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Sample records for grating lpg technology

  1. LPG fuel

    International Nuclear Information System (INIS)

    Dagnas, F.X.; Jeuland, N.; Fouquet, J.P.; Lauraire, S.; Coroller, P.

    2005-01-01

    LPG fuel has become frequently used through a distribution network with 2 000 service stations over the French territory. LPG fuel ranks number 3 world-wide given that it can be used on individual vehicles, professional fleets, or public transport. What is the environmental benefit of LPG fuel? What is the technology used for these engines? What is the current regulation? Government commitment and dedication on support to promote LPG fuel? Car makers projects? Actions to favour the use of LPG fuel? This article gathers 5 presentations about this topic given at the gas conference

  2. Green LPG

    Energy Technology Data Exchange (ETDEWEB)

    Hulteberg, Christian; Brandin, Jan; Leveau, Andreas (Biofuel-Solution AB, Limhamn (Sweden))

    2010-12-15

    The use of energy gases with renewable origins will become important with diminishing fossil resources. This as the infrastructure of the gaseous fuels is well built out and the distribution networks already exist. LPG is one of the most versatile fuels around, perfect for rural areas and in many other applications. The fossil origin of the fuel will, in today's climate and environmental debate, however position it as a thing of the past and not part of the future energy supply. The technology and development performed under this and previous programs with the Swedish Gas Centre will however suggest a way to bridge this conception and make LPG a part of the future energy mix. This report constitutes the results from the development performed under the SGC program 210 and is aimed at verifying the results from the previous SGC program 198, proving the concept for producing propane from renewable glycerol. Attractive and potentially profitable LPG premium segments that can be reached by producing bio-propane would be the autogas market. Another attractive segment to target is the outdoor and camping segment, where there already exist awareness for nature and the environment. A third interesting segment is in small-scale heat or combined heat and power generation, where a premium price can be reaped for renewable energy as well as the addition of LPG to biogas. Another important aspect of the renewable LPG is that it motivates external stakeholders, such as local, regional, national and international governments as well as environmental and other lobby groups to consider LPG a part of the future energy mix and not a thing of the past. A good starting point for two and three carbon energy gases is glycerine, with its three carbon backbone. The reason for focusing on glycerine is its benign chemical nature, it is: - Harmless from a toxic standpoint; - Chemically inert; - Non-corrosive; - Relatively high energy density; - Zero carbon dioxide emissions. It is also

  3. Measurement of chloride-ion concentration with long-period grating technology

    Science.gov (United States)

    Tang, Jaw-Luen; Wang, Jian-Neng

    2007-06-01

    A simple and low-cost long-period fiber grating (LPG) sensor suited for chloride-ion concentration measurement is presented. The LPG sensor is found to be sensitive to the refractive index of the medium around the cladding surface of the sensing grating, thus offering the prospect of development of practical sensors such as an ambient index sensor or a chemical concentration indicator with high stability and reliability. We measured chloride ions in a typical concrete sample immersed in salt water solutions with different weight concentrations ranging from 0% to 25%. Results show that the LPG sensor exhibited a linear decrease in the transmission loss and resonance wavelength shift when the concentration increased. The measurement accuracy for the concentration of salt in water solution is estimated to be 0.6% and the limit of detection for chloride ions is about 0.04%. To further enhance its sensitivity for chloride concentrations, we coated a monolayer of colloidal gold nanoparticles as the active material on the grating surface of the LPG sensor. The operating principle of sensing is based on the sensitivity of localized surface plasmon resonance of self-assembled gold colloids on the grating section of the LPG. With this method, a factor of two increase in the sensitivity of detecting chemical solution concentrations was obtained. The advantages of this type of fiber-optic sensor are that it is compact, relatively simple to construct and easy to use. Moreover, the sensor has the potential capability for on-site, in vivo and remote sensing, and it has potential use as a disposable sensor.

  4. Terahertz bandwidth all-optical Hilbert transformers based on long-period gratings.

    Science.gov (United States)

    Ashrafi, Reza; Azaña, José

    2012-07-01

    A novel, all-optical design for implementing terahertz (THz) bandwidth real-time Hilbert transformers is proposed and numerically demonstrated. An all-optical Hilbert transformer can be implemented using a uniform-period long-period grating (LPG) with a properly designed amplitude-only grating apodization profile, incorporating a single π-phase shift in the middle of the grating length. The designed LPG-based Hilbert transformers can be practically implemented using either fiber-optic or integrated-waveguide technologies. As a generalization, photonic fractional Hilbert transformers are also designed based on the same optical platform. In this general case, the resulting LPGs have multiple π-phase shifts along the grating length. Our numerical simulations confirm that all-optical Hilbert transformers capable of processing arbitrary optical signals with bandwidths well in the THz range can be implemented using feasible fiber/waveguide LPG designs.

  5. The significance of LPG in Turkish vehicular transportation: liquefied petroleum gases (LPG) in fueled systems

    Energy Technology Data Exchange (ETDEWEB)

    Balat, Mustafa [Besikduzu, Trabzon (Turkey)

    2005-04-15

    Liquefied petroleum gases (LPG) are in widespread use in homes, industry and agriculture. Among the many uses of these gases are heating and refrigeration, as a supplement for natural gas, as fuel for industrial equipment and mobile homes, in the manufacture of ethylene, and as a solvent. Worldwide LPG production is limited to about 10% of total gasoline and diesel fuel consumption and is used to a great extent for domestic and industrial purposes. Since LPG burns cleaner with less carbon build-up and oil contamination, engine wear is reduced and the life of some components, such as rings and bearings, is much longer than with gasoline. The high octane of LPG also minimizes wear from engine knock. The rapid development of LPG technology, including ease of vehicular conversion and estimations of increased LPG availability, suggest LPG will soon be recognized as a premium automotive fuel. (Author)

  6. 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.

  7. LPG based all plastic pressure sensor

    DEFF Research Database (Denmark)

    Bundalo, Ivan-Lazar; Lwin, R.; Leon-Saval, S.

    2015-01-01

    A prototype all-plastic pressure sensor is presented and characterized for potential use as an endoscope. The sensor is based on Long Period Gratings (LPG) inscribed with a CO2 laser in 6-ring microstructured PMMA fiber. Through a latex coated, plastic 3D-printed transducer pod, external pressure...... is converted to longitudinal elongation of the pod and therefore of the fiber containing the LPG. The sensor has been characterised for pressures of up to 160 mBar in an in-house built pressure chamber. Furthermore, the influence of the fiber prestrain, fiber thickness and the effect of different glues...

  8. 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.

  9. 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.

  10. Fluoride contamination sensor based on optical fiber grating technology

    Science.gov (United States)

    Jadhav, Mangesh S.; Laxmeshwar, Lata S.; Akki, Jyoti F.; Raikar, P. U.; Kumar, Jitendra; Prakash, Om; Raikar, U. S.

    2017-11-01

    A number of distinct advantages of the optical fiber technology in the field of sensors and communications which leads to enormous applications. Fiber Bragg grating (FBG) developed from the fabrication of photosensitive fiber through phase mask technique is used in the present report. The designed fiber sensor used for the detection and determination of contaminants in drinking water at ppm & ppb level and it is considered as a special type of concentration sensor. The test samples of drinking water have been collected from different regions. In this paper we have calibrated the FBG sensor to detect Flouride concentration in drinking water in the range of 0.05-8 ppm. According to WHO, the normal range of fluoride content in drinking water is about 0.7 ppm to 1.5 ppm. The results for resultant spectral shifts for test samples are closely agree with standard values.

  11. Japan and LPG

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    About 20 million metric tonnes of Liquefied Petroleum Gases (LPG) are consumed each year in Japan, of which 14,5 million metric tonnes are imported from Saudi Arabia and United Arab Emirates. This paper presents LPG industry in Japan and gives informations on the present status: supply and demand, imports, market, distribution

  12. The worldwide LPG market

    International Nuclear Information System (INIS)

    Dermont, V.

    1998-01-01

    The market of liquefied petroleum gases (LPG) concerns mainly the domestic uses (space and sanitary heating, cooking) but also some small industries, the agriculture and chemistry sectors and the transportation sector. This paper analyzes the European demand of LPG fuels by sector. (J.S.)

  13. Installation of a technological center for highly efficient optical gratings at Helmholtz-Zentrum Berlin (HZB)

    International Nuclear Information System (INIS)

    Loechel, B; Erko, A; Lemke, St; Senf, F; Nelles, B; Schmidt, M

    2013-01-01

    In 2009 Carl Zeiss stopped the manufacture of precision gratings. All users of their gratings were very concerned about this decision, since they all need precision gratings for their experiments. One of the institutes of the HZB, the Institute for Nanometer Optics and Technology (INT), has extensive experience in micro fabrication (technology group). In spring 2010, HZB decided to take over the old C. Zeiss grating fabrication and build up its own technology center for grating fabrication. In March 2010, the INT applied to the Senate of Berlin for funding for our project from the European Regional Development Fund (ERDF). In October 2010, HZB received an approval of its application from the Senate of Berlin (contract No 20072013 2/43). Using this governmental support, HZB will install all necessary equipment and processes to fulfill these demands until end of 2013.

  14. Analysis on two technologic errors of color separation grating used for ICF

    International Nuclear Information System (INIS)

    Chen Dewei; Li Yongping

    2003-01-01

    In this paper, the depth of color separation grating applied in ICF system is optimized firstly for good separating effect. After this, duty cycle error and the trapezoid structure are analyzed. A probable scope of technologic error that make the color separation grating have good effect is given in the end

  15. Transmission Grating and Optics Technology Development for the Arcus Explorer Mission

    Science.gov (United States)

    Heilmann, Ralf; Arcus Team

    2018-01-01

    Arcus is a high-resolution x-ray spectroscopy MIDEX mission selected for a Phase A concept study. It is designed to explore structure formation through measurements of hot baryon distributions, feedback from black holes, and the formation and evolution of stars, disks, and exoplanet atmospheres. The design provides unprecedented sensitivity in the 1.2-5 nm wavelength band with effective area above 450 sqcm and spectral resolution R > 2500. The Arcus technology is based on 12 m-focal length silicon pore optics (SPO) developed for the European Athena mission, and critical-angle transmission (CAT) x-ray diffraction gratings and x-ray CCDs developed at MIT. The modular design consists of four parallel channels, each channel holding an optics petal, followed by a grating petal. CAT gratings are lightweight, alignment insensitive, high-efficiency x-ray transmission gratings that blaze into high diffraction orders, leading to high spectral resolution. Each optics petal represents an azimuthal sub-aperture of a full Wolter optic. The sub-aperturing effect increases spectral resolving power further. Two CCD readout strips receive photons from each channel, including higher-energy photons in 0th order. Each optics petal holds 34 SPO modules. Each grating petal holds 34 grating windows, and each window holds 4-6 grating facets. A grating facet consists of a silicon grating membrane, bonded to a flexure frame that interfaces with the grating window. We report on a sequence of tests with increasing complexity that systematically increase the Technology Readiness Level (TRL) for the combination of CAT gratings and SPOs towards TLR 6. CAT gratings have been evaluated in x rays for diffraction efficiency (> 30% at 2.5 nm) and for resolving power (R> 10,000). A CAT grating/SPO combination was measured at R ~ 3100 at blaze angles smaller than design values, exceeding Arcus requirements. Efficiency and resolving power were not impacted by vibration and thermal testing of gratings. A

  16. The performances of the LPG-fueled vehicle

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    Todays, LPG-fueled vehicles are simply equipped with transformed classical petrol engines. The LPG consumption is greater but the emission of pollutants is greatly reduced (from 40 to 98% for the CO and from 30 to 80% for the HC and NOx, depending on the temperature of use). This short paper summarizes the environmental advantages of the LPG-fueled vehicles and the forthcoming technological evolutions expected in Europe, Japan and the USA. (J.S.)

  17. The Italian LPG market

    International Nuclear Information System (INIS)

    Anon.

    1998-01-01

    As happened in other European countries, the Italian LPG consumption market narrowed in 1997 for climatic reasons. Still, with some 3,5 million tones it is the first LPG market in Europe thanks to automotive LPG which represents some 1,2 million tones, for 1,4 million tones for the bulk and 760, 000 tonnes for bottled products. Another characteristic of the Italian market: demand is slightly lowering in the North while increasing in the South and in the large islands. (author)

  18. Flammability characteristics of LPG

    International Nuclear Information System (INIS)

    Cardillo, Paolo

    2005-01-01

    The use of LPG is continuous increase not only in the domestic field but also in the field of the transports. Consequently, there is a renewed interest for its flammability characteristics in order to decide the necessary conditions of safety. The main components of LPG are hydrocarbons containing three or four carbon atoms. The normal components of LPG are propane and butane; small concentrations of other hydrocarbons (isobutene, propylene, butane, ethane, pentane) may also be present. Different mixtures of LGP have different and physical characteristics with a different behavior during the use. Also flammability characteristics can be different according to the composition. In this paper at firsts the flammability characteristics of the main components of LGP, taken singularly, are examinated; subsequently some examples of calculation of the flammability limits of different mixture are reported [it

  19. Perspectives of the LPG-fuel market

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    In today's context of environment protection cares and in agreement with the actions carried out by the local authorities and organizations, the LPG-fuel appears in the media with a reviving good and credible reputation. However, one can ask about its real perspectives of development. This short paper analyses the conditions for this development at the international and at the national scale. LPG-fuel is the most used and most performing alternative fuel in the world and can contribute to the energy independence of the countries with national LPG resources. Its technological mastery leads progressively the car manufacturers to propose vehicles already equipped with dual-fuel engines, but to reach its expected success, LPG-fuel needs a financial aid from the national authorities in the form of taxes reduction. Its privileged markets are the taxicabs, the public transportation systems and the fleets of intervention vehicles. In France, the network of LPG distribution stations is progressively reinforcing but a revision of the legal texts concerning the training of personnel and the approval of repair shops must be updated. (J.S.)

  20. The LPG-fuel industry

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    The LPG-fuel industry comprises several professionals from various domains such as assembly shops for vehicles transformation, materials manufacturers for public distribution stations and companies which produce and commercialize the LPG-fuel. This paper summarizes the administrative and technical liabilities of these professionals, with the technical qualification required, the regulations concerning the official approval of transformation kits and pressure tanks. The French network of public distribution stations for LPG-fuel is shared between five independent dispensers with their own economic policy which represents about 700 LPG-stations. However, the safety regulations concerning LPG-fuels considerably limit the installation of LPG facilities in urban areas. A cost-benefit comparison between LPG and other liquid fuels is given in inset and takes into account the transformation costs of the vehicle. (J.S.)

  1. LPG world supply and demand

    International Nuclear Information System (INIS)

    Holmes, Ch.

    2008-01-01

    Over the course of this decade, the global LPG market has moved from being tight, where supply barely exceeded non-price sensitive demand, to the current market situation where supply growth has outstripped demand growth to such an extent that current fundamentals suggest that considerable length will prevail in the market over the near term. As is the case for many other energy commodity markets, the LPG industry has experienced a considerable transformation over the last five years with many new LPG supply projects coming on-stream and demand growth in many developing markets slowing in response to higher energy prices. The near term challenge for LPG producers will be securing outlets for output as the market becomes increasingly oversupplied. With expanding LPG supply and a worldwide tightness in the naphtha market, it is expected that petrochemical consumers will favor relatively low priced LPG over naphtha and the resulting increase in LPG cracking rates will go some way to reducing the expected supply surplus. However, the timing of several new LPG supply projects and the start-up of LPG-based petrochemical plants in the Middle-East are expected to impact global LPG trade and pricing over the next few years. Thus, at this point in time, the global LPG market has a high degree of uncertainty with questions remaining over the impact of high energy (and LPG) prices on traditional and developing market demand, the timing of new supply projects and the combined effect of these two factors on international LPG prices. World LPG production has been rising in nearly every region of the world over the last few years and totaled about 229 million tons in 2007, which is some 30 million tons per year higher than in 2000. The exception is North America which accounts for the largest share of global LPG supply at about 24% but production there has remained relatively flat in recent years. Strong LPG production growth in the Middle-East which contributed to about 19% of

  2. Power and LPG production with LNG import

    International Nuclear Information System (INIS)

    Mak, J.Y.

    2004-01-01

    When used in power cogeneration, Liquefied Natural Gas (LNG) is both energy efficient and can eliminate seawater or fuel gas consumption as well as the associated environmental impacts of conventional regasification processes. However, some liquefied natural gas (LNG) sources have heating values higher than current North American natural gas pipelines can allow for. LNG from these cannot be injected into gas pipelines without several heating control processing steps. This paper outlines two new technologies developed to address this issue. The first is a power cogeneration process using LNG as a heat sink. The second technology involves a fractionation process removing Liquid Propane Gas (LPG) components from imported LNG, thereby controlling heat value. Both technologies are applicable in grassroots installations as well as being suitable for retrofitting to existing LNG regasification for power generation and LPG production. It was concluded that power cogeneration with a mixed fluid power cycle recovered a significant portion of energy in LNG liquefaction plants. Additionally, it was also possible to fractionate high quality LPG from LNG at a low cost, with the residue being further re-condensed and re-utilized for power generation. It was also concluded that the LNG fractionation process would add flexibility to the LNG receiving terminals, allowing the import of lower quality LNG to North America, while also generating additional revenues from LPG production. 3 refs., 5 tabs., 6 figs

  3. Technology for Polymer Optical Fiber Bragg Grating Fabrication and Interrogation

    DEFF Research Database (Denmark)

    Ganziy, Denis

    The aim of this project is to develop a new, high-quality interrogator for FBG sensor systems, which combines high performance with costeffectiveness. The work includes the fields of optical system design, signal processing, and algorithm investigation. We present an efficient and fast peak...... analyze and investigate errors and drawbacks, which are typical for spectrometer-based interrogators: undersampling, grating internal reflection, photo response nonuniformity, pixel crosstalk and temperature and long term drift. We propose a novel type of multichannel Digital Micromirror Device (DMD......) based interrogator, where the linear detector is replaced with a commercially available DMD, which leads to cost reduction and better performance. Original optical design, which utilizes advantages of a retro-reflect optical scheme, has been developed in Zemax. We test the presented interrogator...

  4. Contact microphone using optical fibre Bragg grating technology

    International Nuclear Information System (INIS)

    Bezombes, F A; Lalor, M J; Burton, D R

    2007-01-01

    A contact microphone using optical fibre Bragg grating has been developed. It enables one to listen and record a human voice and/or breathing by monitoring the vibration generated by the outer wall of the throat during speech. This system can have many applications such as detecting defects in vocal folds, measuring and monitoring the vibration and defection generated by intubations of a patient throat and other voice related problem, low level speaking recording and transmitting is also possible, the microphone can be also used to monitor breathing and the system can be used as a microphone in very harsh environments for example it would allow one to hear the patient during a cat scan

  5. European strategic issues for LPG

    International Nuclear Information System (INIS)

    Anon.

    2006-01-01

    A Strategic Team was set up at the AEGPL to: define an energy long term scenario, formulate a LPG road map, identify a positioning for LPG and determine a new image and a new name for the Association. The project will be presented in October, said Main De Greve (SHV) during the AEGPL Congress in Istanbul, where he presented a very interesting analysis on the LPG social and business environment. We publish this text below. (authors)

  6. Domestic LPG interventions in South Africa: Challenges and lessons

    International Nuclear Information System (INIS)

    Kimemia, David; Annegarn, Harold

    2016-01-01

    A majority of grid-connected households in South Africa use electricity for cooking and heating tasks. This thermal intensive use of electricity has a high load factor and is a contributory factor of electricity demand outstripping supply at peak demand periods. The government has promoted liquefied petroleum gas (LPG) as an alternative thermal energy source for household cooking and heating. This study evaluates the long-term successes, challenges and social impacts of an LPG intervention project that was piloted in Atteridgeville Township, a typical low-income suburb. The data was gathered through one-on-one household interviews with a sample of the beneficiaries. The results indicate that seven years after the LPG intervention, about 70% of the beneficiaries continue to use LPG and report that the intervention has improved their welfare. Fast cooking is cited as the key tangible benefit of LPG technology in households, followed by saving on electricity bills. The project would have achieved more success through better community engagement, including strict beneficiary selection criteria; a long-term LPG distribution and maintenance plan; and inclusion of recurring monthly LPG subsidies for indigent households. The study discusses the subset of factors necessary for successful rollouts of similar energy projects. - Highlights: •LPG has replaced earlier combustion fuels as preferred energy for cooking. •Fast cooking, cleanliness and saving on electricity bills are the key benefits. •The demand for LPG has stimulated economic models for supply and delivery. •Periodic shortages and non-adherence to price caps deter market expansion.

  7. What is LPG-fuel?

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    The LPG-f (Liquefied Petroleum Gas) fuels are better known by the public users for their domestic applications (cooking, sanitary water heating and building heating). This paper describes the chemical composition and properties of LPG fuels together with their environmental advantages (low S content and NOx and CO emissions, no particulates) with respect to other fossil fuels. Advantages for vehicle engines (cleaner combustion, no dilution of the engine lubricant) and passengers (reduction of noise pollution) are summarized. The worldwide production/consumption of LPG is given. (J.S.)

  8. Visible Wavelength Color Filters Using Dielectric Subwavelength Gratings for Backside-Illuminated CMOS Image Sensor Technologies.

    Science.gov (United States)

    Horie, Yu; Han, Seunghoon; Lee, Jeong-Yub; Kim, Jaekwan; Kim, Yongsung; Arbabi, Amir; Shin, Changgyun; Shi, Lilong; Arbabi, Ehsan; Kamali, Seyedeh Mahsa; Lee, Hong-Seok; Hwang, Sungwoo; Faraon, Andrei

    2017-05-10

    We report transmissive color filters based on subwavelength dielectric gratings that can replace conventional dye-based color filters used in backside-illuminated CMOS image sensor (BSI CIS) technologies. The filters are patterned in an 80 nm-thick poly silicon film on a 115 nm-thick SiO 2 spacer layer. They are optimized for operating at the primary RGB colors, exhibit peak transmittance of 60-80%, and have an almost insensitive response over a ± 20° angular range. This technology enables shrinking of the pixel sizes down to near a micrometer.

  9. The European automotive LPG market

    International Nuclear Information System (INIS)

    Anon.

    1998-01-01

    The European automotive LPG market could reach at least 4 % of the European fuel market in 2005 versus 1 % in 1990. This would represent a rise of about 35 % in automotive LPG sales (from 2,4 million tonnes in 1997 to 7 million tonnes estimated for 2005). This was underlined by Alain Deleuse, Primagaz group's Marketing Director, in the paper he delivered at the AEGPL Budapest Convention. We publish large excepts of this paper. (author)

  10. A stronger perfume for LPG

    Energy Technology Data Exchange (ETDEWEB)

    Willcox, C.K.

    1996-11-01

    The odorisation of Liquefied Petroleum Gas (LPG) is undertaken to improve the safe use and transport of this popular fuel. Effective LPG odorisation should enable leaks to be detected by any person with a normal sense of smell before gas concentrations reach a hazardous level. The objective is identical to that for odorising natural gas. However, the physical characteristics of propane and butane present particular difficulties. These do not occur with natural gas, which has a dynamic, flowing, simple-phase system. (author)

  11. A stronger perfume for LPG

    International Nuclear Information System (INIS)

    Willcox, C.K.

    1996-01-01

    The odorisation of Liquefied Petroleum Gas (LPG) is undertaken to improve the safe use and transport of this popular fuel. Effective LPG odorisation should enable leaks to be detected by any person with a normal sense of smell before gas concentrations reach a hazardous level. The objective is identical to that for odorising natural gas. However, the physical characteristics of propane and butane present particular difficulties. These do not occur with natural gas, which has a dynamic, flowing, simple-phase system. (author)

  12. Normal incidence spectrophotometer using high density transmission grating technology and highly efficiency silicon photodiodes for absolute solar EUV irradiance measurements

    Science.gov (United States)

    Ogawa, H. S.; Mcmullin, D.; Judge, D. L.; Korde, R.

    1992-01-01

    New developments in transmission grating and photodiode technology now make it possible to realize spectrometers in the extreme ultraviolet (EUV) spectral region (wavelengths less than 1000 A) which are expected to be virtually constant in their diffraction and detector properties. Time dependent effects associated with reflection gratings are eliminated through the use of free standing transmission gratings. These gratings together with recently developed and highly stable EUV photodiodes have been utilized to construct a highly stable normal incidence spectrophotometer to monitor the variability and absolute intensity of the solar 304 A line. Owing to its low weight and compactness, such a spectrometer will be a valuable tool for providing absolute solar irradiance throughout the EUV. This novel instrument will also be useful for cross-calibrating other EUV flight instruments and will be flown on a series of Hitchhiker Shuttle Flights and on SOHO. A preliminary version of this instrument has been fabricated and characterized, and the results are described.

  13. Comparative study of long-period gratings written in a boron co-doped fiber by an electric arc and UV irradiation

    International Nuclear Information System (INIS)

    Smietana, M; Bock, W J; Mikulic, P

    2010-01-01

    The paper presents for the first time a comparative study of long-period gratings (LPGs) written by point-by-point UV irradiation and by electrical arc discharges. These gratings were inscribed in a highly photosensitive boron co-doped fiber that can be considered as a suitable platform for LPG writing using either technology. The experimental transmission data for the manufactured LPG devices fit well when compared to the simulations we carried out in parallel. As a result of each of these writing processes, we were able to obtain a remarkably good quality of grating. Two reasons could explain the observed small differences between the spectra: a slight mismatch of the period of the gratings and an unintentional tapering of the fiber during the arc-based processes. We also found that the UV irradiation at λ = 248 nm can cause clearly visible damage to the fiber's surface. As a result of the UV writing, a coupling to the asymmetrical cladding modes can take place. Moreover, the gratings written using the two technologies show a very similar refractive index and temperature-sensing properties. The only differences between them can come from a physical deformation of the fiber induced by the electric arc discharges

  14. Fast Inscription of Long Period Gratings in Microstructured Polymer Optical Fibers

    DEFF Research Database (Denmark)

    Min, Rui; Marques, Carlos; Nielsen, Kristian

    2018-01-01

    We demonstrate 20 dB long period grating (LPG) fast inscription in microstructured polymer optical fibers (mPOFs) using a point-by-point technique obtaining an LPG total length of 25 mm. Two 248 nm UV laser pulses of 15 ns duration have been employed for every inscription point, which means a time...

  15. Preliminary study on the combustion and emission in a direct injection LPG spark ignition engine

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Seungmook; Lee, Seokhwan [Korea Institute of Machinery and Materials (Korea, Republic of)

    2010-07-01

    In the energy sector, with the implementation of stringent regulations on combustion emissions and the depletion of conventional fuels, there is an important need for low carbon fuel and advanced engine technology. Korea is the country with the most LPG vehicles in the world and the aim of this study, performed by the Korea Institute of Machinery and Materials, is to compare the performance of LPG direct injection spark ignition (DISI) with gasoline DISI. Heat release analyses were conducted to determine the combustion characteristics of both systems and experiments were performed to determine gaseous and nanoparticle emissions. Results showed that LPG provides a better thermal efficiency than gasoline and that THC, NOx, and particulate emissions were lower for LPG than for gasoline. This study demonstrated that LPG DISI can provide better combustion efficiency and lower emissions than gasoline DISI.

  16. 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...

  17. A novel biomimetic whisker technology based on fiber Bragg grating and its application

    Science.gov (United States)

    Zhao, Chenlu; Jiang, Qi; Li, Yibin

    2017-09-01

    The paper describes a novel, biomimetic whisker-based sensing technology following the basic design of the facial whiskers of animals such as rats and mice. The sensor consists of a 3× 2 whisker array on each side of a robot. In experiments with the artificial whiskers, the motor drives rotating whiskers, and the center wavelength of a fiber Bragg grating pasted on the whisker will shift when the whisker touches an obstacle. The distance will be obtained by processing the wavelength shift data with algorithms. Then the shape recognition can be realized by postprocessing the distance data. The experimental results prove that the whisker array is capable of accurately gathering the distance and shape information of an object.

  18. Management for the LPG downstream business

    International Nuclear Information System (INIS)

    Christiansen, C.

