    Science.gov (United States)

    Radosh, Alice; Simkin, Linda

    2016-11-01

    Despite increasing awareness of the importance of sexuality for older adults, research and popular literature rarely acknowledge what we term "sexual bereavement" - mourning the loss of sexual intimacy when predeceased. The reluctance to acknowledge sexual bereavement may create "disenfranchised grief" leaving the bereaved unsupported in coping with this aspect of mourning. This preliminary study focuses on women in the United States and sought to determine whether they anticipate missing sex if predeceased, whether they would want to talk about this loss, and identified factors associated with communicating about sexual bereavement. Findings from our survey of 104 women, 55 years and older, most of whom were heterosexual, revealed that a large majority (72%) anticipates missing sex with their partner and 67% would want to initiate a discussion about this. An even higher percentage would want friends to initiate the topic. Yet, 57% of participants report it would not occur to them to initiate a discussion with a widowed friend about the friend's loss. Disenfranchised grief can have negative emotional and physical consequences. This paper suggests a role for friends and professionals in addressing this neglected issue. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. The grating as an accelerating structure

    International Nuclear Information System (INIS)

    Fernow, R.C.

    1991-02-01

    This report considers the use of a diffraction grating as an accelerating structure for charged particle beams. We examine the functional dependence of the electromagnetic fields above the surface of a grating. Calculations are made of the strength of the accelerating modes for structures with π and 2π phase advance per period and for incident waves polarized with either the E or H vector along the grooves of the grating. We consider examples of using gratings in a laser linac and in a grating lens. We also briefly examine previous results published about this subject. 36 refs

  3. Curved VPH gratings for novel spectrographs

    Science.gov (United States)

    Clemens, J. Christopher; O'Donoghue, Darragh; Dunlap, Bart H.

    2014-07-01

    The introduction of volume phase holographic (VPH) gratings into astronomy over a decade ago opened new possibilities for instrument designers. In this paper we describe an extension of VPH grating technology that will have applications in astronomy and beyond: curved VPH gratings. These devices can disperse light while simultaneously correcting aberrations. We have designed and manufactured two different kinds of convex VPH grating prototypes for use in off-axis reflecting spectrographs. One type functions in transmission and the other in reflection, enabling Offnerstyle spectrographs with the high-efficiency and low-cost advantages of VPH gratings. We will discuss the design process and the tools required for modelling these gratings along with the recording layout and process steps required to fabricate them. We will present performance data for the first convex VPH grating produced for an astronomical spectrograph.

  4. Point-by-point written fiber-Bragg gratings and their application in complex grating designs.

    Science.gov (United States)

    Marshall, Graham D; Williams, Robert J; Jovanovic, Nemanja; Steel, M J; Withford, Michael J

    2010-09-13

    The point-by-point technique of fabricating fibre-Bragg gratings using an ultrafast laser enables complete control of the position of each index modification that comprises the grating. By tailoring the local phase, amplitude and spacing of the grating's refractive index modulations it is possible to create gratings with complex transmission and reflection spectra. We report a series of grating structures that were realized by exploiting these flexibilities. Such structures include gratings with controlled bandwidth, and amplitude- and phase-modulated sampled (or superstructured) gratings. A model based on coupled-mode theory provides important insights into the manufacture of such gratings. Our approach offers a quick and easy method of producing complex, non-uniform grating structures in both fibres and other mono-mode waveguiding structures.

  5. Financial history and financial economics

    OpenAIRE

    Turner, John D.

    2014-01-01

    This essay looks at the bidirectional relationship between financial history and financial economics. It begins by giving a brief history of financial economics by outlining the main topics of interest to financial economists. It then documents and explains the increasing influence of financial economics upon financial history, and warns of the dangers of applying financial economics unthinkingly to the study of financial history. The essay proceeds to highlight the many insights that financi...

  6. Feasibility evaluation of a neutron grating interferometer with an analyzer grating based on a structured scintillator

    Science.gov (United States)

    Kim, Youngju; Kim, Jongyul; Kim, Daeseung; Hussey, Daniel. S.; Lee, Seung Wook

    2018-03-01

    We introduce an analyzer grating based on a structured scintillator fabricated by a gadolinium oxysulfide powder filling method for a symmetric Talbot-Lau neutron grating interferometer. This is an alternative way to analyze the Talbot self-image of a grating interferometer without using an absorption grating to block neutrons. Since the structured scintillator analyzer grating itself generates the signal for neutron detection, we do not need an additional scintillator screen as an absorption analyzer grating. We have developed and tested an analyzer grating based on a structured scintillator in our symmetric Talbot-Lau neutron grating interferometer to produce high fidelity absorption, differential phase, and dark-field contrast images. The acquired images have been compared to results of a grating interferometer utilizing a typical absorption analyzer grating with two commercial scintillation screens. The analyzer grating based on the structured scintillator enhances interference fringe visibility and shows a great potential for economical fabrication, compact system design, and so on. We report the performance of the analyzer grating based on a structured scintillator and evaluate its feasibility for the neutron grating interferometer.

  7. Varied line-space gratings and applications

    International Nuclear Information System (INIS)

    McKinney, W.R.

    1991-01-01

    This paper presents a straightforward analytical and numerical method for the design of a specific type of varied line-space grating system. The mathematical development will assume plane or nearly-plane spherical gratings which are illuminated by convergent light, which covers many interesting cases for synchrotron radiation. The gratings discussed will have straight grooves whose spacing varies across the principal plane of the grating. Focal relationships and formulae for the optical grating-pole-to-exist-slit distance and grating radius previously presented by other authors will be derived with a symbolic algebra system. It is intended to provide the optical designer with the tools necessary to design such a system properly. Finally, some possible advantages and disadvantages for application to synchrotron to synchrotron radiation beamlines will be discussed

  8. Complications: acknowledging, managing, and coping with human error.

    Science.gov (United States)

    Helo, Sevann; Moulton, Carol-Anne E

    2017-08-01

    Errors are inherent in medicine due to the imperfectness of human nature. Health care providers may have a difficult time accepting their fallibility, acknowledging mistakes, and disclosing errors. Fear of litigation, shame, blame, and concern about reputation are just some of the barriers preventing physicians from being more candid with their patients, despite the supporting body of evidence that patients cite poor communication and lack of transparency as primary drivers to file a lawsuit in the wake of a medical complication. Proper error disclosure includes a timely explanation of what happened, who was involved, why the error occurred, and how it will be prevented in the future. Medical mistakes afford the opportunity for individuals and institutions to be candid about their weaknesses while improving patient care processes. When a physician takes the Hippocratic Oath they take on a tremendous sense of responsibility for the care of their patients, and often bear the burden of their mistakes in isolation. Physicians may struggle with guilt, shame, and a crisis of confidence, which may thwart efforts to identify areas for improvement that can lead to meaningful change. Coping strategies for providers include discussing the event with others, seeking professional counseling, and implementing quality improvement projects. Physicians and health care organizations need to find adaptive ways to deal with complications that will benefit patients, providers, and their institutions.

  9. Nanoporous Polymeric Grating-Based Biosensors

    KAUST Repository

    Gao, Tieyu

    2012-05-02

    We demonstrate the utilization of an interferometrically created nanoporous polymeric gratings as a platform for biosensing applications. Aminopropyltriethoxysilane (APTES)-functionalized nanoporous polymeric gratings was fabricated by combining holographic interference patterning and APTES-functionalization of pre-polymer syrup. The successful detection of multiple biomolecules indicates that the biofunctionalized nanoporous polymeric gratings can act as biosensing platforms which are label-free, inexpensive, and applicable as high-throughput assays. Copyright © 2010 by ASME.

  10. EUV properties of two diffraction gratings

    International Nuclear Information System (INIS)

    Cotton, D.; Chakrabarti, S.; Edelstein, J.; Pranke, J.; Christensen, A.B.

    1988-01-01

    The efficiency and scattering characteristics of a mechanically ruled grating (MRG) and a holographically ruled grating (HRG) are presented. One of these gratings will be employed in the Extreme Ultraviolet Spectrometer, an instrument of the Remote Atmospheric and Ionospheric Detector System to be flown aboard a TIROS satellite in 1991. The HRG showed much less Lyman alpha scattering, while the MRG had the better efficiency over most of the spectral range covered. 8 refs

  11. Nanoporous Polymeric Grating-Based Biosensors

    KAUST Repository

    Gao, Tieyu; Hsiao, Vincent; Zheng, Yue Bing; Huang, Tony Jun

    2012-01-01

    We demonstrate the utilization of an interferometrically created nanoporous polymeric gratings as a platform for biosensing applications. Aminopropyltriethoxysilane (APTES)-functionalized nanoporous polymeric gratings was fabricated by combining holographic interference patterning and APTES-functionalization of pre-polymer syrup. The successful detection of multiple biomolecules indicates that the biofunctionalized nanoporous polymeric gratings can act as biosensing platforms which are label-free, inexpensive, and applicable as high-throughput assays. Copyright © 2010 by ASME.

  12. Fibre gratings for high temperature sensor applications

    Science.gov (United States)

    Canning, J.; Sommer, K.; Englund, M.

    2001-07-01

    Phosphosilicate fibre gratings can be stabilized at temperatures in excess of 500 °C for sensor applications by optimizing thermal and UV presensitization recipes. Furthermore, the use of 193 nm presensitization prevents the formation of OH absorption bands, extending the use of fibre gratings across the entire wavelength spectrum. Gratings for operation at 700 °C retaining up to 70% reflectivity after 30 min are demonstrated.

  13. AICPA allows low-cost options for compiled financial statements.

    Science.gov (United States)

    Reinstein, Alan; Luecke, Randall W

    2002-02-01

    The AICPA Accounting and Review Services Committee's (ARSC) SSARS No. 8, Amendment to Statement on Standards for Accounting and Review Services No. 1, Compilation and Review of Financial Statements, issued in October 2000, allows financial managers to provide plain-paper, compiled financial statements for the exclusive use of management. Such financial statements were disallowed in 1979 when the AICPA issued SSARS No. 1, Compilation and Review of Financial Statements. With the issuance of SSARS No. 8, financial managers can prepare plain-paper, compiled financial statements when third parties are not expected to rely on the financial statements, management acknowledges such restrictions in writing, and management acknowledges its primary responsibility for the adequacy of the financial statements.

  14. Biosensing with optical fiber gratings

    Science.gov (United States)

    Chiavaioli, Francesco; Baldini, Francesco; Tombelli, Sara; Trono, Cosimo; Giannetti, Ambra

    2017-06-01

    Optical fiber gratings (OFGs), especially long-period gratings (LPGs) and etched or tilted fiber Bragg gratings (FBGs), are playing an increasing role in the chemical and biochemical sensing based on the measurement of a surface refractive index (RI) change through a label-free configuration. In these devices, the electric field evanescent wave at the fiber/surrounding medium interface changes its optical properties (i.e. intensity and wavelength) as a result of the RI variation due to the interaction between a biological recognition layer deposited over the fiber and the analyte under investigation. The use of OFG-based technology platforms takes the advantages of optical fiber peculiarities, which are hardly offered by the other sensing systems, such as compactness, lightness, high compatibility with optoelectronic devices (both sources and detectors), and multiplexing and remote measurement capability as the signal is spectrally modulated. During the last decade, the growing request in practical applications pushed the technology behind the OFG-based sensors over its limits by means of the deposition of thin film overlays, nanocoatings, and nanostructures, in general. Here, we review efforts toward utilizing these nanomaterials as coatings for high-performance and low-detection limit devices. Moreover, we review the recent development in OFG-based biosensing and identify some of the key challenges for practical applications. While high-performance metrics are starting to be achieved experimentally, there are still open questions pertaining to an effective and reliable detection of small molecules, possibly up to single molecule, sensing in vivo and multi-target detection using OFG-based technology platforms.

  15. Biosensing with optical fiber gratings

    Directory of Open Access Journals (Sweden)

    Chiavaioli Francesco

    2017-06-01

    Full Text Available Optical fiber gratings (OFGs, especially long-period gratings (LPGs and etched or tilted fiber Bragg gratings (FBGs, are playing an increasing role in the chemical and biochemical sensing based on the measurement of a surface refractive index (RI change through a label-free configuration. In these devices, the electric field evanescent wave at the fiber/surrounding medium interface changes its optical properties (i.e. intensity and wavelength as a result of the RI variation due to the interaction between a biological recognition layer deposited over the fiber and the analyte under investigation. The use of OFG-based technology platforms takes the advantages of optical fiber peculiarities, which are hardly offered by the other sensing systems, such as compactness, lightness, high compatibility with optoelectronic devices (both sources and detectors, and multiplexing and remote measurement capability as the signal is spectrally modulated. During the last decade, the growing request in practical applications pushed the technology behind the OFG-based sensors over its limits by means of the deposition of thin film overlays, nanocoatings, and nanostructures, in general. Here, we review efforts toward utilizing these nanomaterials as coatings for high-performance and low-detection limit devices. Moreover, we review the recent development in OFG-based biosensing and identify some of the key challenges for practical applications. While high-performance metrics are starting to be achieved experimentally, there are still open questions pertaining to an effective and reliable detection of small molecules, possibly up to single molecule, sensing in vivo and multi-target detection using OFG-based technology platforms.

  16. Running gratings in photoconductive materials

    DEFF Research Database (Denmark)

    Kukhtarev, N. V.; Kukhtareva, T.; Lyuksyutov, S. F.

    2005-01-01

    Starting from the three-dimensional version of a standard photorefractive model (STPM), we obtain a reduced compact Set of equations for an electric field based on the assumption of a quasi-steady-state fast recombination. The equations are suitable for evaluation of a current induced by running...... gratings at small-contrast approximation and also are applicable for the description of space-charge wave domains. We discuss spatial domain and subharmonic beam formation in bismuth silicon oxide (BSO) crystals in the framework of the small-contrast approximation of STPM. The experimental results...

  17. 21 CFR 133.146 - Grated cheeses.

    Science.gov (United States)

    2010-04-01

    ... Products § 133.146 Grated cheeses. (a) Description. Grated cheeses is the class of foods prepared by..., and skim milk cheese for manufacturing may not be used. All cheese ingredients used are either made... ___ cheese”, the name of the cheese filling the blank. (ii) If only parmesan and romano cheeses are used and...

  18. The Flexibility of Pusher Furnace Grate

    Directory of Open Access Journals (Sweden)

    Słowik J.A.

    2016-12-01

    Full Text Available The lifetime of guide grates in pusher furnaces for heat treatment could be increased by raising the flexibility of their structure through, for example, the replacement of straight ribs, parallel to the direction of grate movement, with more flexible segments. The deformability of grates with flexible segments arranged in two orientations, i.e. crosswise (perpendicular to the direction of compression and lengthwise (parallel to the direction of compression, was examined. The compression process was simulated using SolidWorks Simulation program. Relevant regression equations were also derived describing the dependence of force inducing the grate deformation by 0.25 mm ‒ modulus of grate elasticity ‒ on the number of flexible segments in established orientations. These calculations were made in Statistica and Scilab programs. It has been demonstrated that, with the same number of segments, the crosswise orientation of flexible segments increases the grate structure flexibility in a more efficient way than the lengthwise orientation. It has also been proved that a crucial effect on the grate flexibility has only the quantity and orientation of segments (crosswise / lengthwise, while the exact position of segments changes the grate flexibility by less than 1%.

  19. Femtosecond laser pulse written Volume Bragg Gratings

    Directory of Open Access Journals (Sweden)

    Richter Daniel

    2013-11-01

    Full Text Available Femtosecond laser pulses can be applied for structuring a wide range of ransparent materials. Here we want to show how to use this ability to realize Volume-Bragg-Gratings in various- mainly non-photosensitive - glasses. We will further present the characteristics of the realized gratings and a few elected applications that have been realized.

  20. A MANUALLY OPERATED CASSAVA GRATING MACHINE

    African Journals Online (AJOL)

    Dr Obe

    1984-09-01

    Sep 1, 1984 ... substantial losses arising from the inability of the person to hold small pieces of cassava roots for grating. Happily, there now exist various. Versions of mechanical graters which are driven by electric motors or small internal combustion engines. In fact, it may be said that cassava grating has been effectively.

  1. The spectral combination characteristic of grating and the bi-grating diffraction imaging effect

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper reports on a new property of grating, namely spectral combination, and on bi-grating diffraction imaging that is based on spectral combination. The spectral combination characteristic of a grating is the capability of combining multiple light beams of different wavelengths incident from specific angles into a single beam. The bi-grating diffraction imaging is the formation of the image of an object with two gratings: the first grating disperses the multi-color light beams from the object and the second combines the dispersed light beams to form the image. We gave the conditions necessary for obtaining the spectral combination. We also presented the equations that relate the two gratings’ spatial frequencies, diffraction orders and positions necessary for obtaining the bi-grating diffraction imaging.

  2. Predicting Rape Victim Empathy Based on Rape Victimization and Acknowledgment Labeling.

    Science.gov (United States)

    Osman, Suzanne L

    2016-06-01

    Two studies examined rape victim empathy based on personal rape victimization and acknowledgment labeling. Female undergraduates (Study 1, n = 267; Study 2, n = 381) from a Northeast U.S. midsize public university completed the Rape-Victim Empathy Scale and Sexual Experiences Survey. As predicted, both studies found that acknowledged "rape" victims reported greater empathy than unacknowledged victims and nonvictims. Unexpectedly, these latter two groups did not differ. Study 1 also found that acknowledged "rape" victims reported greater empathy than victims who acknowledged being "sexually victimized." Findings suggest that being raped and acknowledging "rape" together may facilitate rape victim empathy. © The Author(s) 2015.

  3. For the acknowledgement of a social value of carbon in the Climate agreement

    International Nuclear Information System (INIS)

    Finon, Dominique

    2015-01-01

    After having outlined that it might be difficult to define a unique price for carbon emissions, the author states that acknowledging a reference price in the Climate agreement would help to guide investment decisions and new financing modes. He proposes that the agreement could include the following article: 'The social and economic value of mitigation actions and their co-benefits to adaptation, health and sustainable development should be recognized and formalized as such. It will help to orient the investment of firms towards low carbon options, to mobilize public funding and to develop financial vehicles to allow scaling up of private investments to support development of low carbon projects and countries' transitions to low-carbon economies. This reference of carbon value will be established by consensus between parties: it should be referred to abatement action costs to reach a global emissions cap as well as the co-benefits of the actions. It will be regularly revised.' The author then discusses how to fill the gap between private and social value of low carbon investments, and how to determine this reference value. He outlines the benefit of a reference value of carbon with respect to a constraining price to reach a credible agreement

  4. Acknowledgements [3. international conference on small angle neutron scattering dedicated to the 80 anniversary of Yu.M. Ostanevich, Dubna (Russian Federation), 6-9 June 2016

    International Nuclear Information System (INIS)

    2017-01-01

    The Organizers of the III International Conference on Small Angle Neutron Scattering dedicated to the 80-th anniversary of Yu. M. Ostanevich, acknowledge the financial support from the Grants of the Governmental Plenipotentiary Representatives of Romania, Slovakia, Czech Republic, scientific projects of the Cooperation Programmes JINR-Romania. Special gratitude to the JINR and FLNP administration and staff is expressed. The conference is also dedicated to the 60th Anniversary of the Joint Institute for Nuclear Research, Dubna. (paper)

  5. Neutron diffraction from holographic gratings in PMMA

    International Nuclear Information System (INIS)

    Havermeyer, F.; Kraetzig, E.; Rupp, R.A.; Schubert, D.W.

    1999-01-01

    Complete text of publication follows. By definition photorefractive materials change the refractive index for light under the action of light. Using the spatially modulated light intensity pattern from the interference of two plane waves, volume phase gratings with accurately defined spacings can be produced. Depending on the material there are many physical origins for these gratings, but in most cases they are linked to a density modulation and, consequently, to a refractive index grating for neutrons. By diffraction of light or neutrons from such gratings even small refractive index changes down to Δn ∼ 10 -7 - 10 -9 can be measured. In our photopolymer system PMMA/MMA (poly(methyl methacrylate) with a content of 10-20% of the residual monomer methyl methacrylate) inhomogeneous illumination leads to local post-polymerisation processes of the residual monomer. The resulting light-optical refractive index grating is caused by the modulation of the monomer/polymer ratio as well as by the modulation of the total density. Only by the unique combination of methods for light and neutron diffraction, available at HOLONS (Holography and Neutron Scattering, instrument at the GKSS research centre), both contributions can be separated. We discuss the angular dependence of the neutron diffraction efficiency for weakly and strongly (efficiencies up to 60% have been achieved) modulated gratings and propose a simple model for the evaluation of the gratings. (author)

  6. The Interim Financial Reporting in the Spirit of the IAS 34 Norm

    OpenAIRE

    Ovidia Doinea

    2008-01-01

    The role of an interim financial reporting is to allow the information users to acknowledge the activity of an entity on period shorter than financial exercise from the perspective of the available profits and cash flows generated as well as from the point of view of its financial position and liquidity. The interim financial reporting includes a complete or condensed set of financial statements which target to update the last financial reporting, usually the annual report. The interim financ...

  7. Fiber Bragg Grating Sensors for Harsh Environments

    Directory of Open Access Journals (Sweden)

    Stephen J. Mihailov

    2012-02-01

    Full Text Available Because of their small size, passive nature, immunity to electromagnetic interference, and capability to directly measure physical parameters such as temperature and strain, fiber Bragg grating sensors have developed beyond a laboratory curiosity and are becoming a mainstream sensing technology. Recently, high temperature stable gratings based on regeneration techniques and femtosecond infrared laser processing have shown promise for use in extreme environments such as high temperature, pressure or ionizing radiation. Such gratings are ideally suited for energy production applications where there is a requirement for advanced energy system instrumentation and controls that are operable in harsh environments. This paper will present a review of some of the more recent developments.

  8. Optical Fiber Grating Hydrogen Sensors: A Review.

    Science.gov (United States)

    Dai, Jixiang; Zhu, Li; Wang, Gaopeng; Xiang, Feng; Qin, Yuhuan; Wang, Min; Yang, Minghong

    2017-03-12

    In terms of hydrogen sensing and detection, optical fiber hydrogen sensors have been a research issue due to their intrinsic safety and good anti-electromagnetic interference. Among these sensors, hydrogen sensors consisting of fiber grating coated with sensitive materials have attracted intensive research interests due to their good reliability and distributed measurements. This review paper mainly focuses on optical fiber hydrogen sensors associated with fiber gratings and various materials. Their configurations and sensing performances proposed by different groups worldwide are reviewed, compared and discussed in this paper. Meanwhile, the challenges for fiber grating hydrogen sensors are also addressed.

  9. Undergraduate experiment with fractal diffraction gratings

    International Nuclear Information System (INIS)

    Monsoriu, Juan A; Furlan, Walter D; Pons, Amparo; Barreiro, Juan C; Gimenez, Marcos H

    2011-01-01

    We present a simple diffraction experiment with fractal gratings based on the triadic Cantor set. Diffraction by fractals is proposed as a motivating strategy for students of optics in the potential applications of optical processing. Fraunhofer diffraction patterns are obtained using standard equipment present in most undergraduate physics laboratories and compared with those obtained with conventional periodic gratings. It is shown that fractal gratings produce self-similar diffraction patterns which can be evaluated analytically. Good agreement is obtained between experimental and numerical results.

  10. Nanoscale freestanding gratings for ultraviolet blocking filters

    Energy Technology Data Exchange (ETDEWEB)

    van Beek, J.T.; Fleming, R.C.; Hindle, P.S.; Prentiss, J.D.; Schattenburg, M.L. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Ritzau, S. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    1998-11-01

    Ultraviolet (UV) blocking filters are needed for atomic flux imaging in environments where high levels of ultraviolet radiation are present. Freestanding gratings are a promising candidate for UV filtering. They have a high aspect ratio ({approximately}13), narrow ({approximately}40 nm) slots, and effectively block UV radiation. The grating fabrication process makes use of several etching, electroplating, and lithographic steps and includes an optional step to plug pinholes induced by particles during processing. Gratings were successfully manufactured and tested. Measured UV transmissions of {approximately}10{sup {minus}5} and particle transmissions of {approximately}10{percent} are in agreement with theoretical predictions. {copyright} {ital 1998 American Vacuum Society.}

  11. Sensitive visual test for concave diffraction gratings.

    Science.gov (United States)

    Bruner, E. C., Jr.

    1972-01-01

    A simple visual test for the evaluation of concave diffraction gratings is described. It is twice as sensitive as the Foucault knife edge test, from which it is derived, and has the advantage that the images are straight and free of astigmatism. It is particularly useful for grating with high ruling frequency where the above image faults limit the utility of the Foucault test. The test can be interpreted quantitatively and can detect zonal grating space errors of as little as 0.1 A.

  12. Thermal annealing of tilted fiber Bragg gratings

    Science.gov (United States)

    González-Vila, Á.; Rodríguez-Cobo, L.; Mégret, P.; Caucheteur, C.; López-Higuera, J. M.

    2016-05-01

    We report a practical study of the thermal decay of cladding mode resonances in tilted fiber Bragg gratings, establishing an analogy with the "power law" evolution previously observed on uniform gratings. We examine how this process contributes to a great thermal stability, even improving it by means of a second cycle slightly increasing the annealing temperature. In addition, we show an improvement of the grating spectrum after annealing, with respect to the one just after inscription, which suggests the application of this method to be employed to improve saturation issues during the photo-inscription process.

  13. Financial Statements

    International Development Research Centre (IDRC) Digital Library (Canada)

    Financial Statements and accompanying notes provided on .... to good governance principles. there is the risk that ...... responsibilities of the centre's internal auditor includes reviewing internal controls, including accounting and financial.

  14. The impact of rape acknowledgment on survivor outcomes: The moderating effects of rape myth acceptance.

    Science.gov (United States)

    Wilson, Laura C; Newins, Amie R; White, Susan W

    2017-11-13

    Little is known about how rape acknowledgment relates to posttrauma functioning; recent research suggests the effect may depend on additional factors. In the current study, the moderating effect of rape myth acceptance (RMA) on the relationships between rape acknowledgment and mental health outcomes was examined. A sample of 181 female rape survivors recruited from a university completed an online survey assessing RMA, rape acknowledgment, depression symptoms, and alcohol use. Generally, the results supported that RMA moderated the influence of rape acknowledgment on depression symptoms and average quantity per drinking episode, but not frequency of alcohol use. The findings demonstrated that when individuals endorsed high levels of RMA, acknowledged rape survivors reported worse outcomes than unacknowledged rape survivors. Among individuals low on RMA, unacknowledged rape survivors reported worse outcomes than acknowledged rape survivors. It is recommended that clinicians recognize the role of survivor beliefs, such as RMA, in the relationship between labeling sexual assault experiences and mental health consequences. © 2017 Wiley Periodicals, Inc.

  15. Financial Derivatives

    OpenAIRE

    Janečková, Alena

    2011-01-01

    1 Abstract/ Financial derivatives The purpose of this thesis is to provide an introduction to financial derivatives which has been, from the legal perspective, described in a not satisfactory manner as quite little literature that can be found about this topic. The main objectives of this thesis are to define the term "financial derivatives" and its particular types and to analyse legal nature of these financial instruments. The last objective is to try to draft future law regulation of finan...

  16. Geometrical optics modeling of the grating-slit test.

    Science.gov (United States)

    Liang, Chao-Wen; Sasian, Jose

    2007-02-19

    A novel optical testing method termed the grating-slit test is discussed. This test uses a grating and a slit, as in the Ronchi test, but the grating-slit test is different in that the grating is used as the incoherent illuminating object instead of the spatial filter. The slit is located at the plane of the image of a sinusoidal intensity grating. An insightful geometrical-optics model for the grating-slit test is presented and the fringe contrast ratio with respect to the slit width and object-grating period is obtained. The concept of spatial bucket integration is used to obtain the fringe contrast ratio.

  17. Fabrication update on critical-angle transmission gratings for soft x-ray grating spectrometers

    Science.gov (United States)

    Heilmann, Ralf K.; Bruccoleri, Alex; Mukherjee, Pran; Yam, Jonathan; Schattenburg, Mark L.

    2011-09-01

    Diffraction grating-based, wavelength dispersive high-resolution soft x-ray spectroscopy of celestial sources promises to reveal crucial data for the study of the Warm-Hot Intergalactic Medium, the Interstellar Medium, warm absorption and outflows in Active Galactic Nuclei, coronal emission from stars, and other areas of interest to the astrophysics community. Our recently developed critical-angle transmission (CAT) gratings combine the advantages of the Chandra high and medium energy transmission gratings (low mass, high tolerance of misalignments and figure errors, polarization insensitivity) with those of blazed reflection gratings (high broad band diffraction efficiency, high resolution through use of higher diffraction orders) such as the ones on XMM-Newton. Extensive instrument and system configuration studies have shown that a CAT grating-based spectrometer is an outstanding instrument capable of delivering resolving power on the order of 5,000 and high effective area, even with a telescope point-spread function on the order of many arc-seconds. We have fabricated freestanding, ultra-high aspect-ratio CAT grating bars from silicon-on-insulator wafers using both wet and dry etch processes. The 200 nm-period grating bars are supported by an integrated Level 1 support mesh, and a coarser external Level 2 support mesh. The resulting grating membrane is mounted to a frame, resulting in a grating facet. Many such facets comprise a grating array that provides light-weight coverage of large-area telescope apertures. Here we present fabrication results on the integration of CAT gratings and the different high-throughput support mesh levels and on membrane-frame bonding. We also summarize recent x-ray data analysis of 3 and 6 micron deep wet-etched CAT grating prototypes.

  18. Access Platforms for Offshore Wind Turbines Using Gratings

    DEFF Research Database (Denmark)

    Andersen, Thomas Lykke; Rasmussen, Michael R.

    2008-01-01

    The paper deals with forces generated by a stationary jet on different types of gratings and a solid plate. The force reduction factors for the different gratings compared to the solid plate mainly depend on the porosity of the gratings, but the geometry of the grating is also of some importance........ The derived reduction factors are expected to be applicable to design of offshore wind turbine access platforms with gratings where slamming also is an important factor....

  19. Adaptable Diffraction Gratings With Wavefront Transformation

    Science.gov (United States)

    Iazikov, Dmitri; Mossberg, Thomas W.; Greiner, Christoph M.

    2010-01-01

    Diffraction gratings are optical components with regular patterns of grooves, which angularly disperse incoming light by wavelength. Traditional diffraction gratings have static planar, concave, or convex surfaces. However, if they could be made so that they can change the surface curvature at will, then they would be able to focus on particular segments, self-calibrate, or perform fine adjustments. This innovation creates a diffraction grating on a deformable surface. This surface could be bent at will, resulting in a dynamic wavefront transformation. This allows for self-calibration, compensation for aberrations, enhancing image resolution in a particular area, or performing multiple scans using different wavelengths. A dynamic grating gives scientists a new ability to explore wavefronts from a variety of viewpoints.

  20. Multiwavelength optical scatterometry of dielectric gratings

    KAUST Repository

    Yashina, Nataliya P.; Melezhik, Petr N.; Sirenko, Kostyantyn; Granet, Gerard

    2012-01-01

    is based on rigorous solutions of 2-D initial boundary value problems of the gratings theory. The quintessence and advantage of the method is the possibility to perform an efficient analysis simultaneously and interactively both for steady state

  1. Fibre Bragg grating for flood embankment monitoring

    Science.gov (United States)

    Markowski, Konrad; Nevar, Stanislau; Dworzanski, Adam; Hackiewicz, Krzysztof; Jedrzejewski, Kazimierz

    2014-11-01

    In this article we present the preliminary studies for the flood embankment monitoring system based on the fibre Bragg gratings. The idea of the system is presented. The Bragg resonance shift is transformed to the change of the power detected by the standard InGaAs photodiode. The discrimination of the received power was executed by another fibre Bragg grating with different parameters. The project of the fully functional system is presented as well.

  2. Grism and immersion grating for space telescope

    Science.gov (United States)

    Ebizuka, Noboru; Oka, Kiko; Yamada, Akiko; Ishikawa, Mami; Kashiwagi, Masako; Kodate, Kashiko; Hirahara, Yasuhiro; Sato, Shuji; Kawabata, Koji S.; Wakaki, Moriaki; Morita, Shin-ya; Simizu, Tomoyuki; Yin, Shaohui; Omori, Hitoshi; Iye, Masanori

    2017-11-01

    The grism is a versatile dispersion element for an astronomical instrument ranging from ultraviolet to infrared. Major benefit of using a grism in a space application, instead of a reflection grating, is the size reduction of optical system because collimator and following optical elements could locate near by the grism. The surface relief (SR) grism is consisted a transmission grating and a prism, vertex angle of which is adjusted to redirect the diffracted beam straight along the direct vision direction at a specific order and wavelength. The volume phase holographic (VPH) grism consists a thick VPH grating sandwiched between two prisms, as specific order and wavelength is aligned the direct vision direction. The VPH grating inheres ideal diffraction efficiency on a higher dispersion application. On the other hand, the SR grating could achieve high diffraction efficiency on a lower dispersion application. Five grisms among eleven for the Faint Object Camera And Spectrograph (FOCAS) of the 8.2m Subaru Telescope with the resolving power from 250 to 3,000 are SR grisms fabricated by a replication method. Six additional grisms of FOCAS with the resolving power from 3,000 to 7,000 are VPH grisms. We propose "Quasi-Bragg grism" for a high dispersion spectroscopy with wide wavelength range. The germanium immersion grating for instance could reduce 1/64 as the total volume of a spectrograph with a conventional reflection grating since refractive index of germanium is over 4.0 from 1.6 to 20 μm. The prototype immersion gratings for the mid-InfraRed High dispersion Spectrograph (IRHS) are successfully fabricated by a nano-precision machine and grinding cup of cast iron with electrolytic dressing method.

  3. Financial Literacy and Financial Behaviour

    NARCIS (Netherlands)

    Sayinzoga, Aussi; Bulte, Erwin H.; Lensink, Robert

    2016-01-01

    We organise a field experiment with smallholder farmers in Rwanda to measure the impact of financial literacy training on financial knowledge and behaviour. The training increased financial literacy of participants, changed their savings and borrowing behaviour and had a positive effect on the

  4. Corrugated grating on organic multilayer Bragg reflector

    Science.gov (United States)

    Jaquet, Sylvain; Scharf, Toralf; Herzig, Hans Peter

    2007-08-01

    Polymeric multilayer Bragg structures are combined with diffractive gratings to produce artificial visual color effects. A particular effect is expected due to the angular reflection dependence of the multilayer Bragg structure and the dispersion caused by the grating. The combined effects can also be used to design particular filter functions and various resonant structures. The multilayer Bragg structure is fabricated by spin-coating of two different low-cost polymer materials in solution on a cleaned glass substrate. These polymers have a refractive index difference of about 0.15 and permit multilayer coatings without interlayer problems. Master gratings of different periods are realized by laser beam interference and replicated gratings are superimposed on the multilayer structure by soft embossing in a UV curing glue. The fabrication process requires only polymer materials. The obtained devices are stable and robust. Angular dependent reflection spectrums for the visible are measured. These results show that it is possible to obtain unexpected reflection effects. A rich variety of color spectra can be generated, which is not possible with a single grating. This can be explained by the coupling of transmission of grating orders and the Bragg reflection band. A simple model permits to explain some of the spectral vs angular dependence of reflected light.

  5. Dynamic optical coupled system employing Dammann gratings

    Science.gov (United States)

    Di, Caihui; Zhou, Changhe; Ru, Huayi

    2004-10-01

    With the increasing of the number of users in optical fiber communications, fiber-to-home project has a larger market value. Then the need of dynamic optical couplers, especially of N broad-band couplers, becomes greater. Though some advanced fiber fusion techniques have been developed, they still have many shortcomings. In this paper we propose a dynamic optical coupled system employing even-numbered Dammann gratings, which have the characteristic that the phase distribution in the first half-period accurately equals to that in the second-period with π phase inversion. In our experiment, we divide a conventional even-numbered Dammann grating into two identical gratings. The system can achieve the beam splitter and combiner as the switch between them according to the relative shift between two complementary gratings. When there is no shift between the gratings, the demonstrated 1×8 dynamic optical coupler achieves good uniformity of 0.06 and insertion loss of around 10.8 dB for each channel as a splitter. When the two gratings have an accurate shift of a half-period between them, our system has a low insertion loss of 0.46 dB as a combiner at a wavelength of 1550 nm.

  6. 25 CFR 16.5 - Acceptance and acknowledgement of service of process.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Acceptance and acknowledgement of service of process. 16... INDIANS OF THE FIVE CIVILIZED TRIBES § 16.5 Acceptance and acknowledgement of service of process. Service by the Field Solicitor or any other person of any process or notice, pursuant to any Federal statute...

  7. Beyond funding: What can acknowledgements reveal about credit distribution in science?

    Energy Technology Data Exchange (ETDEWEB)

    Paul-Hus, A.; DiazFaes, A.; Desrochers, N.; Costas, R.; Sainte-Marie, M.; Macaluso, B.; Lariviere, V.

    2016-07-01

    Funding acknowledgements found in scientific publications have been used for decades to study the role of funding in science production. However, beyond funding information, acknowledgements convey the indebtedness of authors to individuals, institutions and organizations that contributed, in some way, to the research that lead to publication. The objective of this paper is to explore the different types of contributions acknowledged in WoS funding acknowledgement (FA) texts. The Correspondence Analysis performed in this study reveals that FAs offer a unique window on research and collaborative practices, credit distribution, and how these vary across disciplines. FAs thus contribute to make the traditionally “invisible contributions” visible to the scientific community. Results presented in this study go further in demonstrating that acknowledgements are not confined to credit attribution, as they include disclosures of conflict of interest. (Author)

  8. Financial mathematics

    CERN Document Server

    Jothi, A Lenin

    2009-01-01

    Financial services, particularly banking and insurance services is the prominent sector for the development of a nation. After the liberalisation of financial sector in India, the scope of getting career opportunities has been widened. It is heartening to note that various universities in India have introduced professional courses on banking and insurance. A new field of applied mathematics has come into prominence under the name of Financial Mathematics. Financial mathematics has attained much importance in the recent years because of the role played by mathematical concepts in decision - m

  9. Two-texture zeros and near-maximal atmospheric neutrino mixing ...

    Indian Academy of Sciences (India)

    S Dev et al. Acknowledgements. RRG gratefully acknowledges the financial support provided by the University Grants. Commission (UGC), Govt. of India, under the Dr D S Kothari postdoctoral fellowship scheme. LS gratefully acknowledges the financial support provided by the UGC, Govt. of India under BSR RFMS scheme ...

  10. Simple design of slanted grating with simplified modal method.

    Science.gov (United States)

    Li, Shubin; Zhou, Changhe; Cao, Hongchao; Wu, Jun

    2014-02-15

    A simplified modal method (SMM) is presented that offers a clear physical image for subwavelength slanted grating. The diffraction characteristic of the slanted grating under Littrow configuration is revealed by the SMM as an equivalent rectangular grating, which is in good agreement with rigorous coupled-wave analysis. Based on the equivalence, we obtained an effective analytic solution for simplifying the design and optimization of a slanted grating. It offers a new approach for design of the slanted grating, e.g., a 1×2 beam splitter can be easily designed. This method should be helpful for designing various new slanted grating devices.

  11. Perturbative approach to continuum generation in a fiber Bragg grating.

    Science.gov (United States)

    Westbrook, P S; Nicholson, J W

    2006-08-21

    We derive a perturbative solution to the nonlinear Schrödinger equation to include the effect of a fiber Bragg grating whose bandgap is much smaller than the pulse bandwidth. The grating generates a slow dispersive wave which may be computed from an integral over the unperturbed solution if nonlinear interaction between the grating and unperturbed waves is negligible. Our approach allows rapid estimation of large grating continuum enhancement peaks from a single nonlinear simulation of the waveguide without grating. We apply our method to uniform and sampled gratings, finding good agreement with full nonlinear simulations, and qualitatively reproducing experimental results.

  12. Acknowledgements; Preface

    Directory of Open Access Journals (Sweden)

    Patrick Valkenburg

    2005-05-01

    Full Text Available Approximately 180 people attended the 10th North American Caribou Workshop which was held immedi¬ately following the annual meeting of the Northwest Section of The Wildlife Society. Participants came from Canada, Greenland, Finland, Norway, Russia, Sweden, and the United States (primarily Alaska. Over 80 papers and posters were presented and about 25% of those are published here in this special edition of Rangifer. Many of the papers, including the keynote address by Dr. Gunter Weller, concerned climate change and global warming.

  13. Iridescence in Meat Caused by Surface Gratings

    Directory of Open Access Journals (Sweden)

    Ali Kemal Yetisen

    2013-11-01

    Full Text Available The photonic structure of cut muscle tissues reveals that the well-ordered gratings diffract light, producing iridescent colours. Cut fibrils protruding from the muscle surface create a two-dimensional periodic array, which diffract light at specific wavelengths upon illumination. However, this photonic effect misleads consumers in a negative way to relate the optical phenomenon with the quality of the product. Here we discuss the fundamentals of this optical phenomenon and demonstrate a methodology for quantitatively measuring iridescence caused by diffraction gratings of muscle tissue surface of pork (Sus scrofa domesticus using reflection spectrophotometry. Iridescence was discussed theoretically as a light phenomenon and spectral measurements were taken from the gratings and monitored in real time during controlled drying. The findings show that the intensity of diffraction diminishes as the surface grating was dried with an air flow at 50 °C for 2 min while the diffracted light wavelength was at 585 ± 9 nm. Our findings indicate that the diffraction may be caused by a blazed surface grating. The implications of the study include providing guidelines to minimise the iridescence by altering the surface microstructure, and in consequence, removing the optical effect.