    1997-01-01

    Traditionally the LPG business is regarded as a low-tech area. Safety has always been top priority, but the applied technology in production as well as distribution has by and large not changed much in the course of the business' 60-year-history. Only few has realised that changes are the necessary mark of the future for this business. Internal and external requirements to the management demand a much higher level of information. The trend dictates a future demand for documented safety. This documentation will only become available through introduction of the latest technology in the business. A technology that also provides decision-making tools for the management to ensure the continued optimum operation of the business. (au)

  19. The application of phase grating to CLM technology for the sub-65nm node optical lithography

    Science.gov (United States)

    Yoon, Gi-Sung; Kim, Sung-Hyuck; Park, Ji-Soong; Choi, Sun-Young; Jeon, Chan-Uk; Shin, In-Kyun; Choi, Sung-Woon; Han, Woo-Sung

    2005-06-01

    As a promising technology for sub-65nm node optical lithography, CLM(Chrome-Less Mask) technology among RETs(Resolution Enhancement Techniques) for low k1 has been researched worldwide in recent years. CLM has several advantages, such as relatively simple manufacturing process and competitive performance compared to phase-edge PSM's. For the low-k1 lithography, we have researched CLM technique as a good solution especially for sub-65nm node. As a step for developing the sub-65nm node optical lithography, we have applied CLM technology in 80nm-node lithography with mesa and trench method. From the analysis of the CLM technology in the 80nm lithography, we found that there is the optimal shutter size for best performance in the technique, the increment of wafer ADI CD varied with pattern's pitch, and a limitation in patterning various shapes and size by OPC dead-zone - OPC dead-zone in CLM technique is the specific region of shutter size that dose not make the wafer CD increased more than a specific size. And also small patterns are easily broken, while fabricating the CLM mask in mesa method. Generally, trench method has better optical performance than mesa. These issues have so far restricted the application of CLM technology to a small field. We approached these issues with 3-D topographic simulation tool and found that the issues could be overcome by applying phase grating in trench-type CLM. With the simulation data, we made some test masks which had many kinds of patterns with many different conditions and analyzed their performance through AIMS fab 193 and exposure on wafer. Finally, we have developed the CLM technology which is free of OPC dead-zone and pattern broken in fabrication process. Therefore, we can apply the CLM technique into sub-65nm node optical lithography including logic devices.

  20. A Feasibility Study on LPG as Marine Fuel; En foerstudie paa gasol som marint braensle

    Energy Technology Data Exchange (ETDEWEB)

    Kjartansson, Sveinbjoern

    2012-06-15

    With the upcoming stricter emission rules fast approaching and the requirements for higher quality fuel, it is inevitable that there will be a change of fuel from HFO to cleaner options. These changes are driven by the knowledge of the health problems associated with emissions from ships in coastal areas. One viable option for meeting these demands for reduced emission is to utilize LPG as a marine fuel. This thesis investigates the harmful chemicals that are present in the exhaust gases, followed by an introduction on LPG as marine fuel. Transport options for LPG and existing engine technology is presented and the feasibility of LPG as a fuel option on the European / Swedish market is studied. The conclusion from this study is that sufficient infrastructure for distribution of LPG is in place to serve potential marine market demand. Engine technology for using LPG as fuel has been developed for a wide range of power outputs. The economic incentive in the fuel price difference alone is likely to attract ship owners to invest in LPG fueled fleets.

  1. The American Liquefied Petroleum Gases market (LPG)

    International Nuclear Information System (INIS)

    Myers, D.N.

    1993-01-01

    The United States is the leading LPG producer and consumer in the world: fuel applications are mainly in the form of propane, the fourth-ranked US source of energy. The US LPG industry serves more than 20 million customers, mainly on the residential, commercial and agricultural markets. 5 tabs., 6 photos

  2. Controlling LPG temperature for SI engine applications

    International Nuclear Information System (INIS)

    Ceviz, Mehmet Akif; Kaleli, Alirıza; Güner, Erdoğan

    2015-01-01

    In this study, the effects of the LPG temperature on the engine performance and the exhaust emission characteristics have been investigated experimentally on an SI engine. In conventional injection systems, the LPG temperature increases excessively during the phase change in pressure regulator, and reduces the engine volumetric efficiency. According to the test results, engine performance and NO emission characteristics can be improved by controlling the LPG temperature before injecting to the engine intake manifold. A new control system taking into account the results of the study has been developed and tested. In order to control the LPG temperature, the coolant flow rate in pressure regulator circuit was arranged by using a control valve activated by a PID controller unit. Results of the study showed that the engine brake power loss can be increased by about 1.85% and NO emissions can be decreased by about 2% as compared to the operation with the original LPG injection system. - Highlights: • Effects of the LPG temperature have been examined. • Engine performance characteristics and exhaust emissions have been studied. • Results reveal that the LPG temperature should be kept in a range. • A prototype LPG temperature control system has been successfully developed

  3. The LPG industry road-map

    International Nuclear Information System (INIS)

    Anon.

    2008-01-01

    This paper presents the challenges of LPG industry in contributing to the economic and social growth in Europe for the coming decades: due to its specific characteristics - both as a product and an industry - LPG can make a meaningful contribution to meeting the Europe's 3 objectives of sustainability, security of supply and competitiveness both now and in the future. LPG industry wants to reinforce its role in meeting some of the world's most pressing challenges: reducing human impact on the environment, protecting human health, and ensuring a secure energy supply. Doubling LPG's contribution to the energy mix in Europe will significantly boost the positive impact of LPG on its users and society as a whole. The LPG industry can play also an important role in the indoor applications sector. Industry estimates suggest that this sector could grow by 55% between 2001 and 2030. However, to transform this potential into a reality, a series of conditions, notably the improvement of existing applications, support in terms of R and D for the development of new applications and an enhanced degree of cooperation with innovative renewable energies, need to be met. As such, it is vital to put a structure in place to promote cooperation and exchanges between public authorities and relevant industrial actors. There are three key type of initiative to be taken: encouraging consumers to switch from conventional fuels to clean alternatives such as LPG, stimulating the modification (retrofitting) of existing vehicles from petrol-fuelled to LPG-fuelled, and encouraging car-makers to place new vehicles powered by LPG, mono-fuel, bi-fuel (LPG/petrol, LPG/biofuel) or hybrid (LPG/electric) on the market. Taken as a whole, the measures outlined above would yield numerous benefits, not only in terms of protecting the environment and human health, but also providing a valuable contribution to rural development in Europe. Expanding the role of LPG in industry throughout the EU yields the

  4. Africa gaining importance in world LPG trade

    International Nuclear Information System (INIS)

    Haun, R.R.; Otto, K.W.; Whitley, S.C.

    1997-01-01

    Major LPG projects planned or under way in Africa will increase the importance of that region's presence in world LPG trade. Supplies will nearly double between 1995 and 2005, at which time they will remain steady for at least 10 years. At the same time that exports are leveling, however, increasing domestic demand for PG is likely to reduce export-market participation by Algeria, Nigeria, Egypt, and Libya. The growth of Africa's participation in world LPG supply is reflected in comparisons for the next 15--20 years. Total world supply of LPG in 1995 was about 165 million metric tons (tonnes), of which Africans share was 7.8 million tonnes. By 2000, world supply will grow to slightly more than 200 million tonnes, with Africa's share expected to increase to 13.2 million tonnes (6.6%). And by 2005, world LPG supply will reach nearly 230 million tonnes; Africa's overall supply volumes by that year will be nearly 16.2 million tonnes (7%). World LPG supply for export in 1995 was on order of 44 million tonnes with Africa supply about 4 million tonnes (9%). By 2005, world export volumes of LPG will reach nearly 70 million tonnes; Africa's share will have grown by nearly 10 million tonnes (14.3%)

  5. Optical fiber grating based technologies and their applications: from nuclear fusion to medical

    NARCIS (Netherlands)

    Cheng, L.K.; Vliegenhart, W.A.; Habisreuther, T.

    2012-01-01

    In the last decades, Fiber Optic (FO) sensor has gained increasing acceptance. Among the different FO sensor types, Fiber Bragg Grating is most widely used due to its commercial availability and the unique multiplexing potential. The latter feature enables the development of large sensor array

  6. Impact of transportation and distribution factors on LPG supplies and prices

    Energy Technology Data Exchange (ETDEWEB)

    Aprea, G

    1980-01-01

    A predicted world LPG surplus of 14-20 million tons/y in the 1980's will not be absorbed even by the US and Japan, which are now the largest LPG consumers, unless market prices and return on investments are favorable enough to justify the investments required for the associated transportation and distribution facilities for new uses for LPG, e.g., as petrochemical feedstock, heating fuel, automotive fuel, or feedstock for the manufacture of high-octane additives. For the petrochemical industry, this implies new technologies and investments to optimize the equilibrium of the plants in connection with the market demand for ethylene, propylene, butadiene, and aromatic feedstocks. World LPG trade should rise from 13 million tons in 1979 to 40 million tons by 1985, of which 17 million tons will be moved on the Japanese captive market, up from about 10 million tons in 1979. The increased use of LPG in 1979 already boosted freight rates, which made shipowners consider new tonnage investment. The need for long-term supplier-user agreements as to LPG supplies and prices is discussed.

  7. LPG fuels in France in 1997

    International Nuclear Information System (INIS)

    Anon.

    1998-01-01

    This short note gives a statement of the sales of butane, propane and LPG fuels in France during the year 1997. Details are given for conditioned butane and propane products, cylinders and fixed reservoirs. (J.S.)

  8. Application of genetic algorithm in quasi-static fiber grating wavelength demodulation technology

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A modified genetic algorithm (GA) has been proposed, which was used to wavelength demodulation in quasi-static fiber grating sensing system. The modification method of GA has been introduced and the relevant mathematical model has been established. The objective function and individual fitness evaluation strategy interrelated with GA are also established. The influence of population size, chromosome size, generations, crossover probability and mutation probability on the GA has been analyzed, and the optimal parameters of modified GA have been obtained. The simulations and experiments, show that the modified GA can be applied to quasi-static fiber grating sensing system, and the wavelength demodulation precision is equal to or less than 3 pm.

  9. All-optical switching based on optical fibre long period gratings modified bacteriorhodopsin

    Science.gov (United States)

    Korposh, S.; James, S.; Partridge, M.; Sichka, M.; Tatam, R.

    2018-05-01

    All-optical switching using an optical fibre long-period gating (LPG) modified with bacteriorhodopsin (bR) is demonstrated. The switching process is based on the photo-induced RI change of bR, which in turn changes the phase matching conditions of the mode coupling by the LPG, leading to modulation of the propagating light. The effect was studied with an LPG immersed into a bR solution and with LPGs coated with the bR films, deposited onto the LPGs using the layer-by-layer electrostatic self-assembly (LbL) method. The dependence of the all-optical switching efficiency upon the concentration of the bR solution and on the grating period of the LPG was also studied. In addition, an in-fibre Mach-Zehnder interferometer (MZI) composed of a cascaded LPG pair separated by 30 mm and modified with bR was used to enhance the wavelength range of all-optical switching. The switching wavelength is determined by the grating period of the LPG. Switching efficiencies of 16% and 35% were observed when an LPG and an MZI were immersed into bR solutions, respectively. The switching time for devices coated with bR-films was within 1 s, 10 times faster than that observed for devices immersed into bR solution.

  10. 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.

  11. Studies on measurement of chloride ion concentration in concrete structures with long-period grating sensors

    Science.gov (United States)

    Tang, Jaw-Luen; Chiang, Tsung-Yu; Chang, Hsiang-Ping; Wang, Jian-Neng

    2006-03-01

    We report the development and demonstration of a simple and low-cost long-period grating (LPG) sensor for chloride ion concentration measurement in concrete structures. The LPG sensor is extremely sensitive to the refractive index of the medium surrounding the cladding surface of the sensing grating, thus allowing it to be used as an ambient index sensor or chemical concentration indicator with high stability and reliability. We have measured chloride ion levels in a concrete sample immersed in salt water solution with different weight concentration ranging from 0 % to 20 %, and results showed that the LPG sensor exhibited a linear decrease in the transmission loss and resonance wavelength shift when the concentration increased. The measurement accuracy for concentration of salt in water solution is estimated to be 0.6 % and the limit of detection for chloride ion is about 0.04 %. To further enhance its sensitivity for chloride concentrations, we have coated gold nanoparticles on the grating surface of the LPG sensor. The sensing mechanism is based on the sensitivity of localized surface plasmon resonance of self-assembled Au colloids on the grating portion of the LPG. With this method, a factor of two increases in sensitivity of detecting chemical solution concentrations was obtained. The advantage of this type of the sensor is relatively simple of construction and ease of use. Moreover, the sensor has the potential capability for on-site, in vivo, and remote sensing, and has the potential use for disposable sensors.

  12. Environmental consequences of parallel marketing of LPG in India

    International Nuclear Information System (INIS)

    Das, T.K.; Deb, C.; Jash, T.

    2000-01-01

    In 1993, the government of India introduced a parallel marketing system for petroleum products, particularly for liquefied petroleum gas (LPG). LPG, under the parallel marketing system, is distributed at higher price without any subsidy. The government distributors, however, distribute LPG at subsidized rate. The consumers who get LPG at higher price, therefore, opt for a mixed energy use. The present study, based on a field survey, deals with the pattern of this mixed energy use and its environmental consequences. (author)

  13. Conformity checking of LPG Transportation Trucks by Modelling and Simulation

    OpenAIRE

    Gallab , Maryam; Bouloiz , Hafida; Tkiouat , Mohamed; Garbolino , Emmanuel

    2016-01-01

    International audience; LPG Loading /unloading site is considered as a dangerous environment of significant risk, especially during LPG transfer operations. These risks may cause catastrophic dangers such as BLEVE (Boiling Liquid Expanding Vapour Explosion), UVCE (Unconfined Vapour Cloud Explosion), etc. The site consists of a tank (RST) containing LPG and threetransfer posts. Two posts allow loading of small carrier tankers 6 tons. The other one transfer post transfer LPG contained injumbo t...

  14. Safety considerations on LPG storage tanks

    International Nuclear Information System (INIS)

    Paff, R.

    1993-01-01

    The safety of liquefied petroleum gas (LPG) storage tanks, in refineries, petrochemicals plants, or distribution storage, is an important concern. Some serious accidents in recent years, have highlighted the need for a good safety policy for such equipment. Accidents in LPG storage are mainly due to losses of containment of the LPG. Formation of a cloud can lead to a ''Unconfined Vapor Cloud Explosion'' (UVCE). Liquid leakage can lead to pool fires in the retention area. In some circumstances the heat input of the tank, combined with the loss of mechanical resistance of the steel under high temperature, can lead to a BLEVE ''Boiling Liquid Expanding Vapor Explosion''. It is obvious that such equipment needs a proper design, maintenance and operating policy. The details to be considered are set out. (4 figures). (Author)

  15. Vienna: a capital transported by LPG

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    For more than 30 years the Austrian capital has chosen the LPG-fuel for its public transportation systems. This choice was advised by the environmental necessity to reduce the emissions of particulates from diesel engines and by the economical will of having a competitive fuel source with respect to diesel fuel. This paper recalls first the historical evolution of Vienna's buses progressively equipped with dual-fuel engines, and since 1976 with LPG fuel engines only. Today's the LPG buses fleet represents about 80% of the Vienna Transport buses. Then, the economical (fuel consumption, investment, exploitation and maintenance costs) and environmental (particulates and CO emissions) balance-sheet of this evolution is analysed. Since 1988, the use of catalytic converters for exhaust systems has allowed a 80% reduction of NOx emissions. (J.S.)

  16. LPG market in sub Saharan Africa

    International Nuclear Information System (INIS)

    Belguedj, M.

    1999-01-01

    This article provides an overview of the current state of the liquefied petroleum gases (LPG) market in sub Saharan Africa (SSA) and analyses the supply and demand patterns, the constraints on supply imposed by the insufficient output from refineries unable to meet the increasing demand, and institutional and regulatory issues. Details are given of the pricing policies, the economic benefits that could be obtained by increasing the scale of operations, the use of subsidies, private sector participation, and LPG activities in Angola, Cameroon, the Congo, and the Ivory Coast. The role of the World Bank in the Africa Gas Initiative to promote the use of natural gas reserves in SSA, and requirements for developing the LPG market are discussed

  17. Analysis of an LPG accidental release

    Energy Technology Data Exchange (ETDEWEB)

    Demichela, M.; Piccinini, N.; Poggio, A.

    2004-03-01

    An industrial LPG storage accident due to the release of propane from a tanker is described in this paper and the sequence of events that led to the collapse of a storage tank is examined using simulation software. A model taking both released flows into account as a radiant thermal contribution in the presence of flames is presented. The progression of the accident is assessed through digitalization and processing of the film of the fireball produced by about 500 L of LPG, whose diameter was calculated as approximately 50 m. (author)

  18. LPG a clean and efficient motor fuel: regulated and non-regulated emissions of a commercial attractive LPG vehicle

    NARCIS (Netherlands)

    Hollemans, B.H.

    1996-01-01

    Excise and other duties measures in Europe, threaten to affect the low price of LPG as a car fuel. As a result, this less polluting fuel would lose position. For this reason the Netherlands LPG industry commissioned TNO to undertake a study which would clearly demonstrate the advantages of LPG. The

  19. France: freeing the block on auto Lpg

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    Can it be hoped, when business starts again this september, that the right conditions will finally exist for LPG motor car fuel in France to get off the ground ? In any case the context seems to lend itself to that end more so than in previous years. Perhaps because measures in favour of a tax incentive - tirelessly sought by the LPG industry with the backing of a large car manufacturer and the support of the 'technical' ministers - have met with powerful trends this time, backed up by public opinion worried at the levels of atmospheric pollution reached in July and August. Perhaps too because all the main players in the sector are ready to rise to the challenge: equipment suppliers offer new, high-performance materials, a manufacturer of Renault's declares itself convinced of the advantages of LPG fuel, while distributors of the product declare themselves ready to accompany tax exemption with an effort regarding tax-free pricing. As elected representatives and societies (one on behalf of the users of LPG, the other for the protection of the environment) have shown equally their support, the components are nearly all assembled. One should guard against premature optimism, however: only the draft finance law for 1996, presented in the Council of Ministers around the 20th September, will tell if the Finance ministry shows itself aware of the arguments put forward. (authors). 3 figs., 1 tab

  20. Fiber Optic Long Period Grating Based Sensor for Coconut Oil Adulteration Detection

    Directory of Open Access Journals (Sweden)

    T. M. Libish

    2010-03-01

    Full Text Available We report the development and demonstration of a Long-Period Grating (LPG based optical fiber sensor for determining the adulteration of coconut oil by palm oil. The fundamental principle of detection is the sensitive dependence of the resonance peaks of LPG on the changes of the refractive index of the environmental medium around the cladding surface of the grating. Refractive index sensing with LPGs employs light coupling between core and cladding modes in the grating section. The transmittance spectra of a long period grating element immersed in different mixtures of coconut oil and palm oil were recorded. Results show that resonance wavelengths and transmission intensities varied as a function of the adulteration level of coconut oil. Detection limit of adulteration was found to be 2 % for coconut oil–palm oil binary mixture.

  1. An Optical Fiber Viscometer Based on Long-Period Fiber Grating Technology and Capillary Tube Mechanism

    Directory of Open Access Journals (Sweden)

    Jian-Neng Wang

    2010-12-01

    Full Text Available This work addresses the development and assessment of a fiber optical viscometer using a simple and low-cost long-period fiber grating (LPFG level sensor and a capillary tube mechanism. Previous studies of optical viscosity sensors were conducted by using different optical sensing methods. The proposed optical viscometer consists of an LPFG sensor, a temperature-controlled chamber, and a cone-shaped reservoir where gravitational force could cause fluid to flow through the capillary tube. We focused on the use of LPFGs as level sensors and the wavelength shifts were not used to quantify the viscosity values of asphalt binders. When the LPFG sensor was immersed in the constant volume (100 mL AC-20 asphalt binder, a wavelength shift was observed and acquired using LabVIEW software and GPIB controller. The time spent between empty and 100 mL was calculated to determine the discharge time. We simultaneously measured the LPFG-induced discharge time and the transmission spectra both in hot air and AC-20 asphalt binder at five different temperatures, 60, 80, 100, 135, and 170 Celsius. An electromechanical rotational viscometer was also used to measure the viscosities, 0.15–213.80 Pa·s, of the same asphalt binder at the above five temperatures. A non-linear regression analysis was performed to convert LPFG-induced discharge time into viscosities. Comparative analysis shows that the LPFG-induced discharge time agreed well with the viscosities obtained from the rotational viscometer.

  2. CFBP and LPG market in 2004

    International Nuclear Information System (INIS)

    Anon.

    2005-01-01

    The French butane and propane committee (CFBP) has presented its activities in liquefied petroleum gases in its 2004 annual report. The success of its initiatives of promotion during the year 2004 has led the CFBP to launch a new campaign of advertisement since January 31, 2005. In its report, the CFBP stresses on the re-start up of the LPG fuel market. The sales of propane gas in tanks have raised by 5.2% between 2003 and 2004. The decay of the traditional market of gas cylinders has been practically stopped thanks to the sales dynamism of small (5-6 kg) cylinders and to the innovations added by some retailers on the 13 kg cylinders (level indicator). The sales of automotive LPG fuels have shown a slower decay during 2004. (J.S.)

  3. Transient evaluation for LPG and oil pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Meliande, Patricia; Do Nascimento, Elson Antonio; Fernandes Lacerda, Rogerio [Federal Fluminense University, Niteroi, RJ (Brazil)

    2010-07-01

    In the last decades, the offshore industry has expanded thanks to the development of equipment for subsea operation. In such installations, protection equipment can be adapted to the installation's design in order to avoid surge pressure effects and ensure safety and integrity of the system, predicting transient effect is therefore very important. The purpose of this study is to predict the surge pressure on refrigerated LPG and gasoline pipelines during unpredicted closure of valves. Flowmaster software was used to carry out the simulations and its results were then validated with a methodology that applied the characteristics method based on Wylie and Streeter assumptions. Results showed that surge pressures during transient effect for both refrigerated LPG and Gasoline pipeline systems were less than the maximum allowable operating pressure and therefore no control dispositive installations are geeded. This study showed that the use of these computer models can ensure the optimization of the system and provide cost effective solutions.

  4. Analisa Pembuatan Tabung Gas Lpg 3 Kg

    Directory of Open Access Journals (Sweden)

    Mustafa -

    2012-11-01

    Full Text Available Program konversi minyak tanah ke LPG merupakan program pemerintah yang bertujuan untuk mengurangisubsidi BBM, dengan mengalihkan pemakaian minyak tanah ke LPG. Tujuan analisa untuk mengetahui proses pembuatantabung gas, proses deep drawing dan metode pengelasan yang baik. Karena masih banyak orang yang takut memakai bahanbakar LPG tersebut karena takut meledak akibat kualitasnya yang kurang bagus. Deep Drawing atau biasa disebut drawingadalah salah satu jenis proses pembentukan logam, dimana bentuk pada umumnya berupa silinder dan selalu mempunyaikedalaman tertentu. Pada proses pembuatan tabung gas elpiji untuk mendisain suatu proses pembentukan logam , sepertipenarikan (drawing. Salah satu pekerjaan yang harus kita lakukan adalah menentukan atau memilih kapasitas mesin(energi, gaya, torsi serta perkakas dan peralatan yang akan digunakan untuk proses tersebut. Pada proses deep drawingdengan kecepatan tekan yang telah ditentukan (sesuai tabel daya tekan maksimal tidak boleh melebihi: 167,330 kg. Padaproses pengelasan circum, tegangan normal mencapai 61.16 kg/cm2, karena masih diatas uji ketahanan hidrostastik, makamasih dalam batas aman.

  5. LPG Dependence after a Suicide Attempt

    Directory of Open Access Journals (Sweden)

    Ebru Aldemir

    2015-01-01

    Full Text Available Inhalant abuse is a problem that is getting more common all around the world. The increase in prevalence of inhalant abuse escalates morbidity and mortality rates. About 22% of people using inhalant have died at their first attempt. Particularly propane, butane, or propane-butane mixture has highest mortality rates. Sudden sniffing death syndrome, cardiomyopathy, central nervous system toxicity, hematological abnormalities, kidney toxicity, and hepatocellular toxicities are the major complications of inhalant abuse. Herein we present a patient with inhalant use disorder. At the age of 19, after a stressful life event he had unsuccessfully tried to suicide by inhaling LPG (liquefied petroleum gas, a mixture of butane and propane gases. After he realized that he had hallucinations and felt better during the inhalation, he started to abuse it. He was addicted to LPG for 10 years at the time of admission. Besides being dangerous for the society security, this intense level of LPG inhalation (12 liters a day not giving any physical harm makes this case interesting.

  6. Environmental payoffs of LPG cooking in India

    Science.gov (United States)

    Singh, D.; Pachauri, S.; Zerriffi, H.

    2017-11-01

    Over two-thirds of Indians use solid fuels to meet daily cooking energy needs, with associated negative environmental, social, and health impacts. Major national initiatives implemented by the Indian government over the last few decades have included subsidies for cleaner burning fuels like liquid petroleum gas (LPG) and kerosene to encourage a transition to these. However, the extent to which these programs have affected net emissions from the use of these improved fuels has not been adequately studied. Here, we estimate the amount of fuelwood displaced and its net emissions impact due to improved access to LPG for cooking in India between 2001 and 2011 using nationally representative household expenditure surveys and census datasets. We account for a suite of climate-relevant emissions (Kyoto gases and other short-lived climate pollutants) and biomass renewability scenarios (a fully renewable and a conservative non-renewable case). We estimate that the national fuelwood displaced due to increased LPG access between 2001 and 2011 was approximately 7.2 million tons. On aggregate, we estimate a net emissions reduction of 6.73 MtCO2e due to the fuelwood displaced from increased access to LPG, when both Kyoto and non-Kyoto climate-active emissions are accounted for and assuming 0.3 as the fraction of non-renewable biomass (fNRB) harvested. However, if only Kyoto gases are considered, we estimate a smaller net emissions decrease of 0.03 MtCO2e (assuming fully renewable biomass harvesting), or 3.05 MtCO2e (assuming 0.3 as the fNRB). We conclude that the transition to LPG cooking in India reduced pressures on forests and achieved modest climate benefits, though uncertainties regarding the extent of non-renewable biomass harvesting and suite of climate-active emissions included in such an estimation can significantly influence results in any given year and should be considered carefully in any analysis and policy-making.

  7. LPG in large pipelines; Operacao com GLP em oleodutos de grande extensao

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Celio Pereira dos; Agostineti, Antonio [PETROBRAS Transporte S.A. (TRANSPETRO), Rio de Janeiro, RJ (Brazil)

    2003-07-01

    OSBRA Pipeline is the largest pipeline of the Brazil. It has its beginning in the Refinery REPLAN, in Sao Paulo and it is going to Brasilia, in the Distrito Federal traveling 980 kilometers through three states and Distrito Federal. Flow rate inferior to one of the project, alterations in the specification of the quality for sale and operational deficiencies contributed to the difficulty of maintenance of the quality of LPG with relationship to the oleaginous residue. A Batch Test was idealized to trace of the possible points of contamination along the pipeline under controlled conditions. Pig separator was used in the interface among the gasoline and LPG, and adopted new procedure, for the operator of the control center, to avoid the start of the pumps that were with its internal lines filled with other product. The results showed viability of the operation with LPG in the OSBRA pipeline, even without need of alterations in the current physical facilities. Some improvements in facilities, as well as, new technologies of pig separator can improve the maintenance of the quality of LPG reducing possibilities of contamination, and also reducing the volume of the interface. (author)

  8. The impact of waterborne LPG imports on US markets

    International Nuclear Information System (INIS)

    Lindsey, L.

    1994-01-01

    After a winter like most of the US has gone through this year it is certainly apropos to discuss the effect of waterborne LPG imports on the market. Due to time constraints this paper will be limited to global LPG activity as it relates to the US. To provide some credibility to the following comments, it should be stated that Commercial Services Company tracks every large LPG carrier in the world from the LPG lifting point to it's discharge destination and the commercial activity involved in the delivery

  9. Leishmania major glycosylation mutants require phosphoglycans (lpg2- but not lipophosphoglycan (lpg1- for survival in permissive sand fly vectors.

    Directory of Open Access Journals (Sweden)

    Anna Svárovská

    2010-01-01

    Full Text Available Sand fly species able to support the survival of the protozoan parasite Leishmania have been classified as permissive or specific, based upon their ability to support a wide or limited range of strains and/or species. Studies of a limited number of fly/parasite species combinations have implicated parasite surface molecules in this process and here we provide further evidence in support of this proposal. We investigated the role of lipophosphoglycan (LPG and other phosphoglycans (PGs in sand fly survival, using Leishmania major mutants deficient in LPG (lpg1(-, and the phosphoglycan (PG-deficient mutant lpg2(-. The sand fly species used were the permissive species Phlebotomus perniciosus and P. argentipes, and the specific vector P. duboscqi, a species resistant to L. infantum development.The lpg2(- mutants did not survive well in any of the three sand fly species, suggesting that phosphoglycans and/or other LPG2-dependent molecules are required for parasite development. In vitro, all three L. major lines were equally resistant to proteolytic activity of bovine trypsin, suggesting that sand fly-specific hydrolytic proteases or other factors are the reason for the early lpg2(- parasite killing. The lpg1(- mutants developed late-stage infections in two permissive species, P. perniciosus and P. argentipes, where their infection rates and intensities of infections were comparable to the wild type (WT parasites. In contrast, in P. duboscqi the lpg1(- mutants developed significantly worse than the WT parasites.In combination with previous studies, the data establish clearly that LPG is not required for Leishmania survival in permissive species P. perniciosus and P. argentipes but plays an important role in the specific vector P. duboscqi. With regard to PGs other than LPG, the data prove the importance of LPG2-related molecules for survival of L. major in the three sand fly species tested.

  10. Analysis of the vaporization of the liquefied gas of the petroleum (LPG) in tanks

    International Nuclear Information System (INIS)

    Alzate Espinosa, Guillermo A; Jaraba V, Xavier F

    2005-01-01

    Putting together thermodynamics (phase behavior), heat transfer and mass transfer fundamentals; it was possible to structure a mathematical and numerical model to simulate the vaporization process of LPG in tanks. The simulation model allows studying any feeding process with gaseous LPG to an appliance, and therefore, to follow changes inside the LPG tank related with LPG composition and its properties, temperature and pressure. A continuous or by cycles supplying process of gaseous LPG from a tank to any appliance promotes a reduction of liquid LPG temperature, an increase on specific gravity of LPG in both phases, and also an increasing in the value calorific of gaseous LPG

  11. French Committee of Butane and Propane. 2015 activity report. Butane, propane, LPG - Immediately available solutions for the future

    International Nuclear Information System (INIS)

    2016-05-01

    This document presents the 2015 highlights of the French LPG fuels industry: 1 - 2015 LPG market; 2 - CFBP missions and 2015 highlights: promotion of LPG industry and uses, contribution to standards development, safety of industrial sites, promoting LPG specificities, safety of LPG transports and training, ensuring clients' installations safety, promoting LPG in the energy mix, promoting LPGc potential, public information

  12. Modeling the performance of coated LPG tanks engulfes in fires

    NARCIS (Netherlands)

    Cozzani, V.; Landucci, G.; Molag, M. (Menso)

    2009-01-01

    The improvement of passive fire protection of storage vessels is a key factor to enhance safety among the LPG distribution chain. A thermal and mechanical model based on finite elements simulations was developed to assess the behaviour of full size tanks used for LPG storage and transportation in

  13. A differential detection scheme of spectral shifts in long-period fiber gratings

    Science.gov (United States)

    Zhelyazkova, Katerina; Eftimov, Tinko; Smietana, Mateusz; Bock, Wojtek

    2010-10-01

    In this work we present an analysis of the response of a compact, simple and inexpensive optoelectronic sensor system intended to detect spectral shifts of a long-period fiber grating (LPG). The system makes use of a diffraction grating and a couple of receiving optical fibers that pick up signals at two different wavelengths. This differential detection system provides the same useful information from an LPG-based sensor as with a conventional laboratory system using optical spectrum analyzers for monitoring the minimum offset of LPG. The design of the fiber detection pair as a function of the parameters of the dispersion grating, the pick-up fiber and the LPG parameters, is presented in detail. Simulation of the detection system responses is presented using real from spectral shifts in nano-coated LPGs caused by the evaporation of various liquids such as water, ethanol and acetone, which are examples of corrosive, flammable and hazardous substances. Fiber optic sensors with similar detection can find applications in structural health monitoring for moisture detection, monitoring the spillage of toxic and flammable substances in industry etc.

  14. 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.

  15. Predicting the performances of a CAMPRO engine retrofitted with liquefied petroleum gas (LPG system using 1-dimensional software

    Directory of Open Access Journals (Sweden)

    Kamaruddin M. Hazeem

    2017-01-01

    Full Text Available Recently, the depletion of petroleum resources and the impact of exhaust emission caused by combustion towards environmental has been forced to all researchers to come out with an alternative ways to prevent this situation become worse. Liquefied petroleum gas (LPG is the most compatible and have a potential to become a source of energy for internal combustion engine. Unfortunately, the investigation of LPG in internal combustion engine among researcher still have a gap in research. Thus, in this study a 1-Dimensional simulation CAMPRO 1.6L engine model using GT-Power is developed to predict the performances of engines that using LPG as a fuel for internal combustion engine. The constructed model simulation will throughout the validation process with the experimental data to make sure the precision of this model. The validation process shows that the results have a good agreement between the simulation model and the experimental data. As a result, the performance of LPG simulation model shows that a Brake Torque (BT, Brake Power (BP and Brake Mean Effective Pressure (BMEP were significantly improved in average of 7% in comparison with gasoline model. In addition, Brake Specific Fuel Consumption (BSFC also shows an improvement by 5%, which is become more economic. Therefore, the developed GT-Power model offer a successful fuel conversion to LPG systems via retrofit technology to provide comprehensive support for implementation of energy efficient and environmental friendly vehicles.

  16. Nanostructured ZnO films for potential use in LPG gas sensors

    Science.gov (United States)

    Latyshev, V. M.; Berestok, T. O.; Opanasyuk, A. S.; Kornyushchenko, A. S.; Perekrestov, V. I.

    2017-05-01

    The aim of the work was to obtain ZnO nanostructures with heightened surface area and to study relationship between formation method and gas sensor properties towards propane-butane mixture (LPG). In order to synthesize ZnO nanostructures chemical and physical formation methods have been utilized. The first one was chemical bath deposition technology and the second one magnetron sputtering of Zn followed by oxidation. Optimal method and technological parameters corresponding to formation of material with the highest sensor response have been determined experimentally. Dynamical gas sensor response at different temperature values and dependencies of the sensor sensitivity on the temperature at different LPG concentrations in air have been investigated. It has been found, that sensor response depends on the sample morphology and has the highest value for the structure consisting of thin nanowires. The factors that lead to the decrease in the gas sensor operating temperature have been determined.

  17. 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...

  18. Reductie BLEVE-frequentie van een LPG-tankauto op een autotankstation

    NARCIS (Netherlands)

    Kok, O.M.P.; Pietersen, C.M.

    1985-01-01

    Uit de LPG-Integraalstudie [4] blijkt dat de BLEVE van de LPG-Tankauto het risico van het autotankstation domineert (bij ondergrondse opslagtank). In deze studie is nagegaan wat de invloed is van een aantal mogelijk te treffen voorzieníngen aan de LPG-tankauto en het LPG-autotankstation op de

  19. Emissions from ethanol- and LPG-fueled vehicles

    International Nuclear Information System (INIS)

    Pitstick, M.E.

    1995-01-01

    This paper addresses the environmental concerns of using neat ethanol and liquefied petroleum gas (LPG) as transportation fuels in the United States. Low-level blends of ethanol (10%) with gasoline have been used as fuels in the United States for more than a decade, but neat ethanol (85% or more) has only been used extensively in Brazil. LPG, which consists mostly of propane, is already used extensively as a vehicle fuel in the United States, but its use has been limited primarily to converted fleet vehicles. Increasing U.S. interest in alternative fuels has raised the possibility of introducing neat-ethanol vehicles into the market and expanding the number of LPG vehicles. Use of such vehicles, and increased production and consumption of fuel ethanol and LPG, will undoubtedly have environmental impacts. If the impacts are determined to be severe, they could act as barriers to the introduction of neat-ethanol and LPG vehicles. Environmental concerns include exhaust and evaporative emissions and their impact on ozone formation and global warming, toxic emissions from fuel combustion and evaporation, and agricultural impacts from production of ethanol. The paper is not intended to be judgmental regarding the overall attractiveness of ethanol or LPG as compared with other transportation fuels. The environmental concerns are reviewed and summarized, but only conclusion reached is that there is no single concern that is likely to prevent the introduction of neat-ethanol-fueled vehicles or the increase in LPG-fueled vehicles

  20. Rancang Bangun Sistem Pengaman Kebocoran Gas LPG (Liquefied Petroleum Gas) Menggunakan Mikrokontroler

    OpenAIRE

    Ismai, Reza Lutfi; Suseno, Jatmiko Endro; Suryono, Suryono

    2017-01-01

    Design of LPG gas leakage safety system using microcontroller has been made in this research. The purpose of this research is to make LPG gas sensor circuit to detect LPG gas concentration and make automation systems for LPG gas leakage protection. LPG gas leakage protection system can be applied for the use of LPG gas safely. Component to detect LPG gas concentration use sensor MQ 5 which can gives resistance as the output value which can be converted into voltage through the voltage devider...

  1. Simulation for thermal response of a spherical LPG tank; Kyukei LPG chozo tanku no netsuoto kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hsi-jen; Lin, Mann-hsing; Chao, Fu-yuan [Tamkang University, Tamsui (Taiwan). Department of Chemical Engineering

    1999-03-05

    Liquefied petroleum gas (LPG) is a very important fuel and chemical feed stock as well; however, the hydrocarbon has been involved in many major fires and explosions. One of these accidents is boiling-liquid, expanding-vapor explosion (BLEVE). It is a phenomenon that results from the sudden release from confinement of a liquid at a temperature above its atmospheric-pressure boiling point. The sudden decrease in pressure results in the explosive vaporization of a fraction of the liquid and a cloud of vapor and mist with the accompanying blast effects. Most BLEVEs involve flammable liquids, and most BLEVE releases are ignited by a surrounding fire and result in a fireball. The primary objective of this paper is to develop a computer model in order to determine the thermal response of a spherical LPG tank involved in fire engulfment accidents. The assessment of the safety spacing between tanks was also discussed. (author)

  2. Novel sensing approach for LPG leakage detection: Part I: Operating Mechanism and Preliminary Results

    KAUST Repository

    Mukhopadhyay, Subhas

    2015-10-30

    Gas sensing technology has been among the topical research work for quite some time. This paper showcases the research done on the detection mechanism of leakage of domestic cooking gas at ambient conditions. MEMS-based interdigital sensors were fabricated on oxidized single crystal silicon surfaces by maskless photolithography technique. The electrochemical impedance analysis of these sensors was done to detect liquefied petroleum gas (LPG) with and without coated particles of tin oxide (SnO2) in form of thin layer.A thin-film of SnO2 was spin-coated on the sensing surface of the interdigital sensor to induce selectivity to LPG that consists of a 60/40 mixture of propane and butane respectively. The paper reports a novel strategy for gas detection under ambient temperature and humidity conditions. The response time of the coated sensor was encouraging and own a promising potential to the development of a complete efficient gas sensing system.

  3. Novel sensing approach for LPG leakage detection: Part I: Operating Mechanism and Preliminary Results

    KAUST Repository

    Mukhopadhyay, Subhas; Nag, Anindya; Zia, Asif; Li, Xie; Kosel, Jü rgen

    2015-01-01

    Gas sensing technology has been among the topical research work for quite some time. This paper showcases the research done on the detection mechanism of leakage of domestic cooking gas at ambient conditions. MEMS-based interdigital sensors were fabricated on oxidized single crystal silicon surfaces by maskless photolithography technique. The electrochemical impedance analysis of these sensors was done to detect liquefied petroleum gas (LPG) with and without coated particles of tin oxide (SnO2) in form of thin layer.A thin-film of SnO2 was spin-coated on the sensing surface of the interdigital sensor to induce selectivity to LPG that consists of a 60/40 mixture of propane and butane respectively. The paper reports a novel strategy for gas detection under ambient temperature and humidity conditions. The response time of the coated sensor was encouraging and own a promising potential to the development of a complete efficient gas sensing system.

  4. The worldwide market will not be short of LPG fuels

    International Nuclear Information System (INIS)

    Anon.

    1998-01-01

    This paper is a synthesis of an internal note of the French Butane and Propane Committee (CFBP) about the perspectives of the worldwide market of LPG fuels. The conclusion of this study is that the market will not be short of LPG, in particular the French market and the automotive fuels. The consumption of LPG fuels for vehicles in France is growing up rapidly (about 100% in 1997 with respect to 1996: 90000 t consumed in 1997 by 70000 vehicles) and the resource remains important and can reach 3 millions of tons per year. (J.S.)

  5. RANCANG BANGUN PROTOTYPE PENANGANAN DINI DAN PENDETEKSI KEBOCORAN LPG BERBASIS MIKROKONTROLER MELALUI SMS

    OpenAIRE

    Iksal, Iksal; Sumiati, Sumiati; Harizal, Harizal

    2017-01-01

    Masalah keamanan dalam pemakaian Gas LPG belakangan ini mendapat perhatian serius, banyak diberitakan terjadinya kebakaran akibat ledakan dari kebcoran Gas LPG. Mengingat mobilitas manusia semakin meningkat yang menuntut mereka tidak berada di dalam ruangan tempat penyimpanan Gas LPG untuk mengawasinya sepanjang waktu. Dibutuhkan sistem yang dapat memonitoring pemakaian Gas LPG secara realtime. Sehingga dapat meminimalisir tingkat kelalaian dalam terjadinya kebocoran Gas LPG.  Berdasarkan lat...

  6. Risk assessment of LPG automotive refuelling facilities

    Energy Technology Data Exchange (ETDEWEB)

    Melchers, R.E. [University of Newcastle, Newcastle (Australia). Dept. of Civil, Surveying and Enviromental Engineering; Feutrill, W.R. [Wesfarmers Kleenheat Gas Pty. Ltd., Perth (Australia)

    2001-12-01

    Quantified risk analysis (QRA) was used for the revision of regulatory separation distances associated with medium size liquefied petroleum gas (LPG) refuelling facilities used in automotive service (gas) stations. Typically these facilities consist of a 7.5 kl pressure vessel, pump, pipework, dispensing equipment and safety equipment. Multi-tank installations are relatively uncommon. This paper describes the hazard scenarios considered, the risk analysis procedure and the selection and application of data for initiating events and for rates of failure of mechanical components and of the pressure vessel. Human errors and intervention possibilities were also considered. Because of the inapplicability of established consequence models and the relatively small scale of the facilities, a number of tests were performed to estimate flame length, flame impingement effects, ignition probabilities and the effectiveness of screening devices. (author)

  7. Early structure of LPG partially premixed conically stabilized flames

    KAUST Repository

    Elbaz, Ayman M.

    2013-01-01

    This paper presents experimental investigation of LPG partially premixed turbulent flames stabilized within a conical nozzle burner under constant degree of partial premixing. The stability limits and mean flame structure are presented based

  8. LPG markets face upheaval as buyers press for change

    International Nuclear Information System (INIS)

    McDonald, Paul

    1999-01-01

    This article focuses on the system used for selling liquefied petroleum gas (LPG) where the sellers set the market price with Saudi Arabia dominating the market. The introduction and acceptance of a new method for setting the export price in relation to the spot price, the production of more LPG for export than forecast, the impact on the Saudi Arabian methyl tertiary butyl ether (MTBE) industry of California's banning MTBE additives to petrol,and the possibility of Asian buyers renegotiating the supply agreements are discussed. Details of Saudi Arabia's petrochemical plants planning to use LPG and world LPG production for 1998 are tabulated. The US market, and new systems for trading and pricing are considered. (UK)

  9. LPG as a Fuel for Diesel Engines-Experimental Investigations

    Science.gov (United States)

    Cristian Nutu, Nikolaos; Pana, Constantin; Negurescu, Niculae; Cernat, Alexandru; Mirica, Ionel

    2017-10-01

    The main objective of the paper is to reduce the pollutant emissions of a compression ignition engine, fuelling the engine with liquefied petroleum gas (LPG), aiming to maintain the energetic performances of the engine. To optimise the engine operation a corelation between the substitute ratio of the diesel fuel with LPG and the adjustments for the investigated regimens must be made in order to limit the maximum pressure and smoke level, knock and rough engine functioning, fuel consumption and the level of the pollutant emissions. The test bed situated in the Thermotechnics, Engines, Thermal Equipments and Refrigeration Instalations Department was adapted to be fuelled with liquefied petroleum gas. A conventional LPG fuelling instalation was adopted, consisting of a LPG tank, a vaporiser, conections between the tank and the vaporiser and a valve to adjust the gaseous fuel flow. Using the diesel-gas methode, in the intake manifold of the engine is injected LPG in gaseous aggregation state and the airr-LPG homogeneous mixture is ignited from the flame appeared in the diesel fuel sprays. To maintain the engine power at the same level like in the standard case of fuelling only with diesel fuel, for each investigated operate regimen the diesel fuel dose was reduced, being energetically substituted with LPG. The engine used for experimental investigations is a turbocharged truck diesel engine with a 10.34 dm3 displacement. The investigated working regimen was 40% load and 1750 rpm and the energetic substitute ratios of the diesel fuel with LPG was situated between [0-25%].

  10. Analysis of tank safety with propane-butane on LPG distribution station

    Directory of Open Access Journals (Sweden)

    Krzysiak Zbigniew

    2017-12-01

    Full Text Available An analysis of the risk of failure in the safety valve – tank with propane-butane (LPG system has been conducted. An uncontrolled outflow of liquid LPG, caused by a failure of the above mentioned system has been considered as a threat. The main research goal of the study is the hazardous analysis of propane-butane gas outflow for the safety valve – LPG tank system. The additional goal is the development of an useful method to fast identify the hazard of a mismatched safety valve. The results of the research analysis have confirmed that safety valves are basic protection of the installation (tank against failures that can lead to loss of life, material damage and further undesired costs of their unreliability. That is why a new, professional computer program has been created that allows for the selection of safety valves or for the verification of a safety valve selection in installations where any technical or technological changes have been made.

  11. Long-period fibre grating writing with a slit-apertured femtosecond laser beam (λ = 1026 nm)

    International Nuclear Information System (INIS)

    Dostovalov, A V; Wolf, A A; Babin, S A

    2015-01-01

    We report on long-period grating (LPG) writing in a standard telecom fibre, SMF-28e+, via refractive index modification by femtosecond pulses. A method is proposed for grating writing with a slit-apertured beam, which enables one to produce LPGs with reduced background losses and a resonance peak markedly stronger than that in the case of grating writing with a Gaussian beam. The method can be used to fabricate LPGs for use as spectral filters of fibre lasers and sensing elements of sensor systems. (fibre and integrated-optical structures)

  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. Fabrication of fiber optic long period gratings operating at the phase matching turning point using an amplitude mask

    Science.gov (United States)

    Hromadka, J.; Correia, R.; Korposh, S.

    2016-05-01

    A fast method for the fabrication of the long period gratings (LPG) optical fibres operating at or near the phase matching turning point (PMTP) with the period of 109.0, 109.5 and 110.0 μm based on an amplitude mask writing system is described. The proposed system allows fabricating 3 cm long LPG sensors operating at PMPT within 20 min that is approximately 8 times faster than point-by-point approach. The reproducibility of the fabrication process was thoroughly studied. The response of the fabricated LPGs to the external change of the refractive index was investigated using water and methanol.

  14. Metal-organic framework thin films on a surface of optical fibre long period grating for chemical sensing

    Science.gov (United States)

    Hromadka, J.; Tokay, B.; James, S.; Korposh, S.

    2017-04-01

    An optical fibre long period grating (LPG) modified with a thin film of HKUST-1, a material from metal organic framework (MOF) family, was employed for the detection of carbon dioxide. The sensing mechanism is based on the measurement of the change of the refractive index (RI) of the coating that is induced by the penetration of CO2 molecules into the HKUST-1 pores. The responses of the resonance bands in the transmission spectrum of an LPG modified with 40 layers of HKUST-1 upon exposure to carbon dioxide in mixture with nitrogen were investigated.

  15. LPG and NH3 Sensing Properties of SnO2 Thick Film Resistors Prepared by Screen Printing Technique

    Directory of Open Access Journals (Sweden)

    A. S. GARDE

    2010-11-01

    Full Text Available The gas sensing behavior of SnO2 thick film resistors deposited on alumina substrates has been investigated for LPG and NH3 gas. The standard screen printing technology was used to prepare the thick films. The films were fired at optimized temperature of 780 0C for 30 minutes. The material characterization was performed by XRD, SEM, FTIR, UV and EDAX for elemental analysis. IR spectroscopy analysis at 2949.26 cm-1 showed the peak assigned to the –Sn-H vibration due to the effect of hybridization i.e. sp3 and the sharp peak at 3734.31 cm-1 assigned to –Sn-OH stretching vibration due to hydrogen bonding. The variation of D.C electrical resistance of SnO2 film samples was measured in air as well as in LPG and NH3 gas atmosphere as a function of temperature. The SnO2 film samples show negative temperature coefficient of résistance. The SnO2 film samples showed the highest sensitivity to 600 ppm of LPG at 230 0C and NH3 at 370 0C. The effect of microstructure on sensitivity, response time and recovery time of the sensor in the presence of LPG and NH3 gases were studied and discussed.

  16. Highly sensitive fiber grating chemical sensors: An effective alternative to atomic absorption spectroscopy

    Science.gov (United States)

    Laxmeshwar, Lata. S.; Jadhav, Mangesh S.; Akki, Jyoti. F.; Raikar, Prasad; Kumar, Jitendra; prakash, Om; Raikar, U. S.

    2017-06-01

    Accuracy in quantitative determination of trace elements like Zinc, present in drinking water in ppm level, is a big challenge and optical fiber gratings as chemical sensors may provide a promising solution to overcome the same. This paper presents design of two simple chemical sensors based on the principle of shift in characteristic wavelength of gratings with change in their effective refractive index, to measure the concentration of Zinc in drinking water using etched short period grating (FBG) and Long period grating (LPG) respectively. Three samples of drinking water from different places have been examined for presence of Zinc. Further, the results obtained by our sensors have also been verified with the results obtained by a standard method, Atomic absorption spectroscopy (AAS). The whole experiment has been performed by fixing the fibers in a horizontal position with the sensor regions at the center of the fibers, making it less prone to disturbance and breaking. The sensitivity of LPG sensor is about 205 times that of the FBG sensor. A few advantages of Fiber grating sensors, besides their regular features, over AAS have also been discussed, that make our sensors potential alternatives for existing techniques in determination of trace elements in drinking water.

  17. LPG diesel dual fuel engine – A critical review

    Directory of Open Access Journals (Sweden)

    B. Ashok

    2015-06-01

    Full Text Available The engine, which uses both conventional diesel fuel and LPG fuel, is referred to as ‘LPG–diesel dual fuel engines’. LPG dual fuel engines are modified diesel engines which use primary fuel as LPG and secondary fuel as diesel. LPG dual fuel engines have a good thermal efficiency at high output but the performance is less during part load conditions due to the poor utilization of charges. This problem can be overcome by varying factors such as pilot fuel quantity, injection timing, composition of the gaseous fuel and intake charge conditions, for improving the performance, combustion and emissions of dual fuel engines. This article reviews about the research work done by the researchers in order to improve the performance, combustion and emission parameters of a LPG–diesel dual fuel engines. From the studies it is shown that the use of LPG in diesel engine is one of the capable methods to reduce the PM and NOx emissions but at same time at part load condition there is a drop in efficiency and power output with respect to diesel operation.

  18. 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.

  19. Poitiers and automotive LPG; Poitiers: la municipalite et le district croient au GPL carburant

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1999-04-01

    Looking for a reduction in its fuel expenses and a reduction in urban air pollution, Poitiers' local authorities ordered 15 LPG fuelled vehicles some 20 years ago. They ran solely with LPG. Today, some 115 vehicles, including two machines for floor cleaning, one for preparation of skating rings and a forklift, run on LPG. These last machines expected, all vehicles can run on LPG or gasoline. (authors)

  20. Recent developments with ALIBI, a model for site specific prediction of LPG tank BLEVE frequency

    Energy Technology Data Exchange (ETDEWEB)

    Goose, M.H. [Health and Safety Executive, Bootle (United Kingdom). Major Hazards Assessment Unit

    1995-12-31

    The concept behind the ALIBI model was first introduced to a technical audience in 1988 at the European Seminar on the Pressurised Storage of Flammable Liquids in London. Since that time it has been developed by SRD (now AEA Technology Consultancy Services) on behalf of HSE (MHAU). Although the structure of the model has remained largely unchanged, efforts have been made to refine the modelling within it. The main effort in refining the modelling has been with the response of LPG tanks to jet flame impingement, and this is described in the paper. (author)

  1. Enhanced refractive index sensor using a combination of a long period fiber grating and a small core singlemode fiber structure

    International Nuclear Information System (INIS)

    Wu, Qiang; Ma, Youqiao; Yang, Minwei; Semenova, Yuliya; Wang, Pengfei; Farrell, Gerald; Chan, Hai Ping; Yuan, Jinhui; Yan, Binbin; Yu, Chongxiu

    2013-01-01

    An enhanced refractive index (RI) sensor based on a combination of a long period fiber grating (LPG) and a small core singlemode fiber (SCSMF) structure is proposed and developed. Since the LPG and SCSMF transmission spectra experience a blue and a red shift respectively as the surrounding RI (SRI) increases, the sensitivity is improved by measuring the separation between the resonant wavelengths of the LPG and SCSMF structures. Experimental results show that the sensor has a sensitivity of 1028 nm/SRI unit in the SRI range from 1.422 to 1.429, which is higher than individual sensitivities of either structure alone used in the experiment. Experimental results agree well with simulation results. (paper)

  2. Reflection-type long period grating biosensor for the detection of drug resistant bacteria: The Opto-bacteria Project

    Science.gov (United States)

    Consales, M.; Quero, G.; Zuppolini, S.; Sansone, L.; Borriello, A.; Giordano, M.; Venturelli, A.; Cusano, A.

    2014-05-01

    We report on the development of a multilayer coated reflection-type long period fiber grating (LPG) biosensor, useful for the detection of antibiotic resistance bacteria. A standard LPG is first transformed in a more practical probe working in reflection mode, then it is coated by a primary layer of aPS and a secondary layer of PMMA in order to increase its surrounding refractive index sensitivity and at the same time provide the necessary conditions for a correct biofunctionalization. Standard linkage chemistry has been applied to anchor the bioreceptors on the probe surface. We show some preliminary results demonstrating the capability of our LPG biosensor to successfully monitor all the biological steps of the biomolecular experiments, including β-lactamase binding detection tests.

  3. Assessment of research and development (R and D) needs in LPG safety and environmental control

    Energy Technology Data Exchange (ETDEWEB)

    DeSteese, J.G.

    1982-05-01

    The report characterizes the LPG industry covering all operations from production to end use, reviews current knowledge of LPG release phenomenology, summarizes the status of current LPG release prevention and control methodology, and identifies any remaining safety and environmental problems and recommends R and D strategies that may mitigate these problems. (ACR)

  4. Risk comparison of LPG and petrol vehicles in public car parks

    NARCIS (Netherlands)

    Molag, M.; Steen, M. van der

    1998-01-01

    LPG is generally considered as a clean fuel for cars in comparison with petrol. Although from an environmentally point of view LPG may be favoured, a further introduction of the use of the fuel is hindered by legislative measures. In some countries cars running on LPG are not allowed to enter public

  5. PENGUJIAN MESIN DIESEL YANG DIMODIFIKASI MENJADI BERBAHAN BAKAN GAS LPG

    OpenAIRE

    Himsar Ambarita

    2017-01-01

    Pada penelitian ini dilakukan modifikasi pada sebuah mesin diesel yang awalnya digerakkan dengan menggunakan bahan bakar diesel menjadi berbahan bakar LPG. Telah dirancang suatu alat uji yang menggunakan sebuah mesin diesel silinder tunggal dengan daya 2,5 kW dan 2,8 kW pada putaran mesin 3000 dan 3600 rpm. Kinerja mesin diesel kecil telah diuji dalam dua bahan bakar berbeda yaitu solar dan LPG. Pada penggunaan bahan bakar solar tidak ada perubahan yang dilakukan pada mesin disel. Pada penggu...