  14. Financial Liberalization and Financial Fragility

    OpenAIRE

    Enrica Detragiache; Asli Demirgüç-Kunt

    1998-01-01

    The authors study the empirical relationship between banking crises and financial liberalization using a panel of data for 53 countries for 1980-95. They find that banking crises are more likely to occur in liberalized financial systems. But financial liberalization's impact on a fragile banking sector is weaker where the institutional environment is strong--especially where there is respect for the rule of law, a low level of corruption, and good contract enforcement. They examine evidence o...

  15. Financial Statements

    International Development Research Centre (IDRC) Digital Library (Canada)

    users make on the basis of the financial information. .... IDRC's brand and reputation could impact partner- .... building and to provide internal services in support of the ...... maintains books of accounts, information systems, and financial and management controls that .... The significant accounting policies of the Centre are: a.

  16. Understanding Financial Fluctuations and Their Relation to Macroeconomic Stability

    OpenAIRE

    Nora Guarata; Carolina Pagliacci

    2017-01-01

    This paper examines how financial fluctuations and macroeconomic stability interact in the case of Venezuela, acknowledging that financial conditions deteriorating the macroeconomic environment can arise with both good and bad macroeconomic performance. An empirical methodology is provided that constructs two indexes, which are fully interpretable and are constructed with a minimum set of assumptions applied to a large number of financial time series. Structural interpretation of indexes is p...

  17. Grating array systems having a plurality of gratings operative in a coherently additive mode and methods for making such grating array systems

    Science.gov (United States)

    Kessler, Terrance J [Mendon, NY; Bunkenburg, Joachim [Victor, NY; Huang, Hu [Pittsford, NY

    2007-02-13

    A plurality of gratings (G1, G2) are arranged together with a wavefront sensor, actuators, and feedback system to align the gratings in such a manner, that they operate like a single, large, monolithic grating. Sub-wavelength-scale movements in the mechanical mounting, due to environmental influences, are monitored by an interferometer (28), and compensated by precision actuators (16, 18, 20) that maintain the coherently additive mode. The actuators define the grating plane, and are positioned in response to the wavefronts from the gratings and a reference flat, thus producing the interferogram that contains the alignment information. Movement of the actuators is also in response to a diffraction-limited spot on the CCD (36) to which light diffracted from the gratings is focused. The actuator geometry is implemented to take advantage of the compensating nature of the degrees of freedom between gratings, reducing the number of necessary control variables.

  18. Diffraction by m-bonacci gratings

    International Nuclear Information System (INIS)

    Monsoriu, Juan A; Giménez, Marcos H; Furlan, Walter D; Barreiro, Juan C; Saavedra, Genaro

    2015-01-01

    We present a simple diffraction experiment with m-bonacci gratings as a new interesting generalization of the Fibonacci ones. Diffraction by these non-conventional structures is proposed as a motivational strategy to introduce students to basic research activities. The Fraunhofer diffraction patterns are obtained with the standard equipment present in most undergraduate physics labs and are compared with those obtained with regular periodic gratings. We show that m-bonacci gratings produce discrete Fraunhofer patterns characterized by a set of diffraction peaks which positions are related to the concept of a generalized golden mean. A very good agreement is obtained between experimental and numerical results and the students’ feedback is discussed. (paper)

  19. An ultra-high-vacuum multiple grating chamber and scan drive with improved grating change

    International Nuclear Information System (INIS)

    Hulbert, S.L.; Holly, D.J.; Middleton, F.H.; Wallace, D.J.; Wisconsin Univ., Stoughton, WI; Wisconsin Univ., Stoughton, WI

    1989-01-01

    We describe a new grating chamber and scan drive which has been designed, built, and tested by Physical Sciences Laboratory of the University of Wisconsin for the new high flux, high-resolution spectroscopy branch line of the TOK hybrid wiggler/undulator on the NSLS VUV ring. The chamber will contain spherical gratings to be used in the Spherical Grating Monochromator (SGM) configuration introduced by Chen and Sette. The grating chamber houses five 180 mm x 35 mm x 30 mm gratings capable of scanning a range of 12 degree (-14 degree to +8 degree with respect to the incoming beam direction) for VUV and soft X-ray diffraction. The gratings can be switched and precisely indexed while under ultra-high vacuum (UHV) at any scan angle and are mechanically isolated from the vacuum chamber to prevent inaccuracies due to chamber distortions. The gratings can separately be adjusted for height, yaw, pitch, and roll, with the latter three performed while in vacuo. The scan drive provides a resolution of 0.03 arc sec with linearity over the 12 degree range of ∼1.5 arc sec and absolute reproducibility of 1 arc sec. 5 refs., 5 figs

  20. Financial Literacy, Financial Education, and Economic Outcomes

    Science.gov (United States)

    Hastings, Justine S.; Madrian, Brigitte C.; Skimmyhorn, William L.

    2013-01-01

    In this article, we review the literature on financial literacy, financial education, and consumer financial outcomes. We consider how financial literacy is measured in the current literature and examine how well the existing literature addresses whether financial education improves financial literacy or personal financial outcomes. We discuss the…

  1. Vacuum Predisperser For A Large Plane-Grating Spectrograph

    Science.gov (United States)

    Engleman, R.; Palmer, B. A.; Steinhaus, D. W.

    1980-11-01

    A plane grating predisperser has been constructed which acts as an "order-sorter" for a large plane-grating spectrograph. This combination can photograph relatively wide regions of spectra in a single exposure with no loss of resolution.

  2. 36 CFR 1206.90 - Must I acknowledge NHPRC grant support?

    Science.gov (United States)

    2010-07-01

    ....90 Must I acknowledge NHPRC grant support? Yes, grantee institutions, grant project directors, or grant staff personnel may publish results of any work supported by an NHPRC grant without review by the...

  3. Multiwavelength optical scatterometry of dielectric gratings

    KAUST Repository

    Yashina, Nataliya P.

    2012-08-01

    Modern scatterometry problems arising in the lithography production of periodic gratings are in the focus of the work. The performance capabilities of a novel theoretical and numerical modeling oriented to these problems are considered. The approach is based on rigorous solutions of 2-D initial boundary value problems of the gratings theory. The quintessence and advantage of the method is the possibility to perform an efficient analysis simultaneously and interactively both for steady state and transient processes of the resonant scattering of electromagnetic waves by the infinite and compact periodic structures. © 2012 IEEE.

  4. Transparent Electrochemical Gratings from a Patterned Bistable Silver Mirror.

    Science.gov (United States)

    Park, Chihyun; Na, Jongbeom; Han, Minsu; Kim, Eunkyoung

    2017-07-25

    Silver mirror patterns were formed reversibly on a polystyrene (PS)-patterned electrode to produce gratings through the electrochemical reduction of silver ions. The electrochemical gratings exhibited high transparency (T > 95%), similar to a see-through window, by matching the refractive index of the grating pattern with the surrounding medium. The gratings switch to a diffractive state upon the formation of a mirror pattern (T modulation, NIR light reflection, and on-demand heat transfer.

  5. Multicore optical fiber grating array fabrication for medical sensing applications

    Science.gov (United States)

    Westbrook, Paul S.; Feder, K. S.; Kremp, T.; Taunay, T. F.; Monberg, E.; Puc, G.; Ortiz, R.

    2015-03-01

    In this work we report on a fiber grating fabrication platform suitable for parallel fabrication of Bragg grating arrays over arbitrary lengths of multicore optical fiber. Our system exploits UV transparent coatings and has precision fiber translation that allows for quasi-continuous grating fabrication. Our system is capable of both uniform and chirped fiber grating array spectra that can meet the demands of medical sensors including high speed, accuracy, robustness and small form factor.

  6. Optically controlled tunable dispersion compensators based on pumped fiber gratings.

    Science.gov (United States)

    Shu, Xuewen; Sugden, Kate; Bennion, Ian

    2011-08-01

    We demonstrate optically tunable dispersion compensators based on pumping fiber Bragg gratings made in Er/Yb codoped fiber. The tunable dispersion for a chirped grating and also a uniform-period grating was successfully demonstrated in the experiment. The dispersion of the chirped grating was tuned from 900 to 1990 ps/nm and also from -600 to -950 ps/nm in the experiment. © 2011 Optical Society of America

  7. Rape myth acceptance and rape acknowledgment: The mediating role of sexual refusal assertiveness.

    Science.gov (United States)

    Newins, Amie R; Wilson, Laura C; White, Susan W

    2018-05-01

    Unacknowledged rape, defined as when an individual experiences an event that meets a legal or empirical definition of rape but the individual does not label it as such, is prevalent. Research examining predictors of rape acknowledgment is needed. Sexual assertiveness may be an important variable to consider, as an individual's typical behavior during sexual situations may influence rape acknowledgment. To assess the indirect effect of rape myth acceptance on rape acknowledgment through sexual refusal assertiveness, an online survey of 181 female rape survivors was conducted. The indirect effects of two types of rape myths (He didn't mean to and Rape is a deviant event) were significant and positive. Specifically, acceptance of these two rape myths was negatively related to sexual refusal assertiveness, which was negatively associated with likelihood of rape acknowledgment. The results of this study indicate that sexual refusal assertiveness is associated with lower likelihood of rape acknowledgment among rape survivors. As a result, it appears that, under certain circumstances, women high in rape myth acceptance may be more likely to acknowledge rape when it results in decreased sexual refusal assertiveness. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Off-plane x-ray reflection grating fabrication

    Science.gov (United States)

    Peterson, Thomas J.; DeRoo, Casey T.; Marlowe, Hannah; McEntaffer, Randall L.; Miles, Drew M.; Tutt, James H.; Schultz, Ted B.

    2015-09-01

    Off-plane X-ray diffraction gratings with precision groove profiles at the submicron scale will be used in next generation X-ray spectrometers. Such gratings will be used on a current NASA suborbital rocket mission, the Off-plane Grating Rocket Experiment (OGRE), and have application for future grating missions. The fabrication of these gratings does not come without challenges. High performance off-plane gratings must be fabricated with precise radial grating patterns, optically at surfaces, and specific facet angles. Such gratings can be made using a series of common micro-fabrication techniques. The resulting process is highly customizable, making it useful for a variety of different mission architectures. In this paper, we detail the fabrication method used to produce high performance off-plane gratings and report the results of a preliminary qualification test of a grating fabricated in this manner. The grating was tested in the off-plane `Littrow' configuration, for which the grating is most efficient for a given diffraction order, and found to achieve 42% relative efficiency in the blaze order with respect to all diffracted light.

  9. Liquid filling of photonic crystal fibres for grating writing

    DEFF Research Database (Denmark)

    Sørensen, Henrik Rokkjær; Canning, John; Lægsgaard, Jesper

    2007-01-01

    liquid filling of photonic crystal fibres reduces the scattering from air–glass interfaces during Bragg grating writing in many layered photonic crystal fibres. Within experimental uncertainty, the grating index modulation of a grating written in germanium-doped photonic crystal fibre with 10 rings...

  10. Speed and the coherence of superimposed chromatic gratings.

    Science.gov (United States)

    Bosten, J M; Smith, L; Mollon, J D

    2016-05-01

    On the basis of measurements of the perceived coherence of superimposed drifting gratings, Krauskopf and Farell (1990) proposed that motion is analysed independently in different chromatic channels. They found that two gratings appeared to slip if each modulated one of the two 'cardinal' color mechanisms S/(L+M) and L/(L+M). If the gratings were defined along intermediate color directions, observers reported a plaid, moving coherently. We hypothesised that slippage might occur in chromatic gratings if the motion signal from the S/(L+M) channel is weak and equivalent to a lower speed. We asked observers to judge coherence in two conditions. In one, S/(L+M) and L/(L+M) gratings were physically the same speed. In the other, the two gratings had perceptually matched speeds. We found that the relative incoherence of cardinal gratings is the same whether gratings are physically or perceptually matched in speed. Thus our hypothesis was firmly contradicted. In a control condition, observers were asked to judge the coherence of stationary gratings. Interestingly, the difference in judged coherence between cardinal and intermediate gratings remained as strong as it was when the gratings moved. Our results suggest a possible alternative interpretation of Krauskopf and Farell's result: the processes of object segregation may precede the analysis of the motion of chromatic gratings, and the same grouping signals may prompt object segregation in the stationary and moving cases. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Deep-etched sinusoidal polarizing beam splitter grating.

    Science.gov (United States)

    Feng, Jijun; Zhou, Changhe; Cao, Hongchao; Lv, Peng

    2010-04-01

    A sinusoidal-shaped fused-silica grating as a highly efficient polarizing beam splitter (PBS) is investigated based on the simplified modal method. The grating structure depends mainly on the ratio of groove depth to grating period and the ratio of incident wavelength to grating period. These ratios can be used as a guideline for the grating design at different wavelengths. A sinusoidal-groove PBS grating is designed at a wavelength of 1310 nm under Littrow mounting, and the transmitted TM and TE polarized waves are mainly diffracted into the zeroth order and the -1st order, respectively. The grating profile is optimized by using rigorous coupled-wave analysis. The designed PBS grating is highly efficient (>95.98%) over the O-band wavelength range (1260-1360 nm) for both TE and TM polarizations. The sinusoidal grating can exhibit higher diffraction efficiency, larger extinction ratio, and less reflection loss than the rectangular-groove PBS grating. By applying wet etching technology on the rectangular grating, which was manufactured by holographic recording and inductively coupled plasma etching technology, the sinusoidal grating can be approximately fabricated. Experimental results are in agreement with theoretical values.

  12. Theoretical Investigation of Subwavelength Gratings and Vertical Cavity Lasers Employing Grating Structures

    DEFF Research Database (Denmark)

    Taghizadeh, Alireza

    This thesis deals with theoretical investigations of a newly proposed grating structure, referred to as hybrid grating (HG) as well as vertical cavity lasers based on the grating reflectors. The HG consists of a near-subwavelength grating layer and an unpatterned high-refractive-index cap layer...... directions, which is analogous to electronic quantum wells in conduction or valence bands. Several interesting configurations of heterostructures have been investigated and their potential in fundamental physics study and applications are discussed. For numerical and theoretical studies, a three...... feasibility than the HCG-based ones. Furthermore, the concept of cavity dispersion in vertical cavities is introduced and its importance in the modal properties is numerically investigated. The dispersion curvature of a cavity mode is interpreted as the effective photon mass of the cavity mode. In a vertical...

  13. Financial assurances

    International Nuclear Information System (INIS)

    Paton, R.F.

    1990-01-01

    US Ecology is a full service waste management company. The company operates two of the nation's three existing low-level radioactive waste (LLRW) disposal facilities and has prepared and submitted license applications for two new LLRW disposal facilities in California and Nebraska. The issue of financial assurances is an important aspect of site development and operation. Proper financial assurances help to insure that uninterrupted operation, closure and monitoring of a facility will be maintained throughout the project's life. Unfortunately, this aspect of licensing is not like others where you can gauge acceptance by examining approved computer codes, site performance standards or applying specific technical formulas. There is not a standard financial assurance plan. Each site should develop its requirements based upon the conditions of the site, type of design, existing state or federal controls, and realistic assessments of future financial needs. Financial assurances at U.S. Ecology's existing sites in Richland, Washington, and Beatty, Nevada, have been in place for several years and are accomplished in a variety of ways by the use of corporate guarantees, corporate capital funds, third party liability insurance, and post closure/long-term care funds. In addressing financial assurances, one can divide the issue into three areas: Site development/operations, third party damages, and long-term care/cleanup

  14. Smart photogalvanic running-grating interferometer

    DEFF Research Database (Denmark)

    Kukhtarev, N. V.; Kukhtareva, T.; Edwards, M. E.

    2005-01-01

    Photogalvanic effect produces actuation of periodic motion of macroscopic LiNbO3 crystal. This effect was applied to the development of an all-optical moving-grating interferometer usable for optical trapping and transport of algae chlorella microorganisms diluted in water with a concentration of...

  15. Computer simulation of multiple dynamic photorefractive gratings

    DEFF Research Database (Denmark)

    Buchhave, Preben

    1998-01-01

    The benefits of a direct visualization of space-charge grating buildup are described. The visualization is carried out by a simple repetitive computer program, which simulates the basic processes in the band-transport model and displays the result graphically or in the form of numerical data. The...

  16. Cylinder and metal grating polarization beam splitter

    Science.gov (United States)

    Yang, Junbo; Xu, Suzhi

    2017-08-01

    We propose a novel and compact metal grating polarization beam splitter (PBS) based on its different reflected and transmitted orders. The metal grating exhibits a broadband high reflectivity and polarization dependence. The rigorous coupled wave analysis is used to calculate the reflectivity and the transmitting spectra and optimize the structure parameters to realize the broadband PBS. The finite-element method is used to calculate the field distribution. The characteristics of the broadband high reflectivity, transmitting and the polarization dependence are investigated including wavelength, period, refractive index and the radius of circle grating. When grating period d = 400 nm, incident wavelength λ = 441 nm, incident angle θ = 60° and radius of circle d/5, then the zeroth reflection order R0 = 0.35 and the transmission zeroth order T0 = 0.08 for TE polarization, however, T0 = 0.34 and R0 = 0.01 for TM mode. The simple fabrication method involves only single etch step and good compatibility with complementary metal oxide semiconductor technology. PBS designed here is particularly suited for optical communication and optical information processing.

  17. Surface Fluctuation Scattering using Grating Heterodyne Spectroscopy

    DEFF Research Database (Denmark)

    Edwards, R. V.; Sirohi, R. S.; Mann, J. A.

    1982-01-01

    Heterodyne photon spectroscopy is used for the study of the viscoelastic properties of the liquid interface by studying light scattered from thermally generated surface fluctuations. A theory of a heterodyne apparatus based on a grating is presented, and the heterodyne condition is given in terms...

  18. Disorder effects in subwavelength grating metamaterial waveguides

    Czech Academy of Sciences Publication Activity Database

    Ortega-Moñux, A.; Čtyroký, Jiří; Cheben, P.; Schmid, J. H.; Wang, S.; Molina-Fernández, I.; Halíř, R.

    2017-01-01

    Roč. 25, č. 11 (2017), s. 12222-12236 ISSN 1094-4087 R&D Projects: GA ČR(CZ) GA16-00329S Institutional support: RVO:67985882 Keywords : Subwavelength grating * Integrated photonics * Diffraction effects Subject RIV: BH - Optics, Masers, Lasers OBOR OECD: Optics (including laser optics and quantum optics) Impact factor: 3.307, year: 2016

  19. Hybrid grating reflectors: Origin of ultrabroad stopband

    Energy Technology Data Exchange (ETDEWEB)

    Park, Gyeong Cheol; Taghizadeh, Alireza; Chung, Il-Sug, E-mail: ilch@fotonik.dtu.dk [DTU Fotonik, Department of Photonics Engineering, Technical University of Denmark, DK-2800 Kgs. Lyngby (Denmark)

    2016-04-04

    Hybrid grating (HG) reflectors with a high-refractive-index cap layer added onto a high contrast grating (HCG) provide a high reflectance close to 100% over a broader wavelength range than HCGs. The combination of a cap layer and a grating layer brings a strong Fabry-Perot (FP) resonance as well as a weak guided mode (GM) resonance. Most of the reflected power results from the FP resonance, while the GM resonance plays a key role in achieving a reflectance close to 100% as well as broadening the stopband. An HG sample with 7 InGaAlAs quantum wells included in the cap layer has been fabricated by directly wafer-bonding a III-V cap layer onto a Si grating layer. Its reflection property has been characterized. This heterogeneously integrated HG reflector may allow for a hybrid III-V on Si laser to be thermally efficient, which has promising prospects for silicon photonics light sources and high-speed operation.

  20. Undergraduate Experiment with Fractal Diffraction Gratings

    Science.gov (United States)

    Monsoriu, Juan A.; Furlan, Walter D.; Pons, Amparo; Barreiro, Juan C.; Gimenez, Marcos H.

    2011-01-01

    We present a simple diffraction experiment with fractal gratings based on the triadic Cantor set. Diffraction by fractals is proposed as a motivating strategy for students of optics in the potential applications of optical processing. Fraunhofer diffraction patterns are obtained using standard equipment present in most undergraduate physics…

  1. Fundamental limit of light trapping in grating structures

    KAUST Repository

    Yu, Zongfu

    2010-08-11

    We use a rigorous electromagnetic approach to analyze the fundamental limit of light-trapping enhancement in grating structures. This limit can exceed the bulk limit of 4n 2, but has significant angular dependency. We explicitly show that 2D gratings provide more enhancement than 1D gratings. We also show the effects of the grating profile’s symmetry on the absorption enhancement limit. Numerical simulations are applied to support the theory. Our findings provide general guidance for the design of grating structures for light-trapping solar cells.

  2. Development of a segmented grating mount system for FIREX-1

    International Nuclear Information System (INIS)

    Ezaki, Y; Tabata, M; Kihara, M; Horiuchi, Y; Endo, M; Jitsuno, T

    2008-01-01

    A mount system for segmented meter-sized gratings has been developed, which has a high precision grating support mechanism and drive mechanism to minimize both deformation of the optical surfaces and misalignments in setting a segmented grating for obtaining sufficient performance of the pulse compressor. From analytical calculations, deformation of the grating surface is less than 1/20 lambda RMS and the estimated drive resolution for piston and tilt drive of the segmented grating is 1/20 lambda, which are both compliant with the requirements for the rear-end subsystem of FIREX-1

  3. Metrology measurements for large-aperture VPH gratings

    Science.gov (United States)

    Zheng, Jessica R.; Gers, Luke; Heijmans, Jeroen

    2013-09-01

    The High Efficiency and Resolution Multi Element Spectrograph (HERMES) for the Australian Astronomical Observatory (AAO) uses four large aperture, high angle of incidence volume phase holographic gratings (VPHG) for high resolution `Galactic archaeology' spectroscopy. The large clear aperture, the high diffraction efficiency, the line frequency homogeneity, and mosaic alignment made manufacturing and testing challenging. We developed new metrology systems at the AAO to verify the performance of these VPH gratings. The measured diffraction efficiencies and line frequency of the VPH gratings received so far meet the vendor's provided data. The wavefront quality for the Blue VPH grating is good but the Green and Red VPH gratings need to be post polishing.

  4. Comparison of methods of alert acknowledgement by critical care clinicians in the ICU setting

    Directory of Open Access Journals (Sweden)

    Andrew M. Harrison

    2017-03-01

    Full Text Available Background Electronic Health Record (EHR-based sepsis alert systems have failed to demonstrate improvements in clinically meaningful endpoints. However, the effect of implementation barriers on the success of new sepsis alert systems is rarely explored. Objective To test the hypothesis time to severe sepsis alert acknowledgement by critical care clinicians in the ICU setting would be reduced using an EHR-based alert acknowledgement system compared to a text paging-based system. Study Design In one arm of this simulation study, real alerts for patients in the medical ICU were delivered to critical care clinicians through the EHR. In the other arm, simulated alerts were delivered through text paging. The primary outcome was time to alert acknowledgement. The secondary outcomes were a structured, mixed quantitative/qualitative survey and informal group interview. Results The alert acknowledgement rate from the severe sepsis alert system was 3% (N = 148 and 51% (N = 156 from simulated severe sepsis alerts through traditional text paging. Time to alert acknowledgement from the severe sepsis alert system was median 274 min (N = 5 and median 2 min (N = 80 from text paging. The response rate from the EHR-based alert system was insufficient to compare primary measures. However, secondary measures revealed important barriers. Conclusion Alert fatigue, interruption, human error, and information overload are barriers to alert and simulation studies in the ICU setting.

  5. Talbot Carpet Simulation for X-ray grating interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Youngju; Oh, Ohsung; Jeong, Hanseong; Kim, Jeongho; Lee, Seung Wook [Pusan National University, Busan (Korea, Republic of); Kim, Jongyul; Moon, Myungkook [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    In this study, Talbot carpet simulator has been developed to visualize the X-ray grating interference patterns in grating interferometer. We have simulated X-ray interference for a variety of simulations and demonstrated a few examples in this summary. Grating interferometer produces interference of X-ray called Talbot pattern with gratings manufactured in micro scale. Talbot pattern is self-images of phase grating which develops interference as beam splitter that is one of gratings consisted of interferometer. As the other gratings, there are source grating makes coherence and analyze grating is used to analyze interference onto detector. Talbot carpet has been studied as the beam behavior which is distinguished with common X-ray imaging systems. It is helpful to understand grating interferometer and possible to expect beams' oscillation for designing theoretically. We confirm pattern has periodicity produced by interference after pi and pi/2 phase grating and changes in the perpendicular direction to entrance face according to phase objects.

  6. Nanostructure Diffraction Gratings for Integrated Spectroscopy and Sensing

    Science.gov (United States)

    Guo, Junpeng (Inventor)

    2016-01-01

    The present disclosure pertains to metal or dielectric nanostructures of the subwavelength scale within the grating lines of optical diffraction gratings. The nanostructures have surface plasmon resonances or non-plasmon optical resonances. A linear photodetector array is used to capture the resonance spectra from one of the diffraction orders. The combined nanostructure super-grating and photodetector array eliminates the use of external optical spectrometers for measuring surface plasmon or optical resonance frequency shift caused by the presence of chemical and biological agents. The nanostructure super-gratings can be used for building integrated surface enhanced Raman scattering (SERS) spectrometers. The nanostructures within the diffraction grating lines enhance Raman scattering signal light while the diffraction grating pattern of the nanostructures diffracts Raman scattering light to different directions of propagation according to their wavelengths. Therefore, the nanostructure super-gratings allows for the use of a photodetector array to capture the surface enhanced Raman scattering spectra.

  7. Precise rotational alignment of x-ray transmission diffraction gratings

    International Nuclear Information System (INIS)

    Hill, S.L.

    1988-01-01

    Gold transmission diffraction gratings used for x-ray spectroscopy must sometimes be rotationally aligned to the axis of a diagnostic instrument to within sub-milliradian accuracy. We have fabricated transmission diffraction gratings with high line-densities (grating period of 200 and 300 nm) using uv holographic and x-ray lithography. Since the submicron features of the gratings are not optically visible, precision alignment is time consuming and difficult to verify in situ. We have developed a technique to write an optically visible alignment pattern onto these gratings using a scanning electron microscope (SEM). At high magnification (15000 X) several submicron lines of the grating are observable in the SEM, making it possible to write an alignment pattern parallel to the grating lines in an electron-beam-sensitive coating that overlays the grating. We create an alignment pattern by following a 1-cm-long grating line using the SEM's joystick-controlled translation stage. By following the same grating line we are assured the traveled direction of the SEM electron beam is parallel to the grating to better than 10 μradian. The electron-beam-exposed line-width can be large (5 to 15 μm wide) depending on the SEM magnification, and is therefore optically visible. The exposed pattern is eventually made a permanent feature of the grating by ion beam etching or gold electroplating. The pattern can be used to accurately align the grating to the axis of a diagnostic instrument. More importantly, the alignment of the grating can be quickly verified in situ

  8. The unique associations between rape acknowledgment and the DSM-5 PTSD symptom clusters.

    Science.gov (United States)

    Wilson, Laura C; Scarpa, Angela

    2017-11-01

    It is well documented in the sexual assault literature that more than half of rape survivors do not label their experience as rape. This is called unacknowledged rape. Although this phenomenon is common and undoubtedly has huge implications for psychotherapy, the impact of acknowledgment status on psychological adjustment is unclear. The present study aimed to delineate the unique impact of rape acknowledgment on psychopathology by examining PTSD symptoms at the cluster level. To examine this, 178 female college students who reported rape completed an online survey, including an assessment of PTSD symptoms in the past month. The results suggested that, after accounting for several covariates, acknowledged rape survivors reported significantly greater levels of intrusion and avoidance symptoms compared to unacknowledged rape survivors. The findings suggest that examining PTSD symptoms at the cluster level may provide more insight into the process of recovery following rape and therefore may better inform treatment decisions. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Affirmation, acknowledgment of in-group responsibility, group-based guilt, and support for reparative measures.

    Science.gov (United States)

    Cehajić-Clancy, Sabina; Effron, Daniel A; Halperin, Eran; Liberman, Varda; Ross, Lee D

    2011-08-01

    Three studies, 2 conducted in Israel and 1 conducted in Bosnia and Herzegovina, demonstrated that affirming a positive aspect of the self can increase one's willingness to acknowledge in-group responsibility for wrongdoing against others, express feelings of group-based guilt, and consequently provide greater support for reparation policies. By contrast, affirming one's group, although similarly boosting feelings of pride, failed to increase willingness to acknowledge and redress in-group wrongdoing. Studies 2 and 3 demonstrated the mediating role of group-based guilt. That is, increased acknowledgment of in-group responsibility for out-group victimization produced increased feelings of guilt, which in turn increased support for reparation policies to the victimized group. Theoretical and applied implications are discussed.

  10. The acknowledge project: toward improved efficiency in the knowledge acquisition process

    International Nuclear Information System (INIS)

    Marty, J.C.; Ramparany, F.

    1990-01-01

    This paper presents a general overview of the ACKnowledge Project (Acquisition of Knowledge). Knowledge Acquisition is a critical and time-consuming phase in the development of expert systems. The ACKnowledge project aims at improving the efficiency of knowledge acquisition by analyzing and evaluating knowledge acquisition techniques, and developing a Knowledge Engineering Workbench that supports the Knowledge Engineer from the early stage of knowledge aquisition up to the implementation of the knowledge base in large and complex application domains such as the diagnosis of dynamic computer networks

  11. Electromagnetically induced grating with Rydberg atoms

    Science.gov (United States)

    Asghar, Sobia; Ziauddin, Qamar, Shahid; Qamar, Sajid

    2016-09-01

    We present a scheme to realize electromagnetically induced grating in an ensemble of strongly interacting Rydberg atoms, which act as superatoms due to the dipole blockade mechanism. The ensemble of three-level cold Rydberg-dressed (87Rb) atoms follows a cascade configuration where a strong standing-wave control field and a weak probe pulse are employed. The diffraction intensity is influenced by the strength of the probe intensity, the control field strength, and the van der Waals (vdW) interaction. It is noticed that relatively large first-order diffraction can be obtained for low-input intensity with a small vdW shift and a strong control field. The scheme can be considered as an amicable solution to realize the atomic grating at the microscopic level, which can provide background- and dark-current-free diffraction.

  12. Theory of Fiber Optical Bragg Grating: Revisited

    Science.gov (United States)

    Tai, H.

    2003-01-01

    The reflected signature of an optical fiber Bragg grating is analyzed using the transfer function method. This approach is capable to cast all relevant quantities into proper places and provides a better physical understanding. The relationship between reflected signal, number of periods, index of refraction, and reflected wave phase is elucidated. The condition for which the maximum reflectivity is achieved is fully examined. We also have derived an expression to predict the reflectivity minima accurately when the reflected wave is detuned. Furthermore, using the segmented potential approach, this model can handle arbitrary index of refraction profiles and compare the strength of optical reflectivity of different profiles. The condition of a non-uniform grating is also addressed.

  13. Straw combustion on slow-moving grates

    DEFF Research Database (Denmark)

    Kær, Søren Knudsen

    2005-01-01

    Combustion of straw in grate-based boilers is often associated with high emission levels and relatively poor fuel burnout. A numerical grate combustion model was developed to assist in improving the combustion performance of these boilers. The model is based on a one-dimensional ‘‘walking......-column’’ approach and includes the energy equations for both the fuel and the gas accounting for heat transfer between the two phases. The model gives important insight into the combustion process and provides inlet conditions for a computational fluid dynamics analysis of the freeboard. The model predictions...... indicate the existence of two distinct combustion modes. Combustion air temperature and mass flow-rate are the two parameters determining the mode. There is a significant difference in reaction rates (ignition velocity) and temperature levels between the two modes. Model predictions were compared...

  14. Varied line-space gratings: past, present and future

    International Nuclear Information System (INIS)

    Hettrick, M.C.

    1985-08-01

    A classically ruled diffraction grating consists of grooves which are equidistant, straight and parallel. Conversely, the so-called ''holographic'' grating (formed by the interfering waves of coherent visible light), although severely constrained by the recording wavelength and recording geometry, has grooves which are typically neither equidistant, straight nor parallel. In contrast, a varied line-space (VLS) grating, in common nomenclature, is a design in which the groove positions are relatively unconstrained yet possess sufficient symmetry to permit mechanical ruling. Such seemingly exotic gratings are no longer only a theoretical curiosity, but have been ruled and used in a wide variety of applications. These include: (1) aberration-corrected normal incidence concave gratings for Seya-Namioka monochromators and optical de-multiplexers, (2) flat-field grazing incidence concave gratings for plasma diagnostics, (3) aberration-corrected grazing incidence plane gratings for space-borne spectrometers, (4) focusing grazing incidence plane grating for synchrotron radiation monochromators, and (5) wavefront generators for visible interferometry of optical surfaces (particularly aspheres). Future prospects of VLS gratings as dispersing elements, wavefront correctors and beamsplitters appear promising. The author discusses the history of VLS gratings, their present applications, and their potential in the future. 61 refs., 24 figs

  15. Response of fiber Bragg gratings to longitudinal ultrasonic waves.

    Science.gov (United States)

    Minardo, Aldo; Cusano, Andrea; Bernini, Romeo; Zeni, Luigi; Giordano, Michele

    2005-02-01

    In the last years, fiber optic sensors have been widely exploited for several sensing applications, including static and dynamic strain measurements up to acoustic detection. Among these, fiber Bragg grating sensors have been indicated as the ideal candidate for practical structural health monitoring in light of their unique advantages over conventional sensing devices. Although this class of sensors has been successfully tested for static and low-frequency measurements, the identification of sensor performances for high-frequency detection, including acoustic emission and ultrasonic investigations, is required. To this aim, the analysis of feasibilty on the use of fiber Bragg grating sensors as ultrasonic detectors has been carried out. In particular, the response of fiber Bragg gratings subjected to the longitudinal ultrasonic (US) field has been theoretically and numerically investigated. Ultrasonic field interaction has been modeled, taking into account the direct deformation of the grating pitch combined with changes in local refractive index due to the elasto-optic effect. Numerical results, obtained for both uniform and Gaussian-apodized fiber Bragg gratings, show that the grating spectrum is strongly influenced by the US field in terms of shape and central wavelength. In particular, a key parameter affecting the grating response is the ratio between the US wavelength and the grating length. Normal operation characterized by changes in wavelength of undistorted Bragg peak is possible only for US wavelengths longer than the grating length. For US wavelengths approaching the grating length, the wavelength change is accompanied by subpeaks formation and main peak amplitude modulation. This effect can be attributed to the nonuniformity of the US perturbation along the grating length. At very high US frequencies, the grating is not sensitive any longer. The results of this analysis provide useful tools for the design of grating-based ultrasound sensors for

  16. Financial flows and the New Developmentalism

    Directory of Open Access Journals (Sweden)

    Fernando J. Cardim de Carvalho

    2018-03-01

    Full Text Available ABSTRACT New Developmentalism has focused its attention on trade problems created, to a large measure, by the divergences between the exchange rate that keeps the current account of the balance of payments balanced and what it calls industrial equilibrium exchange rate, the rate that would preserve the competitiveness of manufacturing firms operating at the state-or-art frontier. ND acknowledges that these rates may be disturbed by financial flows, but the role of capital account movements may be underestimated. The paper argues that financial flows have indeed been underestimated, which may make more difficult to devise efficacious policies to correct the problem of currency overvaluation.

  17. J. Astrophys. Astr. (2014) 35, 745–746 Acknowledgments Journal of ...

    Indian Academy of Sciences (India)

    BetiCiciJoan

    Vidal, V., Chile von Fay-Siebenburgen, Robertus, Sheffield, United Kingdom. Wadadekar Yogesh, Pune, India. Wei Hao, China. Wickramasinghe Thulsi, New Jersey, United States. Wiita, Paul, J., New Jersey, United States. Yadav, Ramakant, Nainital, India. Yashiro Seiji, Washington, United States. 746. Acknowledgements.

  18. 47 CFR 80.1117 - Procedure for receipt and acknowledgement of distress alerts.

    Science.gov (United States)

    2010-10-01

    ..._locations.html. The ITU-R Recommendation can be purchased from the International Telecommunication Union... identification of the station sending the distress message, spoken three times; (3) The words THIS IS (or DE... station acknowledging receipt, spoken three times; (5) The word RECEIVED (or RRR spoken as ROMEO ROMEO...

  19. 76 FR 3859 - Trade Acknowledgment and Verification of Security-Based Swap Transactions

    Science.gov (United States)

    2011-01-21

    ... automation and the purported assignment of positions by transferring parties to third parties without notice... over-the- counter derivatives market and improve operational performance, by increasing automation... acknowledgments to their counterparties? 2. What are the current market practices with respect to confirming SBS...

  20. Acknowledging the patient with back pain: A systematic review based on thematic synthesis

    DEFF Research Database (Denmark)

    Damsgaard, Janne Brammer; Bastrup, Lene; Norlyk, Annelise

    are ignored by the health professionals, who are often concerned about identifying the cause. This can result in patients feeling mistrusted, marginalised and reluctant to speak out. Therefore, telling about experiences and perceptions is important for back patients in order to feel accepted and acknowledged...

  1. 48 CFR 252.235-7010 - Acknowledgment of support and disclaimer.

    Science.gov (United States)

    2010-10-01

    ...) contract number(s)). (b) All material, except scientific articles or papers published in scientific... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Acknowledgment of support... ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CLAUSES AND FORMS SOLICITATION PROVISIONS AND CONTRACT...

  2. Financial sector taxation: Financial activities tax or financial transaction tax?

    Directory of Open Access Journals (Sweden)

    Danuše Nerudová

    2011-01-01

    Full Text Available The recent financial crises has revealed the need to improve and ensure the stability of the financial sector to reduce negative externalities, to ensure fair and substantial contribution of the financial sector to the public finances and the need to consolidate public finance. All those needs represent substantial arguments for the discussion about the introduction of financial sector taxation. There are discussed in the paper two possible schemes of financial sector taxation – financial transaction tax and financial activities tax. The aim of the paper is to research the possibility of the introduction of financial sector taxation, to discuss the pros and cons of two major candidates on financial sector taxation – financial transaction tax and financial activities tax and to suggest the possible candidate suitable for the implementation on the EU level. Financial transaction tax represents the tool suitable mainly on global level, for only in that case enables generate sufficient financial resources. From EU point of view is considered as less suitable, for it bears the risk of reallocation. Therefore the introduction of financial activities tax on EU level is considered as a better solution for the financial sector taxation in the EU, for financial sector is exempted from value added tax. With respect to the fact, that the implementation would represent the innovative approach to the financial sector taxation, there are no empirical proves and therefore this could be the subject of further research.

  3. Financial crimes and financial misdemeanours

    OpenAIRE

    Bamford, Colin

    2007-01-01

    The author argues that undesirable behaviour in the financial markets has not been countered by appropriate controls. Article by Colin Bamford (Barrister, 3-4 South Square) published in Amicus Curiae - Journal of the Society for Advanced Legal Studies. The Journal is produced by the Society for Advanced Legal Studies at the Institute of Advanced Legal Studies, University of London.

  4. An X-ray grazing incidence phase multilayer grating

    CERN Document Server

    Chernov, V A; Mytnichenko, S V

    2001-01-01

    An X-ray grazing incidence phase multilayer grating, representing a thin grating placed on a multilayer mirror, is proposed. A high efficiency of grating diffraction can be obtained by the possibility of changing the phase shift of the wave diffracted from the multilayer under the Bragg and total external reflection conditions. A grazing incidence phase multilayer grating consisting of Pt grating stripes on a Ni/C multilayer and optimized for the hard X-ray range was fabricated. Its diffraction properties were studied at photon energies of 7 and 8 keV. The obtained maximum value of the diffraction efficiency of the +1 grating order was 9% at 7 keV and 6.5% at 8 keV. The data obtained are in a rather good accordance with the theory.

  5. Phasor analysis of binary diffraction gratings with different fill factors

    International Nuclear Information System (INIS)

    MartInez, Antonio; Sanchez-Lopez, Ma del Mar; Moreno, Ignacio

    2007-01-01

    In this work, we present a simple analysis of binary diffraction gratings with different slit widths relative to the grating period. The analysis is based on a simple phasor technique directly derived from the Huygens principle. By introducing a slit phasor and a grating phasor, the intensity of the diffracted orders and the grating's resolving power can be easily obtained without applying the usual Fourier transform operations required for these calculations. The proposed phasor technique is mathematically equivalent to the Fourier transform calculation of the diffraction order amplitude, and it can be useful to explain binary diffraction gratings in a simple manner in introductory physics courses. This theoretical analysis is illustrated with experimental results using a liquid crystal device to display diffraction gratings with different fill factors

  6. Phasor analysis of binary diffraction gratings with different fill factors

    Energy Technology Data Exchange (ETDEWEB)

    MartInez, Antonio [Departamento de Ciencia de Materiales, Optica y TecnologIa Electronica, Universidad Miguel Hernandez, 03202 Elche (Spain); Sanchez-Lopez, Ma del Mar [Instituto de BioingenierIa y Departamento de Fisica y Arquitectura de Computadores, Universidad Miguel Hernandez, 03202 Elche (Spain); Moreno, Ignacio [Departamento de Ciencia de Materiales, Optica y TecnologIa Electronica, Universidad Miguel Hernandez, 03202 Elche (Spain)

    2007-09-11

    In this work, we present a simple analysis of binary diffraction gratings with different slit widths relative to the grating period. The analysis is based on a simple phasor technique directly derived from the Huygens principle. By introducing a slit phasor and a grating phasor, the intensity of the diffracted orders and the grating's resolving power can be easily obtained without applying the usual Fourier transform operations required for these calculations. The proposed phasor technique is mathematically equivalent to the Fourier transform calculation of the diffraction order amplitude, and it can be useful to explain binary diffraction gratings in a simple manner in introductory physics courses. This theoretical analysis is illustrated with experimental results using a liquid crystal device to display diffraction gratings with different fill factors.