  6. Experimental analysis on a spark ignition petrol engine fuelled with LPG (liquefied petroleum gas)

    International Nuclear Information System (INIS)

    Masi, Massimo

    2012-01-01

    The use of LPG (liquefied petroleum gas) as alternative fuel to petrol is common practise in spark ignition engines. While the main driving force to the use of LPG still remains the low cost for the end user, its favourable pollutant emissions, in particular carbon dioxide, will in the middle term probably increase interest in LPG as an IC engine fuel. In addition, there are both theoretical and technical reasons to consider LPG as an attractive fuel also in terms of engine performance. Despite the continuously increasing stock production of dual-fuel (petrol–LPG) passenger car models, doubts still exist about both real engine performance in LPG operation and the reliability of the dual-fuel feeding system. This paper deals with the theoretical advantages of using LPG as fuel for SI engines. Brake performance tests of a passenger car engine fed with petrol and LPG are analysed and compared. The stock engine has been equipped with a “third-generation” standard kit for dual-fuel operation. The performance reductions in LPG operation are discussed in both steady state and transient condition. The results of some modifications to the set-up of both the petrol and LPG metering devices, designed for a better justification of the measured performance, are also presented. -- Highlights: ► Experimental research on the actual performances of an SI engine fed with petrol and gaseous LPG. ► Theoretical advantages and drawbacks of fuelling SI ICE’s with LPG. ► Brake performance analysis shows a noticeable gap between LPG and petrol operation. ► Local measurements confirm that the thermodynamic operation of the evaporator-pressure reducer device is crucial for the engine performance. ► The performance of the up-to-date kit for petrol–LPG dual-fuel operation is greatly affected by the settings of the mechanical components of the LPG evaporator device.

  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. Manufacturing a Long-Period Grating with Periodic Thermal Diffusion Technology on High-NA Fiber and Its Application as a High-Temperature Sensor.

    Science.gov (United States)

    Shen, Xiang; Dai, Bin; Xing, Yingbin; Yang, Luyun; Li, Haiqing; Li, Jinyan; Peng, Jingang

    2018-05-08

    We demonstrated a kind of long-period fiber grating (LPFG), which is manufactured with a thermal diffusion treatment. The LPFG was inscribed on an ultrahigh-numerical-aperture (UHNA) fiber, highly doped with Ge and P, which was able to easily diffuse at high temperatures within a few seconds. We analyzed how the elements diffused at a high temperature over 1300 °C in the UHNA fiber. Then we developed a periodically heated technology with a CO₂ laser, which was able to cause the diffusion of the elements to constitute the modulations of an LPFG. With this technology, there is little damage to the outer structure of the fiber, which is different from the traditional LPFG, as it is periodically tapered. Since the LPFG itself was manufactured under high temperature, it can withstand higher temperatures than traditional LPFGs. Furthermore, the LPFG presents a higher sensitivity to high temperature due to the large amount of Ge doping, which is approximately 100 pm/°C. In addition, the LPFG shows insensitivity to the changing of the environment’s refractive index and strain.

  9. 33 CFR 165.103 - Safety and Security Zones; LPG Vessel Transits in Portland, Maine, Captain of the Port Zone...

    Science.gov (United States)

    2010-07-01

    ... within a 500-yard radius of any Liquefied Petroleum Gas (LPG) vessel while it is moored at the LPG... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety and Security Zones; LPG... and Security Zones; LPG Vessel Transits in Portland, Maine, Captain of the Port Zone, Portsmouth...

  10. Fire safety of LPG in marine transportation. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Martinsen, W.E.; Johnson, D.W.; Welker, J.R.

    1980-06-01

    This report contains an analytical examination of cargo spill and fire hazard potential associated with the marine handling of liquefied petroleum gas (LPG) as cargo. Principal emphasis was on cargo transfer operations for ships unloading at receiving terminals, and barges loading or unloading at a terminal. Major safety systems, including emergency shutdown systems, hazard detection systems, and fire extinguishment and control systems were included in the analysis. Spill probabilities were obtained from fault tree analyses utilizing composite LPG tank ship and barge designs. Failure rates for hardware in the analyses were generally taken from historical data on similar generic classes of hardware, there being very little historical data on the specific items involved. Potential consequences of cargo spills of various sizes are discussed and compared to actual LPG vapor cloud incidents. The usefulness of hazard mitigation systems (particularly dry chemical fire extinguishers and water spray systems) in controlling the hazards posed by LPG spills and spill fires is also discussed. The analysis estimates the probability of fatality for a terminal operator is about 10/sup -6/ to 10/sup -5/ per cargo transfer operation. The probability of fatality for the general public is substantially less.

  11. Conformity checking of LPG Transportation Trucks by Modelling and Simulation

    Directory of Open Access Journals (Sweden)

    Gallab Maryam

    2017-01-01

    Full Text Available LPG Loading /unloading site is considered as a dangerous environment of significant risk, especially during LPG transfer operations. These risks may cause catastrophic dangers such as BLEVE (Boiling Liquid Expanding Vapour Explosion, UVCE (Unconfined Vapour Cloud Explosion, etc. The site consists of a tank (RST containing LPG and threetransfer posts. Two posts allow loading of small carrier tankers 6 tons. The other one transfer post transfer LPG contained injumbo tankers 20 tons inside the tank. The industrial site at risks chooses to demonstrate the need for a modelling-simulation approach. The aim is to check first compliance and authorization of the truck when it enters the site for loading /unloading, to verify the authorization to make the transfer, and then, to identify the driver and his training to ensure that the transfer operations are going to take place without incident. Sometimes, it may happen that Consignment Operator (CO is busy orabsent and thus the driver operates alone without being authorized, in this case the site risks a loss of control due to a lack of resources. The modelling-simulation will be done using multi-agent systems that will present the drivers, trucks, PO and loading unloading posts as agents in order to have a model facilitating this checking.

  12. 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...

  13. Volatile Organic Compounds Sensing Using Optical Fibre Long Period Grating with Mesoporous Nano-Scale Coating

    Directory of Open Access Journals (Sweden)

    Jiri Hromadka

    2017-02-01

    Full Text Available A long period grating (LPG modified with a mesoporous film infused with a calixarene as a functional compound was employed for the detection of individual volatile organic compounds (VOCs and their mixtures. The mesoporous film consisted of an inorganic part, SiO2 nanoparticles (NPs, along with an organic moiety of poly(allylamine hydrochloride polycation PAH, which was finally infused with the functional compound, p-sulphanato calix[4]arene (CA[4] or p-sulphanato calix[8]arene (CA[8]. The LPG sensor was designed to operate at the phase matching turning point to provide the highest sensitivity. The sensing mechanism is based on the measurement of the refractive index (RI change induced by a complex of the VOCs with calixarene. The LPG, modified with a coating of 5 cycles of (SiO2 NPs/PAH and infused with CA[4] or CA[8], was exposed to chloroform, benzene, toluene and acetone vapours. The British Standards test of the VOCs emissions from material (BS EN ISO 16000-9:2006 was used to test the LPG sensor performance.

  14. Detection of premature browning in ground beef with an integrated optical-fibre based sensor using reflection spectroscopy and fibre Bragg grating technology

    International Nuclear Information System (INIS)

    O'Farrell, M; Sheridan, C; Lewis, E

    2007-01-01

    This paper reports on an optical fibre based sensor system to detect the occurrence of premature browning in ground beef. Premature browning (PMB) occurs when, at a temperature below the pasteurisation temperature of 71 deg. C, there are no traces of pink meat left in the patty. PMB is more frequent if poorer quality beef or beef that has been stored under imperfect conditions. The experimental work pertaining to this paper involved cooking fresh meat and meat that has been stored in a freezer for, 1 week, 1 month and 3 months and recording the reflected spectra and temperature at the core of the product, during the cooking process, in order to develop a classifier based on the spectral response and using a Self-Organising Map (SOM) to classify the patties into one of four categories, based on their colour. Further tests were also carried out on developing an all-optical fibre sensor for measuring both the temperature and colour in a single integrated probe. The integrated probe contains two different sensor concepts, one to monitor temperature, based on Fibre Bragg Grating (FBG) technology and a second for meat quality, based on reflection spectroscopy in the visible wavelength range

  15. 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.

  16. A simulation for predicting potential cooling effect on LPG-fuelled vehicles

    Science.gov (United States)

    Setiyo, M.; Soeparman, S.; Wahyudi, S.; Hamidi, N.

    2016-03-01

    Liquefied Petroleum Gas vehicles (LPG Vehicles) provide a potential cooling effect about 430 kJ/kg LPG consumption. This cooling effect is obtained from the LPG phase change from liquid to vapor in the vaporizer. In the existing system, energy to evaporate LPG is obtained from the coolant which is circulated around the vaporizer. One advantage is that the LPG (70/30 propane / butane) when expanded from 8 bar to at 1.2 bar, the temperature is less than -25 °C. These conditions provide opportunities to evaporate LPG with ambient air flow, then produce a cooling effect for cooling car's cabin. In this study, some LPG mix was investigated to determine the optimum condition. A simulation was carried out to estimate potential cooling effects of 2000 cc engine from 1000 rpm to 6000 rpm. In this case, the mass flow rate of LPG is a function of fuel consumption. The simulation result shows that the LPG (70/30 propane/butane) provide the greatest cooling effect compared with other mixtures. In conclusion, the 2000 cc engine fueled LPG at 3000 rpm provides potential cooling effect more than 1.3 kW, despite in the low engine speed (1000 rpm) only provides about 0.5 kW.

  17. 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

  18. 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...

  19. Influence of cooled exhaust gas recirculation on performance, emissions and combustion characteristics of LPG fuelled lean burn SI engine

    Science.gov (United States)

    Ravi, K.; Pradeep Bhasker, J.; Alexander, Jim; Porpatham, E.

    2017-11-01

    On fuel perspective, Liquefied Petroleum Gas (LPG) provides cleaner emissions and also facilitates lean burn signifying less fuel consumption and emissions. Lean burn technology can attain better efficiencies and lesser combustion temperatures but this temperature is quite sufficient to facilitate formation of nitrogen oxide (NOx). Exhaust Gas Recirculation (EGR) for NOx reduction has been considered allover but extremely little literatures exist on the consequence of EGR on lean burn LPG fuelled spark ignition (SI) engine. The following research is carried out to find the optimal rate of EGR addition to reduce NOx emissions without settling on performance and combustion characteristics. A single cylinder diesel engine is altered to operate as LPG fuelled SI engine at a compression ratio of 10.5:1 and arrangements to provide different ratios of cooled EGR in the intake manifold. Investigations are done to arrive at optimum ratio of the EGR to reduce emissions without compromising on performance. Significant reductions in NOx emissions alongside HC and CO emissions were seen. Higher percentages of EGR further diluted the charge and lead to improper combustion and thus increased hydrocarbon emissions. Cooled EGR reduced the peak in-cylinder temperature which reduced NOx emissions but lead to misfire at lower lean limits.

  20. Selective vancomycin detection using optical fibre long period gratings functionalised with molecularly imprinted polymer nanoparticles.

    Science.gov (United States)

    Korposh, Sergiy; Chianella, Iva; Guerreiro, Antonio; Caygill, Sarah; Piletsky, Sergey; James, Stephen W; Tatam, Ralph P

    2014-05-07

    An optical fibre long period grating (LPG) sensor modified with molecularly imprinted polymer nanoparticles (nanoMIPs) for the specific detection of antibiotics is presented. The operation of the sensor is based on the measurement of changes in refractive index induced by the interaction of nanoMIPs deposited onto the cladding of the LPG with free vancomycin (VA). The binding of nanoMIPs to vancomycin was characterised by a binding constant of 4.3 ± 0.1 × 10(-8) M. The lowest concentration of analyte measured by the fibre sensor was 10 nM. In addition, the sensor exhibited selectivity, as much smaller responses were obtained for high concentrations (∼700 μM) of other commonly prescribed antibiotics such as amoxicillin, bleomycin and gentamicin. In addition, the response of the sensor was characterised in a complex matrix, porcine plasma, spiked with 10 μM of VA.

  1. Sensing Characteristics of Side-Hole Fiber-Based Long-Period Grating

    Directory of Open Access Journals (Sweden)

    Yi Xin

    2013-01-01

    Full Text Available Long-period gratings (LPGs have been fabricated in a side-hole fiber (SHF by using a pulsed CO2 laser. Sensing characteristics of this SHF-LPG to temperature surrounding refractive index and bend have been investigated. Experimental results show that resonant wavelength of the SHF-LPG has a blue shift with temperature with sensitivity of −0.11 nm/°C, a blue shift with increasing sensitivity with surrounding refractive index ranging from 1.335 to 1.44 (the maximum sensitivity is achieved when the surrounding refractive index reaches the effective index of the fiber cladding, and a red shift with bend-direction-dependent sensitivity up to 9.36 nm/m−1.

  2. Thermal Response Analyses of Spherical LPG Storage Tank

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hsijen.; Lin, Mannhsing.; Chao, Fuyuan

    1999-02-01

    Liquefied petroleum gas (LPG) is a very important fuel and chemical feed stock as well; however, the hydrocarbon has been involved in many major fires and explosions. One of these accidents is boiling-liquid, expanding-vapor explosion (BLEVE). It is a phenomenon that results from the sudden release form confinement of a liquid at a temperature above its atmospheric-pressure boiling point. The sudden decrease in pressure results in the explosive vaporization of a fraction of the liquid and a cloud of vapor and mist with the accompanying blast effects. Most BLEVEs involve flammable liquids, and most BELEVE releases are ignited by a surrounding fire and result in a fireball. The primary objective of this paper is to develop a computer model in order to determine the thermal response of a spherical LPG tank involved in fire engulfment accidents. The assessment of the safety spacing between tanks was also discussed. (author)

  3. LNG and LPG total involvement of Pullman Kellogg

    Energy Technology Data Exchange (ETDEWEB)

    1978-10-01

    A discussion of Pullman Kellogg activity covers a new LNG terminal in Belgium; construction of LNG 2 for Sonatrach in Algeria; an LPG recovery system in Kuwait; the Trunkline Gas Co. LNG project at Lake Charles, La.; and the Cove Point, Md., facility for Columbia Gas System Inc. and Consolidated Natural Gas Co., which will be capable of mooring two 750,000 bbl LNG tankers simultaneously.

  4. Designing a Prototype LPG Injection Electronic Control Unit for a Carburetted Gasoline Engine

    Directory of Open Access Journals (Sweden)

    Barış ERKUŞ

    2015-07-01

    Full Text Available In this study, the originally carburetted gasoline engine was converted to gas-phase liquefied petroleum gas (LPG injection engine by using an after market LPG conversion kit's components except the electronic control unit (ECU. Instead of after market LPG injection ECU, the ECU which was designed considering the effects of  electromagnetic interference (EMI, was used for controlling injection. The designed ECU was tested in terms of EMI while the engine was being run and it was detected that the EMI noises could be suppressed as possible by taken measures. Designed ECU was used in performance tests at different engine conditions and the results obtained with LPG injection were compared with the results obtained with LPG carburetion. According to the performance test results, LPG injection ECU designed in this study could help to achieve low exhaust emissions and high engine performance.  

  5. 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

  6. Far East LPG sales will grow faster than in West

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    LPG sales through 2010 in regions east of the Suez Canal (East of Suez) will grow at more than twice those in regions west of the canal. East-of-Suez sales will grow at more than 4.0%/year, compared to slightly less than 2.0%/year growth in sales West of Suez. East-of-Suez sales will reach 92 million tons/year (tpy) by 2010, accounting for 39% of the worldwide total. This share was 31% in1995 and only 27% in 1990. LPG sales worldwide will reach 192 million tons in 2000 and 243 million tpy by 2010. In 1995, they were 163 million tons. These are some of the major conclusions of a recent study by Frank R. Spadine, Christine Kozar, and Rudy Clark of New York City-based consultant Poten and Partners Inc. Details of the study are in the fall report ''World Trade in LPG 1990--2010''. This paper discusses demand segments, seaborne balance, Western sources, largest trading region, North American supplies, and other supplies

  7. Analisis Pengaruh Konsentrasi Gas LPG Menggunakan Sensor TGS 2610 Berbasis Mikrokontroler AVR ATMega8535

    OpenAIRE

    Nurhalimah

    2011-01-01

    Telah dilakukan analisis kuantitatif gas dalam LPG. Penelitian ini dilakukan untuk mengukur konsentrasi gas LPG terhadap sensor. Metoda yang digunakan untuk mengukur konsentrasi gas LPG yaitu sensor gas semikonduktor jenis TGS 2610 keluaran Figaro yang digunakan untuk mendeteksi keberadaan gas. Sementara yang menjadi pusat pengendalian dari seluruh alat yang dirancang digunakan mikrokontroler AVR ATMega8535. Selain itu sistem yang dirancang dilengkapi LCD sebagai tampilan nilai konsentrasi ga...

  8. Deteksi Kebocoran Gas LPG Menggunakan Detektor Arduino dengan Algoritma Fuzzy Logic Mandani

    OpenAIRE

    Hakim, Lukman; Yonatan, Vidi

    2017-01-01

    Bencana kebakaran yang diakibatkan oleh kebocoran gas LPG (Liquid  Petroleum   Gas) mengalami kenaikan setiap tahun dari tahun 2011 sampai 2015 diantaranya 17% diakibatkan oleh kebocoran gas. Penggunaan detektor kebocoran gas LPG menggunakan arduino yang dilengkapi sensor gas dan suhu memberikan kemudahan untuk deteksi secara awal terjadinya kebocoran dan kebakaran. Perancangan detektor kebocoran gas LPG menggunakan algoritma fuzzy logic mandani, dilengkapi dengan informasi mel...

  9. Deteksi Kebocoran Gas LPG Menggunakan Detektor Arduino dengan Algoritma Fuzzy Logic Mandani

    OpenAIRE

    Lukman Hakim; Vidi Yonatan

    2017-01-01

    Bencana kebakaran yang diakibatkan oleh kebocoran gas LPG (Liquid  Petroleum   Gas) mengalami kenaikan setiap tahun dari tahun 2011 sampai 2015 diantaranya 17% diakibatkan oleh kebocoran gas. Penggunaan detektor kebocoran gas LPG menggunakan arduino yang dilengkapi sensor gas dan suhu memberikan kemudahan untuk deteksi secara awal terjadinya kebocoran dan kebakaran. Perancangan detektor kebocoran gas LPG menggunakan algoritma fuzzy logic mandani, dilengkapi dengan informasi melalui Short Mess...

  10. Spark Ignition LPG for Hydrogen Gas Combustion the Reduction Furnace ME-11 Process

    International Nuclear Information System (INIS)

    Achmad Suntoro

    2007-01-01

    Reverse engineering method for automatic spark-ignition system of LPG to burn hydrogen gaseous in the reducing process of ME-11 furnace has been successfully implemented using local materials. A qualitative study to the initial behaviour of the LPG flame system has created an idea by modification to install an automatic spark-ignition of the LPG on the reducing furnace ME-11. The automatic spark-ignition system has been tested and proved working well. (author)

  11. 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.

  12. Kecamatan Tampan oleh Dinas Perindustrian dan Perdagangan Kota Pekanbaru (Studi Kasus: Pangkalan Lpg 3 Kg)

    OpenAIRE

    Faisal, Andini; Yuliani, Febri

    2015-01-01

    LPG 3 kg has become a very important requirement. It can be seen from the demand for LPG 3 kg is increasing every year, both in use for households or for the development of micro enterprises. The purpose of this research was to determine how the LPG 3 kg distribution control in the Kelurahan Sidomulyo Barat Kecamatan Tampan by the Department of Industry and Trade of Pekanbaru City (case study: Sub Distributor LPG 3 kg) and to determine the factors that affect the control in the distribution o...

  13. Asia, North America lead way in growth of NGL, LPG trade

    International Nuclear Information System (INIS)

    Otto, K.; Gist, R.; Whitley, C.; Haun, R.

    1998-01-01

    Recent analyses of world NGL trade indicate that important changes in LPG supply and demand are under way in Asia and North America. LPG markets in the 1990s reflect a rapidly shifting balance between East-of-Suez and West-of-Suez markets. This shift has increased concern about availability of future LPG supplies for Asia. The paper discusses world developments, East versus West of Suez, end uses and supplies in Asia, Canadian ethane, propane, butane, and natural gasoline, Mexican ethane, LPG, and natural gasoline, US ethane, propane, butanes, and iso-C 4 and C 5

  14. A forum on LPG vehicles and leasing; Un forum sur les vehicules GPL et la LLD

    Energy Technology Data Exchange (ETDEWEB)

    Fridman, G.

    1999-04-01

    As a specialist of vehicle leasing, Axus France cooperated with Arthur Andersen, Butagaz and Volvo to promote the LPG solution to managers. Axus France offers with LPG vehicles leasing a range of tailor made products and services. Thus, the company estimates that LPG economics applied through vehicle leasing are not sufficiently large from Diesel (its calculation gives only 2 %) on some utilizations. This is why Axus offers an extra incitement to its customers, by keeping the financial risk linked to the LPG vehicle resale. (authors)

  15. 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.

  16. Simultaneous measurement of refractive index and temperature based on intensity demodulation using matching grating method.

    Science.gov (United States)

    Qi, Liang; Zhao, Chun-Liu; Kang, Juan; Jin, Yongxing; Wang, Jianfeng; Ye, Manping; Jin, Shangzhong

    2013-07-01

    A solution refractive index (SRI) and temperature simultaneous measurement sensor with intensity-demodulation system based on matching grating method were demonstrated. Long period grating written in a photonic crystal fiber (LPG-PCF), provides temperature stable and wavelength dependent optical intensity transmission. The reflective peaks of two fiber Bragg gratings (FBGs), one of which is etched then sensitive to both SRI and temperature, another (FBG2) is only sensitive to temperature, were located in the same linear range of the LPG-PCF's transmission spectrum. An identical FBG with FBG2 was chosen as a matching FBG. When environments (SRI and temperature) change, the wavelength shifts of the FBGs are translated effectively to the reflection intensity changes. By monitoring output lights of unmatching and matching paths, the SRI and temperature were deduced by a signal processing unit. Experimental results show that the simultaneous refractive index and temperature measurement system work well. The proposed sensor system is compact and suitable for in situ applications at lower cost.

  17. 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.

  18. 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.

  19. Sensing Features of Long Period Gratings in Hollow Core Fibers

    Directory of Open Access Journals (Sweden)

    Agostino Iadicicco

    2015-04-01

    Full Text Available We report on the investigation of the sensing features of the Long-Period fiber Gratings (LPGs fabricated in hollow core photonic crystal fibers (HC-PCFs by the pressure assisted Electric Arc Discharge (EAD technique. In particular, the characterization of the LPG in terms of shift in resonant wavelengths and changes in attenuation band depth to the environmental parameters: strain, temperature, curvature, refractive index and pressure is presented. The achieved results show that LPGs in HC-PCFs represent a novel high performance sensing platform for measurements of different physical parameters including strain, temperature and, especially, for measurements of environmental pressure. The pressure sensitivity enhancement is about four times greater if we compare LPGs in HC and standard fibers. Moreover, differently from LPGs in standard fibers, these LPGs realized in innovative fibers, i.e., the HC-PCFs, are not sensitive to surrounding refractive index.

  20. Long-period gratings in photonic crystal fibers operating near the phase-matching turning point for evanescent chemical and biochemical sensing

    Science.gov (United States)

    Kanka, Jiri

    2012-06-01

    Fiber-optic long-period grating (LPG) operating near the dispersion turning point in its phase matching curve (PMC), referred to as a Turn Around Point (TAP) LPG, is known to be extremely sensitive to external parameters. Moreover, in a TAP LPG the phase matching condition can be almost satisfied over large spectral range, yielding a broadband LPG operation. TAP LPGs have been investigated, namely for use as broadband mode convertors and biosensors. So far TAP LPGs have been realized in specially designed or post-processed conventional fibers, not yet in PCFs, which allow a great degree of freedom in engineering the fiber's dispersion properties through the control of the PCF structural parameters. We have developed the design optimization technique for TAP PCF LPGs employing the finite element method for PCF modal analysis in a combination with the Nelder-Mead simplex method for minimizing the objective function based on target-specific PCF properties. Using this tool we have designed TAP PCF LPGs for specified wavelength ranges and refractive indices of medium in the air holes. Possible TAP PCF-LPG operational regimes - dual-resonance, broadband mode conversion and transmitted intensity-based operation - will be demonstrated numerically. Potential and limitations of TAP PCF-LPGs for evanescent chemical and biochemical sensing will be assessed.

  1. Fuel switching from wood to LPG can benefit the environment

    International Nuclear Information System (INIS)

    Nautiyal, Sunil; Kaechele, Harald

    2008-01-01

    The Himalaya in India is one of the world's biodiversity hotspots. Various scientific studies have reported and proven that many factors are responsible for the tremendous decline of the Himalayan forests. Extraction of wood biomass from the forests for fuel is one of the factors, as rural households rely entirely on this for their domestic energy. Efforts continue for both conservation and development of the Himalayan forests and landscape. It has been reported that people are still looking for more viable solutions that could help them to improve their lifestyle as well as facilitate ecosystem conservation and preservation of existing biodiversity. In this direction, we have documented the potential of the introduction of liquefied petroleum gas (LPG), which is one of the solutions that have been offered to the local people as a substitute for woodfuel to help meet their domestic energy demand. The results of the current study found dramatic change in per capita woodfuel consumption in the last two decades in the villages where people are using LPG. The outcome showed that woodfuel consumption had been about 475 kg per capita per year in the region, but after introduction of LPG, this was reduced to 285 kg per capita per year in 1990-1995, and was further reduced to 46 kg per capita per year in 2000-2005. Besides improving the living conditions of the local people, this transformation has had great environmental consequences. Empirical evidence shows that this new paradigm shift is having positive external effects on the surrounding forests. Consequently, we have observed a high density of tree saplings and seedlings in adjacent forests, which serves as an assessment indicator of forest health. With the help of the current study, we propose that when thinking about a top-down approach to conservation, better solutions, which are often ignored, should be offered to local people

  2. LPG Maruziyeti Sonucu Ölüm Olgu Sunumu

    Directory of Open Access Journals (Sweden)

    Ayşe Kurtuluş

    2009-12-01

    Full Text Available LPG (liquefied petrol gases- sıvılaştırılmış petrol gazları, basınç altında sıvı hale getirilmiş hafif alifatik hidrokarbon olan bütan (C4H10 ve propan (CjHg karışımından oluşan renksiz ve hafif bir kokuya sahip bir gazdır. LPG kaynaklı ölümler genellikle kazaya bağlı olarak karşımıza çıkmakta ve intihar daha seyrek görülmektedir. Bütan ve propana bağlı ölümün asfiksi, vagal inhibisyon, respiratuar depresyon ve aritmiler olmak üzere dört mekanizma ile meydana gelebileceği belirtilmektedir. Bu çalışmada, vücudunun tamamını battaniye ile örtüp, açık mutfak tüpünden uzanan hortumun ucunu battaniyenin altına sokarak özel düzenek hazırlayan ve bu düzenekle yatağında intihar eden 64 yaşmda bir erkek olgu sunulmuştur. Seyrek görülen bu olguya ait bulgular, literatür eşliğinde tartışılmıştır. Anahtar kelimeler:LPG, bütan, propan, intihar

  3. Pengaruh Perubahan Saat Penyalaan (Ignition Timing) Terhadap Prestasi Mesin Pada Sepeda Motor 4 Langkah Dengan Bahan Bakar Lpg

    OpenAIRE

    Yunianto, Bambang

    2010-01-01

    Bahan bakar LPG merupakan bahan bakar gas yang ramah lingkungan, sehingga dapat dijadikan bahan bakar alternatif selain bahan bakar bensin Performa Mesin bensin yang dioperasikan dengan menggunakan bahan bakar gas LPG mengalami penurunan. Penurunan ini terjadi dikarenakan karakteristik sifat bahan bakar bensin berbeda dengan LPG. Hal ini dapat diatasi dengan mengatur saat penyalaan sehingga lebih sesuai dengan karakteristik gas LPG. Dari hasil pengujian diperoleh bahwa dengan pengaturan saat ...

  4. Energy poverty reduction by fuel switching. Impact evaluation of the LPG conversion program in Indonesia

    NARCIS (Netherlands)

    Andadari, R.K.; Mulder, P.; Rietveld, P.

    2014-01-01

    In low- and middle-income countries, Liquefied Petroleum Gas (LPG) can be an attractive alternative to the widespread use of traditional kerosene. Not only is LPG a relatively clean, safe and cost-effective fuel for households, its large-scale adoption also reduces the heavy burden of kerosene

  5. 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.

  6. NUMERICAL STUDY ON COOLING EFFECT POTENTIAL FROM VAPORIZER DEVICE OF LPG VEHICLE

    Directory of Open Access Journals (Sweden)

    MUJI SETIYO

    2017-07-01

    Full Text Available Over fuel consumption and increased exhaust gas due to the A/C system have become a serious problem. On the other hand, the LPG-fueled vehicle provides potential cooling from LPG phase changes in the vaporizer. Therefore, this article presents the potential cooling effect calculation from 1998 cm3 spark ignition (SI engine. A numerical study is used to calculate the potential heat absorption of latent and sensible heat transfer during LPG is expanded in the vaporizer. Various LPG compositions are also simulated through the engine speed range from 1000 to 6000 rpm. The result shows that the 1998 cm3 engine capable of generating the potential cooling effect of about 1.0 kW at 1000 rpm and a maximum of up to 1.8 kW at 5600 rpm. The potential cooling effects from the LPG vaporizer contributes about 26% to the A/C system works on eco-driving condition.

  7. Modelling the pressurization induced by solar radiation on above ground installations of LPG pipeline systems

    Science.gov (United States)

    Leporini, M.; Terenzi, A.; Marchetti, B.; Giacchetta, G.; Polonara, F.; Corvaro, F.; Cocci Grifoni, R.

    2017-11-01

    Pipelining Liquefied Petroleum Gas (LPG) is a mode of LPG transportation more environmentally-friendly than others due to the lower energy consumption and exhaust emissions. Worldwide, there are over 20000 kilometers of LPG pipelines. There are a number of codes that industry follows for the design, fabrication, construction and operation of liquid LPG pipelines. However, no standards exist to modelling particular critical phenomena which can occur on these lines due to external environmental conditions like the solar radiation pressurization. In fact, the solar radiation can expose above ground pipeline sections at pressure values above the maximum Design Pressure with resulting risks and problems. The present work presents an innovative practice suitable for the Oil & Gas industry to modelling the pressurization induced by the solar radiation on above ground LPG pipeline sections with the application to a real case.

  8. Energy poverty reduction by fuel switching. Impact evaluation of the LPG conversion program in Indonesia

    International Nuclear Information System (INIS)

    Andadari, Roos Kities; Mulder, Peter; Rietveld, Piet

    2014-01-01

    In low- and middle-income countries, Liquefied Petroleum Gas (LPG) can be an attractive alternative to the widespread use of traditional kerosene. Not only is LPG a relatively clean, safe and cost-effective fuel for households, its large-scale adoption also reduces the heavy burden of kerosene consumption subsidies on government budgets. Against this background, we evaluate the impact of a large government program to substitute LPG for kerosene in Indonesia. Using a household survey across urban, suburban and rural regions we find that this program was very effective in causing a large scale shift from kerosene to LPG. This shift was positively influenced by level of education, household size and household income. Contradicting the energy-ladder model, the LPG program, reinforced by an increase in the price of kerosene, led to increased stacking of fuels, including increasing consumption of both electricity and traditional biomass. In addition, our analysis shows that the LPG program failed to substantially reduce the overall number of energy-poor people, but it has been effective in alleviating extreme energy-poverty. Finally, we find that medium and higher income households in suburban areas benefitted most from the LPG program. - Highlights: • Impact evaluation of a government program to substitute LPG for kerosene in Indonesia. • The program caused a large scale shift from kerosene to LPG. • Contradicting the energy-ladder model, the program led to increased stacking of fuels. • The program did not substantially reduce overall energy poverty, but alleviated extreme energy-poverty. • Medium and higher income households in suburban areas benefitted most from the LPG program

  9. Design and Performance of LPG Fuel Mixer for Dual Fuel Diesel Engine

    Science.gov (United States)

    Desrial; Saputro, W.; Garcia, P. P.

    2018-05-01

    Small horizontal diesel engines are commonly used for agricultural machinery, however, availability of diesel fuel become one of big problems especially in remote area. Conversely, in line with government policy for conversion of kerosene into LPG for cooking, then LPG become more popular and available even in remote area. Therefore, LPG is potential fuel to replace the shortage of diesel fuel for operating diesel engine in remote area. The purpose of this study was to design mixing device for using dual fuel i.e. LPG and diesel fuel and evaluate its performance accordingly. Simulation by using CFD was done in order to analyze mixture characteristics of LPG in air intake manifold. The performance test was done by varying the amount of LPG injected in intake air at 20%, 25%, 30%, 35%, until 40%, respectively. Result of CFD contour simulation showed the best combination when mixing 30% LPG into the intake air. Performance test of this research revealed that mixing LPG in air intake can reduce the diesel fuel consumption about 0.7 l/hour (without load) and 1.14 l/hour (with load). Diesel engine revolution increases almost 300 rpm faster than when using diesel fuel only. Based on economic analysis, using the fuel combination (diesel fuel – LPG) is not recommended in the area near SPBU where the price of diesel fuel is standard. However, using the fuel combination LPG-diesel fuel is highly recommended in the remote areas in Indonesia where price of diesel fuel is comparatively expensive which will provide cheaper total fuel cost for diesel engine operation.

  10. 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...

  11. Performance evaluation of reverse logistics: A case of LPG agency

    Directory of Open Access Journals (Sweden)

    Kottala Sri Yogi

    2015-12-01

    Full Text Available Majority of the manufacturing companies are incorporating the practice of reverse logistics in their value chain. In manufacturing processes, the concept of reverse logistics plays a vital role in enhancing the company’s profit margin for sustainable business growth. For every company, there is a need of performance measurement system to be established as successful business tool. However to predict better results, how smartly the inputs for the transformation or business process are being effectively and efficiently used has to be analyzed. Drawing attention to the growing popularity in adapting the best practices of reverse logistics among different manufacturing industries, this paper aims to build a methodology in order to measure the performance of liquefied petroleum gas (LPG agencies. To do so, it has undertaken the Asian emerging market-India as a case study and improved the understanding of performance measurement in reverse logistics to refilling LPG cylinders. Further, it has suggested a framework affecting the implementation of reverse logistics activities and its network.

  12. Feasibility study for bottled gas and LPG in Poland

    International Nuclear Information System (INIS)

    1992-04-01

    With a total population of ca. 40 million, Poland has an annual consumption of liquefied petroleum gas amounting to 180,000 tons, used by 2.5 million bottled-gas consumers. The consumer pattern is expected to change, with an increasing market for gas for industrial purposes and for heating. Distribution systems will also change to include tank installations in many sizes and transport with large tank lorries. LPG is estimated to be competitive with other forms of energy, and the market is expected to increase to up to ca. 500,000 tons per year. Restricting factors are shortage of supply and lack of approved applications, transport equipment and tank facilities. A list of existing bottle gas companies and evaluation of the technical facilities in the Polish Oil and Gas Company in Gydnia are included. Bottled gas is currently distributed under normal conditions and, market prices for LPG have remained stable in Poland. Detailed studies of the current distribution network in the Suwalki area are given. It should be possible to extend the existing distribution network. A proposal for the establishment of standard tank installations and the gas supply for the town of Augustow is presented. Considerable investments will have to be made in terminals, tank plants and transport equipment, and international oil companies are expected to play an important role in this market. The European Bank for Restructuring and Development could possibly contribute to the financing of the pipe network. (AB)

  13. Modeling the performance of coated LPG tanks engulfed in fires

    Energy Technology Data Exchange (ETDEWEB)

    Landucci, Gabriele [CONPRICI - Dipartimento di Ingegneria Chimica, Chimica Industriale e Scienza dei Materiali, Universita di Pisa, via Diotisalvi n.2, 56126 Pisa (Italy); Molag, Menso [Nederlandse Organisatie voor toegepast-natuurwetenschappelijk onderzoek TNO, Princetonlaan 6, 3584 CB Utrecht (Netherlands); Cozzani, Valerio, E-mail: valerio.cozzani@unibo.it [CONPRICI - Dipartimento di Ingegneria Chimica, Mineraria e delle Tecnologie Ambientali, Alma Mater Studiorum - Universita di Bologna, Via Terracini 28 - 40131 Bologna (Italy)

    2009-12-15

    The improvement of passive fire protection of storage vessels is a key factor to enhance safety among the LPG distribution chain. A thermal and mechanical model based on finite elements simulations was developed to assess the behaviour of full size tanks used for LPG storage and transportation in fire engulfment scenarios. The model was validated by experimental results. A specific analysis of the performance of four different reference coating materials was then carried out, also defining specific key performance indicators (KPIs) to assess design safety margins in near-miss simulations. The results confirmed the wide influence of coating application on the expected vessel time to failure due to fire engulfment. A quite different performance of the alternative coating materials was evidenced. General correlations were developed among the vessel time to failure and the effective coating thickness in full engulfment scenarios, providing a preliminary assessment of the coating thickness required to prevent tank rupture for a given time lapse. The KPIs defined allowed the assessment of the available safety margins in the reference scenarios analyzed and of the robustness of thermal protection design.

  14. New pemex agency, smog checks greet Mexican LPG vehicle users

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This paper reports that the relaxation of prohibitions on the use of propane as a motor fuel has spurred sizeable business activity in carburetion and higher demand for LPG throughout Mexico and particularly in Mexico City. However, a number of unforeseen problems have developed that required tough, immediate solutions. After the alternative fuels project began at city hall in Mexico City, publicity spread nationwide, reportedly spurring conversion activity in many other cities. That led to additional demand for fuel of a magnitude that few people had anticipated. In order to assume control of the situation, the national oil company, Pemex, established an official LPG Motor Fuel Department on June 1. Operating in conjunction with the Ministry of Industry, the new department has been busy registering every major propane-powered fleet in the country. Most important, the rate of conversion work must now be pegged to the availability of fuel. It is believed that conversion activity has become more evenly paced since the new Pemex agency took over.over

  15. Modeling the performance of coated LPG tanks engulfed in fires

    International Nuclear Information System (INIS)

    Landucci, Gabriele; Molag, Menso; Cozzani, Valerio

    2009-01-01

    The improvement of passive fire protection of storage vessels is a key factor to enhance safety among the LPG distribution chain. A thermal and mechanical model based on finite elements simulations was developed to assess the behaviour of full size tanks used for LPG storage and transportation in fire engulfment scenarios. The model was validated by experimental results. A specific analysis of the performance of four different reference coating materials was then carried out, also defining specific key performance indicators (KPIs) to assess design safety margins in near-miss simulations. The results confirmed the wide influence of coating application on the expected vessel time to failure due to fire engulfment. A quite different performance of the alternative coating materials was evidenced. General correlations were developed among the vessel time to failure and the effective coating thickness in full engulfment scenarios, providing a preliminary assessment of the coating thickness required to prevent tank rupture for a given time lapse. The KPIs defined allowed the assessment of the available safety margins in the reference scenarios analyzed and of the robustness of thermal protection design.

  16. 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.

  17. Report of study group 3.3 ''LNG and LPG peak shaving and satellite plants''; Rapport du groupe d'etude 3.3 ''usines d'ecretement de pointes et stations satellites GNL et GPL''

    Energy Technology Data Exchange (ETDEWEB)

    Klein Nagelvoort, R.

    2000-07-01

    This report presents a world-wide overview of LNG and LPG Peak Shaving and Satellite Plants, compiled by the study group 3.3 of the International Gas Union. The scope of the work of the study group includes: - LPG peak shavers (LPG + air, N{sub 2}) in gas distribution networks; - LPG peak shavers for start-up and back-up fuel for LNG terminals and power stations; - LNG peak shavers for gas distribution networks; - Small-scale liquefaction plants for distribution to satellites and dedicated consumers (e.g. power generators, chemical plants, trucking companies etc.); - LNG peak shavers as back-up for large consumers; - Alternative liquefaction technologies for LNG and LPG (e.g. refrigeration cycles, supersonic expansion, thermo-acoustic designs); - Alternative storage tank designs for LNG and LPG. The report presents an overview of current installations world-wide and considers the prospects of technological developments with respect to equipment, remote operations and safety constraints. It also includes where possible a review of capital and operating costs, regulations, and an identification of opportunities and trends. The report collates the information available to the study group at the time of the writing, which may explain some heterogeneity in the document. (author)

  18. 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.

  19. 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)

  20. PENGARUH PERUBAHAN SAAT PENYALAAN (IGNITION TIMING TERHADAP PRESTASI MESIN PADA SEPEDA MOTOR 4 LANGKAH DENGAN BAHAN BAKAR LPG

    Directory of Open Access Journals (Sweden)

    Bambang Yunianto

    2012-07-01

    Full Text Available Bahan bakar LPG merupakan bahan bakar gas yang ramah lingkungan, sehingga dapat dijadikan bahan bakar alternatif selain bahan bakar bensin Performa Mesin bensin yang dioperasikan dengan menggunakan bahan bakar gas LPG mengalami penurunan. Penurunan ini terjadi dikarenakan karakteristik sifat bahan bakar bensin berbeda dengan LPG. Hal ini dapat diatasi dengan mengatur saat penyalaan sehingga lebih sesuai dengan karakteristik gas LPG. Dari hasil pengujian diperoleh bahwa dengan pengaturan saat penyalaan 11° sebelum TMA, menghasilkan prestasi (Torsi dan Daya yang dekat dengan prestasi motor bensin yaitu hanya selisih 3 %. Prestasi terbaik pada mesin bahan bakar bensin ataupun LPG berkisar pada putaran 4000 s.d 5000 rpm

  1. 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.

  2. 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.

  3. Performance and emissions of a heavy-duty diesel/LPG dual fuel engine

    Energy Technology Data Exchange (ETDEWEB)

    Schaberg, Paul [Sasol Technology, Cape Town (South Africa)

    2013-06-01

    This paper describes an investigation into the combustion characteristics and exhaust emissions of a heavy-duty truck engine which has been equipped with an aftermarket conversion kit to enable operation as a diesel/LPG (Liquefied Petroleum Gas) dual fuel engine. During operation diesel fuel is displaced by LPG which is vaporised and metered into the inlet manifold by means of solenoid injectors. It was found that, as the LPG fuelling rate is increased, the cylinder pressure rise rates and peak cylinder pressures increase, as do the carbon monoxide and unburned hydrocarbon emissions. At higher loads it was found that the LPG autoignites independently of the diesel fuel, resulting in very high rates of cylinder pressure rise. Particulate and nitrogen oxide emissions remain largely unchanged, and carbon dioxide emissions are reduced due to the lower carbon content of the LPG fuel. Different LPG compositions were also investigated and it was found that the LPG properties that have the most significant effect on combustion and emissions were the autoignition and volatility characteristics. (orig.)

  4. Conceptual Model of Supply Chain Structure Mapping - A Case of Subsidized LPG Commodity in Yogyakarta

    Science.gov (United States)

    Sulistio, Joko; Thoif, Afifuddin; Fitri Alindira, Aulia

    2016-01-01

    — In 2007, the government launched a conversion program of kerosene to LPG by issuing a Presidential Regulation No. 104/2007 on Supply, Distribution and Pricing LPG 3 Kg. Article 2 on the regulation says that setting the supply, distribution, and pricing of LPG 3 Kg include planning an annual sales volume of enterprises, the reference price and the retail price and conditions of export and import of LPG 3 Kg in order to reduce subsidies Kerosene especially to divert the use of kerosene according to government policy. In principle, the purpose of this policy is to reduce energy subsidies on commodities, especially Kerosene. Although the government claimed the conversion program is success, there are few problems arising from conversion program. In 2014, many scarcity and high price of LPG 3 Kg were reported. In this case, Pertamina was given full authority to manage all supply chain and distribution. Because the root of the problem of scarcity that occurred in the supply chain system has not been explained, the proposed solutions will also be partial and not comprehensive. Thus, this research will build a structural map of the causes of supply chain system LPG 3 Kg, as well as providing a comprehensive picture of system dynamics of LPG 3 Kg supply chain system which applied in Indonesia. And the result is expected as in form of Causal Loop Diagram of supply chain system.

  5. Bi-fuel System - Gasoline/LPG in A Used 4-Stroke Motorcycle - Fuel Injection Type

    Science.gov (United States)

    Suthisripok, Tongchit; Phusakol, Nachaphat; Sawetkittirut, Nuttapol

    2017-10-01

    Bi-fuel-Gasoline/LPG system has been effectively and efficiently used in gasoline vehicles with less pollutants emission. The motorcycle tested was a used Honda AirBlade i110 - fuel injection type. A 3-litre LPG storage tank, an electronic fuel control unit, a 1-mm LPG injector and a regulator were securely installed. The converted motorcycle can be started with either gasoline or LPG. The safety relief valve was set below 48 kPa and over 110 kPa. The motorcycle was tuned at the relative rich air-fuel ratio (λ) of 0.85-0.90 to attain the best power output. From dynamometer tests over the speed range of 65-100 km/h, the average power output when fuelling LPG was 5.16 hp; dropped 3.9% from the use of gasoline91. The average LPG consumption rate from the city road test at the average speed of 60 km/h was 40.1 km/l, about 17.7% more. This corresponded to lower LPG’s energy density of about 16.2%. In emission, the CO and HC concentrations were 44.4% and 26.5% lower. Once a standard gas equipment set with ECU and LPG injector were securely installed and the engine was properly tuned up to suit LPG’s characteristics, the converted bi-fuel motorcycle offers efficiently, safely and economically performance with environmental friendly emission.

  6. Effects of spark plug configuration on combustion and emission characteristics of a LPG fuelled lean burn SI engine

    Science.gov (United States)

    Ravi, K.; Khan, Manazir Ahmed; Pradeep Bhasker, J.; Porpatham, E.

    2017-11-01

    Introduction of technological innovation in automotive engines in reducing pollution and increasing efficiency have been under contemplation. Gaseous fuels have proved to be a promising way to reduce emissions in Spark Ignition (SI) engines. In particular, LPG settled to be a favourable fuel for SI engines because of their higher hydrogen to carbon ratio, octane rating and lower emissions. Wide ignition limits and efficient combustion characteristics make LPG suitable for lean burn operation. But lean combustion technology has certain drawbacks like poor flame propagation, cyclic variations etc. Based on copious research it was found that location, types and number of spark plug significantly influence in reducing cyclic variations. In this work the influence of single and dual spark plugs of conventional and surface discharge electrode type were analysed. Dual surface discharge electrode spark plug enhanced the brake thermal efficiency and greatly reduced the cyclic variations. The experimental results show that rate of heat release and pressure rise was more and combustion duration was shortened in this configuration. On the emissions front, the NOx emission has increased whereas HC and CO emissions were reduced under lean condition.

  7. Liquefied petroleum gas (LPG) poisoning: report of two cases and review of the literature.

    Science.gov (United States)

    Fukunaga, T; Yamamoto, H; Tanegashima, A; Yamamoto, Y; Nishi, K

    1996-10-25

    Two autopsy cases of men who died while connecting a liquefied petroleum gas (LPG) pipe are reported. Their blood concentrations of propane (the main content of LPG) were 0.12 and 3.40 mg/100 g, respectively. The cause of death after exposure of LPG has generally been considered to be asphyxia from hypoxia. The large differences in the blood propane levels found here and reported in the literature, however, suggest that direct toxic effects of propane poisoning may be the cause of death in some cases. Propane concentrations and the cause of death are reviewed and discussed.

  8. Study of the cycle variability at an automotive diesel engine fuelled with LPG

    Directory of Open Access Journals (Sweden)

    Nemoianu Liviu

    2017-01-01

    Full Text Available Liquid Petroleum Gas is a viable alternative fuel for diesel engines due to its ability of emissions and fuel consumption reduction. Combustion variability at LPG diesel engine is analysed for maximum pressure, maximum pressure angle and indicated mean effective pressure. Combustion variability is influenced by the increase of LPG cycle dose which lead to the increase of the cycle variability coefficients values, but without exceeding the admitted values that provide diesel engine reliability. Analysis of COV values establishes the maximum admitted values of LPG cycle.

  9. 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.

  10. A comparative analysis of liquefied petroleum gas (LPG) and kerosene related burns.

    Science.gov (United States)

    Ahuja, Rajeev B; Dash, Jayant K; Shrivastava, Prabhat

    2011-12-01

    Previous studies from our department reflected a trend of decreasing incidence of burns culminating from rising income levels, which were bringing about a change in the cooking fuel in many urban households [1,2]. These studies also indicated a changing scenario of increased incidence of burns from LPG mishaps [2]. In the absence of much information on the subject we felt it rather imperative to comparatively study the pattern of burn injuries resulting from LPG and kerosene. This prospective study was conducted on the clinical database of consecutive patients admitted with burns sustained due to LPG and kerosene from 1st January 2009 to 31st May 2010 (17 months). Data recorded for each patient included; age, gender, religion, socioeconomic status, literacy level, type of family unit, marital status, type of dwelling unit, mode of injury and its exact mechanism, place of incident, level of cooking stove, extent of burns (%TBSA), presence of features of inhalation injury, number of patients affected in a single mishap, size of LPG cylinder used, length of hospital stay and mortality. Of 731 flame burn patients in this study, 395 (54%) were due to kerosene burns and 200 (27.4%) from LPG mishaps. Significantly, the majority of injuries, in both the groups, occurred in lower middle class families living as nuclear units, in a single room dwelling, without a separate kitchen. Majority of LPG burns (70.5%, 141 patients) resulted from a gas leak and 25.5% were from cooking negligence (51 patients). 50.5% of kerosene accidents were from 'stove mishaps' and 49% due to cooking negligence. In all kerosene accidents the stove was kept at floor level but in LPG group 20.6% had the stove placed on a platform. There was a slight difference in mean TBSA burns; 51% in kerosene group compared to 41.5% TBSA in LPG group. There were nine episodes in LPG group in which there were more than three burn victims admitted for treatment. Very importantly, 77% patients in LPG group were from

  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-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.

  13. 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

  14. Design Guidelines for Bus Transit Systems Using Liquefied Petroleum Gas (LPG) as an Alternative Fuel.

    Science.gov (United States)

    1996-09-01

    The use of alternative fuels to power transit buses is steadily increasing. Several fuels, including Liquefied Petroleum Gas (LPG), Compressed Natural Gas (CNG), and Methanol/Ethanol, are already being used in buses. At present, there do not exist co...

  15. Kecepatan Pembakaran Premixed Campuran Minyak Jarak - Liquefied Petroleum Gas (LPG pada Circular Tube Burner

    Directory of Open Access Journals (Sweden)

    Defmit B.N. Riwu

    2016-10-01

    Full Text Available This study was conducted to determine the characteristics of premixed combustion of a mixture of castor oil - LPG on a circular tube burner. Percentage of LPG fuel in a mixture of jatropha curcas oil - LPG varied as much as 10%, 20%, 30%, and 40% of the mass flow jatropha curcas oil vapor. Considering the flame of fire there are two angles formed which describe burning velocity. Also there are formed two cones of fire where the bright blue inside cone is a premixed flame, while the outer blue white cone is flame a diffusion flame. An increase in the percentage of LPG makes the value of top and bottom angle increase. So that the burning velocity on the upper angle decrease whilst on bottom angle increase.

  16. Deteksi Kebocoran Gas LPG Menggunakan Detektor Arduino dengan Algoritma Fuzzy Logic Mandani

    Directory of Open Access Journals (Sweden)

    Lukman Hakim

    2017-10-01

    Full Text Available Bencana kebakaran yang diakibatkan oleh kebocoran gas LPG (Liquid  Petroleum   Gas mengalami kenaikan setiap tahun dari tahun 2011 sampai 2015 diantaranya 17% diakibatkan oleh kebocoran gas. Penggunaan detektor kebocoran gas LPG menggunakan arduino yang dilengkapi sensor gas dan suhu memberikan kemudahan untuk deteksi secara awal terjadinya kebocoran dan kebakaran. Perancangan detektor kebocoran gas LPG menggunakan algoritma fuzzy logic mandani, dilengkapi dengan informasi melalui Short Message Service (SMS dan Buzzer. Detektor kebocoran gas LPG dapat melakukan indikasi terjadinya bocor pada konsentrasi gas rata-rata 456 ppm dari 10 pengujian dan indikasi api merah 23,30 dapat mengenal terjadinya kebakaran, detektor mengirimkan SMS kepada pemilik rumah dan pemadam kebakaran.

  17. PRODUCTION OF HYDROGEN FROM THE STEAM AND OXIDATIVE REFORMING OF LPG: THERMODYNAMIC AND EXPERIMENTAL STUDY

    Directory of Open Access Journals (Sweden)

    P. P. Silva

    2015-09-01

    Full Text Available AbstractThe objective of this paper was to use a thermodynamic analysis to find operational conditions that favor the production of hydrogen from steam and oxidative reforming of liquefied petroleum gas (LPG. We also analyzed the performance of a catalyst precursor, LaNiO3, in order to compare the performance of the obtained catalyst with the thermodynamic equilibrium predictions. The results showed that it is possible to produce high concentrations of hydrogen from LPG reforming. The gradual increase of temperature and the use of high water concentrations decrease the production of coke and increase the formation of H2. The reaction of oxidative reforming of LPG was more suitable for the production of hydrogen and lower coke formation. Furthermore the use of an excess of water (H2O/LPG =7.0 and intermediate temperatures (973 K are the most suitable conditions for the process.

  18. Influence of H{sub 2}O{sub 2} on LPG fuel performance evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Muhammad Saad, E-mail: iqbalmouj@gmail.com; Ahmed, Iqbal, E-mail: iqbalmouj@gmail.com; Mutalib, Mohammad Ibrahim bin Abdul, E-mail: iqbalmouj@gmail.com; Nadeem, Saad, E-mail: iqbalmouj@gmail.com; Ali, Shahid, E-mail: iqbalmouj@gmail.com [Department of Chemical Engineering, Faculty of Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak (Malaysia)

    2014-10-24

    The objective of this mode of combustion is to insertion of hydrogen peroxide (H{sub 2}O{sub 2}) to the Liquefied Petroleum Gas (LPG) combustion on spark plug ignition engines. The addition of hydrogen peroxide may probably decrease the formation of NO{sub x}, CO{sub x} and unburned hydrocarbons. Hypothetically, Studies have shown that addition of hydrogen peroxide to examine the performance of LPG/H{sub 2}O{sub 2} mixture in numerous volumetric compositions starting from lean LPG until obtaining a better composition can reduce the LPG fuel consumption. The theory behind this idea is that, the addition of H{sub 2}O{sub 2} can cover the lean operation limit, increase the lean burn ability, diminution the burn duration along with controlling the exhaust emission by significantly reducing the greenhouse gaseous.

  19. Influence of H2O2 on LPG fuel performance evaluation

    International Nuclear Information System (INIS)

    Khan, Muhammad Saad; Ahmed, Iqbal; Mutalib, Mohammad Ibrahim bin Abdul; Nadeem, Saad; Ali, Shahid

    2014-01-01

    The objective of this mode of combustion is to insertion of hydrogen peroxide (H 2 O 2 ) to the Liquefied Petroleum Gas (LPG) combustion on spark plug ignition engines. The addition of hydrogen peroxide may probably decrease the formation of NO x , CO x and unburned hydrocarbons. Hypothetically, Studies have shown that addition of hydrogen peroxide to examine the performance of LPG/H 2 O 2 mixture in numerous volumetric compositions starting from lean LPG until obtaining a better composition can reduce the LPG fuel consumption. The theory behind this idea is that, the addition of H 2 O 2 can cover the lean operation limit, increase the lean burn ability, diminution the burn duration along with controlling the exhaust emission by significantly reducing the greenhouse gaseous

  20. Explosion accident at LPG storage in Mexico. Bleve of PEMEX Co

    Energy Technology Data Exchange (ETDEWEB)

    Sakurai Yoshio (The Yasuda Fire and Marine Insurance Co., Ltd., Tokyo, (Japan))

    1989-09-01

    This paper reports the BLEVE (Boiling Expanding Vapor Explosion) which occurred at LPG storage-supply plant of PEMEX Co. (Petroles Mexicanos Co.) in San Juan Ixhuatepec, Mexico on 19th of Nov., 1984. As the actual spot of the explosion is close to residential areas, 50 persons died, 200 was missing, and 723 were injured. Another adjacent LPG storage burned down by the spreading fire, and 200,000 residents retired to safety places. A part of the LPG supply Pipes was destroyed, from where LPG leaked and ignited. During one hour and a half, 15 violent explosions occurred, 9 of which were recorded by the seismometer set up at University of Mexico, about 10km apart. 3 refs., 5 figs.

  1. Support to the electric power, natural gas or liquefied petroleum gas (LPG) vehicles

    International Nuclear Information System (INIS)

    2006-01-01

    This document brings together the different financial incentives proposed to the acquisition and utilization of electric power, natural gas or LPG vehicles. The financial assistance of the ADEME, the fiscal incentives and other proposals are detailed. (A.L.B.)