  7. Towards freeform curved blazed gratings using diamond machining

    Science.gov (United States)

    Bourgenot, C.; Robertson, D. J.; Stelter, D.; Eikenberry, S.

    2016-07-01

    Concave blazed gratings greatly simplify the architecture of spectrographs by reducing the number of optical components. The production of these gratings using diamond-machining offers practically no limits in the design of the grating substrate shape, with the possibility of making large sag freeform surfaces unlike the alternative and traditional method of holography and ion etching. In this paper, we report on the technological challenges and progress in the making of these curved blazed gratings using an ultra-high precision 5 axes Moore-Nanotech machine. We describe their implementation in an integral field unit prototype called IGIS (Integrated Grating Imaging Spectrograph) where freeform curved gratings are used as pupil mirrors. The goal is to develop the technologies for the production of the next generation of low-cost, compact, high performance integral field unit spectrometers.

  8. Apodized grating coupler using fully-etched nanostructures

    International Nuclear Information System (INIS)

    Wu Hua; Li Chong; Guo Xia; Li Zhi-Yong

    2016-01-01

    A two-dimensional apodized grating coupler for interfacing between single-mode fiber and photonic circuit is demonstrated in order to bridge the mode gap between the grating coupler and optical fiber. The grating grooves of the grating couplers are realized by columns of fully etched nanostructures, which are utilized to digitally tailor the effective refractive index of each groove in order to obtain the Gaussian-like output diffractive mode and then enhance the coupling efficiency. Compared with that of the uniform grating coupler, the coupling efficiency of the apodized grating coupler is increased by 4.3% and 5.7%, respectively, for the nanoholes and nanorectangles as refractive index tunes layer. (paper)

  9. Grate-firing of biomass for heat and power production

    DEFF Research Database (Denmark)

    Yin, Chungen; Rosendahl, Lasse; Kær, Søren Knudsen

    2008-01-01

    bed on the grate, and the advanced secondary air supply (a real breakthrough in this technology) are highlighted for grate-firing systems. Amongst all the issues or problems associated with grate-fired boilers burning biomass, primary pollutant formation and control, deposition formation and corrosion......As a renewable and environmentally friendly energy source, biomass (i.e., any organic non-fossil fuel) and its utilization are gaining an increasingly important role worldwide Grate-firing is one of the main competing technologies in biomass combustion for heat and power production, because it can...... combustion mechanism, the recent breakthrough in the technology, the most pressing issues, the current research and development activities, and the critical future problems to be resolved. The grate assembly (the most characteristic element in grate-fired boilers), the key combustion mechanism in the fuel...

  10. Highly sensitive detection of molecular interactions with plasmonic optical fiber grating sensors.

    Science.gov (United States)

    Voisin, Valérie; Pilate, Julie; Damman, Pascal; Mégret, Patrice; Caucheteur, Christophe

    2014-01-15

    Surface Plasmon resonance (SPR) optical fiber biosensors constitute a miniaturized counterpart to the bulky prism configuration and offer remote operation in very small volumes of analyte. They are a cost-effective and relatively straightforward technique to yield in situ (or even possibly in vivo) molecular detection. The biosensor configuration reported in this work uses nanometric-scale gold-coated tilted fiber Bragg gratings (TFBGs) interrogated by light polarized radially to the optical fiber outer surface, so as to maximize the optical coupling with the SPR. These gratings were recently associated to aptamers to assess their label-free biorecognition capability in buffer and serum solutions. In this work, using the well-acknowledged biotin-streptavidin pair as a benchmark, we go forward in the demonstration of their unique sensitivity. In addition to the monitoring of the self-assembled monolayer (SAM) in real time, we report an unprecedented limit of detection (LOD) as low as 2 pM. Finally, an immunosensing experiment is realized with human transferrin (dissociation constant Kd~10(-8) M(-1)). It allows to assess both the reversibility and the robustness of the SPR-TFBG biosensors and to confirm their high sensitivity. © 2013 Published by Elsevier B.V.

  11. The cross waveguide grating: proposal, theory and applications.

    Science.gov (United States)

    Muñoz, Pascual; Pastor, Daniel; Capmany, José

    2005-04-18

    In this paper a novel grating-like integrated optics device is proposed, the Cross Waveguide Grating (XWG). The device is based upon a modified configuration of a traditional Arrayed Waveguide Grating (AWG). The Arrayed Waveguides part is changed, as detailed along this document, giving the device both the ability of multi/demultiplexing and power splitting/coupling. Design examples and transfer function simulations show good agreement with the presented theory. Finally, some of the envisaged applications are outlined.

  12. Observation of narrowband intrinsic spectra of Brillouin dynamic gratings.

    Science.gov (United States)

    Song, Kwang Yong; Yoon, Hyuk Jin

    2010-09-01

    We experimentally demonstrate that the reflection spectrum of a Brillouin dynamic grating in a polarization-maintaining fiber can be much narrower than the intrinsic linewidth of the stimulated Brillouin scattering, matching well with the theory of a fiber Bragg grating in terms of the linewidth and the reflectivity. A 3 dB bandwidth as narrow as 10.5 MHz is observed with the Brillouin dynamic grating generated in a 9 m uniform fiber.

  13. Department of Defense Agency Financial Report for FY 2010

    Science.gov (United States)

    2010-11-15

    and upgrades, or to calculate depreciation . DOD acknowledged that it did not meet U.S. GAAP for the financial reporting of personal property, and...and accounts payable, do not comply with Generally Accepted Accounting Principles ( GAAP ) because they are dependent on the noncompliant legacy...principles generally accepted in the United States of America (U.S. GAAP ) and that DOD financial management and feeder systems were unable to adequately

  14. Cu-exchanged heteropoly acids as efficient and reusable catalysts ...

    Indian Academy of Sciences (India)

    Administrator

    neous catalysts has received considerable interest in different areas of organic ... easily recovered from the reaction mixture by simple filtration and can be re-used after ..... Acknowledgements. We gratefully acknowledge the financial support.

  15. Nanoporous Polymeric Grating-Based Optical Biosensors (Preprint)

    National Research Council Canada - National Science Library

    Hsiao, Vincent K; Waldeisen, John R; Lloyd, Pamela F; Bunning, Timothy J; Huang, Tony J

    2007-01-01

    .... The fabrication process of the nanoporous polymeric grating involves holographic interference patterning and a functionalized pre-polymer syrup that facilitates the immobilization of biomolecules...

  16. High-mechanical-strength single-pulse draw tower gratings

    Science.gov (United States)

    Rothhardt, Manfred W.; Chojetzki, Christoph; Mueller, Hans Rainer

    2004-11-01

    The inscription of fiber Bragg gratings during the drawing process is a very useful method to realize sensor arrays with high numbers of gratings and excellent mechanical strength and also type II gratings with high temperature stability. Results of single pulse grating arrays with numbers up to 100 and definite wavelengths and positions for sensor applications were achieved at 1550 nm and 830 nm using new photosensitive fibers developed in IPHT. Single pulse type I gratings at 1550 nm with more than 30% reflectivity were shown first time to our knowledge. The mechanical strength of this fiber with an Ormocer coating with those single pulse gratings is the same like standard telecom fibers. Weibull plots of fiber tests will be shown. At 830 nm we reached more than 10% reflectivity with single pulse writing during the fiber drawing in photosensitive fibers with less than 16 dB/km transmission loss. These gratings are useful for stress and vibration sensing applications. Type II gratings with reflectivity near 100% and smooth spectral shape and spectral width of about 1 nm are temperature stable up to 1200 K for short time. They are also realized in the fiber drawing process. These gratings are useful for temperature sensor applications.

  17. Bragg Fibers with Soliton-like Grating Profiles

    Directory of Open Access Journals (Sweden)

    Bugaychuk S.

    2016-01-01

    Full Text Available Nonlinear dynamical system corresponding to the optical holography in a nonlocal nonlinear medium with dissipation contains stable localized spatio-temporal states, namely the grid dissipative solitons. These solitons display a non-uniform profile of the grating amplitude, which has the form of the dark soliton in the reflection geometry. The transformation of the grating amplitude gives rise many new atypical effects for the beams diffracted on such grating, and they are very suitable for the fiber Brass gratings. The damped nonlinear Schrodinger equation is derived that describes the properties of the grid dissipative soliton.

  18. Spherical grating based x-ray Talbot interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Cong, Wenxiang, E-mail: congw@rpi.edu, E-mail: xiy2@rpi.edu, E-mail: wangg6@rpi.edu; Xi, Yan, E-mail: congw@rpi.edu, E-mail: xiy2@rpi.edu, E-mail: wangg6@rpi.edu; Wang, Ge, E-mail: congw@rpi.edu, E-mail: xiy2@rpi.edu, E-mail: wangg6@rpi.edu [Biomedical Imaging Center, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

    2015-11-15

    Purpose: Grating interferometry is a state-of-the-art x-ray imaging approach, which can acquire information on x-ray attenuation, phase shift, and small-angle scattering simultaneously. Phase-contrast imaging and dark-field imaging are very sensitive to microstructural variation and offers superior contrast resolution for biological soft tissues. However, a common x-ray tube is a point-like source. As a result, the popular planar grating imaging configuration seriously restricts the flux of photons and decreases the visibility of signals, yielding a limited field of view. The purpose of this study is to extend the planar x-ray grating imaging theory and methods to a spherical grating scheme for a wider range of preclinical and clinical applications. Methods: A spherical grating matches the wave front of a point x-ray source very well, allowing the perpendicular incidence of x-rays on the grating to achieve a higher visibility over a larger field of view than the planer grating counterpart. A theoretical analysis of the Talbot effect for spherical grating imaging is proposed to establish a basic foundation for x-ray spherical gratings interferometry. An efficient method of spherical grating imaging is also presented to extract attenuation, differential phase, and dark-field images in the x-ray spherical grating interferometer. Results: Talbot self-imaging with spherical gratings is analyzed based on the Rayleigh–Sommerfeld diffraction formula, featuring a periodic angular distribution in a polar coordinate system. The Talbot distance is derived to reveal the Talbot self-imaging pattern. Numerical simulation results show the self-imaging phenomenon of a spherical grating interferometer, which is in agreement with the theoretical prediction. Conclusions: X-ray Talbot interferometry with spherical gratings has a significant practical promise. Relative to planar grating imaging, spherical grating based x-ray Talbot interferometry has a larger field of view and

  19. Spherical grating based x-ray Talbot interferometry

    International Nuclear Information System (INIS)

    Cong, Wenxiang; Xi, Yan; Wang, Ge

    2015-01-01

    Purpose: Grating interferometry is a state-of-the-art x-ray imaging approach, which can acquire information on x-ray attenuation, phase shift, and small-angle scattering simultaneously. Phase-contrast imaging and dark-field imaging are very sensitive to microstructural variation and offers superior contrast resolution for biological soft tissues. However, a common x-ray tube is a point-like source. As a result, the popular planar grating imaging configuration seriously restricts the flux of photons and decreases the visibility of signals, yielding a limited field of view. The purpose of this study is to extend the planar x-ray grating imaging theory and methods to a spherical grating scheme for a wider range of preclinical and clinical applications. Methods: A spherical grating matches the wave front of a point x-ray source very well, allowing the perpendicular incidence of x-rays on the grating to achieve a higher visibility over a larger field of view than the planer grating counterpart. A theoretical analysis of the Talbot effect for spherical grating imaging is proposed to establish a basic foundation for x-ray spherical gratings interferometry. An efficient method of spherical grating imaging is also presented to extract attenuation, differential phase, and dark-field images in the x-ray spherical grating interferometer. Results: Talbot self-imaging with spherical gratings is analyzed based on the Rayleigh–Sommerfeld diffraction formula, featuring a periodic angular distribution in a polar coordinate system. The Talbot distance is derived to reveal the Talbot self-imaging pattern. Numerical simulation results show the self-imaging phenomenon of a spherical grating interferometer, which is in agreement with the theoretical prediction. Conclusions: X-ray Talbot interferometry with spherical gratings has a significant practical promise. Relative to planar grating imaging, spherical grating based x-ray Talbot interferometry has a larger field of view and

  20. Fiber facet gratings for high power fiber lasers

    Science.gov (United States)

    Vanek, Martin; Vanis, Jan; Baravets, Yauhen; Todorov, Filip; Ctyroky, Jiri; Honzatko, Pavel

    2017-12-01

    We numerically investigated the properties of diffraction gratings designated for fabrication on the facet of an optical fiber. The gratings are intended to be used in high-power fiber lasers as mirrors either with a low or high reflectivity. The modal reflectance of low reflectivity polarizing grating has a value close to 3% for TE mode while it is significantly suppressed for TM mode. Such a grating can be fabricated on laser output fiber facet. The polarizing grating with high modal reflectance is designed as a leaky-mode resonant diffraction grating. The grating can be etched in a thin layer of high index dielectric which is sputtered on fiber facet. We used refractive index of Ta2O5 for such a layer. We found that modal reflectance can be close to 0.95 for TE polarization and polarization extinction ratio achieves 18 dB. Rigorous coupled wave analysis was used for fast optimization of grating parameters while aperiodic rigorous coupled wave analysis, Fourier modal method and finite difference time domain method were compared and used to compute modal reflectance of designed gratings.

  1. Funding Acknowledgements in the Web of Science: inconsistencies in data collection and standardization of funding organizations

    Energy Technology Data Exchange (ETDEWEB)

    Van Honk, J.; Calero-Medina, C.; Costas, R.

    2016-07-01

    Funding acknowledgements (FAs), as provided by the Web of Science, are a recent inclusion in the bibliometric toolset. They are starting to be used to study the presence, relationships and effects of funding and funders in the production of new scientific research. The incorporation of this new source of information comes with the need to understand how these data are collected and indexed in the database. This paper discusses important inconsistencies related to the method by which the data for FA and funders are selected, extracted and indexed by WoS, thereby highlighting the need to construct a thesaurus for the data. Problematic areas are found to be the quality of the input data and the conceptualization of what does and does not constitute a funding acknowledgement. Based on this critical analysis of the data and the identification of the main issues, we provide several recommendations for researchers, funders, WoS and other users of the data. (Author)

  2. High-accuracy measurement and compensation of grating line-density error in a tiled-grating compressor

    Science.gov (United States)

    Zhao, Dan; Wang, Xiao; Mu, Jie; Li, Zhilin; Zuo, Yanlei; Zhou, Song; Zhou, Kainan; Zeng, Xiaoming; Su, Jingqin; Zhu, Qihua

    2017-02-01

    The grating tiling technology is one of the most effective means to increase the aperture of the gratings. The line-density error (LDE) between sub-gratings will degrade the performance of the tiling gratings, high accuracy measurement and compensation of the LDE are of significance to improve the output pulses characteristics of the tiled-grating compressor. In this paper, the influence of LDE on the output pulses of the tiled-grating compressor is quantitatively analyzed by means of numerical simulation, the output beams drift and output pulses broadening resulting from the LDE are presented. Based on the numerical results we propose a compensation method to reduce the degradations of the tiled grating compressor by applying angular tilt error and longitudinal piston error at the same time. Moreover, a monitoring system is setup to measure the LDE between sub-gratings accurately and the dispersion variation due to the LDE is also demonstrated based on spatial-spectral interference. In this way, we can realize high-accuracy measurement and compensation of the LDE, and this would provide an efficient way to guide the adjustment of the tiling gratings.

  3. TRAILER Project Overview. Tagging, Recognition and Acknowledgment of Informal Learning ExpeRiences

    NARCIS (Netherlands)

    García-Peñalvo, Francisco J.; Zangrando, Valentina; García Holgado, Alicia; Conde González, Miguel Ángel; Seoane Pardo, Antonio; Alier Forment, Marc; Janssen, José; Griffiths, Dai; Mykowska, Aleksandra; Ribeiro Alves, Gustavo; Minovic, Miroslav

    2012-01-01

    García-Peñalvo, F. J., Zangrando, V., García Holgado, A., Conde González, M. Á., Seoane Pardo, A. M., Alier Forment, M., Janssen, J., et al. (2012). TRAILER Project Overview. Tagging, Recognition and Acknowledgment of Informal Learning ExpeRiences. In F. J. García, L. Vicent, M. Ribó, A. Climent, J.

  4. COACHES' PERCEPTIONS OF COMPETENCE AND ACKNOWLEDGEMENT OF TRAINING NEEDS RELATED TO PROFESSIONAL COMPETENCES

    Directory of Open Access Journals (Sweden)

    Sofia Santos

    2010-03-01

    Full Text Available The purpose of the present study was to examine coaches' perceptions of competence and acknowledgement of training needs related to professional competences according to the professional experience and academic education. The participants were 343 coaches from several sports, who answered to a questionnaire that includes a scale focused on perceptions of competence and another scale on acknowledgment of training needs. An exploratory factor analysis with Maximum Likelihood Factoring was used with Oblimin rotation for the identification of emergent factors. Comparison on coaches' perceptions in function of coaching experience and coaches' academic background were made applying One-way ANOVA and Tukey's post hoc multiple comparisons. Factor analysis on coaches' perceptions of competence and acknowledgement of training needs made apparent three main areas of competences, i.e. competences related to annual and multi-annual planning; competences related to orientation towards practice and competition; and personal and coaching education competences. Coaches' perceptions were influenced by their experience, as low experienced coaches rated themselves at lower levels of competence and with more training needs; also coaches with high education, in Physical Education or others, perceived themselves as more competent than coaches with no higher education. Finally, the majority of the coaches perceived themselves to be competent but, nevertheless, they indicated to have training needs, which brings an important feedback to coach education. This suggests that coaches are interested in increasing their knowledge and competence in a broad range of areas which should be considered in future coach education programs

  5. Streaked, x-ray-transmission-grating spectrometer

    International Nuclear Information System (INIS)

    Ceglio, N.M.; Roth, M.; Hawryluk, A.M.

    1981-08-01

    A free standing x-ray transmission grating has been coupled with a soft x-ray streak camera to produce a time resolved x-ray spectrometer. The instrument has a temporal resolution of approx. 20 psec, is capable of covering a broad spectral range, 2 to 120 A, has high sensitivity, and is simple to use requiring no complex alignment procedure. In recent laser fusion experiments the spectrometer successfully recorded time resolved spectra over the range 10 to 120 A with a spectral resolving power, lambda/Δlambda of 4 to 50, limited primarily by source size and collimation effects

  6. Financial Statements Analysis

    OpenAIRE

    Tănase Alin-Eliodor

    2014-01-01

    This article focuses on analyzing of a consolidated financial statements of a hypothetically SME. The interpretation of the financial position and performances is based on the more than 40 financial key ratios computed by using financial data from consolidated income statement, consolidated financial position and cash flow. However additional data from notes to financial statements are provided.

  7. Understanding Financial Statements. Financial Matters. Board Basics.

    Science.gov (United States)

    McCarthy, John H.; Turner, Robert M.

    1998-01-01

    This booklet for trustees of higher education institutions offers guidelines to help trustees understand the institution's financial statements. Individual sections describe the three major financial statements and cover topics such as: (1) standards of the Financial Accounting Standards Board; (2) the "statement of financial position,"…

  8. Polynomial modal analysis of lamellar diffraction gratings in conical mounting.

    Science.gov (United States)

    Randriamihaja, Manjakavola Honore; Granet, Gérard; Edee, Kofi; Raniriharinosy, Karyl

    2016-09-01

    An efficient numerical modal method for modeling a lamellar grating in conical mounting is presented. Within each region of the grating, the electromagnetic field is expanded onto Legendre polynomials, which allows us to enforce in an exact manner the boundary conditions that determine the eigensolutions. Our code is successfully validated by comparison with results obtained with the analytical modal method.

  9. Linear Fresnel Spectrometer Chip with Gradient Line Grating

    Science.gov (United States)

    Choi, Sang Hyouk (Inventor); Park, Yeonjoon (Inventor)

    2015-01-01

    A spectrometer that includes a grating that disperses light via Fresnel diffraction according to wavelength onto a sensing area that coincides with an optical axis plane of the grating. The sensing area detects the dispersed light and measures the light intensity associated with each wavelength of the light. Because the spectrometer utilizes Fresnel diffraction, it can be miniaturized and packaged as an integrated circuit.

  10. Electromagnetically induced two-dimensional grating assisted by incoherent pump

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yu-Yuan; Liu, Zhuan-Zhuan; Wan, Ren-Gang, E-mail: wrg@snnu.edu.cn

    2017-04-25

    We propose a scheme for realizing electromagnetically induced two-dimensional grating in a double-Λ system driven simultaneously by a coherent field and an incoherent pump field. In such an atomic configuration, the absorption is suppressed owing to the incoherent pumping process and the probe can be even amplified, while the refractivity is mainly attributed to the dynamically induced coherence. With the help of a standing-wave pattern coherent field, we obtain periodically modulated refractive index without or with gain, and therefore phase grating or gain-phase grating which diffracts a probe light into high-order direction efficiently can be formed in the medium via appropriate manipulation of the system parameters. The diffraction efficiency attainable by the present gratings can be controlled by tuning the coherent field intensity or the interaction length. Hence, the two-dimensional grating can be utilized as all-optical splitter or router in optical networking and communication. - Highlights: • Two-dimensional grating is coherently induced in four-level atoms. • Phase and gain-phase gratings are obtained assisted by incoherent pump. • The diffraction power is improved due to the enhanced refraction modulation. • The gratings can be utilized as multi-channel all-optical splitter and router.

  11. Discrete dipole approximation simulation of bead enhanced diffraction grating biosensor

    International Nuclear Information System (INIS)

    Arif, Khalid Mahmood

    2016-01-01

    We present the discrete dipole approximation simulation of light scattering from bead enhanced diffraction biosensor and report the effect of bead material, number of beads forming the grating and spatial randomness on the diffraction intensities of 1st and 0th orders. The dipole models of gratings are formed by volume slicing and image processing while the spatial locations of the beads on the substrate surface are randomly computed using discrete probability distribution. The effect of beads reduction on far-field scattering of 632.8 nm incident field, from fully occupied gratings to very coarse gratings, is studied for various bead materials. Our findings give insight into many difficult or experimentally impossible aspects of this genre of biosensors and establish that bead enhanced grating may be used for rapid and precise detection of small amounts of biomolecules. The results of simulations also show excellent qualitative similarities with experimental observations. - Highlights: • DDA was used to study the relationship between the number of beads forming gratings and ratio of first and zeroth order diffraction intensities. • A very flexible modeling program was developed to design complicated objects for DDA. • Material and spatial effects of bead distribution on surfaces were studied. • It has been shown that bead enhanced grating biosensor can be useful for fast detection of small amounts of biomolecules. • Experimental results qualitatively support the simulations and thus open a way to optimize the grating biosensors.

  12. Photoanisotropic polarization gratings beyond the small recording angle regime

    NARCIS (Netherlands)

    Xu, M.; De Boer, D.K.G.; Van Heesch, C.M.; Wachters, A.J.H.; Urbach, H.P.

    2010-01-01

    Polarization gratings can be realized by polarization holographic recording in photoanisotropic materials. In this paper, we study two types of polarization gratings. One is recorded with two orthogonally circularly (OC) polarized beams and the other one with two orthogonally linearly (OL) polarized

  13. Holographic gratings in photorefractive polymers without external electric field

    DEFF Research Database (Denmark)

    Kukhtarev, N.; Lyuksyutov, S.; Buchhave, Preben

    1997-01-01

    Using anomalous large diffusion we report a recording of reflection type gratings in a PVK-based photorefractive polymer without any external electric field. The diffraction efficiency of the gratings was measured to be 7%. An efficient modulation of beams during two-beam coupling up to 12...

  14. Smith-Purcell radiation from concave dotted gratings

    Science.gov (United States)

    Sergeeva, D. Yu.; Tishchenko, A. A.; Aryshev, A. S.; Strikhanov, M. N.

    2018-02-01

    We present the first-principles theory of Smith-Purcell effect from the concave dotted grating consisting of bent chains of separated micro- or nanoparticles. The numerical analysis demonstrates that the obtained spectral-angular distributions change significantly depending on the structure of the grating.

  15. Talbot effect of the defective grating in deep Fresnel region

    Science.gov (United States)

    Teng, Shuyun; Wang, Junhong; Zhang, Wei; Cui, Yuwei

    2015-02-01

    Talbot effect of the grating with different defect is studied theoretically and experimentally in this paper. The defects of grating include the loss of the diffraction unit, the dislocation of the diffraction unit and the modulation of the unit separation. The exact diffraction distributions of three kinds of defective gratings are obtained according to the finite-difference time-domain (FDTD) method. The calculation results show the image of the missing or dislocating unit appears at the Talbot distance (as mentioned in K. Patorski Prog. Opt., 27, 1989, pp.1-108). This is the so-called self-repair ability of grating imaging. In addition, some more phenomena are discovered. The loss or the dislocation of diffraction unit causes the diffraction distortion within a certain radial angle. The regular modulation of unit separation changes the original diffraction, but the new periodicity of the diffraction distribution rebuilds. The self-imaging of grating with smaller random modulation still keeps the partial self-repair ability, and yet this characteristic depends on the modulation degree of defective grating. These diffraction phenomena of the defective gratings are explained by use of the diffraction theory of grating. The practical experiment is also performed and the experimental results confirm the theoretic predictions.

  16. Analysis of the optical parameters of phase holographic gratings

    Directory of Open Access Journals (Sweden)

    Є.О. Тихонов

    2008-03-01

    Full Text Available  Suitability of 2- wave approximation of the coupled waves theory tor description of holographic phase gratings recorded on photopolymer compound ФПК-488 is proved. Using the basic formulas of the theory, main grating optical parameters - a depth of modulation and finished thickness are not measured immediately are determined.

  17. Slit and phase grating diffraction with a double crystal diffractometer

    International Nuclear Information System (INIS)

    Treimer, Wolfgang; Hilger, Andre; Strobl, Markus

    2006-01-01

    The lateral coherence properties of a neutron beam (λ=0.5248nm) in a double crystal diffractometer (DCD) were studied by means of single slit diffraction and by diffraction by different perfect Silicon phase gratings. Perfect agreements were found for the lateral coherence length measured with the slit and for the one determined by Silicon phase gratings, however, some peculiarities are still present

  18. The Off-plane Grating Rocket Experiment

    Science.gov (United States)

    Donovan, Benjamin

    2018-01-01

    The next generation of X-ray spectrometers necessitate significant increases in both resolution and effective area to achieve the science goals set forth in the 2010 Decadal Survey and the 2013 Astrophysics Roadmap. The Off-plane Grating Rocket Experiment (OGRE), an X-ray spectroscopy suborbital rocket payload currently scheduled for launch in Q3 2020, will serve as a testbed for several key technologies which can help achieve the desired performance increases of future spectrometers. OGRE will be the first instrument to fly mono-crystalline silicon X-ray mirrors developed at NASA Goddard Space Flight Center. The payload will also utilize an array of off-plane gratings manufactured at The Pennsylvania State University. Additionally, the focal plane will be populated with an array of four electron-multiplying CCDs developed by the Open University and XCAM Ltd. With these key technologies, OGRE hopes to achieve the highest resolution on-sky soft X-ray spectrum to date. We discuss the optical design, expected performance, and the current status of the payload.

  19. Magnetoresistance and magnetization in submicron ferromagnetic gratings

    Science.gov (United States)

    Shearwood, C.; Blundell, S. J.; Baird, M. J.; Bland, J. A. C.; Gester, M.; Ahmed, H.; Hughes, H. P.

    1994-05-01

    A technique for engineering micron and submicron scale structures from magnetic films of transition metals has been developed using a combination of electron- and ion-beam lithography enabling high-quality arrays of submicron magnetic Fe wires to be fabricated. This process can be used to fabricate novel devices from a variety of metal combinations which would not be possible by the usual liftoff metallization method. The structure and magnetic properties are reported of an epitaxial 25 nm Fe(001)/GaAs(001) film and the wire gratings which are fabricated from it. The width of the wires in the grating is 0.5 μm for all structures studied, but the separation of each wire is varied in the range 0.5 to 16 μm. An artificially induced shape anisotropy field of around 1 kG, consistent with a magnetostatic calculation, was observed for all separations studied. The field dependence of the magneto-optic Kerr effect and magnetoresistance (MR) data is consistent with a twisted magnetization configuration across the width of the sample beneath saturation for transverse applied fields. In this case, the detailed form of the field dependence of the MR is strikingly modified from that observed in the continuous film and is consistent with coherent rotation of the magnetization.

  20. Study on talbot pattern for grating interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Ju; Oh, Oh Sung; Lee, Seung Wook [Dept. of School of Mechanical Engineering, Pusan National University, Busan (Korea, Republic of); Kim, Jong Yul [Neutron Instrument Division, Korea Atomic Energy Reserch Institute, Daejeon (Korea, Republic of)

    2015-04-15

    One of properties which X-ray and Neutron can be applied nondestructive test is penetration into the object with interaction leads to decrease in intensity. X-ray interaction with the matter caused by electrons, Neutron caused by atoms. They share applications in nondestructive test area because of their similarities of interaction mechanism. Grating interferometer is the one of applications produces phase contrast image and dark field image. It is defined by Talbot interferometer and Talbot-Lau interferometer according to Talbot effect and Talbot-Lau effect respectively. Talbot interferometer works with coherence beam like X-ray, and Talbot-Lau has an effect with incoherence beam like Neutron. It is important to expect the interference in grating interferometer compared normal nondestructive system. In this paper, simulation works are conducted according to Talbot and Talbot-Lau interferometer in case of X-ray and Neutron. Variation of interference intensity with X-ray and Neutron based on wave theory is constructed and calculate elements consist the system. Additionally, Talbot and Talbot-Lau interferometer is simulated in different kinds of conditions.

  1. A Single-Element Plane Grating Monochromator

    Directory of Open Access Journals (Sweden)

    Michael C. Hettrick

    2016-01-01

    Full Text Available Concerted rotations of a self-focused varied line-space diffraction grating about its groove axis and surface normal define a new geometric class of monochromator. Defocusing is canceled, while the scanned wavelength is reinforced at fixed conjugate distances and horizontal deviation angle. This enables high spectral resolution over a wide band, and is of particular advantage at grazing reflection angles. A new, rigorous light-path formulation employs non-paraxial reference points to isolate the lateral ray aberrations, with those of power-sum ≤ 3 explicitly expanded for a plane grating. Each of these 14 Fermat equations agrees precisely with the value extracted from numerical raytrace simulations. An example soft X-ray design (6° deviation angle and 2 × 4 mrad aperture attains a resolving power > 25 , 000 over a three octave scan range. The proposed rotation scheme is not limited to plane surfaces or monochromators, providing a new degree of freedom in optical design.

  2. Modern Theory of Gratings Resonant Scattering: Analysis Techniques and Phenomena

    CERN Document Server

    Sirenko, Yuriy K

    2010-01-01

    Diffraction gratings are one of the most popular objects of analysis in electromagnetic theory. The requirements of applied optics and microwave engineering lead to many new problems and challenges for the theory of diffraction gratings, which force us to search for new methods and tools for their resolution. In Modern Theory of Gratings, the authors present results of the electromagnetic theory of diffraction gratings that will constitute the base of further development of this theory, which meet the challenges provided by modern requirements of fundamental and applied science. This volume covers: spectral theory of gratings (Chapter 1) giving reliable grounds for physical analysis of space-frequency and space-time transformations of the electromagnetic field in open periodic resonators and waveguides; authentic analytic regularization procedures (Chapter 2) that, in contradistinction to the traditional frequency-domain approaches, fit perfectly for the analysis of resonant wave scattering processes; paramet...

  3. Polarization sensitivity testing of off-plane reflection gratings

    Science.gov (United States)

    Marlowe, Hannah; McEntaffer, Randal L.; DeRoo, Casey T.; Miles, Drew M.; Tutt, James H.; Laubis, Christian; Soltwisch, Victor

    2015-09-01

    Off-Plane reflection gratings were previously predicted to have different efficiencies when the incident light is polarized in the transverse-magnetic (TM) versus transverse-electric (TE) orientations with respect to the grating grooves. However, more recent theoretical calculations which rigorously account for finitely conducting, rather than perfectly conducting, grating materials no longer predict significant polarization sensitivity. We present the first empirical results for radially ruled, laminar groove profile gratings in the off-plane mount which demonstrate no difference in TM versus TE efficiency across our entire 300-1500 eV bandpass. These measurements together with the recent theoretical results confirm that grazing incidence off-plane reflection gratings using real, not perfectly conducting, materials are not polarization sensitive.

  4. Unified design of sinusoidal-groove fused-silica grating.

    Science.gov (United States)

    Feng, Jijun; Zhou, Changhe; Cao, Hongchao; Lu, Peng

    2010-10-20

    A general design rule of deep-etched subwavelength sinusoidal-groove fused-silica grating as a highly efficient polarization-independent or polarization-selective device is studied based on the simplified modal method, which shows that the device structure depends little on the incident wavelength, but mainly on the ratio of groove depth to incident wavelength and the ratio of wavelength to grating period. These two ratios could be used as the design guidelines for wavelength-independent structure from deep ultraviolet to far infrared. The optimized grating profile with a different function as a polarizing beam splitter, a polarization-independent two-port beam splitter, or a polarization-independent grating with high efficiency of -1st order is obtained at a wavelength of 1064 nm, and verified by using the rigorous coupled-wave analysis. The performance of the sinusoidal grating is better than a conventional rectangular one, which could be useful for practical applications.

  5. Self Referencing Heterodyne Transient Grating Spectroscopy with Short Wavelength

    Directory of Open Access Journals (Sweden)

    Jakob Grilj

    2015-04-01

    Full Text Available Heterodyning by a phase stable reference electric field is a well known technique to amplify weak nonlinear signals. For short wavelength, the generation of a reference field in front of the sample is challenging because of a lack of suitable beamsplitters. Here, we use a permanent grating which matches the line spacing of the transient grating for the creation of a phase stable reference field. The relative phase among the two can be changed by a relative translation of the permanent and transient gratings in direction orthogonal to the grating lines. We demonstrate the technique for a transient grating on a VO2 thin film and observe constructive as well as destructive interference signals.

  6. Diffraction efficiency calculations of polarization diffraction gratings with surface relief

    Science.gov (United States)

    Nazarova, D.; Sharlandjiev, P.; Berberova, N.; Blagoeva, B.; Stoykova, E.; Nedelchev, L.

    2018-03-01

    In this paper, we evaluate the optical response of a stack of two diffraction gratings of equal one-dimensional periodicity. The first one is a surface-relief grating structure; the second, a volume polarization grating. This model is based on our experimental results from polarization holographic recordings in azopolymer films. We used films of commercially available azopolymer (poly[1-[4-(3-carboxy-4-hydroxyphenylazo) benzenesulfonamido]-1,2-ethanediyl, sodium salt]), shortly denoted as PAZO. During the recording process, a polarization grating in the volume of the material and a relief grating on the film surface are formed simultaneously. In order to evaluate numerically the optical response of this “hybrid” diffraction structure, we used the rigorous coupled-wave approach (RCWA). It yields stable numerical solutions of Maxwell’s vector equations using the algebraic eigenvalue method.

  7. The influence of grating shape formation fluctuation on DFB laser diode threshold condition

    Science.gov (United States)

    Bao, Shiwei; Song, Qinghai; Xie, Chunmei

    2018-03-01

    Not only the grating material refractive index itself but also the Bragg grating physical shape formation affects the coupling strength greatly. The Bragg grating shape includes three factors, namely grating depth, duty ratio and grating angle. During the lithography and wet etching process, there always will be some fluctuation between the target and real grating shape formation after fabrication process. This grating shape fluctuation will affect the DFB coupling coefficient κ , and then consequently threshold current and corresponding wavelength. This paper studied the grating shape formation fluctuation influence to improve the DFB fabrication yield. A truncated normal random distribution fluctuation is considered in this paper. The simulation results conclude that it is better to choose relative thicker grating depth with lower refractive index to obtain a better fabrication tolerance, while not quite necessary to spend too much effort on improving lithography and wet etching process to get a precisely grating duty ratio and grating angle.

  8. FINANCIAL DEPTH AND FINANCIAL ACCESS IN INDONESIA

    Directory of Open Access Journals (Sweden)

    Sigit Setiawan

    2015-05-01

    Full Text Available This study is intended to analyze the current levels of financial depth and financial access in Indonesia and to analyze the factors affecting them. The analysis method used was a combination of descriptive quantitative, benchmarking, and literature reviews. The conclusion is that the financial depth in Indonesia has not shown a satisfactory level since it was the lowest, or the second lowest ranked country among the sampled countries. Meanwhile, the financial access in Indonesia is relatively better than its financial depth, especially for financial markets, in which Indonesia ranks in the lower average group. From literature reviews, it can be inferred that the main factor driving the poor financial depth in Indonesia is non-competitiveness of the institutions; whereas the driving force of poor financial access in Indonesia are geographical constraints, poverty, a high income gap, and a less than effective national financial development policy.

  9. On results of monitoring of environmental radiation around Rokkasho reprocessing facilities (fiscal year 1995) (acknowledgement)

    International Nuclear Information System (INIS)

    1997-01-01

    The Nuclear Safety Commission received the report on this matter from the expert committee on environmental radiation monitoring central evaluation on August 30, 1996, and acknowledged it after the deliberation. The report was recognized as appropriate. The monitoring was carried out according to the monitoring plan for environmental radiation around Rokkasho reprocessing facilities. The monitoring plan is outlined. At the time of the deliberation, the propriety of the techniques of monitoring and technical level carried out by Japan Nuclear Fuel Service Co. was examined. As the result, it was confirmed that the techniques of monitoring and technical level were appropriate. The results of monitoring are reported. (K.I.)

  10. FINANCIAL INSTABILITY, FINANCIAL DEVELOPMENT AND POVERTY

    Directory of Open Access Journals (Sweden)

    Ionescu Cristian

    2012-12-01

    Full Text Available There is a positive relationship between financial development and economic growth in short-run and long-run. Financial development is beneficial to the reduction of poverty. But the financial instability which accompanies financial development is is costly for the poor and reduces the positive effect of financial development on the reduction of poverty. The paper aims to analyze in detail the relationship and the (direct and indirect effects between these variables, taking into account their economic and social importance. It is also highlighted the correlation between the financial economy and the real economy, emphasizing the impact on social welfare involved by the interaction of the above mentioned variables.

  11. Values in environmental research: Citizens’ views of scientists who acknowledge values

    Science.gov (United States)

    McCright, Aaron M.; Allen, Summer; Dietz, Thomas

    2017-01-01

    Scientists who perform environmental research on policy-relevant topics face challenges when communicating about how values may have influenced their research. This study examines how citizens view scientists who publicly acknowledge values. Specifically, we investigate whether it matters: if citizens share or oppose a scientist’s values, if a scientist’s conclusions seem contrary to or consistent with the scientist’s values, and if a scientist is assessing the state of the science or making a policy recommendation. We conducted two 3x2 factorial design online experiments. Experiment 1 featured a hypothetical scientist assessing the state of the science on the public-health effects of exposure to Bisphenol A (BPA), and Experiment 2 featured a scientist making a policy recommendation on use of BPA. We manipulated whether or not the scientist expressed values and whether the scientist’s conclusion appeared contrary to or consistent with the scientist’s values, and we accounted for whether or not subjects’ values aligned with the scientist’s values. We analyzed our data with ordinary least squares (OLS) regression techniques. Our results provide at least preliminary evidence that acknowledging values may reduce the perceived credibility of scientists within the general public, but this effect differs depending on whether scientists and citizens share values, whether scientists draw conclusions that run contrary to their values, and whether scientists make policy recommendations. PMID:29069087

  12. ABORt: Acknowledgement-Based Opportunistic Routing Protocol for High Data Rate Multichannel WSNs

    Directory of Open Access Journals (Sweden)

    Hamadoun Tall

    2017-10-01

    Full Text Available The ease of deployment and the auto-configuration capabilities of Wireless Sensor Networks (WSNs make them very attractive in different domains like environmental, home automation or heath care applications. The use of multichannel communications in WSNs helps to improve the overall performance of the network. However, in heavy traffic scenarios, routing protocols should be adapted to allow load balancing and to avoid losing data packets due to congestion and queue overflow. In this paper, we present an Acknowledgement-Based Opportunistic Routing (ABORt protocol designed for high data rate multichannel WSNs. It is a low overhead protocol that does not rely on synchronization for control traffic exchange during the operational phase of the network. ABORt is an opportunistic protocol that relies on link layer acknowledgements to disseminate routing metrics, which helps to reduce overhead. The performance of ABORt is evaluated using the Cooja simulator and the obtained results show that ABORt has a high packet delivery ratio with reduced packet end-to-end delay compared to two single channel routing protocols and two multichannel routing protocols that use number of hops and expected transmission count as routing metrics.