  2. Cooking Fuels in Lagos, Nigeria: Factors Associated with Household Choice of Kerosene or Liquefied Petroleum Gas (LPG

    Directory of Open Access Journals (Sweden)

    Obianuju B. Ozoh

    2018-03-01

    Full Text Available Cooking with dirty-burning fuels is associated with health risk from household air pollution. We assessed the prevalence of and factors associated with the use of cooking fuels, and attitudes and barriers towards use of liquefied petroleum gas (LPG. This was a cross-sectional, population-based survey conducted in 519 households in Lagos, Nigeria. We used a structured questionnaire to obtain information regarding choice of household cooking fuel and the attitudes towards the use of LPG. Kerosene was the most frequently used cooking fuel (n = 475, 91.5%; primary use n = 364, 70.1% followed by charcoal (n = 159, 30.6%; primary use n = 88, 17% and LPG (n = 86, 16.6%; primary use n = 63, 12.1%. Higher level of education, higher income and younger age were associated with LPG vs. kerosene use. Fuel expenditure on LPG was significantly lower than for kerosene ( N (Naira 2169.0 ± 1507.0 vs. N 2581.6 ± 1407.5. Over 90% of non-LPG users were willing to switch to LPG but cited safety issues and high cost as potential barriers to switching. Our findings suggest that misinformation and beliefs regarding benefits, safety and cost of LPG are important barriers to LPG use. An educational intervention program could be a cost-effective approach to improve LPG adoption and should be formally addressed through a well-designed community-based intervention study.

  3. Cooking Fuels in Lagos, Nigeria: Factors Associated with Household Choice of Kerosene or Liquefied Petroleum Gas (LPG).

    Science.gov (United States)

    Ozoh, Obianuju B; Okwor, Tochi J; Adetona, Olorunfemi; Akinkugbe, Ayesha O; Amadi, Casmir E; Esezobor, Christopher; Adeyeye, Olufunke O; Ojo, Oluwafemi; Nwude, Vivian N; Mortimer, Kevin

    2018-03-31

    Cooking with dirty-burning fuels is associated with health risk from household air pollution. We assessed the prevalence of and factors associated with the use of cooking fuels, and attitudes and barriers towards use of liquefied petroleum gas (LPG). This was a cross-sectional, population-based survey conducted in 519 households in Lagos, Nigeria. We used a structured questionnaire to obtain information regarding choice of household cooking fuel and the attitudes towards the use of LPG. Kerosene was the most frequently used cooking fuel ( n = 475, 91.5%; primary use n = 364, 70.1%) followed by charcoal ( n = 159, 30.6%; primary use n = 88, 17%) and LPG ( n = 86, 16.6%; primary use n = 63, 12.1%). Higher level of education, higher income and younger age were associated with LPG vs. kerosene use. Fuel expenditure on LPG was significantly lower than for kerosene ( N (Naira) 2169.0 ± 1507.0 vs. N 2581.6 ± 1407.5). Over 90% of non-LPG users were willing to switch to LPG but cited safety issues and high cost as potential barriers to switching. Our findings suggest that misinformation and beliefs regarding benefits, safety and cost of LPG are important barriers to LPG use. An educational intervention program could be a cost-effective approach to improve LPG adoption and should be formally addressed through a well-designed community-based intervention study.

  4. 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.

  5. Differential Impact of LPG-and PG-Deficient Leishmania major Mutants on the Immune Response of Human Dendritic Cells.

    Directory of Open Access Journals (Sweden)

    Michelle A Favila

    2015-12-01

    Full Text Available Leishmania major infection induces robust interleukin-12 (IL12 production in human dendritic cells (hDC, ultimately resulting in Th1-mediated immunity and clinical resolution. The surface of Leishmania parasites is covered in a dense glycocalyx consisting of primarily lipophosphoglycan (LPG and other phosphoglycan-containing molecules (PGs, making these glycoconjugates the likely pathogen-associated molecular patterns (PAMPS responsible for IL12 induction.Here we explored the role of parasite glycoconjugates on the hDC IL12 response by generating L. major Friedlin V1 mutants defective in LPG alone, (FV1 lpg1-, or generally deficient for all PGs, (FV1 lpg2-. Infection with metacyclic, infective stage, L. major or purified LPG induced high levels of IL12B subunit gene transcripts in hDCs, which was abrogated with FV1 lpg1- infections. In contrast, hDC infections with FV1 lpg2- displayed increased IL12B expression, suggesting other PG-related/LPG2 dependent molecules may act to dampen the immune response. Global transcriptional profiling comparing WT, FV1 lpg1-, FV1 lpg2- infections revealed that FV1 lpg1- mutants entered hDCs in a silent fashion as indicated by repression of gene expression. Transcription factor binding site analysis suggests that LPG recognition by hDCs induces IL-12 in a signaling cascade resulting in Nuclear Factor κ B (NFκB and Interferon Regulatory Factor (IRF mediated transcription.These data suggest that L. major LPG is a major PAMP recognized by hDC to induce IL12-mediated protective immunity and that there is a complex interplay between PG-baring Leishmania surface glycoconjugates that result in modulation of host cellular IL12.

  6. 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.

  7. 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.

  8. Antargaz: 1. independent French LPG marketer; Antargaz: 1. destributeur francais independant de GPL

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2001-04-01

    Francois Varagne, recently appointed President and General Manager of Antargaz, displayed on 12 April in Paris the configuration and the ambitions of the company. A major player on the French LPG market, Antargaz makes today a new start. On the basis of its 744 000 tonnes (around 400 millions gallons) sold in 2000, Antargaz ranks as the second LPG distributor in France with a share of some 24%. Antargaz is now the first independent marketer in France, ahead of the other French independent actors: Primagaz France (around 20% of the market) and Vitogaz (some 3.5%). Thus, key factors changed in the French LPG sector. If we except marketers under 5%, there were last year one large independent (Primagaz) and three LPG marketers linked to refiners: Butagaz (as Shell affiliate + BP's French LPG output), Elf Antargaz (as Elf Aquitaine's affiliate) and Totalgaz (as TotalFina's affiliate). Today, again without counting marketers under 5%, there are two LPG marketers linked to refiners (Butagaz and Totalgaz) and two large independents. Antargaz's strategy is focused on existing markets as well as new ones and new applications: in the domestic and commercial sectors, in industry, auto-gas, mains distribution, in the leisure sector, in agriculture. It has also a role to play in Europe.

  9. LPG consumption in the long term: supply, pricing demand with particular reference to the petrochemical sector

    International Nuclear Information System (INIS)

    Shammas, P.

    1996-01-01

    Supply of LPG is forecast to grow over the next decade from the present level of 180 million t/y to about 185-190 million t/y, depending on demand in Asia which is rising rapidly and on new LPG export projects. Most of the increase in supply will come from new gas and crude oil production, from new LPG ventures, and from refineries reducing the n-butane content of motor gasoline. Pricing will remain volatile as a result of crude oil price volatility, variations in the winter weather in the Northern Hemisphere, and as result of competition between ethane, PPG, naphtha and condensate as ethylene cracker feedstocks. Demand for LPG in OECD countries will continue to show steady growth. The increase in demand will be more rapid in the relatively less developed OECD countries, as the trend in Spain has shown in recent years. Provided that the LPG price is competitive, demand in China, South-East Asia and the Indian sub-continent could grow beyond current projections. Consumption in these countries will depend on the installation of distribution facilities and the rate at which LPG can substitute for traditional fuels and kerosene as well as compete for limited disposable incomes. (author)

  10. Early Leakage Protection System of LPG (Liquefied Petroleum Gas) Based on ATMega 16 Microcontroller

    Science.gov (United States)

    Sriwati; Ikhsan Ilahi, Nur; Musrawati; Baco, Syarifuddin; Suyuti'Andani Achmad, Ansar; Umrianah, Ejah

    2018-04-01

    LPG (Liquefied Petroleum Gas). LPG is a hydrocarbon gas production from refineries and gas refinery with the major components of propane gas (C3H8) and butane (C4H10). Limit flame (Flammable Range) or also called gas with air. Value Lower Explosive Limit (LEL) is the minimum limit of the concentration of fuel vapor in the air which if there is no source of fire, the gas will be burned. While the value of the Upper Explosive Limit (UEL), which limits the maximum concentration of fuel vapor in the air, which if no source of fire, the gas will be burned. Protection system is a defend mechanism of human, equipment, and buildings around the protected area. Goals to be achieved in this research are to design a protection system against the consequences caused by the leakage of LPG gas based on ATmega16 microcontroller. The method used in this research is to reduce the levels of leaked LPG and turned off the power source when the leakage of LPG is on the verge of explosive limit. The design of this protection system works accurately between 200 ppm up to 10000 ppm, which is still below the threshold of explosive. Thus protecting the early result of that will result in the leakage of LPG gas.

  11. 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

  12. [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

  13. Grizzli mobile systems and LPG delivery management; Grizzli mobile systems

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2000-07-01

    Complete text of publication follows: Grizzli Mobile Systems (and its sister companies) specialists in data communications and system solutions, offer their complete management solution for LPG deliveries, right through from remote reading of the gas level in the tank, through route management, management of the delivery itself and finally on-site invoicing and payment. The system permits a supplier to really differentiate itself from its competitors in terms of customer service and control of its operations. Domestic gas tanks are often difficult to access; visual reading of the gauge is not always easy and often leads to the customer re-ordering in panic mode. The supplier has also to react in panic mode to the customer. Grizzli Mobile Systems has developed a radio module that is fitted to the gas tank that calls, at regular set intervals with the tank level to a Call Rider gateway plug. The Call Rider is a small box plugged into the regular telephone socket (also supplying multiple operator telephony and other home automation services). As soon as the gas level reaches a predetermined minimum level, this radio information is relayed via the Internet to the LPG supplier. The supplier can then arrange (in non-panic mode) to deliver gas to the customer, via conventional means or by use of an interactive radio display (attached to a refrigerator or similar by magnets) that communicates with the Call Rider by radio. Once a delivery date has been set, a Grizzli Mobile Systems' dispatch system, installed at the supplier's headquarters creates and transfers routes via GSM communications to its fleet of delivery vehicles. A main-frame mapping software provides real-time follow-up and status checks of the vehicles using the GPS functionality and imports data back from the vehicles and updates databases. The driver is also assisted in localizing delivery sites. Inside the cabin of the vehicle the driver has available a Fujitsu PenCentra pen computer, a Microsoft

  14. Texas LPG fuel cell development and demonstration project

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2004-07-26

    The State Energy Conservation Office has executed its first Fuel Cell Project which was awarded under a Department of Energy competitive grant process. The Texas LPG Fuel Processor Development and Fuel Cell Demonstration Program is a broad-based public/private partnership led by the Texas State Energy Conservation Office (SECO). Partners include the Alternative Fuels Research and Education Division (AFRED) of the Railroad Commission of Texas; Plug Power, Inc., Latham, NY, UOP/HyRadix, Des Plaines, IL; Southwest Research Institute (SwRI), San Antonio, TX; the Texas Natural Resource Conservation Commission (TNRCC), and the Texas Department of Transportation (TxDOT). The team proposes to mount a development and demonstration program to field-test and evaluate markets for HyRadix's LPG fuel processor system integrated into Plug Power's residential-scale GenSys(TM) 5C (5 kW) PEM fuel cell system in a variety of building types and conditions of service. The program's primary goal is to develop, test, and install a prototype propane-fueled residential fuel cell power system supplied by Plug Power and HyRadix in Texas. The propane industry is currently funding development of an optimized propane fuel processor by project partner UOP/HyRadix through its national checkoff program, the Propane Education and Research Council (PERC). Following integration and independent verification of performance by Southwest Research Institute, Plug Power and HyRadix will produce a production-ready prototype unit for use in a field demonstration. The demonstration unit produced during this task will be delivered and installed at the Texas Department of Transportation's TransGuide headquarters in San Antonio, Texas. Simultaneously, the team will undertake a market study aimed at identifying and quantifying early-entry customers, technical and regulatory requirements, and other challenges and opportunities that need to be addressed in planning commercialization of the units

  15. 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.

  16. Comparison of Performance Characteristics of LPG and Gasoline - Fuelled Single Cylinder SI Engine

    Directory of Open Access Journals (Sweden)

    Saad Abdul Qadir Abdul Azeez

    2016-07-01

    Full Text Available The investigations have been concentrated on decreasing fuel consumption by using alternative fuels and on lowering the concentration of toxic  components in combustion products. LPG as an alternative to gasoline  has  emerged  as  a  solution  to  the  deteriorating  urban  air  quality  problem,  especially  in  an  oil country like Iraq. LPG has already been used as cooking fuel in Iraq. In the present paper  practical tests of various operating parameters and concerns have been prepared for better understanding of operating conditions and constrains for a LPG fueled internal combustion engine.The results show that HUCR for gasoline was 8:1, and for LPG was 10:1. bsfc reduced by using LPG at its HUCR, while at CR=8:1 it became higher than that for gasoline. Volumetric efficiency reduced by using  LPG  due  to  its  gaseous  nature,  but  it  was  improved  when  the  engine  was  run  at  HUCR.  Brake thermal efficiency depends  on bsfc and bp, so LPG preceded gasoline at medium speeds and torques. Exhaust gas temperatures reduced by using LPG, the minimum values were when the engine operated at CR= 8:1. The maximum values were for gasoline share.

  17. Experimental study of dual fuel engine performance using variable LPG composition and engine parameters

    International Nuclear Information System (INIS)

    Elnajjar, Emad; Selim, Mohamed Y.E.; Hamdan, Mohammad O.

    2013-01-01

    Highlights: • The effect of using variable LPG is studied. • Five fuels with propane to butane % volume ratio are: 100-70-55-25-0. • 100% Propane composition shows the highest noise levels with similar performance. • At 45° BTDC injection timing 55% Propane LPG the only fuel experience knocking. • LPG fuels gave similar engine performance, with differences in levels of noise. - Abstract: The present work investigates experimentally the effect of LPG fuel with different composition and engine parameters on the performance of a dual compression engine. Five different blends of LPG fuels are used with Propane to Butane volume ratio of 100:0, 70:30, 55:45, 25:75, and 0:100. A single cylinder, naturally aspirated, four strokes, indirectly injected, water cooled modified Ricardo E6 engine, is used in this study. The study is carried out by measuring the cylinder pressure, engine load, engine speed, crank angle, and the fuel’s flow rate. The engine performance under variable LPG fuel composition, engine load, pilot fuel injection timing, compression ratio, pilot fuel mass and engine speed, are estimated by comparing the following engine parameters: the cylinder maximum pressure, the indicated mean effective pressure, the maximum rate of pressure rise, and the thermal efficiency. The experimental data indicates that the engine parameters are playing a major role on the engine’s performance. Different LPG fuel composition did not show a major effect on the engine efficiency but directly impacted the levels of generated combustion noise

  18. Long-Period Gratings in Highly Germanium-Doped, Single-Mode Optical Fibers for Sensing Applications

    Science.gov (United States)

    Schlangen, Sebastian; Bremer, Kort; Zheng, Yulong; Böhm, Sebastian; Steinke, Michael; Wellmann, Felix; Neumann, Jörg; Overmeyer, Ludger

    2018-01-01

    Long-period fiber gratings (LPGs) are well known for their sensitivity to external influences, which make them interesting for a large number of sensing applications. For these applications, fibers with a high numerical aperture (i.e., fibers with highly germanium (Ge)-doped fused silica fiber cores) are more attractive since they are intrinsically photosensitive, as well as less sensitive to bend- and microbend-induced light attenuations. In this work, we introduce a novel method to inscribe LPGs into highly Ge-doped, single-mode fibers. By tapering the optical fiber, and thus, tailoring the effective indices of the core and cladding modes, for the first time, an LPG was inscribed into such fibers using the amplitude mask technique and a KrF excimer laser. Based on this novel method, sensitive LPG-based fiber optic sensors only a few millimeters in length can be incorporated in bend-insensitive fibers for use in various monitoring applications. Moreover, by applying the described inscription method, the LPG spectrum can be influenced and tailored according to the specific demands of a particular application. PMID:29702600

  19. Long-Period Gratings in Highly Germanium-Doped, Single-Mode Optical Fibers for Sensing Applications

    Directory of Open Access Journals (Sweden)

    Sebastian Schlangen

    2018-04-01

    Full Text Available Long-period fiber gratings (LPGs are well known for their sensitivity to external influences, which make them interesting for a large number of sensing applications. For these applications, fibers with a high numerical aperture (i.e., fibers with highly germanium (Ge-doped fused silica fiber cores are more attractive since they are intrinsically photosensitive, as well as less sensitive to bend- and microbend-induced light attenuations. In this work, we introduce a novel method to inscribe LPGs into highly Ge-doped, single-mode fibers. By tapering the optical fiber, and thus, tailoring the effective indices of the core and cladding modes, for the first time, an LPG was inscribed into such fibers using the amplitude mask technique and a KrF excimer laser. Based on this novel method, sensitive LPG-based fiber optic sensors only a few millimeters in length can be incorporated in bend-insensitive fibers for use in various monitoring applications. Moreover, by applying the described inscription method, the LPG spectrum can be influenced and tailored according to the specific demands of a particular application.

  20. 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...

  1. Grating scattering BRDF and imaging performances: A test survey performed in the frame of the flex mission

    Science.gov (United States)

    Harnisch, Bernd; Deep, Atul; Vink, Ramon; Coatantiec, Claude

    2017-11-01

    Key components in optical spectrometers are the gratings. Their influence on the overall infield straylight of the spectrometer depends not only on the technology used for grating fabrication but also on the potential existence of ghost images caused by irregularities of the grating constant. For the straylight analysis of spectrometer no general Bidirectional Reflectance Distribution Function (BRDF) model of gratings exist, as it does for optically smooth surfaces. These models are needed for the determination of spectrometer straylight background and for the calculation of spectrometer out of band rejection performances. Within the frame of the Fluorescence Earth Explorer mission (FLEX), gratings manufactured using different technologies have been investigated in terms of straylight background and imaging performance in the used diffraction order. The gratings which have been investigated cover a lithographically written grating, a volume Bragg grating, two holographic gratings and an off-the-shelf ruled grating. In this paper we present a survey of the measured bidirectional reflectance/transmittance distribution function and the determination of an equivalent surface micro-roughness of the gratings, describing the scattering of the grating around the diffraction order. This is specifically needed for the straylight modeling of the spectrometer.

  2. High sensitive reflection type long period fiber grating biosensor for real time detection of thyroglobulin, a differentiated thyroid cancer biomarker: the Smart Health project

    Science.gov (United States)

    Quero, G.; Severino, R.; Vaiano, P.; Consales, M.; Ruvo, M.; Sandomenico, A.; Borriello, A.; Giordano, M.; Zuppolini, S.; Diodato, L.; Cutolo, A.; Cusano, A.

    2015-09-01

    We report the development of a reflection-type long period fiber grating (LPG) biosensor able to perform the real time detection of thyroid cancer markers in the needle washout of fine-needle aspiration biopsy. A standard LPG is first transformed in a practical probe working in reflection mode, then it is coated by an atactic-polystyrene overlay in order to increase its surrounding refractive index sensitivity and to provide, at the same time, the desired interfacial properties for a stable bioreceptor immobilization. The results provide a clear demonstration of the effectiveness and sensitivity of the developed biosensing platform, allowing the in vitro detection of human Thyroglobulin at sub-nanomolar concentrations.

  3. Sistem Monitoring Pendeteksi Kebocoran LPG berbasis Mikrokontroller ATmega16 menggunakan RF APC220

    Directory of Open Access Journals (Sweden)

    RATNA SUSANA

    2016-02-01

    Full Text Available Abstrak Penggunaan LPG sebagai bahan bakar alternatif pengganti bahan bakar minyak dirasakan lebih efektif dan praktis. Namun kandungan senyawa di dalamnya memiliki efek yang negatif jika menguap di udara bebas. Sistem detektor gas LPG dapat menjadi salah satu solusi untuk mengetahui lebih dini terjadinya kebocoran gas. Implementasi sistem detektor gas LPG pada penelitian ini berupa sistem monitoring nirkabel yang dilengkapi alarm sebagai indikasi jika terjadi kebocoran gas. Sistem terdiri dari bagian Remote Controller dan Master Controller. Remote Controller menggunakan mikrokontroler ATMega16 yang terintegrasi dengan sensor MQ5, LCD dan transceiver RF APC220. Sedangkan Master Controller berupa komputer (PC yang dapat menampilkan kondisi ruangan yang dideteksi oleh bagian Remote Controller. Sistem berhasil mendeteksi gas LPG dan menampilkan kadar konsentrasinya dalam rentang 200 sampai dengan 1000 ppm. Ketika kadar konsentrasi gas mencapai 5000 ppm, alarm aktif secara otomatis dan memberikan status waspada. Pengiriman data secara nirkabel dengan adanya sejumlah penghalang berhasil dilakukan sampai jarak 200 m. Kata kunci: Sistem Monitoring, Remote Controller, Master Controller, LPG, RF APC220   Abstract The use of LPG as a fuel alternative to fossil fuels may be more effective and practical. Neverfluless its compound has a negative effect if it evaporates to the air. LPG gas detector system may be one solution to determine the early occurrence of gas leak. The detector system implementation in this study was a wireless monitoring system that had alarm to indicate if there was the gas leak. The system consisted of the Remote Controller and the Master Controller. Remote Controller used ATmega16 microcontroller integrated with MQ5 sensor, LCD and RF transceiver APC220. While the Master Controller in the form of a computer (PC that could display a room condition was detected by the Remote Controller section. LPG gas system successfully detected

  4. Particle and carbon dioxide emissions from passenger vehicles operating on unleaded petrol and LPG fuel

    International Nuclear Information System (INIS)

    Ristovski, Z.D.; Jayaratne, E.R.; Morawska, L.; Ayoko, G.A.; Lim, M.

    2005-01-01

    A comprehensive study of the particle and carbon dioxide emissions from a fleet of six dedicated liquefied petroleum gas (LPG) powered and five unleaded petrol (ULP) powered new Ford Falcon Forte passenger vehicles was carried out on a chassis dynamometer at four different vehicle speeds-0 (idle), 40, 60, 80 and 100 km h -1 . Emission factors and their relative values between the two fuel types together with a statistical significance for any difference were estimated for each parameter. In general, LPG was found to be a 'cleaner' fuel, although in most cases, the differences were not statistically significant owing to the large variations between emissions from different vehicles. The particle number emission factors ranged from 10 11 to 10 13 km -1 and was over 70% less with LPG compared to ULP. Corresponding differences in particle mass emission factor between the two fuels were small and ranged from the order of 10 μg km -1 at 40 to about 1000 μg km -1 at 100 km h -1 . The count median particle diameter (CMD) ranged from 20 to 35 nm and was larger with LPG than with ULP in all modes except the idle mode. Carbon dioxide emission factors ranged from about 300 to 400 g km -1 at 40 km h -1 , falling with increasing speed to about 200 g km -1 at 100 km h -1 . At all speeds, the values were 10% to 18% greater with ULP than with LPG

  5. Co-firing used engine lubrication oil with LPG in furnaces

    International Nuclear Information System (INIS)

    Al-Omari, S.A.-B.; Shaheen, A.; Al Fakhr, A.; Al-Hosani, A.; Al Yahyai, M.

    2010-01-01

    Combustion and heat transfer characteristics obtained based co-firing LPG with used engine oils (UEO) in a furnace, are investigated experimentally. In an attempt to assess UEO as a fuel, the UEO-based results are compared with results obtained using two other fuels, namely diesel, and a used cooking oil (UCkO). To ease its admission to the furnace and its subsequent vaporization and combustion, UEO is preheated by allowing it to flow upwardly in a vertical pipe surrounded by hot gases generated from LPG combustion. UEO that reaches the tip of the pipe un-vaporized, spills and hence has the chance to further heatup and vaporize as it exchanges heat with the upwardly flowing LPG combustion gases, in a counter flow process. Runs are divided into three groups based on the mass ratio of the liquid-fuel/LPG and the mass flow rate of the LPG supplied to the furnace. Ranges of these quantities over which UEO qualify as a good fuel and/or good promoter to radiation have been identified.

  6. Co-firing used engine lubrication oil with LPG in furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Al-Omari, S.A.-B.; Shaheen, A.; Al Fakhr, A.; Al-Hosani, A.; Al Yahyai, M. [Mechanical Engineering Department, UAE University, Al-Ain (United Arab Emirates)

    2010-06-15

    Combustion and heat transfer characteristics obtained based co-firing LPG with used engine oils (UEO) in a furnace, are investigated experimentally. In an attempt to assess UEO as a fuel, the UEO-based results are compared with results obtained using two other fuels, namely diesel, and a used cooking oil (UCkO). To ease its admission to the furnace and its subsequent vaporization and combustion, UEO is preheated by allowing it to flow upwardly in a vertical pipe surrounded by hot gases generated from LPG combustion. UEO that reaches the tip of the pipe un-vaporized, spills and hence has the chance to further heatup and vaporize as it exchanges heat with the upwardly flowing LPG combustion gases, in a counter flow process. Runs are divided into three groups based on the mass ratio of the liquid-fuel/LPG and the mass flow rate of the LPG supplied to the furnace. Ranges of these quantities over which UEO qualify as a good fuel and/or good promoter to radiation have been identified. (author)

  7. NKT cell activation by Leishmania mexicana LPG: Description of a novel pathway.

    Science.gov (United States)

    Zamora-Chimal, Jaime; Fernández-Figueroa, Edith A; Ruiz-Remigio, Adriana; Wilkins-Rodríguez, Arturo A; Delgado-Domínguez, José; Salaiza-Suazo, Norma; Gutiérrez-Kobeh, Laila; Becker, Ingeborg

    2017-02-01

    NKT cells have been associated with protection against Leishmania donovani, yet their role in infections with Leishmania mexicana has not been addressed, nor has the activation pathway been defined after stimulation with Leishmania mexicana lipophosphoglycan (LPG). We analyzed the activation of NKT cells and their cytokine production in response to Leishmania mexicana LPG. Additionally we compared NKT-cell numbers and cytokine profile in lymph nodes of skin lesions induced by Leishmania mexicana in BALB/c and C57BL/6 mice. We show that LPG activates NKT cells primarily through the indirect pathway, initiating with TLR2 stimulation of dendritic cells (DC), thereby enhancing TLR2, MHC II, and CD86 expressions and IL-12p70 production. This leads to IFN-γ production by NKT cells. C57BL/6 mice showed enhanced DC activation, which correlated with augmented IFN-γ production by NKT cells. Additionally, infected C57BL/6 mice showed elevated percentages of NKT cells with higher IFN-γ and IL-4 production in lymph nodes. We conclude that the response of NKT cells towards Leishmania mexicana LPG initiates with the indirect activation, after binding of LPG to TLR2 in DC. This indirect activation pathway enables NKT cells to produce IFN-γ during the innate phase of Leishmania infection, the magnitude of which differs between mouse strains. Copyright © 2016 The Authors. Published by Elsevier GmbH.. All rights reserved.

  8. Effect of variation in LPG composition on emissions and performance in a dual fuel diesel engine

    Energy Technology Data Exchange (ETDEWEB)

    H.E. Saleh [Mattaria, Helwan University, Cairo (Egypt). Department of Mechanical Power Engineering

    2008-10-15

    This paper investigates the effect of variation in LPG composition on emissions and performance characteristics in a dual fuel engine run on diesel fuel and five gaseous fuel of LPG with different composition. To quantify the best LPG composition for dual fuel operation especially in order to improve the exhaust emissions quality while maintaining high thermal efficiency comparable to a conventional diesel engine, a two-cylinder, naturally aspirated, four-stroke, DI diesel engine converted to run as pilot-injected dual fuel engine. The tests and data collection were performed under various conditions of load at constant engine speed. From the results, it is observed that the exhaust emissions and fuel conversion efficiency of the dual fuel engine are found to be affected when different LPG composition is used as higher butane content lead to lower NOx levels while higher propane content reduces CO levels. Fuel No. 3 (70% propane, 30% butane) with mass fraction 40% substitution of the diesel fuel was the best LPG composition in the dual fuel operation except that at part loads. Also, tests were made for fuel No. 3-diesel blend in the dual fuel operation at part loads to improve the engine performances and exhaust emissions by using the Exhaust Gas Recirculation (EGR) method. 26 refs., 15 figs., 5 tabs.

  9. GlidArc-assisted production of synthesis gas from LPG (Propane)

    International Nuclear Information System (INIS)

    Czernichowski, A.; Czernichowski, P.; Czernichowski, M.