  13. Plane grating monochromators for synchrotron radiation

    International Nuclear Information System (INIS)

    Howells, M.R.

    1979-01-01

    The general background and theoretical basis of plane grating monochromators (PGM's) is reviewed and the particular case of grazing incidence PGM's suitable for use with synchrotron radiation is considered in detail. The theory of reflection filtering is described and the problem of the finite source distance is shown to be of special importance with high brightness storage rings. The design philosophy of previous instruments is discussed and a new scheme proposed, aimed at dealing with the problem of the finite source distance. This scheme, involving a parabolic collimating mirror fabricated by diamond turning, is considered in the context of Wolter-type telescopes and microscopes. Some practical details concerning an instrument presently under construction using the new design are presented

  14. Magnetomechanically induced long period fiber gratings

    International Nuclear Information System (INIS)

    Causado-Buelvas, Jesus D.; Gomez-Cardona, Nelson D.; Torres, Pedro

    2008-01-01

    In this work, we report a simple, flexible method to create long period fiber gratings mechanically by controlling the repulsion/attraction force between two magnets that pressing a plate with a periodic array of small glass cylinders to a short length of optical fiber. Via the photoelastic effect, the pressure points induce the required periodic refractive index modulation to create the LPFG. We found that the induced device exhibits spectral characteristics similar to those of other types of LPFG. As the optical properties of LPFGs are directly related to the nature of the applied perturbations, we show, to our knowledge for the frrst time, how is the evolution of birefringence effects in mechanically induced LPFGs

  15. Gratings in passive and active optical waveguides

    DEFF Research Database (Denmark)

    Berendt, Martin Ole

    1999-01-01

    will not only couple to the backward propagating fundamental mode, but also to cladding modes. Cladding modes are strongly bound, but slightly leaky, higher-order modes in the core-cladding-air index structure. If the waveguide is not surrounded by air, but by a recoating the cladding modes become highly...... attenuated. In either case the cladding mode coupling gives loss on the short wavelength side of the reflection band. The cladding mode coupling loss is a major problem for the utilization of fiber Bragg gratings in wavelength division multiplexed (WDM) system. In this project, a numerical model for cladding...... mode coupling has been developed. The model can predict the spectral location and size of coupling, for various fiber designs. By the aid of this modeling tool, a fiber has been optimized to give low cladding-mode losses. The optimized fiber has been produced and the predicted reduction of cladding...

  16. Plasmonic Transmission Gratings – Fabrication and Characterization

    DEFF Research Database (Denmark)

    Sierant, Aleksandra; Jany, Benedykt; Bartoszek-Bober, Dobrosława

    Surface plasmon polaritons (SPPs) are collective electron oscillations, confined at metal-dielectric interfaces. Coupling incident photons to SPPs may lead to spectrally broad field enhancement and confinement below the diffraction limit [1]. This phenomenon facilitates various applications......, including highly sensitive refractive index sensing [2], and plasmonic dipole mirrors for cold atoms [3]. Key to a successful application is a strong photon-to-SPP coupling. To this end, prism-based coupling is classically used, but this method contradicts compact device applications. An alternative...... the proposed plasmonic transmission gratings via near-field optical scanning microscopy (NSOM) and goniometric far field measurements. We support the evidence of our analyses with numerical calculations, carried out via rigorous coupled wave analysis (RCWA) and finite-difference in time-domain (FDTD...

  17. MEMS tunable grating micro-spectrometer

    Science.gov (United States)

    Tormen, Maurizio; Lockhart, R.; Niedermann, P.; Overstolz, T.; Hoogerwerf, A.; Mayor, J.-M.; Pierer, J.; Bosshard, C.; Ischer, R.; Voirin, G.; Stanley, R. P.

    2017-11-01

    The interest in MEMS based Micro-Spectrometers is increasing due to their potential in terms of flexibility as well as cost, low mass, small volume and power savings. This interest, especially in the Near-Infrared and Mid- Infrared, ranges from planetary exploration missions to astronomy, e.g. the search for extra solar planets, as well as to many other terrestrial fields of application such as, industrial quality and surface control, chemical analysis of soil and water, detection of chemical pollutants, exhausted gas analysis, food quality control, process control in pharmaceuticals, to name a few. A compact MEMS-based Spectrometer for Near- Infrared and Mid-InfraRed operation have been conceived, designed and demonstrated. The design based on tunable MEMS blazed grating, developed in the past at CSEM [1], achieves state of the art results in terms of spectral resolution, operational wavelength range, light throughput, overall dimensions, and power consumption.

  18. Fast tunable blazed MEMS grating for external cavity lasers

    Science.gov (United States)

    Tormen, Maurizio; Niedermann, Philippe; Hoogerwerf, Arno; Shea, Herbert; Stanley, Ross

    2017-11-01

    Diffractive MEMS are interesting for a wide range of applications, including displays, scanners or switching elements. Their advantages are compactness, potentially high actuation speed and in the ability to deflect light at large angles. We have designed and fabricated deformable diffractive MEMS grating to be used as tuning elements for external cavity lasers. The resulting device is compact, has wide tunability and a high operating speed. The initial design is a planar grating where the beams are free-standing and attached to each other using leaf springs. Actuation is achieved through two electrostatic comb drives at either end of the grating. To prevent deformation of the free-standing grating, the device is 10 μm thick made from a Silicon on Insulator (SOI) wafer in a single mask process. At 100V a periodicity tuning of 3% has been measured. The first resonant mode of the grating is measured at 13.8 kHz, allowing high speed actuation. This combination of wide tunability and high operating speed represents state of the art in the domain of tunable MEMS filters. In order to improve diffraction efficiency and to expand the usable wavelength range, a blazed version of the deformable MEMS grating has been designed. A key issue is maintaining the mechanical properties of the original device while providing optically smooth blazed beams. Using a process based on anisotropic KOH etching, blazed gratings have been obtained and preliminary characterization is promising.

  19. Radiative properties tailoring of grating by comb-drive microactuator

    International Nuclear Information System (INIS)

    Jiao, Y.; Liu, L.H.; Liu, L.J.; Hsu, P.-F.

    2014-01-01

    Micro-scale grating structures are widely researched in recent years. Although micro-scale fabrication technology is highly advanced today, with grating aspect ratio greater than 25:1 being achievable some fabrication requirements, such as fine groove processing, are still challenging. Comb-drive microactuator is proposed in this paper to be utilized on simple binary grating structures for tailoring or modulating spectral radiation properties by active adjustment. The rigorous coupled-wave analysis (RCWA) is used to calculate the absorptance of proposed structures and to investigate the impacts brought by the geometry and displacement of comb-drive microactuator. The results show that the utilization of comb-drive microactuator on grating improves the absorptance of simple binary grating while avoiding the difficulty fine groove processing. Spectral radiation property tailoring after gratings are fabricated becomes possible with the comb-drive microactuator structure. - Highlights: • A microscale grating structure with comb-driven microactuator is proposed. • The movement of microactuator changes peak absorptance resonance wavelength. • Geometric and displacement effects of comb finger on absorptance are investigated. • Both RCWA and LC circuit models are developed to predict the resonance wavelength. • Resonance frequency equations of LC circuits allow quick design analysis

  20. Suppressing Ghost Diffraction in E-Beam-Written Gratings

    Science.gov (United States)

    Wilson, Daniel; Backlund, Johan

    2009-01-01

    A modified scheme for electron-beam (E-beam) writing used in the fabrication of convex or concave diffraction gratings makes it possible to suppress the ghost diffraction heretofore exhibited by such gratings. Ghost diffraction is a spurious component of diffraction caused by a spurious component of grating periodicity as described below. The ghost diffraction orders appear between the main diffraction orders and are typically more intense than is the diffuse scattering from the grating. At such high intensity, ghost diffraction is the dominant source of degradation of grating performance. The pattern of a convex or concave grating is established by electron-beam writing in a resist material coating a substrate that has the desired convex or concave shape. Unfortunately, as a result of the characteristics of electrostatic deflectors used to control the electron beam, it is possible to expose only a small field - typically between 0.5 and 1.0 mm wide - at a given fixed position of the electron gun relative to the substrate. To make a grating larger than the field size, it is necessary to move the substrate to make it possible to write fields centered at different positions, so that the larger area is synthesized by "stitching" the exposed fields.

  1. Holographic diffraction gratings as laser radiation protection filters

    International Nuclear Information System (INIS)

    Pantelic, D.; Pantelic, G.

    2006-01-01

    Holographic volume diffraction gratings are used as attenuation filters, due to their selective spectral transmission. They can be tailored to reflect or transmit narrow spectral ranges by adjusting spatial frequency of Bragg grating in carefully chosen photosensitive materials, like silver-halide emulsion or di-chromated gelatin layers. If properly recorded and chemically processed, resulting gratings can significantly attenuate light at wavelengths corresponding to various laser spectral lines. Thus, they can be used as filters in laser protection goggles. We analyze the characteristics of Bragg gratings necessary to obtain high attenuation coefficients. Also, their angular selectivity is taken into account and corresponding experimental conditions are investigated. Although di-chromated gelatin seems to be almost ideal material, due to its almost 100% diffraction efficiency, environmental stability is poor (degradation under humid environment), thus making its practical usage difficult. Thus, we have analyzed alternative materials like di-chromated pullulan, which is stable under normal environmental conditions (without drop in diffraction efficiency after prolonged exposure to humidity). Pullulan is polymer (polysaccharide) of biologic origin produced by certain bacteria. If doped with chromium ions it becomes photosensitive, enabling recording of diffraction gratings with spatial frequency of more than 3000 lines/mm. Material is chemically processed by mixture of isopropyl alcohol and water. Both thick and thin layers can be produced by gravity settling. Spectral properties of resulting gratings are analyzed, showing that they can significantly attenuate laser light of particular wavelength, depending of grating period and its slant angle. (authors)

  2. Extended asymmetric-cut multilayer X-ray gratings.

    Science.gov (United States)

    Prasciolu, Mauro; Haase, Anton; Scholze, Frank; Chapman, Henry N; Bajt, Saša

    2015-06-15

    The fabrication and characterization of a large-area high-dispersion blazed grating for soft X-rays based on an asymmetric-cut multilayer structure is reported. An asymmetric-cut multilayer structure acts as a perfect blazed grating of high efficiency that exhibits a single diffracted order, as described by dynamical diffraction throughout the depth of the layered structure. The maximum number of grating periods created by cutting a multilayer deposited on a flat substrate is equal to the number of layers deposited, which limits the size of the grating. The size limitation was overcome by depositing the multilayer onto a substrate which itself is a coarse blazed grating and then polish it flat to reveal the uniformly spaced layers of the multilayer. The number of deposited layers required is such that the multilayer thickness exceeds the step height of the substrate structure. The method is demonstrated by fabricating a 27,060 line pairs per mm blazed grating (36.95 nm period) that is repeated every 3,200 periods by the 120-μm period substrate structure. This preparation technique also relaxes the requirements on stress control and interface roughness of the multilayer film. The dispersion and efficiency of the grating is demonstrated for soft X-rays of 13.2 nm wavelength.

  3. [Diffraction gratings used in x-ray spectroscopy]: Final report

    International Nuclear Information System (INIS)

    Smith, H.I.

    1988-01-01

    This subcontract was initiated in order to facilitate the development at MIT of technologies for fabricating the very fine diffraction grating required in x-ray spectroscopy at Lawrence Livermore Laboratory (LLL). These gratings are generally gold transmission gratings with spatial periods of 200 nm or less. The major focus of our efforts was to develop a means of fabricating gratings of 100 nm period. We explored two approaches: e-beam fabrication of x-ray lithography masks, and achromatic holographic lithography. This work was pursued by Erik Anderson as a major component of his Ph.D. thesis. Erik was successful in both the e-beam and holographic approaches. However, the e-beam method proved to be highly impractical: exposure times of about 115 days would be required to cover an area of 1 cm 2 . The achromatic holography, on the other hand, should be capable of exposing areas well in excess of 1 cm 2 in times under 1 hour. Moreover, 100 nm-period gratings produced by achromatic holography are coherent over their entire area whereas gratings produced by e-beam lithography are coherent only over areas /approximately/100 μm. The remainder of this report consists of portions excerpted from Erik Anderson's thesis. These contain all the details of our work on 100 nm period gratings. 26 refs., 17 figs

  4. Review of High-Speed Fiber Optic Grating Sensors Systems

    Energy Technology Data Exchange (ETDEWEB)

    Udd, E; Benterou, J; May, C; Mihailov, S J; Lu, P

    2010-03-24

    Fiber grating sensors can be used to support a wide variety of high speed measurement applications. This includes measurements of vibrations on bridges, traffic monitoring on freeways, ultrasonic detection to support non-destructive tests on metal plates and providing details of detonation events. This paper provides a brief overview of some of the techniques that have been used to support high speed measurements using fiber grating sensors over frequency ranges from 10s of kHz, to MHZ and finally toward frequencies approaching the GHz regime. Very early in the development of fiber grating sensor systems it was realized that a high speed fiber grating sensor system could be realized by placing an optical filter that might be a fiber grating in front of a detector so that spectral changes in the reflection from a fiber grating were amplitude modulated. In principal the only limitation on this type of system involved the speed of the output detector which with the development of high speed communication links moved from the regime of 10s of MHz toward 10s of GHz. The earliest deployed systems involved civil structures including measurements of the strain fields on composite utility poles and missile bodies during break tests, bridges and freeways. This was followed by a series of developments that included high speed fiber grating sensors to support nondestructive testing via ultrasonic wave detection, high speed machining and monitoring ship hulls. Each of these applications involved monitoring mechanical motion of structures and thus interest was in speeds up to a few 10s of MHz. Most recently there has been interest in using fiber grating to monitor the very high speed events such as detonations and this has led to utilization of fiber gratings that are consumed during an event that may require detection speeds of hundreds of MHz and in the future multiple GHz.

  5. Design of compressors for FEL pulses using deformable gratings

    Science.gov (United States)

    Bonora, Stefano; Fabris, Nicola; Frassetto, Fabio; Giovine, Ennio; Miotti, Paolo; Quintavalla, Martino; Poletto, Luca

    2017-06-01

    We present the optical layout of soft X-rays compressors using reflective grating specifically designed to give both positive or negative group-delay dispersion (GDD). They are tailored for chirped-pulse-amplification experiments with FEL sources. The optical design originates from an existing compressor with plane gratings already realized and tested at FERMI, that has been demonstrated capable to introduce tunable negative GDD. Here, we discuss two novel designs for compressors using deformable gratings capable to give both negative and positive GDD. Two novel designs are discussed: 1) a design with two deformable gratings and an intermediate focus between the twos, that is demonstrated capable to introduce positive GDD; 2) a design with one deformable grating giving an intermediate focus, followed by a concave mirror and a plane grating, that is capable to give both positive and negative GDD depending on the distance between the second mirror and the second grating. Both the designs are tunable in wavelength and GDD, by acting on the deformable gratings, that are rotated to tune the wavelength and the GDD and deformed to introduce the radius required to keep the spectral focus. The deformable gratings have a laminar profile and are ruled on a thin silicon plane substrate. A piezoelectric actuator is glued on the back of the substrate and is actuated to give a radius of curvature that is varying from infinite (plane) to few meters. The ruling procedure, the piezoelectric actuator and the efficiency measurements in the soft X-rays will be presented. Some test cases are discussed for wavelengths shorter than 12 nm.

  6. Numerical modelling of a straw-fired grate boiler

    DEFF Research Database (Denmark)

    Kær, Søren Knudsen

    2004-01-01

    The paper presents a computational fluid dynamics (CFD) analysis of a 33 MW straw-fired grate boiler. Combustion on the grate plays akey-role in the analysis of these boilers and in this work a stand-alone code was used to provide inlet conditions for the CFD analysis. Modelpredictions were...... compared with available gas temperature and species concentration measurements showing good agreement. Combustionof biomass in grate-based boilers is often associated with high emission levels and relatively high amounts of unburnt carbon in the fly ash.Based on the CFD analysis, it is suggested that poor...

  7. Grating-assisted surface acoustic wave directional couplers

    Science.gov (United States)

    Golan, G.; Griffel, G.; Seidman, A.; Croitoru, N.

    1991-07-01

    Physical properties of novel grating-assisted Y directional couplers are examined using the coupled-mode theory. A general formalism for the analysis of the lateral perturbed directional coupler properties is presented. Explicit expressions for waveguide key parameters such as coupling length, grating period, and other structural characterizations, are obtained. The influence of other physical properties such as time and frequency response or cutoff conditions are also analyzed. A plane grating-assisted directional coupler is presented and examined as a basic component in the integrated acoustic technology.

  8. Ultra-compact silicon nitride grating coupler for microscopy systems

    OpenAIRE

    Zhu, Yunpeng; Wang, Jie; Xie, Weiqiang; Tian, Bin; Li, Yanlu; Brainis, Edouard; Jiao, Yuqing; Van Thourhout, Dries

    2017-01-01

    Grating couplers have been widely used for coupling light between photonic chips and optical fibers. For various quantum-optics and bio-optics experiments, on the other hand, there is a need to achieve good light coupling between photonic chips and microscopy systems. Here, we propose an ultra-compact silicon nitride (SiN) grating coupler optimized for coupling light from a waveguide to a microscopy system. The grating coupler is about 4 by 2 mu m(2) in size and a 116 nm 1 dB bandwidth can be...

  9. A reconfigurable optofluidic Michelson interferometer using tunable droplet grating.

    Science.gov (United States)

    Chin, L K; Liu, A Q; Soh, Y C; Lim, C S; Lin, C L

    2010-04-21

    This paper presents a novel optofluidic Michelson interferometer based on droplet microfluidics used to create a droplet grating. The droplet grating is formed by a stream of plugs in the microchannel with constant refractive index variation. It has a real-time tunability in the grating period through varying the flow rates of the liquids and index variation via different combinations of liquids. The optofluidic Michelson interferometer is highly sensitive and is suitable for the measurement of biomedical and biochemical buffer solutions. The experimental results show that it has a sensitivity of 66.7 nm per refractive index unit (RIU) and a detection range of 0.086 RIU.

  10. Aplanatic grazing incidence diffraction grating: a new optical element

    International Nuclear Information System (INIS)

    Hettrick, M.C.

    1986-01-01

    We present the theory of a grazing incidence reflection grating capable of imaging at submicron resolution. The optic is mechanically ruled on a spherical or cylindrical surface with varied groove spacings, delivering diffraction-limited response and a wide field of view at a selected wavelength. Geometrical aberrations are calculated on the basis of Fermat's principle, revealing significant improvements over a grazing incidence mirror. Aplanatic and quasi-aplanatic versions of the grating have applications in both imaging and scanning microscopes, microprobes, collimators, and telescopes. A 2-D crossed system of such gratings, similar to the grazing incidence mirror geometry of Kirkpatrick and Baez, could potentially provide spatial resolutions of --200 A

  11. Financial Village Standing in Indonesian Financial System

    Directory of Open Access Journals (Sweden)

    Herry Purnomo

    2015-12-01

    Full Text Available Financial resources of the village that are sourced from a country or a Regional Finance Financial based Law Number 6 Year 2014 of The Village is the mandate of the law that must be allocated to the village. The interconnectedness of the financial position of the village in the financial system of the country or Region concerned the Financial administrative and territorial relations, and there is no setting directly regarding the finances of the village as part of the financial system of the country or the financial area. In respect of the elements of the crime of corruption deeds against financial irregularities of the village there are still disagreements on the interpretation of the law in trapping the perpetrators of corruption on the village chief that implies not satisfy the principle of legality and legal certainty in the ruling of the matter of financial irregularities. In fact, many of the village chief or Councilor caught the criminal offence of corruption over the use of financial irregularities. This research analyzes How the financial position of the village in the financial system of the country or region, as well as whether the financial resources of the village is derived from the state budget or region budget managed in village budget belongs to the category of village finances and whether tort against the financial management of the village can be categorized as a criminal act corruption. How To Cite: Purnomo, H. (2015. Financial Village Standing in Indonesian Financial System. Rechtsidee, 2(2, 121-140. doi:http://dx.doi.org/10.21070/jihr.v2i2.81

  12. FINANCIAL DEPTH AND FINANCIAL ACCESS IN INDONESIA

    OpenAIRE

    Sigit Setiawan

    2015-01-01

    This study is intended to analyze the current levels of financial depth and financial access in Indonesia and to analyze the factors affecting them. The analysis method used was a combination of descriptive quantitative, benchmarking, and literature reviews. The conclusion is that the financial depth in Indonesia has not shown a satisfactory level since it was the lowest, or the second lowest ranked country among the sampled countries. Meanwhile, the financial access in Indonesia is relativel...

  13. The Paradox of Increasing Both Enrollment and Graduation Rates: Acknowledging Elephants in the Ivory Tower

    Science.gov (United States)

    Mulvenon, Sean W.; Robinson, Daniel H.

    2014-01-01

    The argument is made that increasing enrollments and graduation rates cannot occur while maintaining academic standards. Several U.S. universities are attempting to increase their enrollments to counter the financial difficulties created by a reduction in state support. These same universities are also under growing pressure from their state…

  14. Strengthening financial management, providing financial safeguard mechanism

    International Nuclear Information System (INIS)

    Sun Wumei

    2010-01-01

    This article reviewed the history of Zhong He Shanxi Uranium Enrichment Company, summarizing an efficient and systematical financial management method during both construction period and operational period of the company. It related to fundamental financial management structure building, integrated budgeting, fund management, cost management, asset management, tax planning and HR management. of financial staffs. (author)

  15. Financial Stress Indices and Financial Crises

    NARCIS (Netherlands)

    Vermeulen, Robert; Hoeberichts, Marco; Vasicek, Borek; Zigraiova, Diana; Smidkova, Katerina; de Haan, Jakob

    This paper develops a Financial Stress Index (FSI) for 28 OECD countries and examines its relationship to crises using a novel database for financial crises. A stress index measures the current state of stress in the financial system and summarizes it in a single statistic. Our results suggest that

  16. Imaging properties of high aspect ratio absorption gratings for use in preclinical x-ray grating interferometry.

    Science.gov (United States)

    Trimborn, Barbara; Meyer, Pascal; Kunka, Danays; Zuber, Marcus; Albrecht, Frederic; Kreuer, Sascha; Volk, Thomas; Baumbach, Tilo; Koenig, Thomas

    2016-01-21

    X-ray grating interferometry is one among various methods that allow extracting the so-called phase and visibility contrasts in addition to the well-known transmission images. Crucial to achieving a high image quality are the absorption gratings employed. Here, we present an in-depth analysis of how the grating type and lamella heights influence the final images. Benchmarking gratings of two different designs, we show that a frequently used proxy for image quality, a grating's so-called visibility, is insufficient to predict contrast-to-noise ratios (CNRs). Presenting scans from an excised rat lung, we demonstrate that the CNRs obtained for transmission and visibility images anti-correlate. This is explained by the stronger attenuation implied by gratings that are engineered to provide high visibilities by means of an increased lamella height. We show that even the visibility contrast can suffer from this effect when the associated reduced photon flux on the detector is not outweighed by a corresponding gain in visibility. Resulting in an inevitable trade-off between the quality of the two contrasts, the question of how an optimal grating should be designed can hence only be answered in terms of Pareto optimality.

  17. Financial Globalization and Inequality

    OpenAIRE

    Kunieda, Takuma

    2008-01-01

    This paper investigates how financial globalization and financial development affect income inequality within a country. We demonstrate that when a country is financially closed to the world market, the Gini coefficient is monotonically decreasing with respect to the degree of financial development, whereas when a country becomes so small due to financial globalization that financial development in the country does not affect the world interest rate, the Gini coefficient is monotonically incr...

  18. Large Retailers’ Financial Services

    OpenAIRE

    Risso, Mario

    2010-01-01

    Over the last few years, large retailers offering financial services have considerably grown in the financial services sector. Retailers are increasing the wideness and complexity of their offer of financial services. Large retail companies provide financial services to their customers following different strategic ways. The provision of financial services in the retailers offer is implemented in several different ways related to the strategies, the structures and the degree of financial know...

  19. The Growing Acknowledgement of Wrongful Conviction – The Australian Response Within an International Context

    Directory of Open Access Journals (Sweden)

    Lynne Weathered

    2013-12-01

    Full Text Available The wrongful conviction of innocent people is being acknowledged in an increasing number of countries around the world. The problem of wrongful conviction is now framed as an international human rights issue. More attention is being given to whether criminal justice systems are providing sufficient measures for the effective review and rectification of wrongful convictions and whether international obligations in that regard are being met. England, Wales, Northern Ireland, Scotland, Norway, Canada and the United States have substantial new mechanisms in place to better identify and correct wrongful convictions but Australia has been slower to respond. While some Australian states have introduced reforms such as DNA innocence testing and a new appeal avenue, many issues remain as highlighted in recent debates as to whether Australia should establish a Criminal Cases Review Commission.

  20. A clinical classification acknowledging neuropsychiatric and cognitive impairment in Huntingtons disease

    DEFF Research Database (Denmark)

    Vinther-Jensen, Tua; Larsen, Ida U; Hjermind, Lena E

    2014-01-01

    based on the presence of involuntary movements and a positive genetic test for the HD CAG repeat expansion. After investigating the frequencies of the triad manifestations in a large outpatient clinical cohort of HD gene-expansion carriers, we propose a new clinical classification.MethodsIn this cross...... medication, and cognitive impairment.ResultsAmong the motor manifest HD gene-expansion carriers, 51.8% presented with the full symptom triad, 25.0% were defined as cognitively impaired in addition to motor symptoms, and 14.3% had neuropsychiatric symptoms along with motor symptoms. Only 8.9% had isolated...... terms, suggesting that the current clinical classification is neither necessarily suitable nor helpful for this patient group. Some premanifest gene-expansion carriers may have psychiatric and/or cognitive symptoms caused by reactive stress or other pathology than HD. Acknowledging this fact we, however...

  1. Acknowledgement of reviewer services to the International Journal Applied Earth Observation and Geoinformation

    Science.gov (United States)

    van der Meer, Freek

    2017-06-01

    Peer review is the backbone of the scientific process. In 2016 a total of 866 scientist provided reviewer services for the International Journal Applied Earth Observation and Geoinformation. Frequent reviewers receive a recognition from the publisher in form of a Certificate of Outstanding Contribution in Reviewing and receive a 30 days free access to Scopus and ScienceDirect. More importantly they gain first hand insight into the latest developments in science as they are the first to read exciting new scientific papers. Nevertheless it is hard to find reviewers as the number of papers submitted to our journal has increased substantially over the last years and more remote sensing journals are put in the market each year. We are grateful to all those individuals that have devoted their precious time to reviewing papers for JAG. This has improved the quality of our communications which is well reflected in the number of citations our papers receive and the impact factor of the journal. JAG ranks third of all 28 remote sensing journals not the least because of the quality of the reviews we provide. As a token of our appreciation it is my pleasure to thank all reviewers that were active in 2016 on behalf of the editorial board, the associate editors, the Publisher and myself as Editor-in-Chief of JAG. To honor them we list all reviewers that provide four or more reviews in 2016:

  2. Pemodelan Tapis Fabry-perot pada Serat Optik dengan Menggunakan Fiber Bragg Grating

    OpenAIRE

    Pramuliawati, Septi; ', Saktioto; ', Defrianto

    2015-01-01

    Fabry-perot filter was successfully developed by a uniform Fiber Bragg Grating in fiber optic. A characterization of Bragg Grating was analyzed by using computational model with second-order of Transfer Matrix Method based on Coupled Mode Theory. The reflectivity, length of grating, and bandwidth were parametrics to determine the performance of single Bragg Grating. The transmission spectrum showed the longer grating is designed, the larger the reflectivity was produced, so that the transmiss...

  3. Blazed Grating Resonance Conditions and Diffraction Efficiency Optical Transfer Function

    KAUST Repository

    Stegenburgs, Edgars

    2017-01-08

    We introduce a general approach to study diffraction harmonics or resonances and resonance conditions for blazed reflecting gratings providing knowledge of fundamental diffraction pattern and qualitative understanding of predicting parameters for the most efficient diffraction.

  4. Grating geophone signal processing based on wavelet transform

    Science.gov (United States)

    Li, Shuqing; Zhang, Huan; Tao, Zhifei

    2008-12-01

    Grating digital geophone is designed based on grating measurement technique benefiting averaging-error effect and wide dynamic range to improve weak signal detected precision. This paper introduced the principle of grating digital geophone and its post signal processing system. The signal acquisition circuit use Atmega 32 chip as core part and display the waveform on the Labwindows through the RS232 data link. Wavelet transform is adopted this paper to filter the grating digital geophone' output signal since the signal is unstable. This data processing method is compared with the FIR filter that widespread use in current domestic. The result indicates that the wavelet algorithm has more advantages and the SNR of seismic signal improve obviously.

  5. Broadband back grating design for thin film solar cells

    KAUST Repository

    Janjua, Bilal; Jabbour, Ghassan E.

    2013-01-01

    In this paper, design based on tapered circular grating structure was studied, to provide broadband enhancement in thin film amorphous silicon solar cells. In comparison to planar structure an absorption enhancement of ~ 7% was realized.

  6. Investigations on birefringence effects in polymer optical fiber Bragg gratings

    DEFF Research Database (Denmark)

    Hu, Xiaolian; Saez-Rodriguez, D.; Bang, Ole

    2014-01-01

    Step-index polymer optical fiber Bragg gratings (POFBGs) and microstructured polymer optical fiber Bragg gratings (mPOFBGs) present several attractive features, especially for sensing purposes. In comparison to FBGs written in silica fibers, they are more sensitive to temperature and pressure...... because of the larger thermo-optic coefficient and smaller Young's modulus of polymer materials. (M)POFBGs are most often photowritten in poly(methylmethacrylate) (PMMA) materials using a continuous-wave 325 nm HeCd laser. For the first time to the best of our knowledge, we study photoinduced...... birefringence effects in (m)POFBGs. To achieve this, highly reflective gratings were inscribed with the phase mask technique. They were then monitored in transmission with polarized light. For this, (m)POF sections a few cm in length containing the gratings were glued to angled silica fibers. Polarization...

  7. Reduction of Bragg-grating-induced coupling to cladding modes

    DEFF Research Database (Denmark)

    Berendt, Martin Ole; Bjarklev, Anders Overgaard; Soccolich, C.E.

    1999-01-01

    gratings in a depressed-cladding fiber are compared with simulations. The model gives good agreement with the measured transmission spectrum and accounts for the pronounced coupling to asymmetrical cladding modes, even when the grating is written with the smallest possible blaze. The asymmetry causing...... this is accounted for by the unavoidable attenuation of the UV light. It is found for the considered fiber designs that a high numerical-aperture fiber increases the spectral separation between the Bragg resonance and the onset of cladding-mode losses. A depressed-cladding fiber reduces the coupling strength......We discuss fiber designs that have been suggested for the reduction of Bragg-grating induced coupling to cladding modes. The discussion is based on a theoretical approach that includes the effect of asymmetry in the UV-induced index grating, made by UV-side writing. Experimental results from...

  8. Distributed Bragg grating frequency control in metallic nano lasers

    NARCIS (Netherlands)

    Marell, M.J.H.; Hill, M.T.

    2010-01-01

    We show that Bragg gratings can be readily incorporated into metallic nano-lasers which exploit waveguides with semiconductor cores, via modulation of the waveguide width. This provides a simple way to implement laser wavelength control.

  9. Dynamic population gratings in rare-earth-doped optical fibres

    Energy Technology Data Exchange (ETDEWEB)

    Stepanov, Serguei [Optics Department, CICESE, km.107 carr. Tijuana-Ensenada, Ensenada, 22860, BC (Mexico)], E-mail: steps@cicese.mx

    2008-11-21

    Dynamic Bragg gratings can be recorded in rare-earth (e.g. Er, Yb) doped optical fibres by two counter-propagating mutually coherent laser waves via local saturation of the fibre optical absorption or gain (in optically pumped fibres). Typical recording cw light power needed for efficient grating formation is of sub-mW-mW scale which results in characteristic recording/erasure times of 10-0.1 ms. This review paper discusses fundamental aspects of the population grating formation, their basic properties, relating wave-mixing processes and also considers different applications of these dynamic gratings in single-frequency fibre lasers, tunable filters, optical fibre sensors and adaptive interferometry.

  10. Dynamic population gratings in rare-earth-doped optical fibres

    International Nuclear Information System (INIS)

    Stepanov, Serguei

    2008-01-01

    Dynamic Bragg gratings can be recorded in rare-earth (e.g. Er, Yb) doped optical fibres by two counter-propagating mutually coherent laser waves via local saturation of the fibre optical absorption or gain (in optically pumped fibres). Typical recording cw light power needed for efficient grating formation is of sub-mW-mW scale which results in characteristic recording/erasure times of 10-0.1 ms. This review paper discusses fundamental aspects of the population grating formation, their basic properties, relating wave-mixing processes and also considers different applications of these dynamic gratings in single-frequency fibre lasers, tunable filters, optical fibre sensors and adaptive interferometry.

  11. Blazed Grating Resonance Conditions and Diffraction Efficiency Optical Transfer Function

    KAUST Repository

    Stegenburgs, Edgars; Alias, Mohd Sharizal B.; Ng, Tien Khee; Ooi, Boon S.

    2017-01-01

    We introduce a general approach to study diffraction harmonics or resonances and resonance conditions for blazed reflecting gratings providing knowledge of fundamental diffraction pattern and qualitative understanding of predicting parameters for the most efficient diffraction.

  12. Fabrication of the polarization independent spectral beam combining grating

    Science.gov (United States)

    Liu, Quan; Jin, Yunxia; Wu, Jianhong; Guo, Peiliang

    2016-03-01

    Owing to damage, thermal issues, and nonlinear optical effects, the output power of fiber laser has been proven to be limited. Beam combining techniques are the attractive solutions to achieve high-power high-brightness fiber laser output. The spectral beam combining (SBC) is a promising method to achieve high average power output without influencing the beam quality. A polarization independent spectral beam combining grating is one of the key elements in the SBC. In this paper the diffraction efficiency of the grating is investigated by rigorous coupled-wave analysis (RCWA). The theoretical -1st order diffraction efficiency of the grating is more than 95% from 1010nm to 1080nm for both TE and TM polarizations. The fabrication tolerance is analyzed. The polarization independent spectral beam combining grating with the period of 1.04μm has been fabricated by holographic lithography - ion beam etching, which are within the fabrication tolerance.

  13. Reconfigurable terahertz grating with enhanced transmission of TE polarized light

    Directory of Open Access Journals (Sweden)

    J. W. He

    2017-07-01

    Full Text Available We demonstrate an optically reconfigurable grating with enhanced transmission of TE-polarized waves in the terahertz (THz waveband. This kind of grating is realized by projecting a grating image onto a thin Si wafer with a digital micromirror device (DMD. The enhanced transmission is caused by a resonance of the electromagnetic fields between the photoexcited strips. The position of the transmission peak shifts with the variation of the period and duty cycle of the photoinduced grating, which can be readily controlled by the DMD. Furthermore, a flattened Gaussian model was applied to describe the distribution of the photoexcited free carriers in the Si wafer, and the simulated transmittance spectra are shown to be in good agreement with the experimental results. In future, the photoexcited carriers could also be used to produce THz diffractive elements with reconfigurable functionality.

  14. Surface Plasmon Polaritons on Silver Gratings for Optimal SERS Response.

    Czech Academy of Sciences Publication Activity Database

    Kalachyova, Y.; Mareš, D.; Lyutakov, O.; Koštejn, Martin; Lapčák, L.; Svorčík, V.

    2015-01-01

    Roč. 119, č. 17 (2015), s. 9506-9512 ISSN 1932-7447 Institutional support: RVO:67985858 Keywords : enhanced raman-scattering * metallic surface * relief gratings Subject RIV: CC - Organic Chemistry Impact factor: 4.509, year: 2015

  15. Recording multiple holographic gratings in silver-doped ...

    Indian Academy of Sciences (India)

    doped photopolymer film using peristrophic multiplexing techniques. Constant and variable exposure scheduling methods were adopted for storing gratings in the film using He–Ne laser (632.8 nm). The role of recording geometry on the dynamic ...

  16. Financial Literacy and Financial Planning in France

    Directory of Open Access Journals (Sweden)

    Luc Arrondel

    2013-07-01

    Full Text Available We study financial literacy in France using the PATER survey and following the Lusardi and Mitchell (2011c approach. We find that some subpopulations are less financially literate than others: women, young and old people as well as less-educated people are more likely to face difficulties when dealing with fundamental financial concepts such as risk diversification and inflation and interest compounding. We also find some differences in financial knowledge depending on the political opinion of the respondents. Finally we show that these differences in financial knowledge are correlated with differences in the propensity to plan: people who score higher on the financial literacy questions are more likely to be engaged in the preparation of a clearly defined financial plan.

  17. The effect of aberrated recording beams on reflecting Bragg gratings

    Science.gov (United States)

    SeGall, Marc; Ott, Daniel; Divliansky, Ivan; Glebov, Leonid B.

    2013-03-01

    The effect of aberrations present in the recording beams of a holographic setup is discussed regarding the period and spectral response of a reflecting volume Bragg grating. Imperfect recording beams result in spatially varying resonant wavelengths and the side lobes of the spectrum are washed out. Asymmetrical spectra, spectral broadening, and a reduction in peak diffraction efficiency may also be present, though these effects are less significant for gratings with wider spectral widths. Reflecting Bragg gratings (RBGs) are used as elements in a variety of applications including spectral beam combining1,2, mode locking3,4, longitudinal and transverse mode selection in lasers5,6, and sensing7,8. For applications requiring narrow spectral selectivity9, or large apertures10, these gratings must have a uniform period throughout the length of the recording medium, which may be on the order of millimeters. However, when using typical recording techniques such as two-beam interference for large aperture gratings and phase-mask recording of fiber gratings, aberrations from the optical elements in the system result in an imperfect grating structure11-13. In this paper we consider the effects of aberrations on large aperture gratings recorded in thick media using the two-beam interference technique. Previous works in analyzing the effects of aberrations have considered the effects of aberrations in a single recording plane where the beams perfectly overlap. Such an approach is valid for thin media (on the order of tens of microns), but for thick recording media (on the order of several millimeters) there will be a significant shift in the positions of the beams relative to each other as they traverse the recording medium. Therefore, the fringe pattern produced will not be constant throughout the grating if one or both beams have a non-uniform wavefront. Such non-uniform gratings may have a wider spectral width, a shifted resonant wavelength, or other problems. It is

  18. Zeonex Microstructured Polymer Optical Fibre Bragg Grating Sensor

    DEFF Research Database (Denmark)

    Woyessa, Getinet; Fasano, Andrea; Markos, Christos

    2016-01-01

    We fabricated an endlessly single mode and humidity insensitive Zeonex microstructured polymer optical fibre (mPOF) for fibre Bragg grating (FBG) temperature and strain sensors. We inscribed and characterise FBGs in Zeonex mPOF for the first time.......We fabricated an endlessly single mode and humidity insensitive Zeonex microstructured polymer optical fibre (mPOF) for fibre Bragg grating (FBG) temperature and strain sensors. We inscribed and characterise FBGs in Zeonex mPOF for the first time....

  19. The potential of diffraction grating for spatial applications

    Science.gov (United States)

    Jourlin, Y.; Parriaux, O.; Pigeon, F.; Tischenko, A. V.

    2017-11-01

    Diffraction gratings are know, and have been fabricated for more than one century. They are now making a come back for two reasons: first, because they are now better understood which leads to the efficient exploitation of what was then called their "anomalies"; secondly, because they are now fabricable by means of the modern manufacturing potential of planar technologies. Novel grating can now perform better than conventional gratings, and address new application fields which were not expected to be theirs. This is the case of spatial applications where they can offer multiple optical functions, low size, low weight and mechanical robustness. The proposed contribution will briefly discuss the use of gratings for spatial applications. One of the most important applications is in the measurement of displacement. Usual translation and rotation sensors are bulky devices, which impose a system breakdown leading to cumbersome and heavy assemblies. We are proposing a miniaturized version of the traditional moving grating technique using submicron gratings and a specific OptoASIC which enables the measurement function to be non-obtrusively inserted into light and compact electro-mechanical systems. Nanometer resolution is possible with no compromise on the length of the measurement range. Another family of spatial application is in the field of spectrometers where new grating types allow a more flexible processing of the optical spectrum. Another family of applications addresses the question of inter-satellite communications: the introduction of gratings in laser cavities or in the laser mirrors enables the stabilization of the emitted polarization, the stabilization of the frequency as well as wide range frequency sweeping without mobile parts.

  20. Dynamic theory of neutron diffraction from a moving grating

    Energy Technology Data Exchange (ETDEWEB)

    Bushuev, V. A., E-mail: vabushuev@yandex.ru [Moscow State University (Russian Federation); Frank, A. I.; Kulin, G. V. [Joint Institute for Nuclear Research (Russian Federation)

    2016-01-15

    A multiwave dynamic theory of diffraction of ultracold neutrons from a moving phase grating has been developed in the approximation of coupled slowly varying amplitudes of wavefunctions. The effect of the velocity, period, and height of grooves of the grating, as well as the spectral angular distribution of the intensity of incident neurons, on the discrete energy spectrum and the intensity of diffraction reflections of various orders has been analyzed.

  1. A phase mask fiber grating and sensing applications

    Directory of Open Access Journals (Sweden)

    Preecha P. Yupapin

    2003-09-01

    Full Text Available This paper presents an investigation of a fabricated fiber grating device characteristics and its applications, using a phase mask writing technique. The use of a most common UV phase laser (KrF eximer laser, with high intensity light source was focussed to the phase mask for writing on a fiber optic sample. The device (i.e. grating characteristic especially, in sensing application, was investigated. The possibility of using such device for temperature and strain sensors is discussed.

  2. Numerical modelling of a straw-fired grate boiler

    DEFF Research Database (Denmark)

    Kær, Søren Knudsen

    2004-01-01

    The paper presents a computational fluid dynamics (CFD) analysis of a 33 MW straw-fired grate boiler. Combustion on the grate plays akey-role in the analysis of these boilers and in this work a stand-alone code was used to provide inlet conditions for the CFD analysis. Modelpredictions were compa...... mixing in the furnace is a key issue leading to these problems. q 2003 Elsevier Ltd. All rights reserved....

  3. Angle-specific transparent conducting electrodes with metallic gratings

    Energy Technology Data Exchange (ETDEWEB)

    Rivolta, N. X. A., E-mail: nicolas.rivolta@umons.ac.be; Maes, B. [Micro- and Nanophotonic Materials Group, Faculty of Science, University of Mons, Avenue Maistriau 19, B-7000 Mons (Belgium)

    2014-08-07

    Transparent conducting electrodes, which are not made from indium tin oxide, and which display a strong angular dependence are useful for various technologies. Here, we introduce a tilted silver grating that combines a large conductance with a strong and angle-specific transmittance. When the light incidence angle matches the tilt angle of the grating, transmittance is close to the maximum along a very broadband range. We explain the behavior through simulations that show in detail the plasmonic and interference effects at play.

  4. Intangible assets linked to consumers: Acknowledgement and evaluation in the business combination detached from Goodwill

    Directory of Open Access Journals (Sweden)

    Spasić Dejan

    2012-01-01

    Full Text Available The development of International Financial Reporting Standards causes new challenges for accounting as a profession. One of those challenges reefers to business combinations treatment in accounting and the related possibility of recognizing intangible assets detached from goodwill. As it usually represents internally generated intangible assets to which the recognition principle cannot be applied according to IAS 38, the author focuses on conditions under which it can be recognized in financial reports of the acquisitor in business combination, according to IFRS 3. Apart from that, the significant attention is dedicated to the methods for determining the fair value of recognizable intangible assets. As the application of market-based methods, the focus in this paper is on income-based methods and their applicability for consumer-related intangible assets valuation. Limitations in using methods for intangible assets valuation both in stable and crisis conditions are presented at the end of this paper.

  5. Intangible assets linked to consumers: Acknowledgement and evaluation in the business combination detached from Goodwill

    OpenAIRE

    Spasić Dejan

    2012-01-01

    The development of International Financial Reporting Standards causes new challenges for accounting as a profession. One of those challenges reefers to business combinations treatment in accounting and the related possibility of recognizing intangible assets detached from goodwill. As it usually represents internally generated intangible assets to which the recognition principle cannot be applied according to IAS 38, the author focuses on conditions under which it can be recognized in financi...

  6. Holographic grating relaxation technique for soft matter science

    Energy Technology Data Exchange (ETDEWEB)

    Lesnichii, Vasilii, E-mail: vasilii.lesnichii@physchem.uni-freiburg.de [Institute of Physical Chemistry, Albertstraße 21, Institute of Macromolecular Chemistry, Stefan-Meier-Str. 31, Albert-Ludwigs Universität, Freiburg im Breisgau 79104 (Germany); ITMO University, Kronverksky prospekt 49, Saint-Petersburg 197101 (Russian Federation); Kiessling, Andy [Institute of Physical Chemistry, Albertstraße 21, Institute of Macromolecular Chemistry, Stefan-Meier-Str. 31, Albert-Ludwigs Universität, Freiburg im Breisgau 79104 (Germany); Current address: Illinois Institute of Technology, 10 West 33rd Street, Chicago,IL60616 (United States); Bartsch, Eckhard [Institute of Physical Chemistry, Albertstraße 21, Institute of Macromolecular Chemistry, Stefan-Meier-Str. 31, Albert-Ludwigs Universität, Freiburg im Breisgau 79104 (Germany); Veniaminov, Andrey, E-mail: veniaminov@phoi.ifmo.ru [ITMO University, Kronverksky prospekt 49, Saint-Petersburg 197101 (Russian Federation)

    2016-06-17

    The holographic grating relaxation technique also known as forced Rayleigh scattering consists basically in writing a holographic grating in the specimen of interest and monitoring its diffraction efficiency as a function of time, from which valuable information on mass or heat transfer and photoinduced transformations can be extracted. In a more detailed view, the shape of the relaxation curve and the relaxation rate as a function of the grating period were found to be affected by the architecture of diffusing species (molecular probes) that constitute the grating, as well as that of the environment they diffuse in, thus making it possible to access and study spatial heterogeneity of materials and different modes of e.g., polymer motion. Minimum displacements and spatial domains approachable by the technique are in nanometer range, well below spatial periods of holographic gratings. In the present paper, several cases of holographic relaxation in heterogeneous media and complex motions are exemplified. Nano- to micro-structures or inhomogeneities comparable in spatial scale with holographic gratings manifest themselves in relaxation experiments via non-exponential decay (stepwise or stretched), spatial-period-dependent apparent diffusion coefficient, or unusual dependence of diffusion coefficient on molecular volume of diffusing probes.

  7. Time-domain Brillouin scattering assisted by diffraction gratings

    Science.gov (United States)

    Matsuda, Osamu; Pezeril, Thomas; Chaban, Ievgeniia; Fujita, Kentaro; Gusev, Vitalyi

    2018-02-01

    Absorption of ultrashort laser pulses in a metallic grating deposited on a transparent sample launches coherent compression/dilatation acoustic pulses in directions of different orders of acoustic diffraction. Their propagation is detected by delayed laser pulses, which are also diffracted by the metallic grating, through the measurement of the transient intensity change of the first-order diffracted light. The obtained data contain multiple frequency components, which are interpreted by considering all possible angles for the Brillouin scattering of light achieved through multiplexing of the propagation directions of light and coherent sound by the metallic grating. The emitted acoustic field can be equivalently presented as a superposition of plane inhomogeneous acoustic waves, which constitute an acoustic diffraction grating for the probe light. Thus the obtained results can also be interpreted as a consequence of probe light diffraction by both metallic and acoustic gratings. The realized scheme of time-domain Brillouin scattering with metallic gratings operating in reflection mode provides access to wide range of acoustic frequencies from minimal to maximal possible values in a single experimental optical configuration for the directions of probe light incidence and scattered light detection. This is achieved by monitoring the backward and forward Brillouin scattering processes in parallel. Potential applications include measurements of the acoustic dispersion, simultaneous determination of sound velocity and optical refractive index, and evaluation of samples with a single direction of possible optical access.

  8. Apodized grating coupler using fully-etched nanostructures

    Science.gov (United States)

    Wu, Hua; Li, Chong; Li, Zhi-Yong; Guo, Xia

    2016-08-01

    A two-dimensional apodized grating coupler for interfacing between single-mode fiber and photonic circuit is demonstrated in order to bridge the mode gap between the grating coupler and optical fiber. The grating grooves of the grating couplers are realized by columns of fully etched nanostructures, which are utilized to digitally tailor the effective refractive index of each groove in order to obtain the Gaussian-like output diffractive mode and then enhance the coupling efficiency. Compared with that of the uniform grating coupler, the coupling efficiency of the apodized grating coupler is increased by 4.3% and 5.7%, respectively, for the nanoholes and nanorectangles as refractive index tunes layer. Project supported by the National Natural Science Foundation of China (Grant Nos. 61222501, 61335004, and 61505003), the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20111103110019), the Postdoctoral Science Foundation of Beijing Funded Project, China (Grant No. Q6002012201502), and the Science and Technology Research Project of Jiangxi Provincial Education Department, China (Grant No. GJJ150998).

  9. Financial planning

    OpenAIRE

    Χατζηγώγου, Αρτεμις Π.

    2003-01-01

    Σκοπός της μελέτης αυτής, είναι η συγκέντρωση όλων των στοιχείων εκείνων που συνθέτουν μια οργανωμένη διαδικασία έρευνας, που είναι γνωστή ως Financial Planning. Θα μπορούσαμε εναλλακτικά να πούμε, ότι βασικά ο χρηματοοικονομικός σχεδιασμός προγραμματίζει, εξευρίσκει και χρησιμοποιεί τα κεφάλαια με τέτοιο τρόπο ώστε η συνεισφορά τους να είναι μεγαλύτερη στην αποτελεσματική λειτουργία της οικονομικής μονάδας. Παρέχει τις γνώσεις των χρηματιστικών αγορών από όπου αντλούνται τα κεφάλαια. Οδηγεί ...

  10. An imaging grating diffractometer for traceable calibration of grating pitch in the range 20 μm to 350 nm

    International Nuclear Information System (INIS)

    Brasil, D A; Alves, J A P; Pekelsky, J R

    2015-01-01

    This work describes the development of a grating diffratometer to provide traceable calibration of grating pitch in range 20 μm to 350 nm. The approach is based on the Littrow configuration in which a laser beam is directed onto the grating which is mounted on a rotary table and can be turned so that each selected diffraction order is retro-reflected in the laser incidence direction. A beamsplitter and a lens direct the reflected diffraction order to form a small image spot on a CCD camera and the spot centering is used to adjust to rotation angle, thereby giving the diffraction angle. Knowing the diffraction angle for several orders and the wavelength of the laser, the average grating pitch can be determined to an uncertainty the order of 14 pm. (paper)

  11. Feasibility of Fiber Bragg Grating and Long-Period Fiber Grating Sensors under Different Environmental Conditions

    Directory of Open Access Journals (Sweden)

    Jian-Neng Wang

    2010-11-01

    Full Text Available This paper presents the feasibility of utilizing fiber Bragg grating (FBG and long-period fiber grating (LPFG sensors for nondestructive evaluation (NDE of infrastructures using Portland cement concretes and asphalt mixtures for temperature, strain, and liquid-level monitoring. The use of hybrid FBG and LPFG sensors is aimed at utilizing the advantages of two kinds of fiber grating to implement NDE for monitoring strains or displacements, temperatures, and water-levels of infrastructures such as bridges, pavements, or reservoirs for under different environmental conditions. Temperature fluctuation and stability tests were examined using FBG and LPFG sensors bonded on the surface of asphalt and concrete specimens. Random walk coefficient (RWC and bias stability (BS were used for the first time to indicate the stability performance of fiber grating sensors. The random walk coefficients of temperature variations between FBG (or LPFG sensor and a thermocouple were found in the range of −0.7499 °C/ to −1.3548 °C/. In addition, the bias stability for temperature variations, during the fluctuation and stability tests with FBG (or LPFG sensors were within the range of 0.01 °C/h with a 15–18 h time cluster to 0.09 °C/h with a 3–4 h time cluster. This shows that the performance of FBG or LPFG sensors is comparable with that of conventional high-resolution thermocouple sensors under rugged conditions. The strain measurement for infrastructure materials was conducted using a packaged FBG sensor bonded on the surface of an asphalt specimen under indirect tensile loading conditions. A finite element modeling (FEM was applied to compare experimental results of indirect tensile FBG strain measurements. For a comparative analysis between experiment and simulation, the FEM numerical results agreed with those from FBG strain measurements. The results of the liquid-level sensing tests show the LPFG-based sensor could discriminate five stationary liquid

  12. Financial Risk Management

    OpenAIRE

    Catalin-Florinel Stanescu; Laurentiu Mircea Simion

    2011-01-01

    Concerns about the financial risk is increasing. In this climate, companies of all types and sizes want a robust framework for financial risk management to meet compliance requirements, contribute to better decision making and increase performance. Financial risk management professionals working with financial institutions and other corporate clients to achieve these objectives.

  13. Multipoint sensor based on fiber Bragg gratings

    International Nuclear Information System (INIS)

    Mendez-Zepeda, O; Munoz-Aguirre, S; Beltran-Perez, G; Castillo-Mixcoatl, J

    2011-01-01

    In some control and industrial measurement systems of physical variables (pressure, temperature, flow, etc) it is necessary one system and one sensor to control each process. On the other hand, there are systems such as PLC (Programmable Logic Control), which can process several signals simultaneously. However it is still necessary to use one sensor for each variable. Therefore, in the present work the use of a multipoint sensor to solve such problem has been proposed. The sensor consists of an optical fiber laser with two Fabry-Perot cavities constructed using fiber Bragg gratings (FBG). In the same system is possible to measure changes in two variables by detecting the intermodal separation frequency of each cavity and evaluate their amplitudes. The intermodal separation frequency depends on each cavity length. The sensor signals are monitored through an oscilloscope or a PCI card and after that acquired by PC, where they are analyzed and displayed. Results of the evaluation of the intermodal frequency separation peak amplitude behavior with FBG stretching are presented.

  14. Fiber Bragg grating based arterial localization device

    Science.gov (United States)

    Ho, Siu Chun Michael; Li, Weijie; Razavi, Mehdi; Song, Gangbing

    2017-06-01

    A critical first step to many surgical procedures is locating and gaining access to a patients vascular system. Vascular access allows the deployment of other surgical instruments and also the monitoring of many physiological parameters. Current methods to locate blood vessels are predominantly based on the landmark technique coupled with ultrasound, fluoroscopy, or Doppler. However, even with experience and technological assistance, locating the required blood vessel is not always an easy task, especially with patients that present atypical anatomy or suffer from conditions such as weak pulsation or obesity that make vascular localization difficult. With recent advances in fiber optic sensors, there is an opportunity to develop a new tool that can make vascular localization safer and easier. In this work, the authors present a new fiber Bragg grating (FBG) based vascular access device that specializes in arterial localization. The device estimates the location towards a local artery based on the bending of a needle inserted near the tissue surrounding the artery. Experimental results obtained from an artificial circulatory loop and a mock artery show the device works best for lower angles of needle insertion and can provide an approximately 40° range of estimation towards the location of a pulsating source (e.g. an artery).

  15. Senior health clinics: are they financially viable?

    Science.gov (United States)

    McAtee, Robin E; Crandall, Debra; Wright, Larry D; Beverly, Claudia J

    2009-07-01

    Are hospital-based outpatient interdisciplinary clinics a financially viable alternative for caring for our burgeoning population of older adults in America? Although highly popular, with high patient satisfaction rates among older adults and their families, senior health clinics (SHCs) can be expensive to operate, with limited quantifiable health outcomes. This study analyzed three geriatric hospital-based interdisciplinary clinics in rural Arkansas by examining their patient profiles, revenues, and expenses. It closely examined the effects of the downstream revenue using the multiplier effect and acknowledged other factors that weigh heavily on the success of SHCs and the care of older adults. The findings highlight the similarities and differences in the three clinics' operating and financial structures in addition to the clinics' and providers' productivity. The analysis presents an evidence-based illustration that SHCs can break even or lose large amounts of money.

  16. Fabrication of high edge-definition steel-tape gratings for optical encoders

    Science.gov (United States)

    Ye, Guoyong; Liu, Hongzhong; Yan, Jiawei; Ban, Yaowen; Fan, Shanjin; Shi, Yongsheng; Yin, Lei

    2017-10-01

    High edge definition of a scale grating is the basic prerequisite for high measurement accuracy of optical encoders. This paper presents a novel fabrication method of steel tape gratings using graphene oxide nanoparticles as anti-reflective grating strips. Roll-to-roll nanoimprint lithography is adopted to manufacture the steel tape with hydrophobic and hydrophilic pattern arrays. Self-assembly technology is employed to obtain anti-reflective grating strips by depositing the graphene oxide nanoparticles on hydrophobic regions. A thin SiO2 coating is deposited on the grating to protect the grating strips. Experimental results confirm that the proposed fabrication process enables a higher edge definition in making steel-tape gratings, and the new steel tape gratings offer better performance than conventional gratings.

  17. Image quality of grating target in model eye when viewed through a small-aperture corneal inlay.

    Science.gov (United States)

    Inoue, Makoto; Bissen-Miyajima, Hiroko; Arai, Hiroyuki; Noda, Toru; Ohnuma, Kazuhiko; Hirakata, Akito

    2014-07-01

    To evaluate the quality of the image of a grating target placed in a model eye and viewed through a small-aperture corneal inlay. Kyorin Eye Center, Tokyo, Japan. Experimental study. A Kamra corneal inlay was placed on the anterior surface of a fluid-filled model eye, and a United States Air Force target and a calibrated scale were placed on the inner surface of the model eye. With a flat contact lens or a contact or noncontact wide-angle viewing system, the contrast of the grating images and the field of view through the inlay were compared with those without the inlay. A blurred dark ring was observed with the flat contact lens and MiniQuad wide-viewing contact lens in the model eye with the inlay. The contrast of the gratings was significantly decreased at 16 cycles/mm (P=.028), 32 cycles/mm (P=.046), and 64 cycles/mm (P=.015). With the Resight noncontact wide-angle viewing system, the field of view was reduced from 62 degrees to 32 degrees when the front lens was at 7.0 mm and slightly reduced from 75 degrees to 62 degrees at 5.0 mm with the inlay. The contrast of grating images observed through the inlay was significantly reduced when viewed with the flat contact lens. The field of view through the wide-angle viewing system was also altered. However, the noncontact wide-angle viewing system may be recommended for vitreous surgeries in eyes with the inlay by adjusting the distance of the front lens from the cornea. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  18. FINANCIAL DEPTH AND FINANCIAL ACCESS IN INDONESIA

    OpenAIRE

    Sigit Setiawan

    2015-01-01

    This study is intended to analyse the current levels of financial depth and financial access in Indonesia and to analyse the factors affecting them. The analysis method used was a combination of descriptive quantitative, benchmarking, and literature reviews. The conclusion is that the financial depth in Indonesia has not shown a satisfactory level since it was the lowest, or the second lowest ranked country among the sampled countries. Meanwhile, the financial access in Indonesia is relativel...

  19. Financial Ratios and Perceived Household Financial Satisfaction

    Directory of Open Access Journals (Sweden)

    Scott Garrett

    2013-08-01

    Full Text Available This paper tests the relative strength of three objective measures of financial health (using the solvency, liquidity, and investment asset ratio in predicting a household’s subjective feeling of current financial satisfaction. Using a sample of 6,923 respondents in the 2008 Health and Retirement Study this paper presents evidence of two main findings: 1 the solvency ratio is most strongly associated with financial satisfaction levels based on a cross-sectional design and 2 changes in the investment asset ratio are most strongly associated with changes in financial satisfaction over time.

  20. Financial Depth and Financial Access in Indonesia

    OpenAIRE

    Setiawan, Sigit

    2015-01-01

    This study is intended to analyse the current levels of financial depth and financial access in Indonesia and to analyse the factors affecting them. The analysis method used was a combination of descriptive quantitative, benchmarking, and literature reviews. The conclusion is that the financial depth in Indonesia has not shown a satisfactory level since it was the lowest, or the second lowest ranked country among the sampled countries. Meanwhile, the financial access in Indonesia is relativel...

  1. Financial analysis as a financial management instrument

    Directory of Open Access Journals (Sweden)

    Stehlíková Beáta

    2001-12-01

    Full Text Available The financial market is one of the elements of the market-oriented economy. The financial analysis is a fundamental element of the financial controlling business. The purpose of this article is to inform briefly about horizontal and vertical financial statements analysis as the source of competitive advantage of the firm. The article is divided into two parts. First describes financial analysis and financial statements generally. Second, it presents a practical contribution of the horizontal and vertical financial statements analysis at the controlled businesses as financial management tools, which identify the financial position, market behaviour, correlations between the net profit and the prohibitively cost and operating profit, the financial activities profit, the income tax etc.Business, which the analysed firm operates in asks a provable claim on the high value of fixed assets. The capital composition of the firm is call to typify for the state-owned enterprise that was transformed to private joint-stock companies. Analysis is specially pleading for the needs considering the price of the borrowed capital in the capital structure rating. Fault factor ø value talks about needs for the cost regulation. Stair-step conception used for counting of the net profit in the accountant period indicates the financial profit, alternatively loss, as the distinguished pre-tax profit element. Picture about firm’s financial results can be completed with the information about the income tax value. Form of financial analyses presented in the article entablature the accents on the necessity to compare several accounting period and on the necessity of complex understanding of statements accounting slide “en bloc”.Financial analyse makes the decision makers possible to screen potential partners before the cooperation starts. On the other side, it makes a possibility to influence the production process, sales and financial management during the accounting

  2. The grief experience of same-sex couples within an Irish context: tacit acknowledgement.

    Science.gov (United States)

    Glackin, Michelle; Higgins, Agnes

    2008-06-01

    This study sought to explore the grief experience of same sex couples. To date, the majority of research in this area has focused on the bereavement experience of individuals whose partner has died from an AIDS/HIV-related illness. The research design used was descriptive exploratory. A multi-pronged sampling strategy was employed to generate participants. Seven people underwent in-depth interviews once the study had received ethical approval. Data were analysed by coding, comparing, and merging codes into higher order themes. Five themes subsequently emerged that captured the essence of the bereavement experience, namely:'tacit acknowledgement'; 'sculpting the distress'; 'multiple losses'; 'seeking support'; and 'journeying anew.' While not all bereaved gay or lesbian partners experience 'disenfranchized grief', particularly if their relationship with the deceased was not hidden, it is clear from the findings of this study that many of the participants did (Doka, 1989;Wallbank, 1998). Health care professionals need to consider their approach to people who identify themselves as gay or lesbian, if they are to provide support structures (formal and informal) to meet their unique needs.

  3. Mens Rea and Methamphetamine: High Time for a Modern Doctrine Acknowledging the Neuroscience of Addiction.

    Science.gov (United States)

    Cusick, Meredith

    2017-04-01

    In American criminal law, actus non facit reum, nisi mens sit rea, "an act does not make one guilty, without a guilty mind." Both actus reus and mens rea are required to justify criminal liability. The Model Penal Code's (MPC) section on culpability has been especially influential on mens rea analysis. An issue of increasing importance in this realm arises when an offensive act is committed while the actor is under the influence of drugs. Several legal doctrines address the effect of intoxication on mental state, including the MPC, limiting or eliminating its relevance to the mens rea analysis. Yet these doctrines do not differentiate between intoxication and addiction. Neuroscience research reveals that drug addiction results in catastrophic damage to the brain resulting in cognitive and behavioral deficits. Methamphetamine addiction is of particular interest to criminal law because it causes extensive neural destruction and is associated with impulsive behavior, violent crime, and psychosis. Furthermore, research has revealed important distinctions between the effects of acute intoxication and addiction. These findings have implications for the broader doctrine of mens rea and, specifically, the intoxication doctrines. This Note argues for the adoption of an addiction doctrine that acknowledges the effect of addiction on mens rea that is distinct from doctrines of intoxication.

  4. Effective length of short Fabry-Perot cavity formed by uniform fiber Bragg gratings.

    Science.gov (United States)

    Barmenkov, Yuri O; Zalvidea, Dobryna; Torres-Peiró, Salvador; Cruz, Jose L; Andrés, Miguel V

    2006-07-10

    In this paper, we describe the properties of Fabry-Perot fiber cavity formed by two fiber Bragg gratings in terms of the grating effective length. We show that the grating effective length is determined by the group delay of the grating, which depends on its diffraction efficiency and physical length. We present a simple analytical formula for calculation of the effective length of the uniform fiber Bragg grating and the frequency separation between consecutive resonances of a Fabry-Perot cavity. Experimental results on the cavity transmission spectra for different values of the gratings' reflectivity support the presented theory.

  5. Practical C++ financial programming

    CERN Document Server

    Oliveira, Carlos

    2015-01-01

    Practical C++ Financial Programming is a hands-on book for programmers wanting to apply C++ to programming problems in the financial industry. The book explains those aspects of the language that are more frequently used in writing financial software, including the STL, templates, and various numerical libraries. The book also describes many of the important problems in financial engineering that are part of the day-to-day work of financial programmers in large investment banks and hedge funds. The author has extensive experience in the New York City financial industry that is now distilled in

  6. Measurement system for diffraction efficiency of convex gratings

    Science.gov (United States)

    Liu, Peng; Chen, Xin-hua; Zhou, Jian-kang; Zhao, Zhi-cheng; Liu, Quan; Luo, Chao; Wang, Xiao-feng; Tang, Min-xue; Shen, Wei-min

    2017-08-01

    A measurement system for diffraction efficiency of convex gratings is designed. The measurement system mainly includes four components as a light source, a front system, a dispersing system that contains a convex grating, and a detector. Based on the definition and measuring principle of diffraction efficiency, the optical scheme of the measurement system is analyzed and the design result is given. Then, in order to validate the feasibility of the designed system, the measurement system is set up and the diffraction efficiency of a convex grating with the aperture of 35 mm, the curvature-radius of 72mm, the blazed angle of 6.4°, the grating period of 2.5μm and the working waveband of 400nm-900nm is tested. Based on GUM (Guide to the Expression of Uncertainty in Measurement), the uncertainties in the measuring results are evaluated. The measured diffraction efficiency data are compared to the theoretical ones, which are calculated based on the grating groove parameters got by an atomic force microscope and Rigorous Couple Wave Analysis, and the reliability of the measurement system is illustrated. Finally, the measurement performance of the system is analyzed and tested. The results show that, the testing accuracy, the testing stability and the testing repeatability are 2.5%, 0.085% and 3.5% , respectively.

  7. Grating-based tomography applications in biomedical engineering

    Science.gov (United States)

    Schulz, Georg; Thalmann, Peter; Khimchenko, Anna; Müller, Bert

    2017-10-01

    For the investigation of soft tissues or tissues consisting of soft and hard tissues on the microscopic level, hard X-ray phase tomography has become one of the most suitable imaging techniques. Besides other phase contrast methods grating interferometry has the advantage of higher sensitivity than inline methods and the quantitative results. One disadvantage of the conventional double-grating setup (XDGI) compared to inline methods is the limitation of the spatial resolution. This limitation can be overcome by removing the analyser grating resulting in a single-grating setup (XSGI). In order to verify the performance of XSGI concerning contrast and spatial resolution, a quantitative comparison of XSGI and XDGI tomograms of a human nerve was performed. Both techniques provide sufficient contrast to allow for the distinction of tissue types. The spatial resolution of the two-fold binned XSGI data set is improved by a factor of two in comparison to XDGI which underlies its performance in tomography of soft tissues. Another application for grating-based X-ray phase tomography is the simultaneous visualization of soft and hard tissues of a plaque-containing coronary artery. The simultaneous visualization of both tissues is important for the segmentation of the lumen. The segmented data can be used for flow simulations in order to obtain information about the three-dimensional wall shear stress distribution needed for the optimization of mechano-sensitive nanocontainers used for drug delivery.

  8. Two-dimensional grating guided-mode resonance tunable filter.

    Science.gov (United States)

    Kuo, Wen-Kai; Hsu, Che-Jung

    2017-11-27

    A two-dimensional (2D) grating guided-mode resonance (GMR) tunable filter is experimentally demonstrated using a low-cost two-step nanoimprinting technology with a one-dimensional (1D) grating polydimethylsiloxane mold. For the first nanoimprinting, we precisely control the UV LED irradiation dosage and demold the device when the UV glue is partially cured and the 1D grating mold is then rotated by three different angles, 30°, 60°, and 90°, for the second nanoimprinting to obtain 2D grating structures with different crossing angles. A high-refractive-index film ZnO is then coated on the surface of the grating structure to form the GMR filter devices. The simulation and experimental results demonstrate that the passband central wavelength of the filter can be tuned by rotating the device to change azimuth angle of the incident light. We compare these three 2D GMR filters with differential crossing angles and find that the filter device with a crossing angle of 60° exhibits the best performance. The tunable range of its central wavelength is 668-742 nm when the azimuth angle varies from 30° to 90°.

  9. Financial Literacy, Confidence and Financial Advice Seeking

    NARCIS (Netherlands)

    Kramer, Marc M.

    2016-01-01

    We find that people with higher confidence in their own financial literacy are less likely to seek financial advice, but no relation between objective measures of literacy and advice seeking. The negative association between confidence and advice seeking is more pronounced among wealthy households.

  10. Welcome to cultural competency: surgery's efforts to acknowledge diversity in residency training.

    Science.gov (United States)

    Ly, Catherine L; Chun, Maria B J

    2013-01-01

    Although cultural competency is not a new concept in healthcare, it has only recently been formally embraced as important in the field of surgery. All physicians, including and especially surgeons, must acknowledge the potential influence of culture in order to provide effective and equitable care for patients of all backgrounds. The Accreditation Council for Graduate Medical Education (ACGME) recognizes cultural competency as a component of "patient care," "professionalism," and "interpersonal and communication skills." A systematic literature search was conducted using the MEDLINE, EBSCOhost, Web of Science, and Google Scholar databases. All publications focusing on surgical residents and the assessment of patient care, professionalism, interpersonal and communication skills, or specifically cultural competency and/or were considered. This initial search resulted in 12 articles. To further refine the review, publications discussing curricula in residencies other than surgery, the assessment of technical, or clinical skills and/or without any explicit focus on cultural competency were excluded. Based on the specified inclusion and exclusion criteria, 5 articles were selected. These studies utilized various methods to improve surgical residents' cultural competency, including lectures, Objective Structural Clinical Examinations (OSCE), and written exercises and evaluations. A number of surgical residency programs have made promising strides in training culturally competent surgeons. Ultimately, in order to maximize our collective efforts to improve the quality of health care, the development of cultural competency curricula must be made a priority and such training should be a requirement for all trainees in surgical residency programs. Copyright © 2013 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  11. Financial Incentives to Promote Active Travel

    Science.gov (United States)

    Martin, Adam; Suhrcke, Marc; Ogilvie, David

    2012-01-01

    Context Financial incentives, including taxes and subsidies, can be used to encourage behavior change. They are common in transport policy for tackling externalities associated with use of motor vehicles, and in public health for influencing alcohol consumption and smoking behaviors. Financial incentives also offer policymakers a compromise between “nudging,” which may be insufficient for changing habitual behavior, and regulations that restrict individual choice. Evidence acquisition The literature review identified studies published between January 1997 and January 2012 of financial incentives relating to any mode of travel in which the impact on active travel, physical activity, or obesity levels was reported. It encompassed macroenvironmental schemes, such as gasoline taxes, and microenvironmental schemes, such as employer-subsidized bicycles. Five relevant reviews and 20 primary studies (of which nine were not included in the reviews) were identified. Evidence synthesis The results show that more-robust evidence is required if policymakers are to maximize the health impact of fiscal policy relating to transport schemes of this kind. Conclusions Drawing on a literature review and insights from the SLOTH (sleep, leisure, occupation, transportation, and home-based activities) time-budget model, this paper argues that financial incentives may have a larger role in promoting walking and cycling than is acknowledged generally. PMID:23159264

  12. CORRECTING ACCOUNTING ERRORS AND ACKNOWLEDGING THEM IN THE EARNINGS TO THE PERIOD

    Directory of Open Access Journals (Sweden)

    BUSUIOCEANU STELIANA

    2013-08-01

    Full Text Available The accounting information is reliable when it does not contain significant errors, is not biasedand accurately represents the transactions and events. In the light of the regulations complying with Europeandirectives, the information is significant if its omission or wrong presentation may influence the decisions users makebased on annual financial statements. Given that the professional practice sees errors in registering or interpretinginformation, as well as omissions and wrong calculations, the Romanian accounting regulations stipulate treatmentsfor correcting errors in compliance with international references. Thus, the correction of the errors corresponding tothe current period is accomplished based on the retained earnings in the case of significant errors or on the currentearnings when the errors are insignificant. The different situations in the professional practice triggered by errorsrequire both knowledge of regulations and professional rationale to be addressed.

  13. Volume phase holographic gratings for the Subaru Prime Focus Spectrograph: performance measurements of the prototype grating set

    Science.gov (United States)

    Barkhouser, Robert H.; Arns, James; Gunn, James E.

    2014-08-01

    The Prime Focus Spectrograph (PFS) is a major instrument under development for the 8.2 m Subaru telescope on Mauna Kea. Four identical, fixed spectrograph modules are located in a room above one Nasmyth focus. A 55 m fiber optic cable feeds light into the spectrographs from a robotic fiber positioner mounted at the telescope prime focus, behind the wide field corrector developed for Hyper Suprime-Cam. The positioner contains 2400 fibers and covers a 1.3 degree hexagonal field of view. Each spectrograph module will be capable of simultaneously acquiring 600 spectra. The spectrograph optical design consists of a Schmidt collimator, two dichroic beamsplitters to separate the light into three channels, and for each channel a volume phase holographic (VPH) grating and a dual- corrector, modified Schmidt reimaging camera. This design provides a 275 mm collimated beam diameter, wide simultaneous wavelength coverage from 380 nm to 1.26 µm, and good imaging performance at the fast f/1.1 focal ratio required from the cameras to avoid oversampling the fibers. The three channels are designated as the blue, red, and near-infrared (NIR), and cover the bandpasses 380-650 nm (blue), 630-970 nm (red), and 0.94-1.26 µm (NIR). A mosaic of two Hamamatsu 2k×4k, 15 µm pixel CCDs records the spectra in the blue and red channels, while the NIR channel employs a 4k×4k, substrate-removed HAWAII-4RG array from Teledyne, with 15 µm pixels and a 1.7 µm wavelength cutoff. VPH gratings have become the dispersing element of choice for moderate-resolution astronomical spectro- graphs due their potential for very high diffraction efficiency, low scattered light, and the more compact instru- ment designs offered by transmissive dispersers. High quality VPH gratings are now routinely being produced in the sizes required for instruments on large telescopes. These factors made VPH gratings an obvious choice for PFS. In order to reduce risk to the project, as well as fully exploit the performance

  14. Fibre Bragg Grating and Long Period Grating Sensors in Polymer Optical Fibres

    DEFF Research Database (Denmark)

    Bundalo, Ivan-Lazar

    mechanisms in polymer fibres using a CO2 laser. One is etching and the other one is perturbation of the microstructured region. After inscription of LPGs, the concept of a biocompatible distributed medical endoscope is presented, where an all-plastic LPG based device is produced. A transducer pod is made...... of applications and pushing the limits. The first part of the work focuses on the fabrication of FBGs in polymer optical fibres. FBGs are a periodic perturbation of the refractive index of the optical fibre core which act as a wavelength specific reflector. The fibres used are made of Polymethyl methacrylate....... In this system a high power CO2 laser is used for the inscription. An LPG is also a periodic perturbation of the guided core mode in fibre, but unlike FBG which reflects the core mode, the LPG couples the core mode to a cladding mode outside the core. We have shown that the LPG grating can be formed through two...

  15. Materiality in Financial Audit

    OpenAIRE

    Adriana Claudia GHIMIS

    2012-01-01

    The financial audit aims toward increasing the credibility of financial informaiton. The purpose of the paper is to outline the most important topics regarding the definition and application of significance limit.

  16. CMS Financial Reports

    Data.gov (United States)

    U.S. Department of Health & Human Services — This section contains the annual CMS financial statements as required under the Chief Financial Officers (CFO) Act of 1990 (P.L. 101-576). The CFO Act marked a major...

  17. Financial Key Ratios

    OpenAIRE

    Tănase Alin-Eliodor

    2014-01-01

    This article focuses on computing techniques starting from trial balance data regarding financial key ratios. There are presented activity, liquidity, solvency and profitability financial key ratios. It is presented a computing methodology in three steps based on a trial balance.

  18. Quarterly Financial Report

    International Development Research Centre (IDRC) Digital Library (Canada)

    acray

    2011-06-30

    Jun 30, 2011 ... 2 IDRC QUARTERLY FINANCIAL REPORT JUNE 2011. Consolidated .... spending on capacity-building projects as well as to management's decision to restrict capacity- building ...... The investments in financial institutions.

  19. Financial Integrity Benchmarks

    Data.gov (United States)

    City of Jackson, Mississippi — This data compiles standard financial integrity benchmarks that allow the City to measure its financial standing. It measure the City's debt ratio and bond ratings....

  20. INNOVATIONS IN FINANCIAL ANALYTICS

    Directory of Open Access Journals (Sweden)

    T. V. Teplova

    2012-01-01

    Full Text Available In this paper as the main feature of innovation in the financial health of a company analyst view the shift to two circuits of key interests of owners of capital (financial stakeholders. Justifi ed by differences key financial systems within the contour ownership interest and the lender three projections: liquidity, the current economic efficiency and growth. In the paper as the main feature of the innovation in the analysis of the financial health of a company is considered a transition to the two circuits of the interests of the key owners of financial capital (financial stakeholders. Justifi ed differences of key financial indicator systems in the framework of the outline of the interests of the owner and the lender by three projections: liquidity, efficiency and the quality of growth. The examples of Russian companies have different interpretations of financial targets and indicators with a choice of activities.

  1. Numerical simulation of a biomass fired grate boiler

    DEFF Research Database (Denmark)

    Yin, Chungen; Rosendahl, Lasse; Kær, Søren Knudsen

    2006-01-01

    Computational fluid dynamic (CFD) analysis of the thermal flow in the combustion furnace of a biomass-fired grate boiler provides crucial insight into the boiler's performance. Quite a few factors play important roles in a general CFD analysis, such as grid, models, discretization scheme and so on....... For a grate boiler, the modeling the interaction of the fuel bed and the gas phase above the bed is also essential. Much effort can be found in literature on developing bed models whose results are introduced into CFD simulations of freeboard as inlet conditions. This paper presents a CFD analysis...... of the largest biomass-fired grate boiler in Denmark. The focus of this paper is to study how significantly an accurate bed model can affect overall CFD results, i.e., how necessarily it is to develop an accurate bed model in terms of the reliability of CFD results. The ultimate purpose of the study is to obtain...

  2. The in-focus variable line spacing plane grating monochromator

    International Nuclear Information System (INIS)

    Reininger, R.

    2011-01-01

    The in-focus variable line spacing plane grating monochromator is based on only two plane optical elements, a variable line spacing plane grating and a plane pre-mirror that illuminates the grating at the angle of incidence that will focus the required photon energy. A high throughput beamline requires only a third optical element after the exit slit, an aberration corrected elliptical toroid. Since plane elements can be manufactured with the smallest figure errors, this monochromator design can achieve very high resolving power. Furthermore, this optical design can correct the deformations induced by the heat load on the optics along the dispersion plane. This should allow obtaining a resolution of 10 meV at 1 keV with currently achievable figure errors on plane optics. The position of the photon source when an insertion device center is not located at the center of the straight section, a common occurrence in new insertion device beamlines, is investigated.

  3. Model based control of grate combustion; Modellbaserad roststyrning

    Energy Technology Data Exchange (ETDEWEB)

    Broden, Henrik; Kjellstroem, Bjoern; Niklasson, Fredrik; Boecher Poulsen, Kristian

    2006-12-15

    An existing dynamic model for grate combustion has been further developed. The model has been used for studies of possible advantages that can be gained from utilisation of measurements of grate temperatures and fuel bed height for control of a boiler after disturbances caused by varying fuel moisture and fuel feeding. The objective was to asses the possibilities to develop a control system that would adjust for such disturbances quicker than measurements of steam output and oxygen in the exhaust. The model is based on dividing the fuel bed into three layers, where the different layers include fuel being dried, fuel being pyrolysed and char reacting with oxygen. The grate below the fuel bed is also considered. A mass balance, an energy balance and a volume balance is considered for each layer in 22 cells along the grate. The energy balances give the temperature distribution and the volume balances the bed height. The earlier version of the model could not handle layers that are consumed. This weakness has now been eliminated. Comparisons between predicted grate temperatures and measurements in a 25 MW boiler fuelled with biofuel have been used for validation of the model. The comparisons include effects of variations in primary air temperature, fuel moisture and output power. The model shows good agreement with observations for changes in the air temperature but the ability of the model to predict effects of changed fuel moisture is difficult to judge since the steam dome pressure control caused simultaneous changes of the primary air flow, which probably had a larger influence on the grate temperature. A linearised, tuned and reduced version of the model was used for design of a linear quadratic controller. This was used for studies of advantages of using measurements of grate temperatures and bed height for control of pusher velocity, grate speed, primary air flow and air temperature after disturbances of fuel moisture and fuel flow. Measurements of the grate

  4. Highly Sensitive Cadmium Concentration Sensor Using Long Period Grating

    Directory of Open Access Journals (Sweden)

    A. S. Lalasangi

    2011-08-01

    Full Text Available In this paper we have proposed a simple and effective Long Period Grating chemical sensor for detecting the traces of Cadmium (Cd++ in drinking water at ppm level. Long Period gratings (LPG were fabricated by point-by-point technique with CO2 laser. We have characterized the LPG concentration sensor sensitivity for different solutions of Cd concentrations varying from 0.01 ppm to 0.04 ppm by injecting white Light source and observed transmitted spectra using Optical Spectrum Analyzer (OSA. Proper reagents have been used in the solutions for detection of the Cd species. The overall shift in wavelength is 10 nm when surrounding medium gradually changed from water to 0.04 ppm of cadmium concentrations. A comparative study has been done using sophisticated spectroscopic atomic absorption spectrometer (AAS and Inductively Coupled Plasma (ICP instruments. The spectral sensitivity enhancement was done by modifying grating surface with gold nanoparticles.