    2003-01-01

    Small and medium size reformers that run on widely available Liquefied Petroleum Gas (LPG, containing mostly the propane) can provide Synthesis Gas (or Hydrogen extracted from it) to some Fuel Cell powered cars, boats, homes, farms etc. reducing therefore costs of the pure Hydrogen distribution. We contribute to such idea realization through our simply, plasma-assisted reformer avoiding a need of poison resistant catalysts or prior LPG desulfurizer. In fact, any level of sulphur in LPG is accepted for our non-catalytic reformer based on high-voltage discharges (called GlidArc). The discharges catalytically assist the exothermic partial oxidation process. Electric power assistance is less than 2% of the Lower Heating Value (LHV) of produced SynGas. Recycling such a small portion of the energy is therefore an acceptable compromise. The unique oxidant source is air. This contribution presents our expanded tests with commercial LPG in a 1-L reactor working at atmospheric pressure. At a 0.1 kW electric power assistance we produce a Nitrogen-diluted SynGas containing up to 45% of H 2 +CO at the output flow rate corresponding up to 2.7 m 3 (n)/h of pure H 2 +CO mixture that is equivalent to LHV output power of 8.6 kW. The LPG is totally reformed at more than 70% energetic efficiency and at the total absence of soot. (author)

  10. Efficacy of water spray protection against propane and butane jet fires impinging on LPG storage tanks

    Energy Technology Data Exchange (ETDEWEB)

    Shirvill, L.C. [Shell Global Solutions (UK), Chester (United Kingdom)

    2004-03-01

    Liquefied petroleum gas (LPG) storage tanks are often provided with water sprays to protect them in the event of a fire. This protection has been shown to be effective in a hydrocarbon pool fire but uncertainties remained regarding the degree of protection afforded in a jet fire resulting from a liquid or two-phase release of LPG. Two projects, sponsored by the Health and Safety Executive, have been undertaken to study, at full scale, the performance of a water spray system on an empty 13 tonne LPG vessel under conditions of jet fire impingement from nearby releases of liquid propane and butane. The results showed that a typical water deluge system found on an LPG storage vessel cannot be relied upon to maintain a water film over the whole vessel surface in an impinging propane or butane jet fire scenario. The deluge affects the fire itself, reducing the luminosity and smoke, resulting in a lower rate of wall temperature rise at the dry patches, when compared with the undeluged case. The results of these studies will be used by the HSE in assessing the risk of accidental fires on LPG installations leading to boiling liquid expanding vapour explosion (BLEVE) incidents. (Author)

  11. Explosion hazards of LPG-air mixtures in vented enclosure with obstacles.

    Science.gov (United States)

    Zhang, Qi; Wang, Yaxing; Lian, Zhen

    2017-07-15

    Numerical simulations were performed to study explosion characteristics of liquefied petroleum gas (LPG) explosion in enclosure with a vent. Unlike explosion overpressure and dynamic pressure, explosion temperature of the LPG-air mixture at a given concentration in a vented enclosure has very little variation with obstacle numbers for a given blockage ratio. For an enclosure without obstacle, explosion overpressures for the stoichiometric mixtures and the fuel-lean mixtures reach their maximum within the vent and that for fuel-rich mixture reaches its maximum beyond and near the vent. Dynamic pressures produced by an indoor LPG explosion reach their maximum always beyond the vent no matter obstacles are present or not in the enclosure. A LPG explosion in a vented enclosure with built-in obstacles is strong enough to make the brick and mortar wall with a thickness of 370mm damaged. If there is no obstacle in the enclosure, the lower explosion pressure of several kPa can not break the brick and mortar wall with a thickness of 370mm. For a LPG explosion produced in an enclosure with a vent, main hazards, within the vent, are overpressure and high temperature. However main hazards are dynamic pressure, blast wind, and high temperature beyond the vent. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. CdO necklace like nanobeads decorated with PbS nanoparticles: Room temperature LPG sensor

    Energy Technology Data Exchange (ETDEWEB)

    Sonawane, N.B. [Department of Physics, School of Physical Sciences, North Maharashtra University, Jalgaon, 425001 M.S. (India); K.A.M.P. & N.K.P. Science College, Pimpalner, Sakri, Dhule, M.S. (India); Baviskar, P.K. [Department of Physics, School of Physical Sciences, North Maharashtra University, Jalgaon, 425001 M.S. (India); Ahire, R.R. [S.G. Patil Science, Sakri, Dhule, M.S. (India); Sankapal, B.R., E-mail: brsankapal@gmail.com [Nano Materials and Device Laboratory, Department of Applied Physics, Visvesvaraya National Institute of Technology, South Ambazari Road, Nagpur, 440010 M.S. (India)

    2017-04-15

    Simple chemical route has been employed to grow interconnected nanobeads of CdO having necklace like structure through air annealing of cadmium hydroxide nanowires. This nanobeads of n-CdO with high surface area has been decorated with p-PbS nanoparticles resulting in the formation of nano-heterojunction which has been utilized effectively as room temperature liquefied petroleum gas (LPG) sensor. The room temperature gas response towards C{sub 2}H{sub 5}OH, Cl{sub 2}, NH{sub 3}, CO{sub 2} and LPG was investigated, among which LPG exhibits significant response. The maximum gas response of 51.10% is achieved with 94.54% stability upon exposure of 1176 ppm concentration of LPG at room temperature (27 °C). The resulting parameters like gas response, response and recovery time along with stability studies has been studied and results are discussed herein. - Highlights: • Conversion of Cd(OH){sub 2} nanowires to CdO nanonecklace by air annealing at 290 °C. • Decoration of PbS nanoparticles over CdO nanobeads by SILAR method. • Formation of n-CdO/p-PbS nano-heterojunction as room temperature LPG sensor. • Maximum gas response of 51.10% with 94.54% stability.

  13. Formulation and Characterization of Cu Doped ZnO Thick Films as LPG Gas Sensor

    Directory of Open Access Journals (Sweden)

    A. V. PATIL

    2010-12-01

    Full Text Available Thick films of pure and various concentrations (1 wt. %, 3 wt. %, 5 wt. %, 7 wt. % and 10 wt. % of Cu-doped ZnO were prepared on alumina substrates using a screen printing technique. These films were fired at a temperature of 700ºC for two hours in an air atmosphere. Morphological, compositional and structural properties of the samples were obtained using the scanning electron microscopy (SEM, Energy dispersive spectroscopy (EDAX and X-ray diffraction techniques respectively. The LPG gas sensing properties of these thick films were investigated at different operating temperatures and LPG gas concentrations. The surface resistance of thick films decreases when exposed to LPG gas. The Cu doped films show significant sensitivity to LPG gas than pure ZnO film. 5 wt. % Cu-doped ZnO film was found to be more sensitive (87.3 % to LPG gas exposed at 300 oC than other doping concentrations with fast response and recovery time.

  14. High-Average-Power Diffraction Pulse-Compression Gratings Enabling Next-Generation Ultrafast Laser Systems

    Energy Technology Data Exchange (ETDEWEB)

    Alessi, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-11-01

    Pulse compressors for ultrafast lasers have been identified as a technology gap in the push towards high peak power systems with high average powers for industrial and scientific applications. Gratings for ultrashort (sub-150fs) pulse compressors are metallic and can absorb a significant percentage of laser energy resulting in up to 40% loss as well as thermal issues which degrade on-target performance. We have developed a next generation gold grating technology which we have scaled to the petawatt-size. This resulted in improvements in efficiency, uniformity and processing as compared to previous substrate etched gratings for high average power. This new design has a deposited dielectric material for the grating ridge rather than etching directly into the glass substrate. It has been observed that average powers as low as 1W in a compressor can cause distortions in the on-target beam. We have developed and tested a method of actively cooling diffraction gratings which, in the case of gold gratings, can support a petawatt peak power laser with up to 600W average power. We demonstrated thermo-mechanical modeling of a grating in its use environment and benchmarked with experimental measurement. Multilayer dielectric (MLD) gratings are not yet used for these high peak power, ultrashort pulse durations due to their design challenges. We have designed and fabricated broad bandwidth, low dispersion MLD gratings suitable for delivering 30 fs pulses at high average power. This new grating design requires the use of a novel Out Of Plane (OOP) compressor, which we have modeled, designed, built and tested. This prototype compressor yielded a transmission of 90% for a pulse with 45 nm bandwidth, and free of spatial and angular chirp. In order to evaluate gratings and compressors built in this project we have commissioned a joule-class ultrafast Ti:Sapphire laser system. Combining the grating cooling and MLD technologies developed here could enable petawatt laser systems to

  15. Early structure of LPG partially premixed conically stabilized flames

    KAUST Repository

    Elbaz, Ayman M.

    2013-01-01

    This paper presents experimental investigation of LPG partially premixed turbulent flames stabilized within a conical nozzle burner under constant degree of partial premixing. The stability limits and mean flame structure are presented based on the mean gas temperature and the concentration of CO, O 2, NO, and HC at the flame early region of reaction. The investigation covered the influence of the nozzle cone angle, the jet exit velocity and the jet equivalence ratio. The stability results show that the flames with cone are more stable than those without cone. For conical stabilized flames, the stability results exhibit three different sensitivity regions between the jet velocity and equivalence ratio. The inflame measurements prove that the flame stability could be attributed to the triple flame structure at the flame leading edge. The data show that the triple flame structure is influenced by cone angle, the jet velocity and the equivalence ratio. The flame is believed to be controlled by the recirculation flow inside the cone. Increasing the cone angle induced higher air entrainment to the reaction zone as depicted by a higher O 2 concentration within the flame leading edge. Increasing the jet velocity to a certain limit enhances the intensity of combustion at the flame leading edge, while excessive increase in jet velocity reduces this intensity. At a fixed jet velocity the higher the equivalence ratio, the higher the amount of fuel diffused and engulfed to the reaction zone, the more delay of the combustion completion and the higher the emission concentrations of the flame. © 2012 Elsevier Inc.

  16. 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).

  17. 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.

  18. Nanofilm-coated long-period fiber grating humidity sensors for corrosion detection in structural health monitoring

    Science.gov (United States)

    Zheng, Shijie; Zhu, Yinian; Krishnaswamy, Sridhar

    2011-04-01

    Long-period gratings (LPGs) have shown their significant promising applications in sensors owing to the attractive features that they posses such as small size, immunity for electromagnetic interference, geometric versatility, multiplexing capability, and resistance to corrosive and hazardous environments. Recent researches have revealed that LPGs written on the standard optical fibers could be used as a powerful sensing platform for structural health monitoring. In this work, we inscribe LPGs into SMF-28 optical fiber by focused-beam CO2 laser, demonstrating as a refractive index sensor for nondestructive chemical detections in the civil infrastructures. Although evanescent-field based LPG sensors have been applied in quantitatively monitoring chemical analytes including moisture, chloride, and corrosion by-product, etc., the sensitivity, selectivity, and response time as well as thermo-stability of such sensors are still the issues for some special purposes. In order to improve those characteristics of the sensors, we propose two types of nano-film to be coated in grating region by electrostatic self-assembly (ESA) deposition processing. The primary coating does not affect on LPG transmission parameters such as resonance wavelength and its intensity that can be used for sensing, but it increases the sensitivity to refractive index change of surrounding material. The secondary coating is for selectively absorption of analyte molecule of interest. Response time of the nanofilm-coated LPG sensor is dependent on the analyte absorption and de-absorption rates as well as the thicknesses of the coating materials, which is also investigated. Multi-channel sensor system is being designed to monitor different analytes simultaneously, which is continuing to further explore the monitoring of structural health conditions through in situ measurements of corrosion in the concrete structures.

  19. LPG in the Totalfina-Elf merger; Le GPL dans la fusion Totalfina-Elf

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2000-04-01

    Elf Aquitaine's take-over by TotalFina was approved on February 9, by the European Commission, with substantial changes to the project initially submitted. One of the main changes involves the sale of Elf Antargaz and of a part of Elf's associated LPG logistics. Rumors say that a dozen of potential buyers were on the ranks in February to acquire this company which is the second French LPG marketer. The sale seems to question the LPG scheme set by TotalFina at the end of 1999. We published in our previous issue this scheme which was designed to give a larger span to the product, with its own management apart from other specialties. (authors)

  20. Experimental and analytical investigation of thermal coating effectiveness for 3 m3 LPG tanks engulfed by fire

    NARCIS (Netherlands)

    Landucci, G.; Molag, M.; Reinders, J.; Cozzani, V.

    2009-01-01

    Two large-scale diesel pool fire engulfment tests were carried out on LPG tanks protected with intumescing materials to test the effectiveness of thermal coatings in the prevention of hot BLEVE accidental scenarios in the road and rail transport of LPG. A specific test protocol was defined to

  1. LPG and NH3 sensing characteristics of DC electrochemically deposited Co3O4 films

    Science.gov (United States)

    Shelke, P. N.; Khollam, Y. B.; Gunjal, S. D.; Koinkar, P. M.; Jadkar, S. R.; Mohite, K. C.

    2015-03-01

    Present communication reports the LPG and NH3 sensing properties of Co3O4 films prepared on throughly cleaned stainless steel (SS) and copper (CU) substrates by using DC electrochemical deposition method followed by air annealing at 350°C/2 h. The resultant films are characterized by using X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM). The LPG and NH3 gas sensing properties of these films are measured at room temperature (RT) by using static gas sensing system at different concentrations of test gas ranging from 25 ppm to 350 ppm. The XRD and Raman spectroscopy studies clearly indicated the formation of pure cubic spinel Co3O4 in all films. The LPG and NH3 gas sensing properties of films showed (i) the increase in sensitivity factor (S.F.) with gas concentrations and (ii) more sensibility to LPG as compared to NH3 gas. In case of NH3 gas (conc. 150 ppm) and LPG gas (conc. 60 ppm) sensing, the maximum S.F. = 270 and 258 are found for the films deposited on CU substrates, respectively. For all films, the response time (3-5 min.) is found to be much higher than the recovery time (30-50 sec). For all films, the response and recovery time are found to be higher for LPG as compared to NH3 gas. Further, repeatability-reproducibility in gas sensing properties is clearly noted by analysis of data for number of cycles recorded for all films from different set of depositions.

  2. Fabrication of high-resolution reflective scale grating for an optical encoder using a patterned self-assembly process

    International Nuclear Information System (INIS)

    Fan, Shanjin; Jiang, Weitao; Li, Xuan; Yu, Haoyu; Lei, Biao; Shi, Yongsheng; Yin, Lei; Chen, Bangdao; Liu, Hongzhong

    2016-01-01

    Steel tape scale grating of a reflective incremental linear encoder has a key impact on the measurement accuracy of the optical encoder. However, it is difficult for conventional manufacturing processes to fabricate scale grating with high-resolution grating strips, due to process and material problems. In this paper, self-assembly technology was employed to fabricate high-resolution steel tape scale grating for a reflective incremental linear encoder. Graphene oxide nanoparticles were adopted to form anti-reflective grating strips of steel tape scale grating. They were deposited in the tape, which had a hydrophobic and hydrophilic grating pattern when the dispersion of the nanoparticles evaporated. A standard lift-off process was employed to fabricate the hydrophobic grating strips on the steel tape. Simultaneously, the steel tape itself presents a hydrophilic property. The hydrophobic and hydrophilic grating pattern was thus obtained. In this study, octafluorocyclobutane was used to prepare the hydrophobic grating strips, due to its hydrophobic property. High-resolution graphene oxide steel tape scale grating with a pitch of 20 μ m was obtained through the self-assembly process. The photoelectric signals of the optical encoder containing the graphene oxide scale grating and conventional scale grating were tested under the same conditions. Comparison test results showed that the graphene oxide scale grating has a better performance in its amplitude and harmonic components than that of the conventional steel tape scale. A comparison experiment of position errors was also conducted, demonstrating an improvement in the positioning error of the graphene oxide scale grating. The comparison results demonstrated the applicability of the proposed self-assembly process to fabricate high-resolution graphene oxide scale grating for a reflective incremental linear encoder. (paper)

  3. Bragg Grating Waveguide Array Ultrafast Laser Inscribed into the Cladding of a Flat Fiber

    Directory of Open Access Journals (Sweden)

    Beecher Stephen J.

    2013-11-01

    Full Text Available We report the fabrication and initial characterization of a waveguide sensor array in the cladding of a flat fiber. The sensor, designed to independently measure the strain on three Bragg grating waveguides, exploits the true three dimensional fabrication technology of ultrafast laser inscription by placing these gratings in a non-planar configuration.

  4. Kajian Eksperimental Perbandingan Performansi Mesin Otto Bahan Bakar Premium dengan Bahan Bakar LPG

    OpenAIRE

    Sitorus, Jefferson

    2013-01-01

    The decreasing availability of fossil fuels led to a variety of ideas how to solve this problem. LPG (Liquefied petroleum gas) is one alternative fuel that can be used in trending engine, one of which is a gasoline engine generator sets in 4-stroke. By modifying the carburetor so the engine can work as when using gasoline. Although the performance of the machine tends to not give optimal results such as engine performance when using gasoline, but has the advantage of LPG fuel, the emissions p...

  5. Local health care system utilizing the LPG (liquid propane gas) network.

    Science.gov (United States)

    Umemoto, T; Hoshi, H; Tsuda, M; Horio, S; Itou, N; Neriki, T

    1998-07-01

    JAC's LPG monitoring network system is mainly provided in mountain villages. However, by using this system, it will be possible to start a Digital Network Program for the Elderly while maintaining superior economic feasibility and public benefit using existing information infrastructures. This project also has the capabilities for the creation of a fire/disaster monitoring system, as well as a health care system by using conventional LPG monitoring systems. Telemedicine is an option for the future, as well, by connecting medical equipment and a tele-conferencing system.

  6. Investigating the influences of liquid LPG injection on spark ignition (SI engine

    Directory of Open Access Journals (Sweden)

    Tukiman Mohd Mustaqim

    2017-01-01

    Full Text Available Liquefied petroleum gas (LPG is one of the alternative fuels that becoming popular to be use in spark ignition engine (SI. This paper briefly presents the influence of energy content to the engine output of 1.6L SI engine of Proton Gen 2. The engine was coupled to a chassis dynamometer and few related apparatus were employed in determine the engine behavior. All data collected were illustrated in graph for further analysis. The engine shows comparable engine output, however, the engine requires some tuning in order to fully utilize the energy content of LPG.

  7. Petroleum products. LPG-c is taking off; Produits petroliers. Le decollage du GPL-c

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    A strong tax reduction and other financial incentives for liquefied petroleum gas, have stimulated LPG consumption in France, with a 60 pc increase between 1995 and 1996. LPG fuels allow for an important reduction in polluting emissions. Other news are presented, which concern the French Petroleum Institute strategy and financing, European regulations on fuel quality, the issue of the decreasing number of service stations in France, new production sites for bio-fuels, issues with petroleum investment international embargoes, the privatization of Elf-Aquitaine, the 1996 truck driver strike, and the Goa international conference between energy producer and user countries

  8. Prediction of electricity and lpg consumption in a hotel using artificial neural networks

    International Nuclear Information System (INIS)

    Montero, L Reiners; Perez T, Carlos; Gongora L, Ever; Marrero, R Secundino

    2009-01-01

    This work was developed in order to improve the current tools for energy planning. This makes possible to predict electricity and LPG consumption in a tourist facility with accuracy higher than 90% by using Artificial Neuronal Networks (ANN) as fitting and predictive models. Local climatology and occupational patterns were used as entering variables for the models. Parametric modeling was performed as starting conditions and then improved with ANN. Matlab tools were used for calculations. The average deviation when predicting electricity consumption was 0.6% with a standard deviation of 4%. For LPG consumption the average deviation was less than 1% with a standard deviation of 1.3%.

  9. Petroleum products. LPG-c is taking off; Produits petroliers. Le decollage du GPL-c

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    A strong tax reduction and other financial incentives for liquefied petroleum gas, have stimulated LPG consumption in France, with a 60 pc increase between 1995 and 1996. LPG fuels allow for an important reduction in polluting emissions. Other news are presented, which concern the French Petroleum Institute strategy and financing, European regulations on fuel quality, the issue of the decreasing number of service stations in France, new production sites for bio-fuels, issues with petroleum investment international embargoes, the privatization of Elf-Aquitaine, the 1996 truck driver strike, and the Goa international conference between energy producer and user countries

  10. 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.

  11. 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.

  12. 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.

  13. 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....

  14. Innovative diffraction gratings for high-resolution resonant inelastic soft x-ray scattering spectroscopy

    International Nuclear Information System (INIS)

    Voronov, D.L.; Warwick, T.; Gullikson, E. M.; Salmassi, F.; Padmore, H. A.

    2016-01-01

    High-resolution Resonant Inelastic X-ray Scattering (RIXS) requires diffraction gratings with very exacting characteristics. The gratings should provide both very high dispersion and high efficiency which are conflicting requirements and extremely challenging to satisfy in the soft x-ray region for a traditional grazing incidence geometry. To achieve high dispersion one should increase the groove density of a grating; this however results in a diffraction angle beyond the critical angle range and results in drastic efficiency loss. The problem can be solved by use of multilayer coated blazed gratings (MBG). In this work we have investigated the diffraction characteristics of MBGs via numerical simulations and have developed a procedure for optimization of grating design for a multiplexed high resolution imaging spectrometer for RIXS spectroscopy to be built in sector 6 at the Advanced Light Source (ALS). We found that highest diffraction efficiency can be achieved for gratings optimized for 4"t"h or 5"t"h order operation. Fabrication of such gratings is an extremely challenging technological problem. We present a first experimental prototype of these gratings and report its performance. High order and high line density gratings have the potential to be a revolutionary new optical element that should have great impact in the area of soft x-ray RIXS.

  15. Regulated and unregulated exhaust gas components from LD vehicles on petrol, diesel, LPG and CNG

    NARCIS (Netherlands)

    Hendriksen, P.; Rijkeboer, R.C.

    1993-01-01

    Four fuels (petrol, LPG, CNG and diesel) are compared on passenger cars and lighter vans. The comparisons are made for the usual regulated components, but also for a number of unregulated components. The project was financed by the Dutch government, the association of gas suppliers, a number of

  16. Synthesis of ZnO nanopencils using wet chemical method and its investigation as LPG sensor

    International Nuclear Information System (INIS)

    Shimpi, Navinchandra G.; Jain, Shilpa; Karmakar, Narayan; Shah, Akshara; Kothari, D.C.; Mishra, Satyendra

    2016-01-01

    Highlights: • Synthesis using a simple and cost-effective wet chemical process. • Uniform, monodispersed and pure nanoparticles. • Pencil shaped rods with sharp tips. • Understanding of Growth mechanism. • Efficient LPG sensing with high response. • Morphology dependent sensing. - Abstract: ZnO nanopencils (NPCs) were prepared by a novel wet chemical process, using triethanolamine (TEA) as a mild base, which is relatively simple and cost effective method as compared to hydrothermal method. ZnO NPCs were characterized using powder X-ray diffraction (XRD), Fourier Transform Infra-Red (FTIR) spectroscopy in mid-IR and far-IR regions, X-ray Photoelectron Spectroscopy (XPS), UV–vis (UV–vis) absorption spectroscopy, room temperature Photoluminescence (PL) spectroscopy and Field Emission Scanning Electron Microscopy (FESEM). ZnO NPCs obtained, were highly pure, uniform and monodispersed.XRD pattern indicated hexagonal unit cell structure with preferred orientation along the c-axis. Sensing behaviour of ZnO NPCs was studied towards Liquefied Petroleum Gas (LPG) at different operating temperatures. The study shows that ZnO NPCs were most sensitive and promising candidate for detection of LPG at 250 °C with gas sensitivity > 60%. The high response towards LPG is due to high surface area of ZnO NPCs and their parallel alignment.

  17. Dual-fuel HCCI operation with DME/LPG/gasoline/hydrogen

    International Nuclear Information System (INIS)

    Bae, C.

    2009-01-01

    The advantages of homogeneous charge compression ignition (HCCI) engines include usage of the different type of fuels, ultra low nitrogen oxide and particulate matter emissions and improved fuel economy. Disadvantages include an excessive combustion rate, engine noise, and hydrocarbon and carbon emissions. An experiment on dual-fuel HCCI operation with dimethyl ether (DME)/liquefied petroleum gas (LPG)/gasoline/hydrogen was presented. The advantages and disadvantages were first presented and the dual-fuel HCCI combustion engine was illustrated through an experimental apparatus. The experimental conditions were also presented in terms of engine speed, DME injection quantity, LPC injection quantity, and LPC composition. Experimental results were discussed for output performance and indicated mean effective pressure (IMEP). It was concluded that the effect of LPG composition in a DME-LPG dual-fueled HCCI engine at various injection quantity and injective timing were observed. Specifically, it was found that propane was a more effective way to increase IMEP in this study, and that in a DME HCCI engine, higher load limit was extended by using LPG as an ignition inhibitor. tabs., figs.

  18. The determination of aldehydes in the exhaust gases of LPG fuelled engines

    NARCIS (Netherlands)

    Rutten, G.A.F.M.; Burtner, C.W.J.; Visser, H.; Rijks, J.A.

    1988-01-01

    The exhaust gas of a LPG fuelled engine is drawn through two bubblers in series in an ice bath, and filled with saturated 2,4-dinitrophenylhydrazine in 2M HCl. After heating the derivatives are extracted with toluene-cyclohexane and 1l samples injected on-column on a OV1 capillary column. Using an

  19. ENERGY EFFICIENCY, ENERGY SAVING POTENTIAL AND ENVIRONMENTAL IMPACT RESEARCH OF LPG CARRIER REFRIGERATION SYSTEM

    Directory of Open Access Journals (Sweden)

    V. О. Bedrosov

    2016-12-01

    Full Text Available Nowadays energy efficiency improvement and global warming are issues of current interest because of the natural resources depletion and extreme climate change. Thus, the problem of formation of strict regulations regarding emissions into the air arises. This paper presents the study of cascade refrigeration system for re-condensing of associated petroleum gas during sea transportation for LPG carrier. The structural optimization has been performed. LPG gas carriers with 266 000 m3 ethane capacity require 15 MW cascade refrigeration system for re-condensing if the temperature in the coastal LPG storage is -70°C, and the temperature for transported Ethan is maintained at  -75°C. For current storage conditions the required system cooling capacity is only 1,078 MW intended for the heat gain rejection from the environment during Ethane transportation. The replacement of ozone-depleting refrigerant R22 to alternative agents: R407C, R404A, R402A, R717, R290, R1270 was estimated. The results of analysis have shown that the proposed improvements can be used to optimize the LPG carrier cascade refrigeration system

  20. Underground rock storage concepts for natural gas and LPG in Finland

    International Nuclear Information System (INIS)

    Saerkkae, P.

    1990-01-01

    Natural gas storage concepts are developed in Finland for both deep, unlined rock storages and cryogenic lined, near-surface storages. For butane and propane, Neste Oy has two unlined rock storages in Porvoo. Up to now, experiences are good on storage of LPG in rock temperature and higher than hydrostatic pressure. (author). 3 refs, 8 figs

  1. Risk reduction in road and rail LPG transportation bij passive fire protection

    NARCIS (Netherlands)

    Molag e.a., M. (Menso)

    2009-01-01

    The potential reduction of risk in LPG (Liquified Petroleum Gas) road transport due to the adoption of passive fire protectionswas investigated. Experimental data available for small scale vessels fully engulfed by a fire were extended to real scale road and rail tankers through a finite elements

  2. Kinetic modeling of liquefied petroleum gas (LPG) reduction of titania in MATLAB

    Science.gov (United States)

    Yin, Tan Wei; Ramakrishnan, Sivakumar; Rezan, Sheikh Abdul; Noor, Ahmad Fauzi Mohd; Izah Shoparwe, Noor; Alizadeh, Reza; Roohi, Parham

    2017-04-01

    In the present study, reduction of Titania (TiO2) by liquefied petroleum gas (LPG)-hydrogen-argon gas mixture was investigated by experimental and kinetic modelling in MATLAB. The reduction experiments were carried out in the temperature range of 1100-1200°C with a reduction time from 1-3 hours and 10-20 minutes of LPG flowing time. A shrinking core model (SCM) was employed for the kinetic modelling in order to determine the rate and extent of reduction. The highest experimental extent of reduction of 38% occurred at a temperature of 1200°C with 3 hours reduction time and 20 minutes of LPG flowing time. The SCM gave a predicted extent of reduction of 82.1% due to assumptions made in the model. The deviation between SCM and experimental data was attributed to porosity, thermodynamic properties and minute thermal fluctuations within the sample. In general, the reduction rates increased with increasing reduction temperature and LPG flowing time.