  5. High performance Si immersion gratings patterned with electron beam lithography

    Science.gov (United States)

    Gully-Santiago, Michael A.; Jaffe, Daniel T.; Brooks, Cynthia B.; Wilson, Daniel W.; Muller, Richard E.

    2014-07-01

    Infrared spectrographs employing silicon immersion gratings can be significantly more compact than spectro- graphs using front-surface gratings. The Si gratings can also offer continuous wavelength coverage at high spectral resolution. The grooves in Si gratings are made with semiconductor lithography techniques, to date almost entirely using contact mask photolithography. Planned near-infrared astronomical spectrographs require either finer groove pitches or higher positional accuracy than standard UV contact mask photolithography can reach. A collaboration between the University of Texas at Austin Silicon Diffractive Optics Group and the Jet Propulsion Laboratory Microdevices Laboratory has experimented with direct writing silicon immersion grating grooves with electron beam lithography. The patterning process involves depositing positive e-beam resist on 1 to 30 mm thick, 100 mm diameter monolithic crystalline silicon substrates. We then use the facility JEOL 9300FS e-beam writer at JPL to produce the linear pattern that defines the gratings. There are three key challenges to produce high-performance e-beam written silicon immersion gratings. (1) E- beam field and subfield stitching boundaries cause periodic cross-hatch structures along the grating grooves. The structures manifest themselves as spectral and spatial dimension ghosts in the diffraction limited point spread function (PSF) of the diffraction grating. In this paper, we show that the effects of e-beam field boundaries must be mitigated. We have significantly reduced ghost power with only minor increases in write time by using four or more field sizes of less than 500 μm. (2) The finite e-beam stage drift and run-out error cause large-scale structure in the wavefront error. We deal with this problem by applying a mark detection loop to check for and correct out minuscule stage drifts. We measure the level and direction of stage drift and show that mark detection reduces peak-to-valley wavefront error

  6. Launching focused surface plasmon in circular metallic grating

    International Nuclear Information System (INIS)

    Kumar, Pawan; Tripathi, V. K.; Kumar, Ashok; Shao, X.

    2015-01-01

    The excitation of focused surface plasma wave (SPW) over a metal–vacuum interface embedded with circular surface grating is investigated theoretically. The normally impinged radiation imparts oscillatory velocity to free electrons that beats with the surface ripple to produce a nonlinear current, driving the SPW. As SPW propagates, it gets focused. The focused radiation has a maximum at the centre of grating and decreases beyond the centre due to diffraction. The amplitude of SPW is fixed for a given groove depth and increases rapidly around the resonance frequency. The intensity at the focus point depends on dimensions of the grating. It increases with the radiation frequency approaching the surface plasmon resonance. The scheme has potential applications for photonic devices and surface enhanced Raman scattering

  7. Applications of laser-induced gratings to spectroscopy and dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Rohlfing, E.A. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    This program has traditionally emphasized two principal areas of research. The first is the spectroscopic characterization of large-amplitude motion on the ground-state potential surface of small, transient molecules. The second is the reactivity of carbonaceous clusters and its relevance to soot and fullerene formation in combustion. Motivated initially by the desire to find improved methods of obtaining stimulated emission pumping (SEP) spectra of transients, most of our recent work has centered on the use of laser-induced gratings or resonant four-wave mixing in free-jet expansions. These techniques show great promise for several chemical applications, including molecular spectroscopy and photodissociation dynamics. The author describes recent applications of two-color laser-induced grating spectroscopy (LIGS) to obtain background-free SEP spectra of transients and double resonance spectra of nonfluorescing species, and the use of photofragment transient gratings to probe photodissociation dynamics.

  8. Rotated grating coupled surface plasmon resonance on wavelength-scaled shallow rectangular gratings

    Science.gov (United States)

    Szalai, A.; Szekeres, G.; Balázs, J.; Somogyi, A.; Csete, Maria

    2013-09-01

    Theoretical investigation of rotated grating coupling phenomenon was performed on a multilayer comprising 416-nmperiodic shallow rectangular polymer grating on bimetal film made of gold and silver layers. During the multilayer illumination by 532 nm wavelength p-polarized light the polar and azimuthal angles were varied. In presence of 0-35 nm, 0-50 nm and 15-50 nm thick polymer-layers at the valleys and hills splitting was observed on the dual-angle dependent reflectance in two regions: (i) close to 0° azimuthal angle corresponding to incidence plane parallel to the periodic pattern (P-orientation); and (ii) around ~33.5°/29°/30° azimuthal angle (C-orientation), in agreement with our previous experimental studies. The near-field study revealed that in P-orientation the E-field is enhanced at the glass side with p/2 periodicity at the first minimum appearing at 49°/50°/52° polar angles, and comprises maxima below both the valleys and hills; while E-field enhancement is observable both at the glass and polymer side with p-periodicity at the second minimum developing at 55°/63/64° tilting, comprising maxima intermittently below the valleys or above the hills. In Corientation coupled plasmonic modes are observable, involving modes propagating along the valleys at the secondary maxima appearing at ~35°/32°/32° azimuthal and ~49°/51°/56° polar angles, while modes confined along the polymer hills are observable at the primary minima, which are coupled most strongly at the ~31.5°/25°/28° azimuthal and ~55°/63°/66° polar angles. The secondary peak observable in C-orientation is proposed for biosensing applications, since the supported modes are confined along the valleys, where biomolecules prefer to attach.

  9. Is there a relationship between research sponsorship and publication impact? An analysis of funding acknowledgments in nanotechnology papers.

    Directory of Open Access Journals (Sweden)

    Jue Wang

    Full Text Available This study analyzes funding acknowledgments in scientific papers to investigate relationships between research sponsorship and publication impacts. We identify acknowledgments to research sponsors for nanotechnology papers published in the Web of Science during a one-year sample period. We examine the citations accrued by these papers and the journal impact factors of their publication titles. The results show that publications from grant sponsored research exhibit higher impacts in terms of both journal ranking and citation counts than research that is not grant sponsored. We discuss the method and models used, and the insights provided by this approach as well as it limitations.

  10. Financial Services Industry

    Science.gov (United States)

    2006-01-01

    www.investopedia.com/features/industryhandbook/banking.asp Mishkin , F. & Eakins, S. (2003). Financial Markets + Institutions (4th ed.). Boston...purposes, participants interact in financial markets for securities, bonds, futures and options, utilizing financial intermediaries such as retail and...nations. U.S. participants, likewise, may also choose to participate in foreign financial institutions in order to gain access to or operate in

  11. Trapezoidal diffraction grating beam splitters in single crystal diamond

    Science.gov (United States)

    Kiss, Marcell; Graziosi, Teodoro; Quack, Niels

    2018-02-01

    Single Crystal Diamond has been recognized as a prime material for optical components in high power applications due to low absorption and high thermal conductivity. However, diamond microstructuring remains challenging. Here, we report on the fabrication and characterization of optical diffraction gratings exhibiting a symmetric trapezoidal profile etched into a single crystal diamond substrate. The optimized grating geometry diffracts the transmitted optical power into precisely defined proportions, performing as an effective beam splitter. We fabricate our gratings in commercially available single crystal CVD diamond plates (2.6mm x 2.6mm x 0.3mm). Using a sputter deposited hard mask and patterning by contact lithography, the diamond is etched in an inductively coupled oxygen plasma with zero platen power. The etch process effectively reveals the characteristic {111} diamond crystal planes, creating a precisely defined angled (54.7°) profile. SEM and AFM measurements of the fabricated gratings evidence the trapezoidal shape with a pitch of 3.82μm, depth of 170 nm and duty cycle of 35.5%. Optical characterization is performed in transmission using a 650nm laser source perpendicular to the sample. The recorded transmitted optical power as function of detector rotation angle shows a distribution of 21.1% in the 0th order and 23.6% in each +/-1st order (16.1% reflected, 16.6% in higher orders). To our knowledge, this is the first demonstration of diffraction gratings with trapezoidal profile in single crystal diamond. The fabrication process will enable beam splitter gratings of custom defined optical power distribution profiles, while antireflection coatings can increase the efficiency.

  12. Financial Advice: Who Pays

    Science.gov (United States)

    Finke, Michael S.; Huston, Sandra J.; Winchester, Danielle D.

    2011-01-01

    Using a cost-benefit framework for financial planning services and proprietary data collected in the summer of 2008, the client characteristics that are associated with the likelihood of paying for professional financial advice, as well as the type of financial services purchased, are identified. Results indicate that respondents who pay for…

  13. Financial Sector Assessment : Morocco

    OpenAIRE

    World Bank; International Monetary Fund

    2017-01-01

    A joint International Monetary Fund (IMF)-World Bank mission visited Rabat and Casablanca in 2015, to assess the soundness and resilience of the banking system, the state of play in financial inclusion and infrastructure, the oversight frameworks for banking, capital markets and financial market infrastructures, crisis preparedness, and update the findings of the Financial Sector Assessme...

  14. Invest in Financial Literacy

    Science.gov (United States)

    Bush, Sarah B.; McGatha, Maggie B.; Bay-Williams, Jennifer M.

    2012-01-01

    The current state of the economy elevates the need to build awareness of financial markets and personal finance among the nation's young people through implementing a financial literacy curriculum in schools. A limited amount of time spent on financial literacy can have a positive effect on students' budgeting skills. This knowledge will only add…

  15. Marketing Financial Aid

    Science.gov (United States)

    Huddleston, Thomas, Jr.; Batty, Burt F.

    1978-01-01

    Student financial assistance services are becoming a major part of the institutional marketing plan as traditional college-age students decline in numbers and price competition among institutions increases. The effect of financial aid on enrollment and admissions processes is discussed along with the role of the financial aid officer. (Author/LBH)

  16. Financial Markets and Compliance

    NARCIS (Netherlands)

    van de Laar, T.A.H.M.; Bleker, Sylvie; Houben, Raf

    2017-01-01

    This chapter will focus on the goals of financial market regulation through the rules of economics, the strategies financial regulation employs to achieve these goals and the insights this provides for the compliance profession. For an overview of the goals and strategies of financial regulation

  17. Essays on financial liberalization

    NARCIS (Netherlands)

    Bumann, Silke

    2015-01-01

    This thesis investigates the effect of financial liberalization on economic growth, income inequality and financial instability. Chapter 1 describes aim and scope of the thesis. Chapter 2 provides a meta-analysis of the literature on financial liberalization and economic growth. It is found that

  18. Laser-induced grating in ZnO

    DEFF Research Database (Denmark)

    Ravn, Jesper N.

    1992-01-01

    A simple approach for the calculation of self-diffraction in a thin combined phase and amplitude grating is presented. The third order nonlinearity, the electron-hole recombination time, and the ambipolar diffusion coefficient in a ZnO crystal are measured by means of laser-induced self-diffracti......A simple approach for the calculation of self-diffraction in a thin combined phase and amplitude grating is presented. The third order nonlinearity, the electron-hole recombination time, and the ambipolar diffusion coefficient in a ZnO crystal are measured by means of laser-induced self...

  19. Recording polarization gratings with a standing spiral wave

    Science.gov (United States)

    Vernon, Jonathan P.; Serak, Svetlana V.; Hakobyan, Rafik S.; Aleksanyan, Artur K.; Tondiglia, Vincent P.; White, Timothy J.; Bunning, Timothy J.; Tabiryan, Nelson V.

    2013-11-01

    A scalable and robust methodology for writing cycloidal modulation patterns of optical axis orientation in photosensitive surface alignment layers is demonstrated. Counterpropagating circularly polarized beams, generated by reflection of the input beam from a cholesteric liquid crystal, direct local surface orientation in a photosensitive surface. Purposely introducing a slight angle between the input beam and the photosensitive surface normal introduces a grating period/orientation that is readily controlled and templated. The resulting cycloidal diffractive waveplates offer utility in technologies requiring diffraction over a broad range of angles/wavelengths. This simple methodology of forming polarization gratings offers advantages over conventional fabrication techniques.

  20. Recording polarization gratings with a standing spiral wave

    Energy Technology Data Exchange (ETDEWEB)

    Vernon, Jonathan P.; Tondiglia, Vincent P.; White, Timothy J.; Bunning, Timothy J. [Air Force Research Laboratory, Materials and Manufacturing Directorate, 3005 Hobson Way, Suite 1, Wright-Patterson Air Force Base, Ohio 45433 (United States); Serak, Svetlana V.; Hakobyan, Rafik S.; Aleksanyan, Artur K.; Tabiryan, Nelson V., E-mail: nelson@beamco.com [BEAM Engineering for Advanced Measurements Company, 809 South Orlando Avenue, Suite I, Winter Park, Florida 32789 (United States)

    2013-11-11

    A scalable and robust methodology for writing cycloidal modulation patterns of optical axis orientation in photosensitive surface alignment layers is demonstrated. Counterpropagating circularly polarized beams, generated by reflection of the input beam from a cholesteric liquid crystal, direct local surface orientation in a photosensitive surface. Purposely introducing a slight angle between the input beam and the photosensitive surface normal introduces a grating period/orientation that is readily controlled and templated. The resulting cycloidal diffractive waveplates offer utility in technologies requiring diffraction over a broad range of angles/wavelengths. This simple methodology of forming polarization gratings offers advantages over conventional fabrication techniques.

  1. Recording polarization gratings with a standing spiral wave

    International Nuclear Information System (INIS)

    Vernon, Jonathan P.; Tondiglia, Vincent P.; White, Timothy J.; Bunning, Timothy J.; Serak, Svetlana V.; Hakobyan, Rafik S.; Aleksanyan, Artur K.; Tabiryan, Nelson V.

    2013-01-01

    A scalable and robust methodology for writing cycloidal modulation patterns of optical axis orientation in photosensitive surface alignment layers is demonstrated. Counterpropagating circularly polarized beams, generated by reflection of the input beam from a cholesteric liquid crystal, direct local surface orientation in a photosensitive surface. Purposely introducing a slight angle between the input beam and the photosensitive surface normal introduces a grating period/orientation that is readily controlled and templated. The resulting cycloidal diffractive waveplates offer utility in technologies requiring diffraction over a broad range of angles/wavelengths. This simple methodology of forming polarization gratings offers advantages over conventional fabrication techniques

  2. Security System Responsive to Optical Fiber Having Bragg Grating

    Science.gov (United States)

    Gary, Charles K. (Inventor); Ozcan, Meric (Inventor)

    1997-01-01

    An optically responsive electronic lock is disclosed comprising an optical fiber serving as a key and having Bragg gratings placed therein. Further, an identification system is disclosed which has the optical fiber serving as means for tagging and identifying an object. The key or tagged object is inserted into a respective receptacle and the Bragg gratings cause the optical fiber to reflect a predetermined frequency spectra pattern of incident light which is detected by a decoder and compared against a predetermined spectrum to determine if an electrical signal is generated to either operate the lock or light a display of an authentication panel.

  3. Time-dependent Bragg diffraction by multilayer gratings

    International Nuclear Information System (INIS)

    André, Jean-Michel; Jonnard, Philippe

    2016-01-01

    Time-dependent Bragg diffraction by multilayer gratings working by reflection or by transmission is investigated. The study is performed by generalizing the time-dependent coupled-wave theory previously developed for one-dimensional photonic crystals (André J-M and Jonnard P 2015 J. Opt. 17 085609) and also by extending the Takagi–Taupin approach of the dynamical theory of diffraction. The indicial response is calculated. It presents a time delay with a transient time that is a function of the extinction length for reflection geometry and of the extinction length combined with the thickness of the grating for transmission geometry. (paper)

  4. Flexible PCPDTBT:PCBM solar cells with integrated grating structures

    DEFF Research Database (Denmark)

    Oliveira Hansen, Roana Melina de; Liu, Yinghui; Madsen, Morten

    2013-01-01

    We report on development of flexible PCPDTBT:PCBM solar cells with integrated diffraction gratings on the bottom electrodes. The presented results address PCPDTBT:PCBM solar cells in an inverted geometry, which contains implemented grating structures whose pitch is tuned to match the absorption...... spectra of the active layer. This optimized solar cell structure leads to an enhanced absorption in the active layer and thus improved short-circuit currents and power conversion efficiencies in the fabricated devices. Fabrication of the solar cells on thin polyimide substrates which are compatible...

  5. Field analysis of two-dimensional focusing grating

    OpenAIRE

    Borsboom, P.P.; Frankena, H.J.

    1995-01-01

    The method that we have developed [P-P. Borsboom, Ph.D. dissertation (Delft University of Technology, Delft, The Netherlands); P-P. Borsboom and H. J. Frankena, J. Opt. Soc. Am. A 12, 1134–1141 (1995)] is successfully applied to a two-dimensional focusing grating coupler. The field in the focal region has been determined for symmetrical chirped gratings consisting of as many as 124 corrugations. The intensity distribution in the focal region agrees well with the approximate predictions of geo...

  6. UV writing of advanced Bragg gratings in optical waveguides

    DEFF Research Database (Denmark)

    Jensen, Jesper Bo Damm

    2002-01-01

    of the novel polarization control method for UV writing of Bragg gratings with advanced apodization profiles including phase shifts. The principle of the polarization control method relies on a spatial separation of the s- and p-polarized components of a linearly polarized UV beam corresponding to half......, Technical University of Denmark. During fabrication the planar waveguides were annealed in an oxygen rich atmosphere. This reduces the photosensitivity to a negligible level and Bragg gratings cannot be written within reasonable time unless the waveguides are sensitized by deuterium loading. Samples were...

  7. Miniaturized NIR scanning grating spectrometer for use in mobile phones

    Science.gov (United States)

    Knobbe, Jens; Pügner, Tino; Grüger, Heinrich

    2016-05-01

    An extremely miniaturized scanning grating spectrometer at the size of a sugar cube has been developed at Fraunhofer IPMS. To meet the requirements for the integration into a mobile phone a new system approach has been pursued. The key component within the system is a silicon-based deflectable diffraction grating with an integrated driving mechanism. A first sample of the new spectrometer was built and characterized. It was found to have a spectral range from 950 nm to 1900 nm at a resolution of 10 nm. The results show that the performance of the new MEMS spectrometer is in good agreement with the requirements for mobile phone integration.

  8. VCSELs and silicon light sources exploiting SOI grating mirrors

    DEFF Research Database (Denmark)

    Chung, Il-Sug; Mørk, Jesper

    2012-01-01

    In this talk, novel vertical-cavity laser structure consisting of a dielectric Bragg reflector, a III-V active region, and a high-index-contrast grating made in the Si layer of a silicon-on-insulator (SOI) wafer will be presented. In the Si light source version of this laser structure, the SOI...... the Bragg reflector. Numerical simulations show that both the silicon light source and the VCSEL exploiting SOI grating mirrors have superior performances, compared to existing silicon light sources and long wavelength VCSELs. These devices are highly adequate for chip-level optical interconnects as well...

  9. Color multiplexing using directional holographic gratings and linear polarization

    International Nuclear Information System (INIS)

    Lugo, L I; Rodriguez, A; Ramirez, G; Guel, S; Nunez, O F

    2011-01-01

    We propose a system of multiplexing and de-multiplexing, which uses a holographic diffraction grating to compel modulated light of different colors to be sent through an optical fiber. Diffraction gratings were fabricated specifically to pick the desired direction in which we wanted the light of different wavelengths to impinge the optic fiber, and also to be separated at the output. It was been found that the system preserves the polarization of light, which give us a one more freedom degree, allowing us to process twice the original information amount.

  10. Geometric effect on second harmonic generation from gold grating

    Science.gov (United States)

    Lu, Jiao; Ding, Baoyong; Huo, Yanyan; Ning, Tingyin

    2018-05-01

    We numerically investigate second harmonic generation from gold gratings of an ideal rectangular and ladder-shaped cross-section. The SHG efficiency from the gold gratings of the ladder-shaped cross-section is significantly enhanced compared with that from the ideal rectangular cross-section with a maximum enhancement factor of around two. The enhancement is ascribe to the nanostructure dependent local fundamental electric field, the nonlinear sources and thus the far field radiation. Our results have a practical meaning in the explanation of experimental SHG measurement, and the modulation of SHG response in the metallic nanostructure.

  11. Fiscal and monetary policy interactions in an endogenous growth model with financial intermediaries

    OpenAIRE

    Espinosa, Marco A.; Yip, Chong K.

    1995-01-01

    We review some inflationary and growth claims surrounding fiscal and monetary policy interactions. While financial intermediation has long been acknowledged as a key mechanism in the transmission of these interactions, only recently have economists incorporated the explicit modeling of such intermediaries in their analyses. Here we model financial intermediaries explicitly. We find that the relation between growth and inflation depends crucially on the agents' degree of relative risk aversion...

  12. Legal traditions and initial endowments in shaping the path of financial development

    OpenAIRE

    Oto-Peralías, Daniel; Romero-Ávila, Diego

    2014-01-01

    The authors acknowledge financial support from the Spanish Ministry of Science and Technology through grant ECO2009-13357, the Spanish Ministry of Economics and Competitiveness through grant ECO2012-35430, and the Andalusian Council of Innovation and Science under Excellence Project SEJ-4546. This paper finds remarkable heterogeneity in the relationship between legal traditions and finance in former colonies. The effect of the British common law on financial development is conditioned by t...

  13. Does financial literacy improve financial inclusion? Cross country evidence

    OpenAIRE

    Grohmann, Antonia; Klühs, Theres; Menkhoff, Lukas

    2017-01-01

    While financial inclusion is typically addressed by improving the financial infrastructure we show that financial literacy, representing the demand-side of financial markets, also has a beneficial effect. We study this effect at the cross-country level, which allows to consider institutional variation. Regarding "access to finance", financial infrastructure and financial literacy are mainly substitutes. However, regarding the "use of financial services", the effect of higher financial literac...

  14. COMPANY ACTIVITY FINANCIAL RISK

    Directory of Open Access Journals (Sweden)

    Caruntu Genu Alexandru

    2012-12-01

    Full Text Available In economic and financial activity, risk is an inherent financial decisions, encountered in daily agenda of managers of companies. Unexpected changes in the price of a product development not only affect the financial results of a company, but can cause even bankruptcy. In fact, the nature of financial decisions involve uncertainty. Financial decisions are made based on cash flows under future contracts, which are par excellence incerte.Activitatea an enterprise that holds any weight in the industry is subject to risks, since it can not predict with certainty different components of its outcome (cost, quantity, price and operating cycle (purchase, processing, sales.

  15. FINANCIAL INSTABILITY IN ROMANIA

    Directory of Open Access Journals (Sweden)

    Cristian, IONESCU

    2014-11-01

    Full Text Available The aim of this paper is to empirically study the concept of financial stability in Romania, from both a monetary policy perspective and a financial perspective. In this paper, I also compute an aggregate index of financial stability, for the period 2008-2013, explaining the correlations between several extremely important macroeconomic and sectorial variables and financial stability. The article also debates the aspect of policy instruments that aim to promote, highlighting the undertaken measures and also giving some measures recommendations, pointing out the main pillars: crises management; cross-sectoral challenges; banking sector; securities markets and capital markets; insurance sector; pensions sector; access to financial services.

  16. Code-Switching to Know a TL Equivalent of an L1 Word: Request-Provision-Acknowledgement (RPA) Sequence

    Science.gov (United States)

    Lucero, Edgar

    2011-01-01

    This article focuses on the learner's use of Code-switching to learn the TL (Target Language) equivalent of an L1 word. The interactional pattern that this situation creates defines the Request-Provision-Acknowledgement (RPA) sequence. The article explains each of the turns of the sequence under the combination of the Ethnomethodological…

  17. 47 CFR 80.1121 - Receipt and acknowledgement of distress alerts by ship stations and ship earth stations.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Receipt and acknowledgement of distress alerts by ship stations and ship earth stations. 80.1121 Section 80.1121 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES STATIONS IN THE MARITIME SERVICES Global Maritime Distress and Safety System (GMDSS)...

  18. Acknowledging individual responsibility while emphasizing social determinants in narratives to promote obesity-reducing public policy: a randomized experiment.

    Science.gov (United States)

    Niederdeppe, Jeff; Roh, Sungjong; Shapiro, Michael A

    2015-01-01

    This study tests whether policy narratives designed to increase support for obesity-reducing public policies should explicitly acknowledge individual responsibility while emphasizing social, physical, and economic (social) determinants of obesity. We use a web-based, randomized experiment with a nationally representative sample of American adults (n = 718) to test hypotheses derived from theory and research on narrative persuasion. Respondents exposed to narratives that acknowledged individual responsibility while emphasizing obesity's social determinants were less likely to engage in counterargument and felt more empathy for the story's main character than those exposed to a message that did not acknowledge individual responsibility. Counterarguing and affective empathy fully mediated the relationship between message condition and support for policies to reduce rates of obesity. Failure to acknowledge individual responsibility in narratives emphasizing social determinants of obesity may undermine the persuasiveness of policy narratives. Omitting information about individual responsibility, a strongly-held American value, invites the public to engage in counterargument about the narratives and reduces feelings of empathy for a character that experiences the challenges and benefits of social determinants of obesity.

  19. Acknowledging individual responsibility while emphasizing social determinants in narratives to promote obesity-reducing public policy: a randomized experiment.

    Directory of Open Access Journals (Sweden)

    Jeff Niederdeppe

    Full Text Available This study tests whether policy narratives designed to increase support for obesity-reducing public policies should explicitly acknowledge individual responsibility while emphasizing social, physical, and economic (social determinants of obesity. We use a web-based, randomized experiment with a nationally representative sample of American adults (n = 718 to test hypotheses derived from theory and research on narrative persuasion. Respondents exposed to narratives that acknowledged individual responsibility while emphasizing obesity's social determinants were less likely to engage in counterargument and felt more empathy for the story's main character than those exposed to a message that did not acknowledge individual responsibility. Counterarguing and affective empathy fully mediated the relationship between message condition and support for policies to reduce rates of obesity. Failure to acknowledge individual responsibility in narratives emphasizing social determinants of obesity may undermine the persuasiveness of policy narratives. Omitting information about individual responsibility, a strongly-held American value, invites the public to engage in counterargument about the narratives and reduces feelings of empathy for a character that experiences the challenges and benefits of social determinants of obesity.

  20. Posttraumatic growth, social acknowledgment as survivors, and sense of coherence in former German child soldiers of World War II.

    Science.gov (United States)

    Forstmeier, Simon; Kuwert, Philipp; Spitzer, Carsten; Freyberger, Harald J; Maercker, Andreas

    2009-12-01

    To examine posttraumatic growth (PTG) and its predictors social acknowledgment as survivors, sense of coherence (SOC), trauma severity, and further factors in former child soldiers more than 60 years after deployment. Cross-sectional. University-based geropsychiatric center in Germany. One hundred three former German child soldiers of World War II, mean age 78 years in which 96% experienced at least one war trauma. Subjects completed the Posttraumatic Growth Inventory, Social Acknowledgment Questionnaire (SAQ), and SOC Scale. Trauma exposure and posttraumatic stress disorder (PTSD) symptoms were assessed by the Posttraumatic Diagnostic Scale. Depression, anxiety, and somatization were assessed using the Brief Symptom Inventory. Number of traumas, recognition by significant others, and general disapproval as facets of social acknowledgment as a survivor, and meaningfulness as a dimension of SOC correlated significantly with PTG. In a multiple hierarchical regression analysis, recognition as a survivor by significant others (SAQ) and meaningfulness (SOC) remained the only significant predictors of PTG. Social acknowledgment as a survivor by significant others and the belief that the world is meaningful are among the most important factors contributing to PTG. Further research should investigate whether treatments of PTSD in people who experienced war traumas recently or many years ago might benefit from a focus on the belief system and the role of family and social support.

  1. Interactive Financial Charts- Agency Financial Reports

    Data.gov (United States)

    General Services Administration — For a visual depiction of GSA's Balance Sheet and Statement of Net Cost, please use the interactive charts to view the financial results for fiscal years 2007-2013.

  2. THE GLOBAL FINANCIAL CRISIS AND NATIONAL FINANCIAL ...

    African Journals Online (AJOL)

    propose solutions aimed at reducing the effects of global financial crisis by ... rates of return leading to more investment and higher growth for developing countries. .... capital can without notice turn into outflows as it did in Russia and East Asia.

  3. Improved thermal and strain performance of annealed polymer optical fiber Bragg gratings

    DEFF Research Database (Denmark)

    Yuan, Scott Wu; Stefani, Alessio; Bache, Morten

    2011-01-01

    We report on a detailed study of the inscription and characterization of fiber Bragg gratings (FBGs) in commercial step index polymer optical fibers (POFs). Through the growth dynamics of the gratings, we identify the effect of UV-induced heating during the grating inscription. We found that FBGs...

  4. Embedding silica and polymer fibre Bragg gratings (FBG) in plastic 3D-printed sensing patches

    DEFF Research Database (Denmark)

    Zubel, Michal G.; Sugden, Kate; Webb, David J.

    2016-01-01

    This paper reports the first demonstration of a silica fibre Bragg grating (SOFBG) embedded in an FDM 3-D printed housing to yield a dual grating temperature-compensated strain sensor. We also report the first ever integration of polymer fibre Bragg grating (POFBG) within a 3-D printed sensing...

  5. Highly efficient blazed grating with multilayer coating for tender X-ray energies

    NARCIS (Netherlands)

    Senf, F.; Bijkerk, Frederik; Eggenstein, F.; Gwalt, G.; Huang, Qiushi; van de Kruijs, Robbert Wilhelmus Elisabeth; Kutz, O.; Lemke, S.; Louis, Eric; Mertin, M.; Packe, I.; Rudolph, I.; Schafers, F.; Siewert, F.; Sokolov, A.; Sturm, Jacobus Marinus; Waberski, C.; Wang, Z.; Wolf, J.; Zeschke, T.; Erko, A.

    2016-01-01

    For photon energies of 1 – 5 keV, blazed gratings with multilayer coating are ideally suited for the suppression of stray and higher orders light in grating monochromators. We developed and characterized a blazed 2000 lines/mm grating coated with a 20 period Cr/C- multilayer. The multilayer

  6. Overview of diffraction gratings technologies for spaceflight satellites and ground-based telescopes

    Science.gov (United States)

    Cotel, A.; Liard, A.; Desserouer, F.; Pichon, P.

    2017-11-01

    The diffraction gratings are widely used in Space-flight satellites for spectrograph instruments or in ground-based telescopes in astronomy. The diffraction gratings are one of the key optical components of such systems and have to exhibit very high optical performances. HORIBA Jobin Yvon S.A.S. (part of HORIBA Group) is in the forefront of such gratings development for more than 40 years. During the past decades, HORIBA Jobin Yvon (HJY) has developed a unique expertise in diffraction grating design and manufacturing processes for holographic, ruled or etched gratings. We will present in this paper an overview of diffraction grating technologies especially designed for space and astronomy applications. We will firstly review the heritage of the company in this field with the space qualification of different grating types. Then, we will describe several key grating technologies developed for specific space or astronomy projects: ruled blazed low groove density plane reflection grating, high-groove density holographic toroidal and spherical grating, and finally transmission Fused Silica Etched (FSE) grism-assembled grating. We will not present the Volume Phase Holographic (VPHG) grating type which is used in Astronomy.

  7. Overview of diffraction gratings technologies for space-flight satellites and astronomy

    Science.gov (United States)

    Cotel, Arnaud; Liard, Audrey; Desserouer, Frédéric; Bonnemason, Francis; Pichon, Pierre

    2014-09-01

    The diffraction gratings are widely used in Space-flight satellites for spectrograph instruments or in ground-based telescopes in astronomy. The diffraction gratings are one of the key optical components of such systems and have to exhibit very high optical performances. HORIBA Jobin Yvon S.A.S. (part of HORIBA Group) is in the forefront of such gratings development for more than 40 years. During the past decades, HORIBA Jobin Yvon (HJY) has developed a unique expertise in diffraction grating design and manufacturing processes for holographic, ruled or etched gratings. We will present in this paper an overview of diffraction grating technologies especially designed for space and astronomy applications. We will firstly review the heritage of the company in this field with the space qualification of different grating types. Then, we will describe several key grating technologies developed for specific space or astronomy projects: ruled blazed low groove density plane reflection grating, holographic blazed replica plane grating, high-groove density holographic toroidal and spherical grating and transmission Fused Silica Etched (FSE) grismassembled grating.

  8. Presenting practice financial information.

    Science.gov (United States)

    Webster, Lee Ann H

    2007-01-01

    Medical practice leadership teams, often consisting primarily of physicians with limited financial backgrounds, must make important business decisions and continuously monitor practice operations. In order to competently perform this duty, they need financial reports that are relevant and easy to understand. This article explores financial reporting and decision-making in a physician practice. It discusses reports and tools, such as ratios, graphs, and comparisons, that practices typically include in their reports. Because profitability and cash flow are often the most important financial considerations for physician practices, reports should generally focus on the impact of various activities and potential decisions upon these concerns. This article also provides communication tips for both those presenting practice financial information and those making the decisions. By communicating effectively, these leaders can best use financial information to improve decision-making and maximize financial performance.

  9. Full transmission modes and steady states in defect gratings,

    NARCIS (Netherlands)

    van Groesen, Embrecht W.C.; Sopaheluwakan, A.; Andonowati, A.; de Ridder, R.M; Altena, G; Geuzebroek, D.H.; Dekker, R

    2003-01-01

    For a symmetric grating structure with a defect, we show that a fully transmitted defect mode in the band gap can be obtained as a superposition of two steady states: an amplified and an attenuated defect state. Without scanning the whole band gap by transmission calculations, this simplifies the

  10. Nanoimprinted reflecting gratings for long-range surface plasmon polaritons

    DEFF Research Database (Denmark)

    Pedersen, Rasmus Haugstrup; Boltasseva, Alexandra; Johansen, Dan Mario

    2007-01-01

    We present a novel design, fabrication, and characterization of reflecting gratings for long-range surface plasmon polaritons (LR-SPPs) at telecom wavelengths. LR-SPP waveguides consisting of a thin (12 nm) gold film embedded in a thick (45 μm) layer of dielectric polymer cladding are structured...

  11. Rational solitons in deep nonlinear optical Bragg grating

    NARCIS (Netherlands)

    Alatas, H.; Iskandar, A.A.; Tjia, M.O.; Valkering, T.P.

    2006-01-01

    We have examined the rational solitons in the Generalized Coupled Mode model for a deep nonlinear Bragg grating. These solitons are the degenerate forms of the ordinary solitons and appear at the transition lines in the parameter plane. A simple formulation is presented for the investigation of the

  12. Plasmonic Optical Fiber-Grating Immunosensing: A Review.

    Science.gov (United States)

    Guo, Tuan; González-Vila, Álvaro; Loyez, Médéric; Caucheteur, Christophe

    2017-11-26

    Plasmonic immunosensors are usually made of a noble metal (in the form of a film or nanoparticles) on which bioreceptors are grafted to sense analytes based on the antibody/antigen or other affinity mechanism. Optical fiber configurations are a miniaturized counterpart to the bulky Kretschmann prism and allow easy light injection and remote operation. To excite a surface plasmon (SP), the core-guided light is locally outcoupled. Unclad optical fibers were the first configurations reported to this end. Among the different architectures able to bring light in contact with the surrounding medium, a great quantity of research is today being conducted on metal-coated fiber gratings photo-imprinted in the fiber core, as they provide modal features that enable SP generation at any wavelength, especially in the telecommunication window. They are perfectly suited for use with cost-effective high-resolution interrogators, allowing both a high sensitivity and a low limit of detection to be reached in immunosensing. This paper will review recent progress made in this field with different kinds of gratings: uniform, tilted and eccentric short-period gratings as well as long-period fiber gratings. Practical cases will be reported, showing that such sensors can be used in very small volumes of analytes and even possibly applied to in vivo diagnosis.

  13. Reflection-grating photorefractive self-pumped ring mirror

    Science.gov (United States)

    D'Iakov, V. A.; Korol'Kov, S. A.; Mamaev, A. V.; Shkunov, V. V.; Zozulia, A. A.

    1991-10-01

    A reflection-grating ring mirror using a photorefractive KNbO2 crystal with a response time of several milliseconds and a reflectivity of as much as 50 percent has been experimentally fabricated. A theoretical analysis of the geometry involved is made which provides only qualitative agreement with the experimental findings.

  14. First Results of ISO-SWS Grating Observations of Jupiter

    NARCIS (Netherlands)

    Encrenaz, Th.; de Graauw, Th.; Schaeidt, S.; Lellouch, E.; Feuchtgruber, H.; Beintema, D. A.; Bezard, B.; Drossart, P.; Griffin, M.; Heras, A.; Kessler, M.; Leech, K.; Morris, A.; Roelfsema, P. R.; Roos-Serote, M.; Salama, A.; Vandenbussche, B.; Valentijn, E. A.; Davies, G. R.; Naylor, D. A.

    1996-01-01

    The spectrum of Jupiter has been recorded on April 12, 1996, between 2.75 and 14.5 mu m, with the grating mode of the Short-Wavelength Spectrometer of ISO (Infrared Space Observatory). The resolving power is 1500 and the sensitivity limit is better than 1 Jy. The corresponding S/N ratio is better

  15. A Manually Operated Cassava Grating Machine | Odigboh | Nigerian ...

    African Journals Online (AJOL)

    The design and development of a manually operated cassava grating machine prototype are presented. The prototype grater is shown to be easy to operate at 30 - 45 rpm to give a product whose quality is as good as that from motorized graters at a throughput of 125 - 185 kg/h. The prototype grater is a powerful alternative ...

  16. Measurement of gas flow velocities by laser-induced gratings

    Energy Technology Data Exchange (ETDEWEB)

    Hemmerling, B; Stampanoni-Panariello, A [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Kozlov, A D.N. [General Physics Institute, Moscow (Russian Federation)

    1999-08-01

    Time resolved light scattering from laser-induced electrostrictive gratings was used for the determination of flow velocities in air at room temperature. By measuring the velocity profile across the width of a slit nozzle we demonstrated the high spatial resolution (about 200 mm) of this novel technique. (author) 3 figs., 1 ref.

  17. Modeling, simulation, and design of SAW grating filters

    Science.gov (United States)

    Schwelb, Otto; Adler, E. L.; Slaboszewicz, J. K.

    1990-05-01

    A systematic procedure for modeling, simulating, and designing SAW (surface acoustic wave) grating filters, taking losses into account, is described. Grating structures and IDTs (interdigital transducers) coupling to SAWs are defined by cascadable transmission-matrix building blocks. Driving point and transfer characteristics (immittances) of complex architectures consisting of gratings, transducers, and coupling networks are obtained by chain-multiplying building-block matrices. This modular approach to resonator filter analysis and design combines the elements of lossy filter synthesis with the transmission-matrix description of SAW components. A multipole filter design procedure based on a lumped-element-model approximation of one-pole two-port resonator building blocks is given and the range of validity of this model examined. The software for simulating the performance of SAW grating devices based on this matrix approach is described, and its performance, when linked to the design procedure to form a CAD/CAA (computer-aided design and analysis) multiple-filter design package, is illustrated with a resonator filter design example.

  18. Topology-optimized broadband surface relief transmission grating

    DEFF Research Database (Denmark)

    Andkjær, Jacob; Ryder, Christian P.; Nielsen, Peter C.

    2014-01-01

    We propose a design methodology for systematic design of surface relief transmission gratings with optimized diffraction efficiency. The methodology is based on a gradient-based topology optimization formulation along with 2D frequency domain finite element simulations for TE and TM polarized plane...

  19. Analysis of higher order harmonics with holographic reflection gratings

    Science.gov (United States)

    Mas-Abellan, P.; Madrigal, R.; Fimia, A.

    2017-05-01

    Silver halide emulsions have been considered one of the most energetic sensitive materials for holographic applications. Nonlinear recording effects on holographic reflection gratings recorded on silver halide emulsions have been studied by different authors obtaining excellent experimental results. In this communication specifically we focused our investigation on the effects of refractive index modulation, trying to get high levels of overmodulation that will produce high order harmonics. We studied the influence of the overmodulation and its effects on the transmission spectra for a wide exposure range by use of 9 μm thickness films of ultrafine grain emulsion BB640, exposed to single collimated beams using a red He-Ne laser (wavelength 632.8 nm) with Denisyuk configuration obtaining a spatial frequency of 4990 l/mm recorded on the emulsion. The experimental results show that high overmodulation levels of refractive index produce second order harmonics with high diffraction efficiency (higher than 75%) and a narrow grating bandwidth (12.5 nm). Results also show that overmodulation produce diffraction spectra deformation of the second order harmonic, transforming the spectrum from sinusoidal to approximation of square shape due to very high overmodulation. Increasing the levels of overmodulation of refractive index, we have obtained higher order harmonics, obtaining third order harmonic with diffraction efficiency (up to 23%) and narrowing grating bandwidth (5 nm). This study is the first step to develop a new easy technique to obtain narrow spectral filters based on the use of high index modulation reflection gratings.

  20. Polarization control method for UV writing of advanced bragg gratings

    DEFF Research Database (Denmark)

    Deyerl, Hans-Jürgen; Plougmann, Nikolai; Jensen, Jesper Bo Damm

    2002-01-01

    We report the application of the polarization control method for the UV writing of advanced fiber Bragg gratings (FBG). We demonstrate the strength of the new method for different apodization profiles, including the Sinc-profile and two designs for dispersion-free square filters. The method has...

  1. Optimization for sinusoidal profiles in surface relief gratings ...

    Indian Academy of Sciences (India)

    2014-02-07

    Feb 7, 2014 ... filometry [7–9] and monitoring of surface self-diffusion of solids under ultrahigh vacuum conditions [10]. In the present work, recording parameters, i.e. exposure time and deve- lopment time for fabrication of such holographic gratings have been optimized to obtain nearly perfect sinusoidal profiles in the ...

  2. POF based glucose sensor incorporating grating wavelength filters

    DEFF Research Database (Denmark)

    Hassan, Hafeez Ul; Aasmul, Søren; Bang, Ole

    2014-01-01

    AND RESEARCH IN POLYMER OPTICAL DEVICES; TRIPOD. Within the domain of TRIPOD, research is conducted on "Plastic Optical Fiber based Glucose Sensors Incorporating Grating Wavelength Filters". Research will be focused to optimized fiber tips for better coupling efficiency, reducing the response time of sensor...

  3. Electrically modulated transparent liquid crystal-optical grating projection

    DEFF Research Database (Denmark)

    Buss, Thomas; Smith, Cameron; Kristensen, Anders

    2013-01-01

    A transparent, fully integrated electrically modulated projection technique is presented based on light guiding through a thin liquid crystal layer covering sub-wavelength gratings. The reported device operates at 10 V with response times of 4.5 ms. Analysis of the liquid crystal alignment shows...

  4. 1060-nm Tunable Monolithic High Index Contrast Subwavelength Grating VCSEL

    DEFF Research Database (Denmark)

    Ansbæk, Thor; Chung, Il-Sug; Semenova, Elizaveta

    2013-01-01

    We present the first tunable vertical-cavity surface-emitting laser (VCSEL) where the top distributed Bragg reflector has been completely substituted by an air-cladded high-index-contrast subwavelength grating (HCG) mirror. In this way, an extended cavity design can be realized by reducing...

  5. Fiber Bragg Grating Based System for Temperature Measurements

    Science.gov (United States)

    Tahir, Bashir Ahmed; Ali, Jalil; Abdul Rahman, Rosly

    In this study, a fiber Bragg grating sensor for temperature measurement is proposed and experimentally demonstrated. In particular, we point out that the method is well-suited for monitoring temperature because they are able to withstand a high temperature environment, where standard thermocouple methods fail. The interrogation technologies of the sensor systems are all simple, low cost and effective as well. In the sensor system, fiber grating was dipped into a water beaker that was placed on a hotplate to control the temperature of water. The temperature was raised in equal increments. The sensing principle is based on tracking of Bragg wavelength shifts caused by the temperature change. So the temperature is measured based on the wavelength-shifts of the FBG induced by the heating water. The fiber grating is high temperature stable excimer-laser-induced grating and has a linear function of wavelength-temperature in the range of 0-285°C. A dynamic range of 0-285°C and a sensitivity of 0.0131 nm/°C almost equal to that of general FBG have been obtained by this sensor system. Furthermore, the correlation of theoretical analysis and experimental results show the capability and feasibility of the purposed technique.

  6. Polarization-Independent Wideband High-Index-Contrast Grating Mirror

    DEFF Research Database (Denmark)

    Bekele, Dagmawi Alemayehu; Park, Gyeong Cheol; Malureanu, Radu

    2015-01-01

    Island-type two-dimensional high-index-contrast grating mirror based on a standard silicon-on-insulator wafer have been experimentally demonstrated. The measured spectra shows a bandwidth of ∼192 nm with a reflectivity over 99% as well as polarization independence. Numerical simulations show...

  7. Design and development of long-period grating sensors for ...

    Indian Academy of Sciences (India)

    Raja Ramanna Centre for Advanced Technology, Indore 450 213. ∗ e-mail: ... Home built CO2 laser (Max power 20 Watt) is focused onto .... Claus R O 1997 Temperature-insensitive and strain insensitive long-period grating sensors for smart.

  8. Holographic construction of open structure, dispersion transmission gratings

    NARCIS (Netherlands)

    Dijkstra, J.H.; Lantwaard, L.J.

    1975-01-01

    A method of fabricating free-standing transmission gratings with line densities of the order of 1000 /nm is described. The technique involves a combination of two well-known procedures: application of photoresist and electroplating for the production of fine metal grids, and holographic

  9. Bragg gratings in air-silica structured fibers

    NARCIS (Netherlands)

    Groothoff, N.; Canning, J.; Buckley, E.; Lyttikainen, K.; Zagari, J.

    2003-01-01

    We report on grating writing in air-silica structured optical fibers with pure silica cores by use of two-photon absorption at 193 nm. A decrease in propagation loss with irradiation was observed. The characteristic growth curves were obtained. © 2003 Optical Society of America.

  10. Programmed Control of Optical Grating Scales for Visual Research.

    Science.gov (United States)

    1980-12-01

    A -AOO .9 AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOO--ETC F/6 14/2 PROGRAMMED CONTROL OF OPTI CAL GRATING SCALES FOR VISUAL RESEARC --ETC(fl...custom system for AMRL. The cost in memory parts alone was $40,000, a good indication that the market is not over-priced. Ca-? western Reserve

  11. High-sensitivity bend angle measurements using optical fiber gratings.

    Science.gov (United States)

    Rauf, Abdul; Zhao, Jianlin; Jiang, Biqiang

    2013-07-20

    We present a high-sensitivity and more flexible bend measurement method, which is based on the coupling of core mode to the cladding modes at the bending region in concatenation with optical fiber grating serving as band reflector. The characteristics of a bend sensing arm composed of bending region and optical fiber grating is examined for different configurations including single fiber Bragg grating (FBG), chirped FBG (CFBG), and double FBGs. The bend loss curves for coated, stripped, and etched sections of fiber in the bending region with FBG, CFBG, and double FBG are obtained experimentally. The effect of separation between bending region and optical fiber grating on loss is measured. The loss responses for single FBG and CFBG configurations are compared to discover the effectiveness for practical applications. It is demonstrated that the sensitivity of the double FBG scheme is twice that of the single FBG and CFBG configurations, and hence acts as sensitivity multiplier. The bend loss response for different fiber diameters obtained through etching in 40% hydrofluoric acid, is measured in double FBG scheme that resulted in a significant increase in the sensitivity, and reduction of dead-zone.

  12. All-silicon nanorod-based Dammann gratings.

    Science.gov (United States)

    Li, Zile; Zheng, Guoxing; He, Ping'An; Li, Song; Deng, Qiling; Zhao, Jiangnan; Ai, Yong

    2015-09-15

    Established diffractive optical elements (DOEs), such as Dammann gratings, whose phase profile is controlled by etching different depths into a transparent dielectric substrate, suffer from a contradiction between the complexity of fabrication procedures and the performance of such gratings. In this Letter, we combine the concept of geometric phase and phase modulation in depth, and prove by theoretical analysis and numerical simulation that nanorod arrays etched on a silicon substrate have a characteristic of strong polarization conversion between two circularly polarized states and can act as a highly efficient half-wave plate. More importantly, only by changing the orientation angles of each nanorod can the arrays control the phase of a circularly polarized light, cell by cell. With the above principle, we report the realization of nanorod-based Dammann gratings reaching diffraction efficiencies of 50%-52% in the C-band fiber telecommunications window (1530-1565 nm). In this design, uniform 4×4 spot arrays with an extending angle of 59°×59° can be obtained in the far field. Because of these advantages of the single-step fabrication procedure, accurate phase controlling, and strong polarization conversion, nanorod-based Dammann gratings could be utilized for various practical applications in a range of fields.

  13. Diffraction from relief gratings on a biomimetic elastomer cast

    International Nuclear Information System (INIS)

    Guerrero, Raphael A.; Aranas, Erika B.

    2010-01-01

    Biomimetic optical elements combine the optimized designs of nature with the versatility of materials engineering. We employ a beetle carapace as the template for fabricating relief gratings on an elastomer substrate. Biological surface features are successfully replicated by a direct casting procedure. Far-field diffraction effects are discussed in terms of the Fraunhofer approximation in Fourier space.

  14. Plasmonic Optical Fiber-Grating Immunosensing: A Review

    Directory of Open Access Journals (Sweden)

    Tuan Guo

    2017-11-01

    Full Text Available Plasmonic immunosensors are usually made of a noble metal (in the form of a film or nanoparticles on which bioreceptors are grafted to sense analytes based on the antibody/antigen or other affinity mechanism. Optical fiber configurations are a miniaturized counterpart to the bulky Kretschmann prism and allow easy light injection and remote operation. To excite a surface plasmon (SP, the core-guided light is locally outcoupled. Unclad optical fibers were the first configurations reported to this end. Among the different architectures able to bring light in contact with the surrounding medium, a great quantity of research is today being conducted on metal-coated fiber gratings photo-imprinted in the fiber core, as they provide modal features that enable SP generation at any wavelength, especially in the telecommunication window. They are perfectly suited for use with cost-effective high-resolution interrogators, allowing both a high sensitivity and a low limit of detection to be reached in immunosensing. This paper will review recent progress made in this field with different kinds of gratings: uniform, tilted and eccentric short-period gratings as well as long-period fiber gratings. Practical cases will be reported, showing that such sensors can be used in very small volumes of analytes and even possibly applied to in vivo diagnosis.

  15. 21 CFR 133.147 - Grated American cheese food.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Grated American cheese food. 133.147 Section 133.147 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION CHEESES AND RELATED CHEESE PRODUCTS Requirements for Specific Standardized...

  16. Single-Molecule Detection in Nanogap-Embedded Plasmonic Gratings

    Directory of Open Access Journals (Sweden)

    Biyan Chen

    2015-07-01

    Full Text Available We introduce nanogap-embedded silver plasmonic gratings for single-molecule (SM visualization using an epifluorescence microscope. This silver plasmonic platform was fabricated by a cost-effective nano-imprint lithography technique, using an HD DVD template. DNA/ RNA duplex molecules tagged with Cy3/Cy5 fluorophores were immobilized on SiO 2 -capped silver gratings. Light was coupled to the gratings at particular wavelengths and incident angles to form surface plasmons. The SM fluorescence intensity of the fluorophores at the nanogaps showed approximately a 100-fold mean enhancement with respect to the fluorophores observed on quartz slides using an epifluorescence microscope. This high level of enhancement was due to the concentration of surface plasmons at the nanogaps. When nanogaps imaged with epifluorescence mode were compared to quartz imaged using total internal reflection fluorescence (TIRF microscopy, more than a 30-fold mean enhancement was obtained. Due to the SM fluorescence enhancement of plasmonic gratings and the correspondingly high emission intensity, the required laser power can be reduced, resulting in a prolonged detection time prior to photobleaching. This simple platform was able to perform SM studies with a low-cost epifluorescence apparatus, instead of the more expensive TIRF or confocal microscopes, which would enable SM analysis to take place in most scientific laboratories.

  17. Optical fibre Bragg grating recorded in TOPAS cyclic olefin copolymer

    DEFF Research Database (Denmark)

    Johnson, I.P.; Yuan, Scott Wu; Stefani, Alessio

    2011-01-01

    A report is presented on the inscription of a fibre Bragg grating into a microstructured polymer optical fibre fabricated from TOPAS cyclic olefin copolymer. This material offers two important advantages over poly (methyl methacrylate), which up to now has formed the basis for polymer fibre Bragg...

  18. Load Coefficients on Grates used for Wind Turbine Access Platforms

    DEFF Research Database (Denmark)

    Andersen, Thomas Lykke; Rasmussen, Michael R.; Frigaard, Peter

    In this report is presented the results of tests carried out at Dept. of Civil Engineering, Aalborg University (AAU) on behalf of DONG Energy A/S and Vattenfall A/S, Denmark. The objective of the tests was to investigate the load coefficient on different platform grates and a solid plate for desi...

  19. Development of tilted fibre Bragg gratings using highly coherent 255 ...

    Indian Academy of Sciences (India)

    R&D C-1 Block, Raja Ramanna Centre for Advanced Technology, Indore 452 013, India. ∗. Corresponding author. E-mail: oprakash@rrcat.gov.in. DOI: 10.1007/s12043-013-0672-7; ePublication: 6 February 2014. Abstract. This paper reports the study on development of tilted fibre Bragg gratings using highly coherent 255 ...

  20. Holographic gratings for spectrographic applications: Study of aberrations

    Science.gov (United States)

    Bhatia, M. S.

    1975-01-01

    The design and fabrication of holographic gratings requires an understanding of Fermat's principle. This principle states that the path of a light ray from one point to another is that which requires the least time. The aberrant, optical path of an object point to an image was studied using Fermat principles.

  1. Antecedents of big data quality : An empirical examination in financial service organizations

    NARCIS (Netherlands)

    Haryadi, Adiska Fardani; Hulstijn, Joris; Wahyudi, A.; van der Voort, H.G.; Janssen, M.F.W.H.A.

    Big data has been acknowledged for its enormous potential. In contrast to the potential, in a recent survey more than half of financial service organizations reported that big data has not delivered the expected value. One of the main reasons for this is related to data quality. The objective of

  2. Antecedents of big data quality : An empirical examination in financial service organizations

    NARCIS (Netherlands)

    Fardani Haryadi, Adiska; Janssen, Marijn; Hulstijn, Joris; van der Voort, Haiko; Wahyudi, Agung

    2016-01-01

    Big data has been acknowledged for its enormous potential. In contrast to the potential, in a recent survey more than half of financial service organizations reported that big data has not delivered the expected value. One of the main reasons for this is related to data quality. The objective of

  3. Three-port beam splitter of a binary fused-silica grating.

    Science.gov (United States)

    Feng, Jijun; Zhou, Changhe; Wang, Bo; Zheng, Jiangjun; Jia, Wei; Cao, Hongchao; Lv, Peng

    2008-12-10

    A deep-etched polarization-independent binary fused-silica phase grating as a three-port beam splitter is designed and manufactured. The grating profile is optimized by use of the rigorous coupled-wave analysis around the 785 nm wavelength. The physical explanation of the grating is illustrated by the modal method. Simple analytical expressions of the diffraction efficiencies and modal guidelines for the three-port beam splitter grating design are given. Holographic recording technology and inductively coupled plasma etching are used to manufacture the fused-silica grating. Experimental results are in good agreement with the theoretical values.

  4. Control of the long period grating spectrum through low frequency flexural acoustic waves

    International Nuclear Information System (INIS)

    Oliveira, Roberson A; Possetti, Gustavo R C; Kamikawachi, Ricardo C; Fabris, José L; Muller, Marcia; Pohl, Alexandre A P; Marques, Carlos A F; Nogueira, Rogério N; Neves, Paulo T Jr; Cook, Kevin; Canning, John; Bavastri, C

    2011-01-01

    We have shown experimental results of the excitation of long period fiber gratings by means of flexural acoustic waves with a wavelength larger than the grating period, validated by numerical simulations. The effect of the acoustic wave on the grating is modeled with the method of assumed modes, which delivers the strain field inside the grating, then used as the input to the transfer matrix method, needed for calculating the grating spectrum. The experimental and numerical results are found to be in good agreement, even though only the strain-optic effects are taken into account

  5. Laser sensor with Bragg gratings of fiber optics to physics parameter measuring

    International Nuclear Information System (INIS)

    Vazquez, R.; Garcia, C.; May, M.; Camas, J.

    2009-01-01

    We present the operation of a fiber laser sensor made by an Erbium Doped Fiber pumped at 980nm, an 4.23 km passive fiber and two fiber Bragg gratings placed at the ends of the laser cavity. Under normal conditions, the Bragg gratings have different reflection wavelengths and laser emission is not generated. The two Bragg gratings can be placed at the same reflection wavelength when the Bragg grating with the lowest reflective wavelength increases their temperature which can be used as a sensor element. The laser generation thus shows that the Bragg grating is increasing their temperature. We used a Peltier cell for to change gradually the temperature. (Author)

  6. Imaging of Volume Phase Gratings in a Photosensitive Polymer, Recorded in Transmission and Reflection Geometry

    Directory of Open Access Journals (Sweden)

    Tina Sabel

    2014-02-01

    Full Text Available Volume phase gratings, recorded in a photosensitive polymer by two-beam interference exposure, are studied by means of optical microscopy. Transmission gratings and reflection gratings, with periods in the order of 10 μm down to 130 nm, were investigated. Mapping of holograms by means of imaging in sectional view is introduced to study reflection-type gratings, evading the resolution limit of classical optical microscopy. In addition, this technique is applied to examine so-called parasitic gratings, arising from interference from the incident reference beam and the reflected signal beam. The appearance and possible avoidance of such unintentionally recorded secondary structures is discussed.

  7. Spectral tuning of the diameter-dependent-chirped Bragg gratings written in microfibers.

    Science.gov (United States)

    Xiao, Peng; Liu, Tong; Feng, Fu-Rong; Sun, Li-Peng; Liang, Hao; Ran, Yang; Jin, Long; Guan, Bai-Ou

    2016-12-26

    Chirped fiber Bragg gratings can straightforwardly and efficiently be fabricated onto microfibers with a uniform phase mask. Due to the variation of the propagating constant, which depends on the fiber diameter, the broadband spectrum of the grating can be formed. Depending on the different responses to the ambient refractive index in different parts of the grating, the bandwidth of the grating can be tuned by changing the surrounding solution. In addition, by being partly immersed in a liquid, the diameter-chirped Bragg grating can act as a broadband Fabry-Perot interferometer, whose spectrum can be tuned by means of controlling the liquid level and ambient refractive index.

  8. Diffraction efficiency of radially-profiled off-plane reflection gratings

    Science.gov (United States)

    Miles, Drew M.; Tutt, James H.; DeRoo, Casey T.; Marlowe, Hannah; Peterson, Thomas J.; McEntaffer, Randall L.; Menz, Benedikt; Burwitz, Vadim; Hartner, Gisela; Laubis, Christian; Scholze, Frank

    2015-09-01

    Future X-ray missions will require gratings with high throughput and high spectral resolution. Blazed off-plane reflection gratings are capable of meeting these demands. A blazed grating profile optimizes grating efficiency, providing higher throughput to one side of zero-order on the arc of diffraction. This paper presents efficiency measurements made in the 0.3 - 1.5 keV energy band at the Physikalisch-Technische Bundesanstalt (PTB) BESSY II facility for three holographically-ruled gratings, two of which are blazed. Each blazed grating was tested in both the Littrow configuration and anti-Littrow configuration in order to test the alignment sensitivity of these gratings with regard to throughput. This paper outlines the procedure of the grating experiment performed at BESSY II and discuss the resulting efficiency measurements across various energies. Experimental results are generally consistent with theory and demonstrate that the blaze does increase throughput to one side of zero-order. However, the total efficiency of the non-blazed, sinusoidal grating is greater than that of the blazed gratings, which suggests that the method of manufacturing these blazed profiles fails to produce facets with the desired level of precision. Finally, evidence of a successful blaze implementation from first diffraction results of prototype blazed gratings produce via a new fabrication technique at the University of Iowa are presented.

  9. Ultra-broadband and wide-angle perfect absorber based on composite metal-semiconductor grating

    Science.gov (United States)

    Li, Xu; Wang, Zongpeng; Hou, Yumin

    2018-01-01

    In this letter, we present an ultra-broadband and wide-angle perfect absorber based on composite Ge-Ni grating. Near perfect absorption above 90% is achieved in a wide frequency range from 150 nm to 4200 nm, which covers almost the full spectrum of solar radiation. The absorption keeps robust in a wide range of incident angle from 0º to 60º. The upper triangle Ge grating works as an antireflection coating. The lower Ni grating works as a reflector and an effective energy trapper. The guided modes inside Ge grating are excited due to reflection of the lower Ni grating surface. In longer wavelength band, gap surface plasmons (GSPs) in the Ni grating are excited and couple with the guided modes inside the Ge grating. The coupled modes extend the perfect absorption band to the near-infrared region (150 nm-4200 nm). This design has potential application in photovoltaic devices and thermal emitters.

  10. Magnetic resonance of rubidium atoms passing through a multi-layered transmission magnetic grating

    International Nuclear Information System (INIS)

    Nagata, Y; Kurokawa, S; Hatakeyama, A

    2017-01-01

    We measured the magnetic resonance of rubidium atoms passing through periodic magnetic fields generated by two types of multi-layered transmission magnetic grating. One of the gratings reported here was assembled by stacking four layers of magnetic films so that the direction of magnetization alternated at each level. The other grating was assembled so that the magnetization at each level was aligned. For both types of grating, the experimental results were in good agreement with our calculations. We studied the feasibility of extending the frequency band of the grating and narrowing its resonance linewidth by performing calculations. For magnetic resonance precision spectroscopy, we conclude that the multi-layered transmission magnetic grating can generate periodic fields with narrower linewidths at higher frequencies when a larger number of layers are assembled at a shorter period length. Moreover, the frequency band of this type of grating can potentially achieve frequencies of up to hundreds of PHz. (paper)

  11. Magneto-Optic Fiber Gratings Useful for Dynamic Dispersion Management and Tunable Comb Filtering

    International Nuclear Information System (INIS)

    Bao-Jian, Wu; Xin, Lu; Kun, Qiu

    2010-01-01

    Intelligent control of dispersion management and tunable comb filtering in optical network applications can be performed by using magneto-optic fiber Bragg gratings (MFBGs). When a nonuniform magnetic field is applied to the MFBG with a constant grating period, the resulting grating response is equivalent to that of a conventional chirped grating. Under a linearly nonuniform magnetic field along the grating, a linear dispersion is achieved in the grating bandgap and the maximal dispersion slope can come to 1260 ps/nm 2 for a 10-mm-long fiber grating at 1550 nm window. Similarly, a Gaussian-apodizing sampled MFBG is also useful for magnetically tunable comb filtering, with potential application to clock recovery from return-to-zero optical signals and optical carrier tracking. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  12. Continuously tunable pulsed Ti:Sa laser self-seeded by an extended grating cavity

    CERN Document Server

    Li, Ruohong; Rothe, Sebastian; Teigelhöfer, Andrea; Mostamand, Maryam

    2016-01-01

    A continuously tunable titanium:sapphire (Ti:Sa) laser self-seeded by an extended grating cavity was demonstrated and characterized. By inserting a partially reflecting mirror inside the cavity of a classic single-cavity grating laser, two oscillators are created: a broadband power oscillator, and a narrowband oscillator with a prism beam expander and a diffraction grating in Littrow configuration. By coupling the grating cavity oscillation into the power oscillator, a power-enhanced narrow-linewidth laser oscillation is achieved. Compared to the classic grating laser, this simple modification significantly increases the laser output power without considerably broadening the linewidth. With most of the oscillating laser power confined inside the broadband power cavity and lower power incident onto the grating, the new configuration also allows higher pump power, which is typically limited by the thermal deformation of the grating coating at high oscillation power.

  13. Investigation on the properties of a laminar grating as a soft x-ray beam splitter

    International Nuclear Information System (INIS)

    Liu Ying; Fuchs, Hans-Joerg; Liu Zhengkun; Chen Huoyao; He Shengnan; Fu Shaojun; Kley, Ernst-Bernhard; Tuennermann, Andreas

    2010-01-01

    Laminar-type gratings as soft x-ray beam splitters for interferometry are presented. Gold-coated grating beam splitters with 1000 lines/mm are designed for grazing incidence operation at 13.9nm. They are routinely fabricated using electron beam lithography and ion etching techniques. The laminar grating is measured to have almost equal absolute efficiencies of about 20% in the zeroth and -1st orders, which enables a fringe visibility up to 0.99 in the interferometer. The discrepancy of the grating profiles between the optimized theoretical and the experimental results is analyzed according to the comparison of the optimized simulation results and the measurement realization of the grating efficiencies. By a precise control of the grating profile, the grating efficiency in the -1st order and the fringe visibility could be improved to 25% and 1, respectively.

  14. Dual-function beam splitter of a subwavelength fused-silica grating.

    Science.gov (United States)

    Feng, Jijun; Zhou, Changhe; Zheng, Jiangjun; Cao, Hongchao; Lv, Peng

    2009-05-10

    We present the design and fabrication of a novel dual-function subwavelength fused-silica grating that can be used as a polarization-selective beam splitter. For TM polarization, the grating can be used as a two-port beam splitter at a wavelength of 1550 nm with a total diffraction efficiency of 98%. For TE polarization, the grating can function as a high-efficiency grating, and the diffraction efficiency of the -1st order is 95% under Littrow mounting. This dual-function grating design is based on a simplified modal method. By using the rigorous coupled-wave analysis, the optimum grating parameters can be determined. Holographic recording technology and inductively coupled plasma etching are used to manufacture the fused-silica grating. Experimental results are in agreement with the theoretical values.

  15. Second-harmonic generation in second-harmonic fiber Bragg gratings.

    Science.gov (United States)

    Steel, M J; de Sterke, C M

    1996-06-20

    We consider the production of second-harmonic light in gratings resonant with the generated field, through a Green's function approach. We recover some standard results and obtain new limits for the uniform grating case. With the extension to nonuniform gratings, we find the Green's function for the second harmonic in a grating with an arbitrary phase shift at some point. We then obtain closed form approximate expressions for the generated light for phase shifts close to π/2 and at the center of the grating. Finally, comparing the uniform and phase-shifted gratings with homogeneous materials, we discuss the enhancement in generated light and the bandwidth over which it occurs, and the consequences for second-harmonic generation in optical fiber Bragg gratings.

  16. Influence of dielectric protective layer on laser damage resistance of gold coated gratings

    Science.gov (United States)

    Wu, Kepeng; Ma, Ping; Pu, Yunti; Xia, Zhilin

    2016-03-01

    Aiming at the problem that the damage threshold of gold coated grating is relatively low, a dielectric film is considered on the gold coated gratings as a protective layer. The thickness range of the protective layer is determined under the prerequisite that the diffraction efficiency of the gold coated grating is reduced to an acceptable degree. In this paper, the electromagnetic field, the temperature field and the stress field distribution in the grating are calculated when the silica and hafnium oxide are used as protective layers, under the preconditions of the electromagnetic field distribution of the gratings known. The results show that the addition of the protective layer changes the distribution of the electromagnetic field, temperature field and stress field in the grating, and the protective layer with an appropriate thickness can improve the laser damage resistance of the grating.

  17. The World Financial Crisis

    OpenAIRE

    F. Gerard Adams

    2009-01-01

    The world financial crisis of 2008 is a consequence of new financial technologies, new accounting methods and new international linkages. These developments have come at a time when governments have returned to an old-fashioned freemarket philosophy. This paper links the systemic financial/economic crisis of 2008 to the new economy developments, globalisation and policy philosophy perspectives of recent decades. It raises the question of how to re-establish confidence once traditional thinkin...

  18. Taxing Financial Activity

    OpenAIRE

    Jack M. Mintz

    2003-01-01

    In most countries, substantial business activity is related to financial intermediation: banking, trusts, investment companies and insurance. Financial businesses play a crucial role in the economy by matching lenders with borrowers as well as facilitating governance of businesses through close monitoring of funds lent to businesses. Financial institutions also reduce risk faced by investors by pooling investments over many different types of business activities and insuring against property,...

  19. RTE - 2012 financial results

    International Nuclear Information System (INIS)

    Ricour, Olivia; Marguier, Marina; Lartigau, Thierry

    2013-01-01

    The mission of RTE, the French electricity Transportation grid, a public service assignment, is to balance the electricity supply and demand in real time. This report presents RTE's financial results for 2012: increase of investments for services to clients, performance results, financial balance, stability of the economical model. RTE's regulated economical model, main financial indicators, 2007-2012 investments, 2012 investments by category, 2012 turnover, 2012 costs structure, taxes, financial balance sheet at the end of 2012, and the share of electricity transport in the electricity price are presented in appendixes

  20. Domesticizing Financial Economies

    DEFF Research Database (Denmark)

    Deville, Joe; Lazarus, Jeanne; Luzzi, Mariana

    show. Third, the “domestication of financial economies”: financial literacy programs developed by governmental bodies, international organizations, and banks have become a ubiquitous layer attached to the assemblage of financial economies in many countries. And last but not least, “domesticizing social...... practices as well as the precise way financial providers are evaluating, sorting and targeting their consumers. We believe these diverse trends are starting to converge, and the ambitions of this paper are both to organize scattered literature and to reflect upon the consequences of the new field...

  1. Forecasting Financial Stress

    OpenAIRE

    Jan Willem Slingenberg; Jakob de Haan

    2011-01-01

    This paper uses a Financial Stress Index (FSI) for 13 OECD countries to examine which variables can help predicting financial stress. A stress index measures the current state of stress in the financial system and summarizes it in a single statistic. We employ three criteria for indicators to be used in constructing a multi-country FSI (the index covers the entire financial system, indicators used are available at a high frequency for many countries for a long period, and are comparable) to c...

  2. The acknowledgement of the Schneeberg lung disease as occupational disease in the first decree of occupational diseases from 1925

    International Nuclear Information System (INIS)

    Schuettmann, W.

    1987-01-01

    The Schneeberg lung disease is the lung cancer, conditioned by radiation which is caused by the influence of radon and of its subsequent products. It has gained a great importance after World War II as a consequence of the intensified mining of uranium ore. From the history of the disease, lasting some centuries, the period of the twenties and thirties of this century is represented in which on one side the conception of the causal importance of radon has made its way little by little, and on the other side the disease was acknowledged as occupational disease within the first decree of occupational diseases in the former German Reich. Evaluating materials from Saxon archives it is described how the legislative preparations to the acknowledgement of the Schneeberg lung disease as occupational disease and the simultaneous research to the elucidation of nature and cause of the disease have penetrated and influenced each other. (author)

  3. Posttraumatic growth, social acknowledgment as survivors, and sense of coherence in former German child soldiers of World War II

    OpenAIRE

    Forstmeier, Simon; Kuwert, P; Spitzer, C; Freyberger, H J; Maercker, Andreas

    2009-01-01

    Objectives: To examine posttraumatic growth and its predictors social acknowledgment as survivors, sense of coherence, trauma severity, and further factors in former child soldiers more than 60 years after deployment. Design: Cross-sectional. Setting: University-based geropsychiatric center in Germany. Participants: 103 former German child soldiers of World War II, mean age 78 years, 96% experienced at least one war trauma. Measurement: Subjects completed the Posttraumatic Growth ...

  4. Financial Wealth Distribution in Revised Financial Accounts

    Directory of Open Access Journals (Sweden)

    Václav Rybáček

    2012-09-01

    Full Text Available Financial statistics undergo dynamic evolution as apparent consequence of their rising importance. Structureof assets, source of fi nancing, price changes or net fi nancial position, all these indicators can detect oncomingfi nancial instability. Financial statistics as a logical extension of the national accounts provide such information.Th e aim of the following text is to present fi nancial statistics, relation between particular accounts, the impact of extraordinary revision carried out in 2011, and also to analyse current wealth distribution as described by fi nancial statistics.

  5. The Usefulness of Financial Statements in Making Financial Diagnosis

    Directory of Open Access Journals (Sweden)

    Mitica Pepi

    2016-01-01

    Full Text Available Our research aims to develop an analysis of the usefulness of financial statements and financial investment in making the diagnosis. Financial analysis is by definition an activity that performance condition is diagnosed entity of the financial year. Financial analysis shall be determined by strengths and weaknesses of financial management based on which will underpin future strategy of the entity to maintain and develop it into a competitive environment. Results of financial analysis depends on the quality, accuracy, relevance and effectiveness of economic information collected and processed. The primary sources of information for financial analysis are the financial statements, which are considered as raw material in the analysis.

  6. Corporate financial restructuring in Asia: implications for financial stability

    OpenAIRE

    Michael Pomerleano

    2007-01-01

    Corporate financial fragility preceding the Asian financial crisis heightened vulnerabilities. Many countries in the region undertook significant corporate financial restructuring after the crisis, with some countries bouncing back much faster than others. These sounder corporate financial practices bode well for financial stability.

  7. Financial Services Marketing.

    Science.gov (United States)

    Olson, Lucretia Maria

    This manual contains student assignments in the financial services area of the marketing process. The individualized competency-based materials are intended to enhance and supplement instruction or to provide the basis for a course of instruction by the teacher-coordinator. Information on skills needed in jobs in financial marketing is first…

  8. Sources of Financial Sociability

    DEFF Research Database (Denmark)

    Thompson, Grahame

    2011-01-01

    This article investigates the sources of sociability in modern financial systems as a prelude to assessing the prospects for financial regulation. Three sources are identified: sociality dependent upon contract, upon relational interdependency, and upon the operation of will and passion. Each of ...

  9. Financial Rogue Waves

    International Nuclear Information System (INIS)

    Yan Zhenya

    2010-01-01

    We analytically give the financial rogue waves in the nonlinear option pricing model due to Ivancevic, which is nonlinear wave alternative of the Black-Scholes model. These rogue wave solutions may he used to describe the possible physical mechanisms for rogue wave phenomenon in financial markets and related fields.

  10. Household financial behavior

    NARCIS (Netherlands)

    Brounen, Dirk; Koedijk, Kees; Pownall, Rachel

    2016-01-01

    Greater personal responsibility toward financial decision-making is being advocated on a global basis. Individuals and households are encouraged to take a more active approach to personal finance. In this paper, we examine behavioral factors, which lead households toward savings and financial

  11. Understanding financial statements.

    Science.gov (United States)

    Tarantino, D P

    2001-01-01

    In his premier column for The Physician Executive, David Tarantino takes a look at those critical "financials" that can make or break a business. If you're considering a career move, you need to know the financial condition of future employers. Learn how to read the statements and glean valuable information from the numbers.

  12. Optimal Fragile Financial Networks

    NARCIS (Netherlands)

    Castiglionesi, F.; Navarro, N.

    2007-01-01

    We study a financial network characterized by the presence of depositors, banks and their shareholders. Belonging to a financial network is beneficial for both the depositors and banks' shareholders since the return to investment increases with the number of banks connected. However, the network is

  13. Consolidating Financial Statements.

    Science.gov (United States)

    Wood, Marcia R.

    This publication is designed to be a desktop reference and assist financial officers in both public and independent institutions of higher education in the preparation of consolidated financial statements. Chapter 1 covers generally accepted accounting principles and other accounting literature, and summarizes reporting rules of the Financial…

  14. Illiquidity and financial crisis

    NARCIS (Netherlands)

    A.M. Pacces (Alessio)

    2013-01-01

    textabstractThis article analyzes the determinants of liquidity crises based on the dynamics of banking and finance under Knightian uncertainty. In this perspective, the facts of the global financial crisis seem to confirm Minsky's hypothesis of endogenous financial instability derived from Keynes's

  15. Financial Sector Assessment : Morocco

    OpenAIRE

    World Bank

    2003-01-01

    This Financial Sector Assessment (FSA) provides a summary of the policy priorities, and main findings intended to assist the Moroccan authorities in evaluating the country's financial system. It reviews the uneasy trade-off between concerns for stability, and development, suggesting Morocco's macroeconomic policies and practices as a whole tend to err more on the side of the concerns of pr...

  16. Financial Sector Assessment : Turkey

    OpenAIRE

    World Bank

    2007-01-01

    A joint International Monetary Fund-World Bank team conducted an assessment of Turkey's financial system in connection with the Financial Sector Assessment Program (FSAP) through missions in April, August-September 2006 and March, 2007. This report provides a summary of the main findings of the assessment and the policy priorities identified. The main objective of the FSAP is to assist the...

  17. Financial Sector Assessment : Mongolia

    OpenAIRE

    World Bank

    2012-01-01

    Owing primarily to extensive investment in new mining projects, Mongolia's economy is on a path of very rapid long-term growth. While financial intermediation in Mongolia has been growing fast, access to finance remains a critical constraint for enterprises, and especially for Small and Medium Enterprises (SMEs). Improving access to financial services will require strengthening the legal a...

  18. Trusts and Financialization

    DEFF Research Database (Denmark)

    Harrington, Brooke

    2017-01-01

    the global spread of financialization: by privileging the rentier–investor within the 15 world economy; by perpetuating a distinctively Anglo-American approach to finance internationally; and by increasing the autonomy of finance vis-a-vis the nation-state. This study shares the primarily descriptive......This article identifies trusts as a legal structure associated with the global spread of financialization. Although trusts originated in Medieval England, they have acquired a new significance in contemporary finance by virtue of their advantages in terms of 10 profit maximization and capital...... and conceptual intent of Krippner’s work on financialization, but extends it in two ways: by comparing trusts to the better- known corporate form of organizing financial activity, and by showing how private 20 capital is implicated in the financialized economy alongside corporate wealth....

  19. Elastomeric polymer resonant waveguide grating based pressure sensor

    International Nuclear Information System (INIS)

    Song, Fuchuan; Xie, Antonio Jou; Seo, Sang-Woo

    2014-01-01

    In this paper, we demonstrate an elastomeric polymer resonant waveguide grating structure to be used as a pressure sensor. The applied pressure is measured by optical resonance spectrum peak shift. The sensitivity—as high as 86.74 pm psi −1 or 12.58 pm kPa −1 —has been experimentally obtained from a fabricated sensor. Potentially, the sensitivity of the demonstrated sensor can be tuned to different pressure ranges by the choices of elastic properties and layer thicknesses of the waveguide and cladding layers. The simulation results agree well with experimental results and indicate that the dominant effect on the sensor is the change of grating period when external pressure is applied. Based on the two-dimensional planar structure, the demonstrated sensor can be used to measure applied surface pressure optically, which has potential applications for optical ultrasound imaging and pressure wave detection/mapping

  20. Moiré volume Bragg grating filter with tunable bandwidth.

    Science.gov (United States)

    Mokhov, Sergiy; Ott, Daniel; Divliansky, Ivan; Zeldovich, Boris; Glebov, Leonid

    2014-08-25

    We propose a monolithic large-aperture narrowband optical filter based on a moiré volume Bragg grating formed by two sequentially recorded gratings with slightly different resonant wavelengths. Such recording creates a spatial modulation of refractive index with a slowly varying sinusoidal envelope. By cutting a specimen at a small angle, to a thickness of one-period of this envelope, the longitudinal envelope profile will shift from a sine profile to a cosine profile across the face of the device. The transmission peak of the filter has a tunable bandwidth while remaining at a fixed resonant wavelength by a transversal shift of incidence position. Analytical expressions for the tunable bandwidth of such a filter are calculated and experimental data from a filter operating at 1064 nm with bandwidth range 30-90 pm is demonstrated.

  1. Development of generalised model for grate combustion of biomass

    DEFF Research Database (Denmark)

    Rosendahl, Lasse; Kær, Søren Knudsen; Sørensen, Henrik

    for two reasons: 1) to improve emission understanding and reduction measures and 2) to improve boundary conditions for CFD-based furnace modelling. The selected approach has been based on a diffusion coefficient formulation, where conservation equations for the concentration of fuel are solved...... in a spatially resolved grid, much in the same manner as in a finite volume CFD code. Within this porous layer of fuel, gas flows according to the Ergun equation. The diffusion coefficient links the properties of the fuel to the grate type and vibration mode, and is determined for each combination of fuel, grate...... is big enough to represent real, full scale conditions, and yet small enough to be operational in terms of parameter studies of different nature. Apart from full SRO data, measurements (gas sampling, velocity, temperature, particle sampling) can be taken through a heated, water-cooled probe...

  2. Magneto-Optic Field Coupling in Optical Fiber Bragg Gratings

    Science.gov (United States)

    Carman, Gregory P. (Inventor); Mohanchandra, Panduranga K. (Inventor); Emmons, Michael C. (Inventor); Richards, William Lance (Inventor)

    2016-01-01

    The invention is a magneto-optic coupled magnetic sensor that comprises a standard optical fiber Bragg grating system. The system includes an optical fiber with at least one Bragg grating therein. The optical fiber has at least an inner core and a cladding that surrounds the inner core. The optical fiber is part of an optical system that includes an interrogation device that provides a light wave through the optical fiber and a system to determine the change in the index of refraction of the optical fiber. The cladding of the optical fiber comprises at least a portion of which is made up of ferromagnetic particles so that the ferromagnetic particles are subject to the light wave provided by the interrogation system. When a magnetic field is present, the ferromagnetic particles change the optical properties of the sensor directly.

  3. Fiber Bragg Grating vibration sensor with DFB laser diode

    Science.gov (United States)

    Siska, Petr; Brozovic, Martin; Cubik, Jakub; Kepak, Stanislav; Vitasek, Jan; Koudelka, Petr; Latal, Jan; Vasinek, Vladimir

    2012-01-01

    The Fiber Bragg Grating (FBG) sensors are nowadays used in many applications. Thanks to its quite big sensitivity to a surrounding environment, they can be used for sensing of temperature, strain, vibration or pressure. A fiber Bragg grating vibration sensor, which is interrogated by a distributed feedback laser diode (DFB) is demonstrated in this article. The system is based on the intensity modulation of the narrow spectral bandwidth of the DFB laser, when the reflection spectrum of the FBG sensor is shifted due to the strain that is applied on it in form of vibrations caused by acoustic wave pressure from loud speaker. The sensor's response in frequency domain and strain is measured; also the factor of sensor pre-strain impact on its sensitivity is discussed.

  4. Planar Bragg Grating Sensors—Fabrication and Applications: A Review

    Directory of Open Access Journals (Sweden)

    I. J. G. Sparrow

    2009-01-01

    Full Text Available We discuss the background and technology of planar Bragg grating sensors, reviewing their development and describing the latest developments. The physical operating principles are discussed, relating device operation to user requirements. Recent performance of such devices includes a planar Bragg grating sensor design which allows refractive index resolution of 1.9×10−6 RIU and temperature resolution of 0.03∘C. This sensor design is incorporated into industrialised applications allowing the sensor to be used for real time sensing in intrinsically safe, high-pressure pipelines, or for insertion probe applications such as fermentation. Initial data demonstrating the ability to identify solvents and monitor long term industrial processes is presented. A brief review of the technology used to fabricate the sensors is given along with examples of the flexibility afforded by the technique.

  5. Effects of ionization and nitrous oxide on grated carrot respiration

    International Nuclear Information System (INIS)

    Chervin, C.

    1992-06-01

    Two treatments (nitrous oxide and irradiation) have been applied on grated carrots to reduce the respiratory crisis induced by wounding. Nitrous oxide inhibited cytochrome c oxidase; but, it neither diminished O 2 consumption of the tissues, nor modified atmospheres in a favourable way for conservation of grated carrots, stored in plastic bags (in the conditions chosen for this study). On the contrary, irradiation inhibited simultaneously the respiratory crisis and the ethylene production, both induced by wounding. This behaviour led to a lower consumption of sugars in irradiated tissues and to the generation of atmospheres, which were better adapted to the conservation needs (it was necessary to use plastic film with high permeability). Finally, an applied study demonstrated that irradiation, by permitting a less denaturing preparation than industrial process, allowed the conservation of produces with a better quality (nutritional, sensory and microbiological). Biochemical analyses have been validated by sensory analyses

  6. A Long-Period Grating Sensor for Wind Turbine Blades

    DEFF Research Database (Denmark)

    Glavind, Lars

    This PhD project concerns the applied research for providing a novel sensor for measurements on wind turbine blades, based on Long-Period Gratings. The idea is based on the utilization of a special asymmetrical optical fibre with Long-Period Gratings for directional sensitive bend sensing...... blade material, where a suitable process and recoating material were investigated. The sensor was implemented and tested on a full scale wind turbine blade placed on a test rig. This first prototype has demonstrated the capability of the sensor for wind turbine blade monitoring, particular...... the possibility to distinguish between the flap- and edge-wise bend directions on the wind turbine blade, providing a selective sensor. The sensor has proven to be very robust and suitable for this application....

  7. An optical tunable filter array based on LCOS phase grating

    Science.gov (United States)

    Feng, Dong; Wan, Zhujun; Chen, Xu; Yan, Shijia; Luo, Zhixiang

    2018-01-01

    This paper reports an optical tunable filter array (TFA) based on a LCOS (liquid crystal on silicon) chip. The input broadband optical beam is first dispersed by a bulk grating and then incident on the LCOS chip. The LCOS chip is phase-only modulated and constructed as a dynamic reflective phase grating. The phase modulation is adjusted to meet the Littrow angle for a specified passband wavelength and thus the optical beam corresponding to this wavelength is steered to the output. The input/output optical beams are coupled to optical fibers with a dual-fiber collimator. Four dualfiber collimators are vertically aligned as the inputs/outputs and the pixels of the LCOS chip are vertically allocated as four independent zones. Thus the device can act as a 4-channel TFA, which is assembled and functionally demonstrated.

  8. Quadratic grating apodized photon sieves for simultaneous multiplane microscopy

    Science.gov (United States)

    Cheng, Yiguang; Zhu, Jiangping; He, Yu; Tang, Yan; Hu, Song; Zhao, Lixin

    2017-10-01

    We present a new type of imaging device, named quadratic grating apodized photon sieve (QGPS), used as the objective for simultaneous multiplane imaging in X-rays. The proposed QGPS is structured based on the combination of two concepts: photon sieves and quadratic gratings. Its design principles are also expounded in detail. Analysis of imaging properties of QGPS in terms of point-spread function shows that QGPS can image multiple layers within an object field onto a single image plane. Simulated and experimental results in visible light both demonstrate the feasibility of QGPS for simultaneous multiplane imaging, which is extremely promising to detect dynamic specimens by X-ray microscopy in the physical and life sciences.

  9. Fiber Bragg grating sensor interrogators on chip: challenges and opportunities

    Science.gov (United States)

    Marin, Yisbel; Nannipieri, Tiziano; Oton, Claudio J.; Di Pasquale, Fabrizio

    2017-04-01

    In this paper we present an overview of the current efforts towards integration of Fiber Bragg Grating (FBG) sensor interrogators. Different photonic integration platforms will be discussed, including monolithic planar lightwave circuit technology, silicon on insulator (SOI), indium phosphide (InP) and gallium arsenide (GaAs) material platforms. Also various possible techniques for wavelength metering and methods for FBG multiplexing will be discussed and compared in terms of resolution, dynamic performance, multiplexing capabilities and reliability. The use of linear filters, array waveguide gratings (AWG) as multiple linear filters and AWG based centroid signal processing techniques will be addressed as well as interrogation techniques based on tunable micro-ring resonators and Mach-Zehnder interferometers (MZI) for phase sensitive detection. The paper will also discuss the challenges and perspectives of photonic integration to address the increasing requirements of several industrial applications.

  10. Flat acoustic lens by acoustic grating with curled slits

    KAUST Repository

    Peng, Pai

    2014-10-01

    We design a flat sub-wavelength lens that can focus acoustic wave. We analytically study the transmission through an acoustic grating with curled slits, which can serve as a material with tunable impedance and refractive index for acoustic waves. The effective parameters rely on the geometry of the slits and are independent of frequency. A flat acoustic focusing lens by such acoustic grating with gradient effective refractive index is designed. The focusing effect is clearly observed in simulations and well predicted by the theory. We demonstrate that despite the large impedance mismatch between the acoustic lens and the matrix, the intensity at the focal point is still high due to Fabry-Perot resonance.

  11. Temperature-insensitive fiber Bragg grating dynamic pressure sensing system.

    Science.gov (United States)

    Guo, Tuan; Zhao, Qida; Zhang, Hao; Zhang, Chunshu; Huang, Guiling; Xue, Lifang; Dong, Xiaoyi

    2006-08-01

    Temperature-insensitive dynamic pressure measurement using a single fiber Bragg grating (FBG) based on reflection spectrum bandwidth modulation and optical power detection is proposed. A specifically designed double-hole cantilever beam is used to provide a pressure-induced axial strain gradient along the sensing FBG and is also used to modulate the reflection bandwidth of the grating. The bandwidth modulation is immune to spatially uniform temperature effects, and the pressure can be unambiguously determined by measuring the reflected optical power, avoiding the complex wavelength interrogation system. The system acquisition time is up to 85 Hz for dynamic pressure measurement, and the thermal fluctuation is kept less than 1.2% full-scale for a temperature range of -10 degrees C to 80 degrees C.

  12. Dense Wavelength Division (De Multiplexers Based on Fiber Bragg Gratings

    Directory of Open Access Journals (Sweden)

    S. BENAMEUR

    2014-05-01

    Full Text Available This study is to measure the impact of demultiplexers based on Fiber Bragg Grating (FBG filter on performance of DWDM system for optical access network. An optical transmission link has been established in which we have inserted a demultiplexer based on four different FBG filters. The first step will be the characterization of FBG’s filters (i.e. uniform FBG, Gaussian apodized Grating, chirped FBG to explain their behavior in the optical link. The simulations were conducted for different fiber’s lengths, filter bandwidth and different received power to get the best system performance. This helped to assess their impact on the link performance in terms of Bit Error Rate (BER.

  13. Laser formation of Bragg gratings in polymer nanocomposite materials

    Energy Technology Data Exchange (ETDEWEB)

    Nazarov, M M; Khaydukov, K V; Sokolov, V I; Khaydukov, E V [Institute on Laser and Information Technologies, Russian Academy of Sciences, Shatura, Moscow Region (Russian Federation)

    2016-01-31

    The method investigated in this work is based on the laser-induced, spatially inhomogeneous polymerisation of nanocomposite materials and allows control over the motion and structuring of nanoparticles. The mechanisms of nanoparticle concentration redistribution in the process of radical photopolymerisation are studied. It is shown that under the condition of spatially inhomogeneous illumination of a nanocomposite material, nanoparticles are diffused from the illuminated areas into the dark fields. Diffraction gratings with a thickness of 8 μm and a refractive index modulation of 1 × 10{sup -2} are written in an OCM-2 monomer impregnated by silicon nanoparticles. The gratings may be used in the development of narrowband filters, in holographic information recording and as dispersion elements in integrated optical devices. (interaction of laser radiation with matter. laser plasma)

  14. Fundamentals of Financial Statements Audit

    OpenAIRE

    World Bank

    2011-01-01

    The purpose of an audit is to enhance the degree of confidence of intended users in the financial statements. The objective of an audit of financial statements is to enable an auditor to express an opinion as to whether the financial statements are prepared, in all material respects, in accordance with International Financial Reporting Standards or another identified financial reporting fr...

  15. Diffraction Efficiency Testing of Sinusoidal and Blazed Off-Plane Reflection Gratings

    Science.gov (United States)

    Tutt, James H.; McEntaffer, Randall L.; Marlowe, Hannah; Miles, Drew M.; Peterson, Thomas J.; Deroo, Casey T.; Scholze, Frank; Laubis, Christian

    2016-09-01

    Reflection gratings in the off-plane mount have the potential to enhance the performance of future high resolution soft X-ray spectrometers. Diffraction efficiency can be optimized through the use of blazed grating facets, achieving high-throughput on one side of zero-order. This paper presents the results from a comparison between a grating with a sinusoidally grooved profile and two gratings that have been blazed. The results show that the blaze does increase throughput to one side of zero-order; however, the total throughput of the sinusoidal gratings is greater than the blazed gratings, suggesting the method of manufacturing the blazed gratings does not produce precise facets. The blazed gratings were also tested in their Littrow and anti-Littrow configurations to quantify diffraction efficiency sensitivity to rotations about the grating normal. Only a small difference in the energy at which efficiency is maximized between the Littrow and anti-Littrow configurations is seen with a small shift in peak efficiency towards higher energies in the anti-Littrow case. This is due to a decrease in the effective blaze angle in the anti-Littrow mounting. This is supported by PCGrate-SX V6.1 modeling carried out for each blazed grating which predicts similar response trends in the Littrow and anti-Littrow orientations.

  16. Asymmetric diffraction by atomic gratings with optical PT symmetry in the Raman-Nath regime

    Science.gov (United States)

    Shui, Tao; Yang, Wen-Xing; Liu, Shaopeng; Li, Ling; Zhu, Zhonghu

    2018-03-01

    We propose and analyze an efficient scheme for the lopsided Raman-Nath diffraction of one-dimensional (1 D ) and two-dimensional (2 D ) atomic gratings with periodic parity-time (PT )-symmetric refractive index. The atomic grating is constructed by the cold-atomic vapor with two isotopes of rubidium, which is driven by weak probe field and space-dependent control field. Using experimentally achievable parameters, we identify the conditions under which PT -symmetric refractive index allows us to observe the lopsided Raman-Nath diffraction phenomenon and improve the diffraction efficiencies beyond what is achievable in a conventional atomic grating. The nontrivial atomic grating is a superposition of an amplitude grating and a phase grating. It is found that the lopsided Raman-Nath diffraction at the exceptional point (EP) of PT -symmetric grating originates from constructive and destructive interferences between the amplitude and phase gratings. Furthermore, we show that the PT -phase transition from unbroken to broken PT -symmetric regimes can modify the asymmetric distribution of the diffraction spectrum and that the diffraction efficiencies in the non-negative diffraction orders can be significantly enhanced when the atomic grating is pushed into a broken PT -symmetric phase. In addition, we also analyze the influence of the grating thickness on the diffraction spectrum. Our scheme may provide the possibility to design a gain-beam splitter with tunable splitting ratio and other optical components in integrated optics.

  17. System Construction for the Measurement of Bragg Grating Characteristics in Optical Fibers

    Science.gov (United States)

    West, Douglas P.

    1995-01-01

    Bragg gratings are used to measure strain in optical fibers. To measure strain they are sometimes used as a smart structure. They must be characterized after they are written to determine their spectral response. This paper deals with the test setup to characterize Bragg grating spectral responses.Bragg gratings are a photo-induced phenomena in optical fibers. The gratings can be used to measure strain by measuring the shift in wavelength. They placed the fibers into a smart structure to measure the stress and strain produced on support columns placed in bridges. As the cable is subjected to strain the grating causes a shift to a longer wavelength if the fiber is stretched and a shift to a shorter wavelength shift if the fiber is compacted. Our applications involve using the fibers to measure stress and strain on airborne systems. There are many ways to write Bragg gratings into optical fibers. Our focus is on side writing the grating. Our capabilities are limited in the production rate of the gratings. The Bragg grating is written into a fiber and becomes a permanent fixture. We are writing the grating to be centered at 1300 nm because that is the standard phase mask wavelength.

  18. Fabrication of 200 nanometer period centimeter area hard x-ray absorption gratings by multilayer deposition

    Science.gov (United States)

    Lynch, S K; Liu, C; Morgan, N Y; Xiao, X; Gomella, A A; Mazilu, D; Bennett, E E; Assoufid, L; de Carlo, F; Wen, H

    2012-01-01

    We describe the design and fabrication trials of x-ray absorption gratings of 200 nm period and up to 100:1 depth-to-period ratios for full-field hard x-ray imaging applications. Hard x-ray phase-contrast imaging relies on gratings of ultra-small periods and sufficient depth to achieve high sensitivity. Current grating designs utilize lithographic processes to produce periodic vertical structures, where grating periods below 2.0 μm are difficult due to the extreme aspect ratios of the structures. In our design, multiple bilayers of x-ray transparent and opaque materials are deposited on a staircase substrate, and mostly on the floor surfaces of the steps only. When illuminated by an x-ray beam horizontally, the multilayer stack on each step functions as a micro-grating whose grating period is the thickness of a bilayer. The array of micro-gratings over the length of the staircase works as a single grating over a large area when continuity conditions are met. Since the layers can be nanometers thick and many microns wide, this design allows sub-micron grating periods and sufficient grating depth to modulate hard x-rays. We present the details of the fabrication process and diffraction profiles and contact radiography images showing successful intensity modulation of a 25 keV x-ray beam. PMID:23066175

  19. Micro powder-injection moulding of metals and ceramics

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Development of micro-MIM/-CIM was started at Forschungszen- ... of microsystems products not only possesses a respectable market poten- .... We gratefully acknowledge the financial support of the Deutsche Forschungsgemeinschaft.

  20. An efficient domino one-pot synthesis of novel spirofuran ...

    Indian Academy of Sciences (India)

    AFSHIN YAZDANI-ELAH-ABADI

    Abstract. A simple and convenient multi-component domino reaction has been described for the synthesis of novel ... interest due to their pharmaceutical and biological activ- ..... We gratefully acknowledge financial support from the Research.

  1. The analytic structure of lattice models – Why can't we solve most ...

    Indian Academy of Sciences (India)

    Department of Mathematics and Statistics, University of Melbourne, Vic. 3010, Australia ... We also show how, for certain problems, it is possible to prove that the solutions are not ...... LaTeX style files. I gratefully acknowledge financial support.

  2. Quantitative assessment of target dependence of pion fluctuation in ...

    Indian Academy of Sciences (India)

    journal of. December 2012 physics pp. 1395–1405. Quantitative assessment ... The analysis reveals the erratic behaviour of the produced pions signifying ..... authors (Sitaram Pal) gratefully acknowledges the financial help from the University.

  3. Preparation and investigations of thermal properties of copper oxide ...

    Indian Academy of Sciences (India)

    The effects of copper oxide, aluminium oxide and graphite on the thermal and structural properties of the organic ... solar energy, and heat regulation of electronics, biomedical ..... We gratefully acknowledge the financial support provided by.

  4. Fulltext PDF

    Indian Academy of Sciences (India)

    2014-10-20

    Oct 20, 2014 ... Among the regulatory elements that control transcription of genes, ... The author gratefully acknowledges the financial supported from CSIR and DBT. ... human erythroid cells and protects against position effect in Drosophila.

  5. Grad-type fourteen-moment theory for dilute granular gases

    Indian Academy of Sciences (India)

    2Department of Mathematics, Indian Institute of Technology Madras, Chennai 600 036, India ... practically no effect on Haff's law. ... Stokes, and Fourier (NSF) laws for dilute granular ...... and PS gratefully acknowledges financial support from.

  6. Fulltext PDF

    Indian Academy of Sciences (India)

    While the power law TRM decay and the absence of aging effects are consistent ...... This work was supported by the Department of Science and Technology, India, under the ... AS gratefully acknowledges the financial support received from.

  7. Possible Effect of the Earth's Inertial Induction on the Orbital Decay ...

    Indian Academy of Sciences (India)

    The theory of velocity dependent inertial induction, based upon extended ... However, accounting for all the known forces act- ing on the ..... The authors gratefully acknowledge the financial support from the National Academy of Sciences ...

  8. Synthesis and characterization of biocompatible hydroxyapatite ...

    Indian Academy of Sciences (India)

    Unknown

    Indian Institute of Technology, Mumbai 400 076, India. MS received 25 March 2003 ... being given the advantage of a biocompatible coating. The purpose of this work is ..... Financial support from CSIR, New Delhi, is gratefully acknowledged.

  9. On diquark clustering in quark–gluon plasma

    Indian Academy of Sciences (India)

    being fermions, we can then use the generalized Pauli principle, i.e.. Pc ... particularly after accounting for the quark exchange interactions between diquarks. ..... gratefully acknowledges the financial help from CSIR, New Delhi, in the form of.

  10. Framework for Financial Ratio Analysis of Audited Federal Financial Reports

    National Research Council Canada - National Science Library

    Brady, Richard

    1999-01-01

    .... With the passage of the Chief Financial Officers Act of 1990, Congress called for the production of financial statements that fully disclose a federal entity's financial position and results of operations...

  11. Fibre Bragg grating and no-core fibre sensors

    CERN Document Server

    Daud, Suzairi

    2018-01-01

    This book focuses on the development and set-up of fibre Bragg grating (FBG) and no-core fibre (NCF) sensors. It discusses the properties of the sensors and modelling of the resulting devices, which include electronic, optoelectronic, photovoltaic, and spintronic devices. In addition to providing detailed explanations of the properties of FBG and NCF sensors, it features a wealth of instructive illustrations and tables, helping to visualize the respective devices’ functions.

  12. Smart architecture for stable multipoint fiber Bragg grating sensor system

    Science.gov (United States)

    Yeh, Chien-Hung; Tsai, Ning; Zhuang, Yuan-Hong; Huang, Tzu-Jung; Chow, Chi-Wai; Chen, Jing-Heng; Liu, Wen-Fung

    2017-12-01

    In this work, we propose and investigate an intelligent fiber Bragg grating (FBG)-based sensor system in which the proposed stabilized and wavelength-tunable single-longitudinal-mode erbium-doped fiber laser can improve the sensing accuracy of wavelength-division-multiplexing multiple FBG sensors in a longer fiber transmission distance. Moreover, we also demonstrate the proposed sensor architecture to enhance the FBG capacity for sensing strain and temperature, simultaneously.

  13. Long period grating based refractometer with polarization-sensitive interrogation

    International Nuclear Information System (INIS)

    Eftimov, T; Bock, W; Mikulic, P; Nikolova, K

    2010-01-01

    We propose a new scheme for the interrogation of long-period fiber gratings (LPGs) which makes use of their polarization properties. Polarization-sensitive interrogation was applied to detect changes due to changes of the external refractive index by using three wavelengths on the International Telecommunication Union (ITU) grid. We show that the new approach can allow for a greater sensitivity and can be used in combination with spectral multiplexing schemes

  14. Spontaneous formation of optically induced surface relief gratings

    International Nuclear Information System (INIS)

    Leblond, H; Barille, R; Ahmadi-Kandjani, S; Nunzi, J-M; Ortyl, E; Kucharski, S

    2009-01-01

    We develop a model based on Fick's law of diffusion as a phenomenological description of the molecular motion, and on the coupled mode theory, to describe single-beam surface relief grating formation in azopolymer thin films. The model allows us to explain the mechanism of spontaneous patterning, and self-organization. It allows us to compute the surface relief profile and its evolution, with good agreement with experiments.

  15. Spontaneous formation of optically induced surface relief gratings

    Energy Technology Data Exchange (ETDEWEB)

    Leblond, H; Barille, R; Ahmadi-Kandjani, S; Nunzi, J-M [Laboratoire POMA, Universite d' Angers, CNRS FRE 2988, 2, Bd Lavoisier, 49045 Angers (France); Ortyl, E; Kucharski, S, E-mail: herve.leblond@univ-angers.f [Wroclaw University of Technology, Faculty of Chemistry, Department of Polymer Engineering and Technology, 50-370 Wroclaw (Poland)

    2009-10-28

    We develop a model based on Fick's law of diffusion as a phenomenological description of the molecular motion, and on the coupled mode theory, to describe single-beam surface relief grating formation in azopolymer thin films. The model allows us to explain the mechanism of spontaneous patterning, and self-organization. It allows us to compute the surface relief profile and its evolution, with good agreement with experiments.

  16. A modified phase diversity wavefront sensor with a diffraction grating

    International Nuclear Information System (INIS)

    Luo Qun; Huang Lin-Hai; Gu Nai-Ting; Rao Chang-Hui

    2012-01-01

    The phase diversity wavefront sensor is one of the tools used to estimate wavefront aberration, and it is often used as a wavefront sensor in adaptive optics systems. However, the performance of the traditional phase diversity wavefront sensor is limited by the accuracy and dynamic ranges of the intensity distribution at the focus and defocus positions of the CCD camera. In this paper, a modified phase diversity wavefront sensor based on a diffraction grating is proposed to improve the ability to measure the wavefront aberration with larger amplitude and higher spatial frequency. The basic principle and the optics construction of the proposed method are also described in detail. The noise propagation property of the proposed method is also analysed by using the numerical simulation method, and comparison between the diffraction grating phase diversity wavefront sensor and the traditional phase diversity wavefront sensor is also made. The simulation results show that the diffraction grating phase diversity wavefront sensor can obviously improve the ability to measure the wavefront aberration, especially the wavefront aberration with larger amplitude and higher spatial frequency

  17. Spatiotemporal optical pulse transformation by a resonant diffraction grating

    Energy Technology Data Exchange (ETDEWEB)

    Golovastikov, N. V.; Bykov, D. A., E-mail: bykovd@gmail.com; Doskolovich, L. L., E-mail: leonid@smr.ru; Soifer, V. A. [Russian Academy of Sciences, Image Processing Systems Institute (Russian Federation)

    2015-11-15

    The diffraction of a spatiotemporal optical pulse by a resonant diffraction grating is considered. The pulse diffraction is described in terms of the signal (the spatiotemporal incident pulse envelope) passage through a linear system. An analytic approximation in the form of a rational function of two variables corresponding to the angular and spatial frequencies has been obtained for the transfer function of the system. A hyperbolic partial differential equation describing the general form of the incident pulse envelope transformation upon diffraction by a resonant diffraction grating has been derived from the transfer function. A solution of this equation has been obtained for the case of normal incidence of a pulse with a central frequency lying near the guided-mode resonance of a diffraction structure. The presented results of numerical simulations of pulse diffraction by a resonant grating show profound changes in the pulse envelope shape that closely correspond to the proposed theoretical description. The results of the paper can be applied in creating new devices for optical pulse shape transformation, in optical information processing problems, and analog optical computations.

  18. Nano-imprint gold grating as refractive index sensor

    International Nuclear Information System (INIS)

    Kumari, Sudha; Mohapatra, Saswat; Moirangthem, Rakesh S.

    2016-01-01

    Large scale of fabrication of plasmonic nanostructures has been a challenging task due to time consuming process and requirement of expensive nanofabrication tools such as electron beam lithography system, focused ion beam system, and extreme UV photolithography system. Here, we present a cost-effective fabrication technique so called soft nanoimprinting to fabricate nanostructures on the larger sample area. In our fabrication process, a commercially available optical DVD disc was used as a template which was imprinted on a polymer glass substrate to prepare 1D polymer nano-grating. A homemade nanoimprinting setup was used in this fabrication process. Further, a label-free refractive index sensor was developed by utilizing the properties of surface plasmon resonance (SPR) of a gold coated 1D polymer nano-grating. Refractive index sensing was tested by exposing different solutions of glycerol-water mixture on the surface of gold nano-grating. The calculated bulk refractive index sensitivity was found to be 751nm/RIU. We believed that our proposed SPR sensor could be a promising candidate for developing low-cost refractive index sensor with high sensitivity on a large scale.

  19. Optical Fiber Thermometer Based on Fiber Bragg Gratings

    Science.gov (United States)

    Rosli, Ekbal Bin; Mohd. Noor, Uzer

    2018-03-01

    Fiber Bragg grating has generated much interest in use as sensors to measure strain, temperature, and other physical parameters. It also the most common component used to develop this sensor with the advantages of simple, intrinsic sensing elements, electrically passive operation, EMI immunity, high sensitivity, compact size and potentially low cost [6]. This paper reports the design of an optical fiber thermometer based on fiber Bragg gratings. The system was developed for detecting temperature and strain by monitoring the shift of Bragg wavelength. The shifting of Bragg wavelength is used to indicate the temperature and strain due to the change in the surrounding temperature and strain. When the temperature and strain reach the exact wavelength level of the system, the temperature and strain value will display on the Arduino liquid crystal display (LCD). The optical fiber will provide the broadband light source and after passing the FBG the Bragg wavelength into the optical spectrum analyzer (OSA). The system is based on FBG as a physical quantity sensor. The temperatures measured is taken from the water bath and that of the strain is provided by amount of slotted mass used. The outcome of this project is to characterize the Bragg wavelength shifting from the fiber Bragg grating output. As the conclusion, this project provides an efficient optical fiber thermometer in measuring temperature and strain in order to replace the use of conventional electrical instruments.

  20. An optical fiber Bragg grating and piezoelectric ceramic voltage sensor

    Science.gov (United States)

    Yang, Qing; He, Yanxiao; Sun, Shangpeng; Luo, Mandan; Han, Rui

    2017-10-01

    Voltage measurement is essential in many fields like power grids, telecommunications, metallurgy, railways, and oil production. A voltage-sensing unit, consisting of fiber Bragg gratings (FBGs) and piezoelectric ceramics, based on which an optical over-voltage sensor was proposed and fabricated in this paper. No demodulation devices like spectrometer or Fabry-Perot filter were needed to gain the voltage signal, and a relatively large sensing frequency range was acquired in this paper; thus, the cost of the sensing system is more acceptable in engineering application. The voltage to be measured was directly applied to the piezoelectric ceramic, and deformation of the ceramics and the grating would be caused because of the inverse piezoelectric effect. With a reference grating, the output light intensity change will be caused by the FBG center wavelength change; thus, the relationship between the applied voltage and the output light intensity was established. Validation of the sensor was accomplished in the frequency range from 50 Hz to 20 kHz and switching impulse waves with a test platform; good linearity of the input-output characteristic was achieved. A temperature validation test was completed, showing that the sensor maintains good temperature stability. Experimental results show that the optical over-voltage sensor can be used for voltage monitoring, and if applied with a voltage divider, the sensor can be used to measure high voltage.

  1. A MEMS torsion magnetic sensor with reflective blazed grating integration

    International Nuclear Information System (INIS)

    Long, Liang; Zhong, Shaolong

    2016-01-01

    A novel magnetic sensor based on a permanent magnet and blazed grating is presented in this paper. The magnetic field is detected by measuring the diffracted wavelength of the blazed grating which is changed by the torsion motion of a torsion sensitive micro-electromechanical system (MEMS) structure with a permanent magnet attached. A V-shape grating structure is obtained by wet etching on a (1 0 0) SOI substrate. When the magnet is magnetized in different directions, the in-plane or out-of-plane magnetic field is detected by a sensor. The MEMS magnetic sensor with a permanent magnet is fabricated after analytical design and bulk micromachining processes. The magnetic-sensing capability of the sensor is tested by fiber-optic detection system. The result shows the sensitivities of the in-plane and out-of-plane magnetic fields are 3.6 pm μ T −1 and 5.7 pm μ T −1 , respectively. Due to utilization of the permanent magnet and fiber-optic detection, the sensor shows excellent capability of covering the high-resolution detection of low-frequency signals. In addition, the sensitive direction of the magnetic sensor can be easily switched by varying the magnetized direction of the permanent magnet, which offers a simple way to achieve tri-axis magnetic sensor application. (paper)

  2. Interrogating adhesion using fiber Bragg grating sensing technology

    Science.gov (United States)

    Rasberry, Roger D.; Rohr, Garth D.; Miller, William K.; Udd, Eric; Blach, Noah T.; Davis, Ryan A.; Olson, Walter R.; Calkins, David; Roach, Allen R.; Walsh, David S.; McElhanon, James R.

    2015-05-01

    The assurance of the integrity of adhesive bonding at substrate interfaces is paramount to the longevity and sustainability of encapsulated components. Unfortunately, it is often difficult to non-destructively evaluate these materials to determine the adequacy of bonding after manufacturing and then later in service. A particularly difficult problem in this regard is the reliable detection/monitoring of regions of weak bonding that may result from poor adhesion or poor cohesive strength, or degradation in service. One promising and perhaps less explored avenue we have recently begun to investigate for this purpose centers on the use of (chirped) fiber Bragg grating sensing technology. In this scenario, a grating is patterned into a fiber optic such that a (broadband) spectral reflectance is observed. The sensor is highly sensitive to local and uniform changes across the length of the grating. Initial efforts to evaluate this approach for measuring adhesive bonding defects at substrate interfaces are discussed. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  3. An optical fiber Bragg grating and piezoelectric ceramic voltage sensor.

    Science.gov (United States)

    Yang, Qing; He, Yanxiao; Sun, Shangpeng; Luo, Mandan; Han, Rui

    2017-10-01

    Voltage measurement is essential in many fields like power grids, telecommunications, metallurgy, railways, and oil production. A voltage-sensing unit, consisting of fiber Bragg gratings (FBGs) and piezoelectric ceramics, based on which an optical over-voltage sensor was proposed and fabricated in this paper. No demodulation devices like spectrometer or Fabry-Perot filter were needed to gain the voltage signal, and a relatively large sensing frequency range was acquired in this paper; thus, the cost of the sensing system is more acceptable in engineering application. The voltage to be measured was directly applied to the piezoelectric ceramic, and deformation of the ceramics and the grating would be caused because of the inverse piezoelectric effect. With a reference grating, the output light intensity change will be caused by the FBG center wavelength change; thus, the relationship between the applied voltage and the output light intensity was established. Validation of the sensor was accomplished in the frequency range from 50 Hz to 20 kHz and switching impulse waves with a test platform; good linearity of the input-output characteristic was achieved. A temperature validation test was completed, showing that the sensor maintains good temperature stability. Experimental results show that the optical over-voltage sensor can be used for voltage monitoring, and if applied with a voltage divider, the sensor can be used to measure high voltage.

  4. Quality of Financial Policies and Financial System Stress

    OpenAIRE

    Udaibir S Das; Plamen Yossifov; Richard Podpiera; Dmitriy L Rozhkov

    2005-01-01

    In this paper, we develop multi-country indices of financial system stress and quality of financial policies and use them in regression analysis of the determinants of financial stress. We find that countries with higher quality of financial policies are better able to contain the effects of macroeconomic pressures on the overall level of stress in the financial system. They are also in a better position to ensure sustainable development of the financial system.

  5. Why Financial Advice Cannot Substitute for Financial Literacy?

    OpenAIRE

    M. Debbich

    2015-01-01

    This paper examines the ability of financial advice provided by sellers of financial services to substitute for financial literacy of customers. I set up a simple theoretical model in which an informed financial advisor communicates with a less informed customer of financial services. Given the existence of a conflict of interest from the advisor's perspective, the model predicts that only well financially sophisticated customers receive relevant information from the advisor. This fact tends ...

  6. Disclosure of Non-Financial Information: Relevant to Financial Analysts?

    OpenAIRE

    ORENS, Raf; LYBAERT, Nadine

    2013-01-01

    The decline in the relevance of financial statement information to value firms leads to calls from organizational stakeholders to convey non-financial information in order to be able to judge firms' financial performance and value. This literature review aims to report extant literature findings on the use of corporate non-financial information by sell-side financial analysts, the information intermediaries between corporate management and investors. Prior studies highlight that financial ana...

  7. Financial globalisation uncertainty/instability is good for financial development

    OpenAIRE

    Asongu, Simplice A.; Koomson, Isaac; Tchamyou, Vanessa S.

    2015-01-01

    Purpose – This study assesses the effect of time-dynamic financial globalisation uncertainty on financial development in 53 African countries for the period 2000-2011. Design/methodology/approach – Financial globalisation uncertainty is estimated as time-dynamic to capture business cycle disturbances while all dimensions identified by the Financial Development and Structure Database of the World Bank are employed, namely: financial depth (money supply and liquid liabilities), financial sy...

  8. Be Vigilant on Financial Statements.

    Science.gov (United States)

    Freed, DeBow

    2002-01-01

    Highlights areas on university's financial statements that warrant careful review by trustees and suggests ways they can check to see whether an institution's financial statements are clear and valid indicators of its financial status. (EV)

  9. The instruments of financial planning

    OpenAIRE

    Durnov, V.

    2011-01-01

    The paper analyzes financial planning efficiency for enterprise management improvement. The author describes the system of financial tools and considers in detail financial planning methods, their strengths and weaknesses

  10. Framing financial culture

    DEFF Research Database (Denmark)

    Just, Sine Nørholm; Mouton, Nicolaas T.O.

    2014-01-01

    between competing frames leads to the conclusion that this political “blame game” is related to struggles over how to define the scandal, how to conceptualize its causes, and policy recommendations. Banks may have lost the battle of “Liborgate,” but the war over the meaning of financial culture is far...... from over. Originality/value – The paper is theoretically and methodologically original in its combination of the theories of framing and stasis, and it provides analytical insights into how sense is made of financial culture in the wake of the financial crisis....

  11. The Geography of Financial Literacy

    OpenAIRE

    Christopher Bumcrot; Judy Lin; Annamaria Lusardi

    2013-01-01

    This paper explores how well equipped today’s households are to make complex financial decisions in the face of often high-cost and high-risk financial instruments. Specifically we focus on financial literacy. Most importantly, we describe the geography of financial literacy, i.e., how financial literacy is distributed across the fifty US states. We describe the correlation of financial literacy and some important aggregate variables, such as state-level poverty rates. Finally, we examine the...

  12. Childhood roots of financial literacy

    OpenAIRE

    Grohmann, Antonia; Kouwenberg, Roy; Menkhoff, Lukas

    2015-01-01

    Financial literacy predicts informed financial decisions, but what explains financial literacy? We use the concept of financial socialization and aim to represent three major agents of financial socialization: family, school and work. Thus we compile twelve relevant childhood characteristics in a new survey study and examine their relation to financial literacy, while controlling for established socio-demographic characteristics. We find in a mediation analysis that both family and school pos...

  13. Unacknowledged Cities: Modernity and Acknowledgement in China Miéville's The City & The City and Marc Isaacs' All White in Barking

    NARCIS (Netherlands)

    Martin, N.

    2013-01-01

    Acknowledgement names a peculiar, and frequently uneasy, relation to knowledge. For example, when one acknowledges as one’s own an act or deed with which one wishes to dissociate oneself, one is simultaneously owning and disowning that act. Through accounts of China Miéville’s novel The City & the

  14. Globalization and the diffusion of ideas: why we should acknowledge the roots of mainstream ideas in global health.

    Science.gov (United States)

    Robert, Emilie; Hajizadeh, Mohammad; El-Bialy, Rowan; Bidisha, Sayema Haque

    2014-06-01

    Although globalization has created ample opportunities and spaces to share experiences and information, the diffusion of ideas, especially in global health, is primarily influenced by the unequal distribution of economic, political and scientific powers around the world. These ideas in global health are generally rooted in High-Income Countries (HICs), and then reach Low- and Middle-Income Countries (LMICs). We argue that acknowledging and addressing this invisible trend would contribute to a greater degree of open discussions in global health. This is expected to favor innovative, alternative, and culturally sound solutions for persistent health problems and reducing inequities.

  15. Time-and-frequency domains approach to data processing in multiwavelength optical scatterometry of dielectric gratings

    KAUST Repository

    Granet, Gérard

    2013-01-01

    This paper focuses on scatterometry problems arising in lithography production of periodic gratings. Namely, the paper introduces a theoretical and numerical-modeling-oriented approach to scatterometry problems and discusses its capabilities. The approach allows for reliable detection of deviations in gratings\\' critical dimensions (CDs) during the manufacturing process. The core of the approach is the one-to-one correspondence between the electromagnetic (EM) characteristics and the geometric/material properties of gratings. The approach is based on highly accurate solutions of initial boundary-value problems describing EM waves\\' interaction on periodic gratings. The advantage of the approach is the ability to perform simultaneously and interactively both in frequency and time domains under conditions of possible resonant scattering of EM waves by infinite or finite gratings. This allows a detection of CDs for a wide range of gratings, and, thus is beneficial for the applied scatterometry. (C) 2013 Optical Society of America

  16. Optimization of top coupling grating for very long wavelength QWIP based on surface plasmon

    Science.gov (United States)

    Wang, Guodong; Shen, Junling; Liu, Xiaolian; Ni, Lu; Wang, Saili

    2017-09-01

    The relative coupling efficiency of two-dimensional (2D) grating based on surface plasmon for very long wavelength quantum well infrared detector is analyzed by using the three-dimensional finite-difference time domain (3D-FDTD) method algorithm. The relative coupling efficiency with respect to the grating parameters, such as grating pitch, duty ratio, and grating thickness, is analyzed. The calculated results show that the relative coupling efficiency would reach the largest value for the 14.5 μm incident infrared light when taking the grating pitch as 4.4 μm, the duty ratio as 0.325, and the grating thickness as 0.07 μm, respectively.

  17. Time-and-frequency domains approach to data processing in multiwavelength optical scatterometry of dielectric gratings

    KAUST Repository

    Granet, Gé rard; Melezhik, Petr N.; Sirenko, Kostyantyn; Yashina, Nataliya P.

    2013-01-01

    This paper focuses on scatterometry problems arising in lithography production of periodic gratings. Namely, the paper introduces a theoretical and numerical-modeling-oriented approach to scatterometry problems and discusses its capabilities. The approach allows for reliable detection of deviations in gratings' critical dimensions (CDs) during the manufacturing process. The core of the approach is the one-to-one correspondence between the electromagnetic (EM) characteristics and the geometric/material properties of gratings. The approach is based on highly accurate solutions of initial boundary-value problems describing EM waves' interaction on periodic gratings. The advantage of the approach is the ability to perform simultaneously and interactively both in frequency and time domains under conditions of possible resonant scattering of EM waves by infinite or finite gratings. This allows a detection of CDs for a wide range of gratings, and, thus is beneficial for the applied scatterometry. (C) 2013 Optical Society of America

  18. Echelle grating multi-order imaging spectrometer utilizing a catadioptric lens

    Science.gov (United States)

    Chrisp, Michael P; Bowers, Joel M

    2014-05-27

    A cryogenically cooled imaging spectrometer that includes a spectrometer housing having a first side and a second side opposite the first side. An entrance slit is on the first side of the spectrometer housing and directs light to a cross-disperser grating. An echelle immersions grating and a catadioptric lens are positioned in the housing to receive the light. A cryogenically cooled detector is located in the housing on the second side of the spectrometer housing. Light from the entrance slit is directed to the cross-disperser grating. The light is directed from the cross-disperser grating to the echelle immersions grating. The light is directed from the echelle immersions grating to the cryogenically cooled detector on the second side of the spectrometer housing.

  19. Correcting groove error in gratings ruled on a 500-mm ruling engine using interferometric control.

    Science.gov (United States)

    Mi, Xiaotao; Yu, Haili; Yu, Hongzhu; Zhang, Shanwen; Li, Xiaotian; Yao, Xuefeng; Qi, Xiangdong; Bayinhedhig; Wan, Qiuhua

    2017-07-20

    Groove error is one of the most important factors affecting grating quality and spectral performance. To reduce groove error, we propose a new ruling-tool carriage system based on aerostatic guideways. We design a new blank carriage system with double piezoelectric actuators. We also propose a completely closed-loop servo-control system with a new optical measurement system that can control the position of the diamond relative to the blank. To evaluate our proposed methods, we produced several gratings, including an echelle grating with 79  grooves/mm, a grating with 768  grooves/mm, and a high-density grating with 6000  grooves/mm. The results show that our methods effectively reduce groove error in ruled gratings.

  20. Polarizing beam splitter of deep-etched triangular-groove fused-silica gratings.

    Science.gov (United States)

    Zheng, Jiangjun; Zhou, Changhe; Feng, Jijun; Wang, Bo

    2008-07-15

    We investigated the use of a deep-etched fused-silica grating with triangular-shaped grooves as a highly efficient polarizing beam splitter (PBS). A triangular-groove PBS grating is designed at a wavelength of 1550 nm to be used in optical communication. When it is illuminated in Littrow mounting, the transmitted TE- and TM-polarized waves are mainly diffracted in the minus-first and zeroth orders, respectively. The design condition is based on the average differences of the grating mode indices, which is verified by using rigorous coupled-wave analysis. The designed PBS grating is highly efficient over the C+L band range for both TE and TM polarizations (>97.68%). It is shown that such a triangular-groove PBS grating can exhibit a higher diffraction efficiency, a larger extinction ratio, and less reflection loss than the binary-phase fused-silica PBS grating.