  3. Synthesis of ZnO nanopencils using wet chemical method and its investigation as LPG sensor

    Energy Technology Data Exchange (ETDEWEB)

    Shimpi, Navinchandra G., E-mail: navin_shimpi@rediffmail.com [Department of Chemistry, University of Mumbai, Santacruz (East), Mumbai-400098 (India); Jain, Shilpa [Department of Chemistry, University of Mumbai, Santacruz (East), Mumbai-400098 (India); Karmakar, Narayan [Department of Physics, University of Mumbai, Santacruz (East), Mumbai-400098 (India); Shah, Akshara [Department of Chemistry, University of Mumbai, Santacruz (East), Mumbai-400098 (India); Kothari, D.C. [Department of Physics, University of Mumbai, Santacruz (East), Mumbai-400098 (India); National Centre for Nanosciences & Nanotechnology, University of Mumbai, Santacruz (East), Mumbai-400098 (India); Mishra, Satyendra [University Institute of Chemical Technology, North Maharashtra University, Jalgaon (India)

    2016-12-30

    Highlights: • Synthesis using a simple and cost-effective wet chemical process. • Uniform, monodispersed and pure nanoparticles. • Pencil shaped rods with sharp tips. • Understanding of Growth mechanism. • Efficient LPG sensing with high response. • Morphology dependent sensing. - Abstract: ZnO nanopencils (NPCs) were prepared by a novel wet chemical process, using triethanolamine (TEA) as a mild base, which is relatively simple and cost effective method as compared to hydrothermal method. ZnO NPCs were characterized using powder X-ray diffraction (XRD), Fourier Transform Infra-Red (FTIR) spectroscopy in mid-IR and far-IR regions, X-ray Photoelectron Spectroscopy (XPS), UV–vis (UV–vis) absorption spectroscopy, room temperature Photoluminescence (PL) spectroscopy and Field Emission Scanning Electron Microscopy (FESEM). ZnO NPCs obtained, were highly pure, uniform and monodispersed.XRD pattern indicated hexagonal unit cell structure with preferred orientation along the c-axis. Sensing behaviour of ZnO NPCs was studied towards Liquefied Petroleum Gas (LPG) at different operating temperatures. The study shows that ZnO NPCs were most sensitive and promising candidate for detection of LPG at 250 °C with gas sensitivity > 60%. The high response towards LPG is due to high surface area of ZnO NPCs and their parallel alignment.

  4. Evaluation of the environmental impact of modern passenger cars on petrol, diesel, automotive LPG and CNG

    NARCIS (Netherlands)

    Hendriksen, P.; Vermeulen, R.J.; Rijkeboer, R.C.; Bremmers, D.A.C.M.; Smokers, R.T.M.; Winkel, R.G.

    2003-01-01

    The project reported here concerns an investigation into the environmental performance of modern passenger cars on four different fuels: petrol, diesel, automotive LPG and CNG. The objectives of the project were twofold: - To make a valid and useful comparison between modern vehicles fuelled by

  5. A study to design the emergency reaction plan for LPG tanks in 5 th ...

    African Journals Online (AJOL)

    PROMOTING ACCESS TO AFRICAN RESEARCH ... On the other hand, today, with increased density and proximity of industrial units, the adverse consequences ... This study aims to identify the risks in LPG storage unit, 5th South Pars Gas Refinery and possible events ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  6. Risk reduction in road and rail LPG transportation by passive fire protection

    NARCIS (Netherlands)

    Paltrinieri, N.; Landucci, G.; Molag, M.; Bonvicini, S.; Spadoni, G.; Cozzani, V.

    2009-01-01

    The potential reduction of risk in LPG (Liquefied Petroleum Gas) road transport due to the adoption of passive fire protections was investigated. Experimental data available for small scale vessels fully engulfed by a fire were extended to real scale road and rail tankers through a finite elements

  7. Ethanol and LPG sensing characteristics of SnO2 activated Cr2 O3 ...

    Indian Academy of Sciences (India)

    Administrator

    between neighbouring grains in a material is an important factor, which determines sensitivity of the .... O2 (gas) f O2 (ads),. (3). Figure 4. Temperature dependence of conductance of pure and activated Cr2O3 sensors. Figure 5. Sensing response to ethanol (a–f) and LPG (g) for different dopant concentrations (0⋅5%) at ...

  8. Effectiveness of replacing catalytic converters in LPG-fueled vehicles in Hong Kong

    Directory of Open Access Journals (Sweden)

    X. Lyu

    2016-05-01

    Full Text Available Many taxis and public buses are powered by liquefied petroleum gas (LPG in Hong Kong. With more vehicles using LPG, they have become the major contributor to ambient volatile organic compounds (VOCs in Hong Kong. An intervention program which aimed to reduce the emissions of VOCs and nitrogen oxides (NOx from LPG-fueled vehicles was implemented by the Hong Kong government in September 2013. Long-term real-time measurements indicated that the program was remarkably effective in reducing LPG-related VOCs, NOx and nitric oxide (NO in the atmosphere. Receptor modeling results further revealed that propane, propene, i-butane, n-butane and NO in LPG-fueled vehicle exhaust emissions decreased by 40.8 ± 0.1, 45.7 ± 0.2, 35.7 ± 0.1, 47.8 ± 0.1 and 88.6 ± 0.7 %, respectively, during the implementation of the program. In contrast, despite the reduction of VOCs and NOx, O3 following the program increased by 0.40 ± 0.03 ppbv (∼  5.6 %. The LPG-fueled vehicle exhaust was generally destructive to OH and HO2. However, the destruction effect weakened for OH and it even turned to positive contribution to HO2 during the program. These changes led to the increases of OH, HO2 and HO2 ∕ OH ratio, which might explain the positive O3 increment. Analysis of O3–VOCs–NOx sensitivity in ambient air indicated VOC-limited regimes in the O3 formation before and during the program. Moreover, a maximum reduction percentage of NOx (i.e., 69 % and the lowest reduction ratio of VOCs ∕ NOx (i.e., 1.1 in LPG-fueled vehicle exhaust were determined to give a zero O3 increment. The findings are of great help to future formulation and implementation of control strategies on vehicle emissions in Hong Kong, and could be extended to other regions in China and around the world.

  9. 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.

  10. 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 ...

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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...

  16. Direct injection of gaseous LPG in a two-stroke SI engine for improved performance

    International Nuclear Information System (INIS)

    Pradeep, V.; Bakshi, Shamit; Ramesh, A.

    2015-01-01

    Improvements in a two-stroke, spark-ignition (2S–SI) engine can be realized by curtailing short-circuiting losses effectively through direct injection of the fuel. Liquefied petroleum gas (LPG) is an alternative transportation fuel that is used in several countries. However, limited information is available on LPG fuelled direct injected engines. Hence, there is a need to study these systems as applied to 2S–SI engines in order to bring out their potential benefits. A manifold injected 2S–SI engine is modified for direct injection of LPG, in gaseous form, from the cylinder head. This engine is evaluated for performance, emission and combustion. Evaluation at various throttle positions and constant speed showed that this system can significantly improve the thermal efficiency and lower the hydrocarbon (HC) emissions. Up to 93% reduction in HC emissions and improved combustion rates are observed compared to the conventional manifold injection system with LPG. CO emissions are higher and peak NO emissions are lower with this system due to the presence of richer in–cylinder trapped mixtures and charge stratification. This system can operate with similar injection timings at different throttle positions which make electronic control simpler. It can work with low injection pressures in the range of 4–5 bars. All these advantages are attractive for commercial viability of this engine. - Highlights: • Energy saving, low pressure, direct gaseous LPG injection in engine. • Significant reduction in HC emissions at all operating conditions. • No significant changes in injection timings for different throttle positions.

  17. Technical evaluation and assessment of CNG/LPG bi-fuel and flex-fuel vehicle viability

    Science.gov (United States)

    Sinor, J. E.

    1994-05-01

    This report compares vehicles using compressed natural gas (CNG), liquefied petroleum gas (LPG), and combinations of the two in bi-fuel or flex-fuel configurations. Evidence shows that environmental and energy advantages can be gained by replacing two-fuel CNG/gasoline vehicles with two-fuel or flex-fuel systems to be economically competitive, it is necessary to develop a universal CNG/LPG pressure-regulator-injector and engine control module to switch from one tank to the other. For flex-fuel CNG/LPG designs, appropriate composition sensors, refueling pumps, fuel tanks, and vaporizers are necessary.

  18. 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°.

  19. 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.

  20. 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.

  1. 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

  2. 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....

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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 ...

  8. Scenario of the emerging shift from gasoline to LPG fuelled cars in Ghana: A case study in Ho Municipality, Volta Region

    International Nuclear Information System (INIS)

    Biscoff, Robert; Akple, Maxwell; Turkson, Richard; Klomegah, Wise

    2012-01-01

    The use of LPG as automotive fuel is on the increase worldwide. In developing countries such as Ghana, the rudimental way of operating LPG cars is of a national concern since there is no clear cut framework within which they function. This paper presents a scenario of development from conversion of gasoline to LPG fuelling system in cars in Ho, Ghana. Data were collected through survey (100 questionnaires), in-depth interviews (2), Focus Group Discussions (3) and direct observations. The result shows LPG conversion is carried out by the local informally trained mechanics especially for Taxis because of its low consumption resulting in more profit. Conversion takes 1–2 day with an average estimated cost of GH□ 450 cedis ($300). The LPG policy in Ghana focuses on domestic purposes hence the fuel being heavily subsidised. Challenges' being faced by the autogas market in Ghana includes; no clear cut policy, low number of refuelling stations, lack of standard conversion and installation kits and unprofessional LPG installers. In order for government to benefit from LPG as automotive fuel, coherent autogas policy should be formulated ensuring the availability of the LPG with price affordability as in the case of gasoline and diesel. - Highlights: ► Cars are converted to LPG system locally because of economic gains relative to emission reduction. ► LPG fuelled cars makes twice profit as compared to gasoline cars. ► Conversion to LPG system takes 1–2 day with an average cost of GH 450 cedis ($300). ► LPG policy in Ghana focus on domestic purposes not for commercial hence heavily subsidised. ► Ghana Government should formulate clear policy on LPG use in cars.

  9. 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

    potential of this technology, a set of three prototype VPH gratings (one each of the blue, red, and NIR designs) was ordered and has been recently delivered. The goal for these prototype units, but not a requirement, was to meet the specifications for the final gratings in order to serve as spares and also as early demonstration and integration articles. In this paper we present the design and specifications for the PFS gratings, the plan and setups used for testing both the prototype and final gratings, and results from recent optical testing of the prototype grating set.

  10. Perspectives of supply of LPG (Liquefied Petroleum Gases) in Brazil; Perespectivas de suprimento de GLP no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Luis Sebastiao [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil); Costa, Gildo Gabriel da; Moreira, Jose Guilherme de Souza [Agencia Nacional do Petroleo, Gas Natural e Biocombustiveis (ANP), Rio de Janeiro, RJ (Brazil)

    2004-07-01

    This work presents the indicative planning of the expansion of the infrastructure from liquefied petroleum gases (LPG) in the five years (2002-07). With base in the forecast of the demand - using the data of the offer, consumption, stock and the evaluation of the existent infrastructure (ports, terminals, tanks etc.) - it is evaluated the storage need and movement of the product. Compared to the period 1998-2003, a decrease was verified accentuated in the very superior consumption to the projected value. One of the causes was the increase in the price of LPG; other, the reduction in the number of the homes with LPG. Being considered the sceneries of LPG in this five years and the number of families, the perspective is the reduction of 5,6% in the consumption of LPG, being reached 6.307 thousand tons in 2007. For the period for an increase of 20% is waited in the offer it interns of the product that, together with the smallest demand, it will provoke a reduction of more than a fourth of the imports: 1.763 kt in 2002, for 403 kt in 2007. In spite of the reduction in the consumption and maintenance of the stock, the estimate of LPG will only increase of 20,6 days for 21,8 days, however the Brazil will be self-sufficient. (author)

  11. 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

  12. Thermal balance of a LPG fuelled, four stroke SI engine with water addition

    International Nuclear Information System (INIS)

    Ozcan, Hakan; Soeylemez, M.S.

    2006-01-01

    The effect of water injection on a spark ignition engine thermal balance and performance has been experimentally investigated. A four stroke, four cylinder conventional engine was used with LPG (liquid petroleum gas) as fuel. Different water to fuel ratios by mass were used with variable engine speed ranging from 1000 to 4500 rpm. The results showed that as the water injection level to the engine increased, the percentage of useful work increased, while the losses other than unaccounted losses decreased. Additionally, the specific fuel consumption decreases, while the engine thermal efficiency increases. The average increase in the brake thermal efficiency for a 0.5 water to fuel mass ratio is approximately 2.7% over the use of LPG alone for the engine speed range studied

  13. The influence of using LPG device on the CO2 emissions from personal passenger cars

    Directory of Open Access Journals (Sweden)

    Viliam Carach

    2007-12-01

    Full Text Available Traffic, mostly the air and car traffic is the biggest producer of CO2 (51% at present. CO2 is one of the most important greenhouse gases with more than 50 % of emissions contributing to this major global ecological problem. A rising concetration of CO2 in the atmosphere leads to higher global temperatures. The main problem is the rise of CO2 emissions in most developed countries despite international undertakings accepted in 80´s. This is the main reason for finding solutions to reduce the amount of CO2 emissions in the traffic. One of many solutions is the use of LPG fuel. The purpose of this article is to quantify the efficiency of using LPG in personal passenger cars.

  14. Liquefied Petroleum Gases (LPG) and the fight against deforestation: the Senegal example

    International Nuclear Information System (INIS)

    Boubacar, B.

    1993-01-01

    Domestic LPG consumption in Senegal is over 40,000 tonnes in 1992, thus preserving more than 33,000 hectares of forest. Three reasons explain the success of the 'butanization' policy implemented by the country in its fight against deforestation: political desire, constant cooperation between the public authorities and distributors, but also a supply of gas and inexpensive cookers. The penetration of these butane cookers on the market occurred mainly in urban areas (it is the leading household appliance of urban families in Senegal), but it is also quite visible in rural areas as well, explained Mr. Boubacar Barry General Manager of Totalgaz Senegal in his speech 'How to fight the Growing Desert with Simple Means and a little imagination' during the 6th World LPG Meeting last October in Marrakech. 2 figs., 3 photos

  15. An assessment of the market for LPG and CNG in Peru's transport sector

    International Nuclear Information System (INIS)

    Boykiw, A. L.

    1999-01-01

    This is an abridged version of the report prepared by Boykiw and Company Limited to provide a technical, statistical and financial assessment of potential sales of liquefied petroleum gases (LPG) or propane, and compressed natural gas (CNG) to the transportation sector in Peru. Results show that use of CNG and LPG in Peru's transportation sector will primarily be a function of the counrty's vehicle population, the economics of conversion and the availability of infrastructure. With regard to conversion, the fact that 62 per cent of the nation's one million vehicles are located in Lima, combined with their age, the prospects appear to be very favourable. Changing to LPG will also benefit the environment since carbon monoxide and nitrogen oxides emissions will be significantly reduced. Similar environmental benefits are expected from the use of CNG. Assuming that low cost first generation conversion kits can be made available, in combination with the growing refueling infrastructure ( from one in 1994 to 9 by the end of 1999, and an additional five in 2000) should result in a dramatic increase in the number of vehicles using LPG. By contrast, the prospect for CNG as vehicle fuel is less favourable because of the much more complex and costly refuelling station required to make it practicable. Based on very incomplete information on the Lima fleet of vehicles and their operating characteristics, the total number of CNG-fuelled vehicles five years after CNG becomes available in Lima, is estimated at between 2,000 and 3,000, and CNG requirements of between 800,000 and 1,500,000 cubic feet per day

  16. Analysis of the carbon monoxide emission by internal combustion engines using LPG as a fuel

    International Nuclear Information System (INIS)

    Dimitrovski, Mile

    2002-01-01

    In this paper a description of the toxic emission reduction as well as a reduction of the toxic components presence in exhaust gases is presented. The analysis of the alternative gaseous fuels application as one of the possibilities for a toxic emission reduction is given. In addition, the results of the CO concentration measurements for two cases: first using gasoline, than liquefied petrol gas (LPG) as a fuel are presented. (Author)

  17. Radiological health implications of lead-210 and polonium-210 accumulations in LPG refineries

    International Nuclear Information System (INIS)

    Summerlin, J. Jr.; Prichard, H.M.

    1985-01-01

    Radon-222, a naturally occurring radioactive noble gas, is often a contaminant in natural gas. During fractionation at processing plants, Radon tends to be concentrated in the Liquified Petroleum Gas (LPG) product stream. Radon-222 decays into a number of radioactive metallic daughters which can plate out on the interior surfaces of plant machinery. The hazards associated with gamma-emitting short-lived radon daughters have been investigated previously. The present work reports an analysis of the hazards associated with the long-lived daughters; Pb-210, Bi-210, and Po-210. These nuclides do not emit appreciable penetrating radiation, and hence do not represent a hazard as long as they remain on the inside surfaces of equipment. However, when equipment that has had prolonged exposure to an LPG stream is disassembled for repair or routine maintenance, opportunities for exposure to radioactive materials can occur. A series of measurements made on an impeller taken from a pump in an LPG facility is reported. Alpha spectroscopy revealed the presence of Po-210, and further measurements showed that the amount on the impeller surface was well above the exempt quantity. Breathing zone measurements made in the course of cleaning the impeller showed that an inhalation exposure equivalent to breathing Po-210 at the Maximum Permissible Concentration (MPC) for 60 hours could be delivered in less than half an hour. It was concluded that maintenance and repair work on LPG and derivitive product stream equipment must be carried out with the realization that a potential radiological health problem exists

  18. LPG sensing characteristics of electrospray deposited SnO2 nanoparticles

    International Nuclear Information System (INIS)

    Gürbüz, Mevlüt; Günkaya, Göktuğ; Doğan, Aydın

    2014-01-01

    Highlights: • SnO 2 nanopowder was deposited on conductive substrates using ESD technique. • Solution flow rate, coating time, substrate–nozzle distance and solid/alcohol ratio were studied to optimize SnO 2 film structure. • The gas sensing properties of tin oxide films were investigated using LPG. • The sensitivity of the films was increased with operating temperature. • The best sensitivity was observed for 20 LEL LPG at 450 °C operating temperature. - Abstract: In this study, SnO 2 films were fabricated on conductive substrate such as aluminum and platinum coated alumina using electro-spray deposition (ESD) method for gas sensor applications. Solution flow rate, coating time, substrate–nozzle distance and solid/alcohol ratio were studied to optimize SnO 2 film structure. The morphology of the deposited films was characterized by stereo and scanning electron microscopy (SEM). The gas sensing properties of tin oxide films were investigated using liquid petroleum gas (LPG) for various lower explosive limit (LEL). The results obtained from microscopic analyses show that optimum SnO 2 films were evaluated at flow rate of 0.05 ml/min, at distance of 6 cm, for 10 min deposition time, for 20 gSnO 2 /L ethanol ratio and at 7 kV DC electric field. By the results obtained from the gas sensing behavior, the sensitivity of the films was increased with operating temperature. The films showed better sensitivity for 20 LEL LPG concentration at 450 °C operating temperature

  19. Identification and quality assessment of beverages using a long period grating fibre-optic sensor modified with a mesoporous thin film

    Directory of Open Access Journals (Sweden)

    Sergiy Korposh

    2014-08-01

    Full Text Available In this study, an optical fibre long period grating (LPG sensor functionalised with a mesoporous thin film was employed for the identification and quality assessment of beverages. The principle of the discrimination of beverages using an LPG sensor is based on the measurement of the change in refractive index of a sensitive film, induced by the binding of the chemical compounds present in the beverage. The sensitive film deposited onto the LPG consisted of poly(allylamine hydrochloride (PAH and silica nanospheres (SiO2 NPs with diameters ranging from 40 nm to 50 nm. PAH imparts selectivity, while the SiO2 NPs endow the film with high porosity and enhanced sensitivity. In this study, five different types of beverages, red and white wines, brandy, nihonshyu (sake, a Japanese rice wine, and shochu (a Japanese distilled beverage, prepared via distillation and fermentation, were used to assess the capability of the sensor to identify the origin of the beverages. In addition, a selection of red wines was used to evaluate the use of the sensor in the assessment of the quality of beverages. The results obtained were benchmarked against those obtained using gas chromatography–mass spectrometry for the determination of volatile compounds contributing to the flavours of a set of red wines. Principal component analysis (PCA was employed for data analysis. This approach enabled both quality assessment of beverages and identification of the methods and materials used for their preparation. Keywords: Long period grating, Mesoporous thin film, Layer-by-layer, Quality assessment, Beverages

  20. Electrophoretic Deposition of SnO2 Nanoparticles and Its LPG Sensing Characteristics

    Directory of Open Access Journals (Sweden)

    Göktuğ Günkaya

    2015-01-01

    Full Text Available Homogenized SnO2 nanoparticles (60 nm in acetylacetone mediums, both with and without iodine, were deposited onto platinum coated alumina substrate and interdigital electrodes using the electrophoretic deposition (EPD method for gas sensor applications. Homogeneous and porous film layers were processed and analyzed at various coating times and voltages. The structure of the deposited films was characterized by a scanning electron microscopy (SEM. The gas sensing properties of the SnO2 films were investigated using liquid petroleum gas (LPG for various lower explosive limits (LEL. The results showed that porous, crack-free, and homogeneous SnO2 films were achieved for 5 and 15 sec at 100 and 150 V EPD parameters using an iodine-free acetylacetone based SnO2 suspension. The optimum sintering for the deposited SnO2 nanoparticles was observed at 500°C for 5 min. The results showed that the sensitivity of the films was increased with the operating temperature. The coated films with EPD demonstrated a better sensitivity for the 20 LEL LPG concentrations at a 450°C operating temperature. The maximum sensitivity of the SnO2 sensors at 450°C to 20 LEL LPG was 30.

  1. ANALYSIS OF OPERATING PARAMETERS AND INDICATORS OF A COMPRESSION IGNITION ENGINE FUELLED WITH LPG

    Directory of Open Access Journals (Sweden)

    Krzysztof GARBALA

    2016-12-01

    Full Text Available This article presents the possibilities for using alternative fuels to power vehicles equipped with compression ignition (CI engines (diesel. Systems for using such fuels have been discussed. Detailed analysis and research covered the LPG STAG autogas system, which is used to power dual-fuel engine units (LPG+diesel. A description of the operation of the autogas system and installation in a vehicle has been presented. The basic algorithms of the controller, which is an actuating element of the whole system, have been discussed. Protection systems of a serial production engine unit to guarantee its factorycontrolled durability standards have been presented. A long-distance test drive and examinations of the engine over 150,000 km in a Toyota Hilux have been performed. Operating parameters and performance indicators of the engine with STAG LPG+diesel fuelling have been verified. Directions and perspectives for the further development of such a system in diesel-powered cars have been also indicated.

  2. Nautical studies for new LPG (Liquefied Petroleum Gases) in Barra do Riacho

    Energy Technology Data Exchange (ETDEWEB)

    Amorim, Anderson B.A.; Biolchini, Luiz C.A. [Petroleo do Brasil S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil); Antunes, Felippe L. [Petrobras Transporte S/A (TRANSPETRO), Rio de Janeiro, RJ (Brazil); Vieira Neto, Tancredo [Poyry Technology, Sao Paulo, SP (Brazil)

    2009-07-01

    PETROBRAS is developing projects to increase the natural gas production, supply and allow transportation to the market. LPG and natural gasoline produced in Cacimbas (ES) will be transferred through pipelines to under construction Barra do Riacho Terminal, to be stored and loaded on ships. In Barra do Riacho, a municipality of Aracruz on the northern coast of the Espirito Santo state, a pulp specialized terminal already operates. The new PETROBRAS terminal will monthly load about 30,000 t of refrigerated LPG and 90,000 m{sup 3} of natural gasoline through a new pier with two berths. This pier will be able to receive tankers up to 60,000 dwt. With the challenge to safely maneuver and berth vessels of this size in a restricted area with operating facilities, PETROBRAS developed a basic design with the support of contracted companies to evaluate the minimum area needed to assure operation and design the best location, minimizing wave disturbance over the new jetty as well as over the existing above mentioned berths. This paper presents the port issues analyzed during the basic design of the new marine refrigerated LPG terminal to be located at Barra do Riacho Port. (author)

  3. Synthesis, characterization and liquefied petroleum gas (LPG) sensing properties of WO3 nano-particles

    Science.gov (United States)

    Singh, Subhash; Majumder, S. B.

    2018-05-01

    Metal oxide sensors, such as ZnO, SnO2, and WO3 etc. have been utilized for several decades for low-costd etection of combustible and toxic gases. In the present work tungsten oxide (WO3) nanoparticles have been prepared by using an economic wet chemical synthesis route. To understand the phase formation behavior of the synthesized powders, X-ray diffraction analysis has been performed. The microstructure evolution of the synthesized powders was characterized by field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). The calcined phase pure WO3 nanoparticles are investigated in terms of LPG gas sensing properties. The gas sensing measurements has been done in two different mode of operation (namely static and dynamic measurements). The degree of oxygen deficiency in the WO3 sensor also affected the sensor properties and the optimum oxygen content of WO3 was necessary to get high sensitivity for LPG. The WO3 sensor shows the excellent sensor properties for LPG at the operating temperature of 250°C.

  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. Grating-based X-ray phase contrast for biomedical imaging applications

    International Nuclear Information System (INIS)

    Pfeiffer, Franz; Willner, Marian; Chabior, Michael; Herzen, Julia; Helmholtz-Zentrum Geesthacht, Geesthacht; Auweter, Sigrid; Reiser, Maximilian; Bamberg, Fabian

    2013-01-01

    In this review article we describe the development of grating-based X-ray phase-contrast imaging, with particular emphasis on potential biomedical applications of the technology. We review the basics of image formation in grating-based phase-contrast and dark-field radiography and present some exemplary multimodal radiography results obtained with laboratory X-ray sources. Furthermore, we discuss the theoretical concepts to extend grating-based multimodal radiography to quantitative transmission, phase-contrast, and dark-field scattering computed tomography. (orig.)

  6. Sub-wavelength grating structure on the planar waveguide (Conference Presentation)

    Science.gov (United States)

    Qing-Song, Zhu; Sheng-Hui, Chen

    2016-10-01

    Making progress in recent years, with the technology of the grating, the grating period can be reduced to shrink the size of the light coupler on a waveguide. The working wavelength of the light coupler can be in the range from the near-infrared to visible. In this study , we used E-gun evaporation system with ion-beam-assisted deposition system to fabricate bottom cladding (SiO2), guiding layer (Ta2O5) and Distributed Bragg Reflector(DBR) of the waveguide on the silicon substrate. Electron-beam lithography is used to make sub-wavelength gratings and reflector grating on the planar waveguide which is a coupling device on the guiding layer. The best fabrication parameters were analyzed to deposit the film. The exposure and development times also influenced to fabricate the grating quality. The purpose is to reduce the device size and enhance coupling efficiency which maintain normal incidence of the light . We designed and developed the device using the Finite-Difference Time-Domain (FDTD) method. The grating period, depth, fill factor, film thickness, Distributed Bragg Reflector(DBR) numbers and reflector grating period have been discussed to enhance coupling efficiency and maintained normal incidence of the light. According to the simulation results, when the wavelength is 1300 nm, the coupling grating period is 720 nm and the Ta2O5 film is 460 nm with 360 nm of reflector grating period and 2 layers of Distributed Bragg Reflector, which had the optimum coupling efficiency and normal incidence angle. In the measurement, We successfully measured the TE wave coupling efficiency of the photoresist grating coupling device.

  7. Simulation Studies of the Dielectric Grating as an Accelerating and Focusing Structure

    International Nuclear Information System (INIS)

    Soong, Ken; Peralta, E.A.; Byer, R.L.; Colby, E.

    2011-01-01

    A grating-based design is a promising candidate for a laser-driven dielectric accelerator. Through simulations, we show the merits of a readily fabricated grating structure as an accelerating component. Additionally, we show that with a small design perturbation, the accelerating component can be converted into a focusing structure. The understanding of these two components is critical in the successful development of any complete accelerator. The concept of accelerating electrons with the tremendous electric fields found in lasers has been proposed for decades. However, until recently the realization of such an accelerator was not technologically feasible. Recent advances in the semiconductor industry, as well as advances in laser technology, have now made laser-driven dielectric accelerators imminent. The grating-based accelerator is one proposed design for a dielectric laser-driven accelerator. This design, which was introduced by Plettner, consists of a pair of opposing transparent binary gratings, illustrated in Fig. 1. The teeth of the gratings serve as a phase mask, ensuring a phase synchronicity between the electromagnetic field and the moving particles. The current grating accelerator design has the drive laser incident perpendicular to the substrate, which poses a laser-structure alignment complication. The next iteration of grating structure fabrication seeks to monolithically create an array of grating structures by etching the grating's vacuum channel into a fused silica wafer. With this method it is possible to have the drive laser confined to the plane of the wafer, thus ensuring alignment of the laser-and-structure, the two grating halves, and subsequent accelerator components. There has been previous work using 2-dimensional finite difference time domain (2D-FDTD) calculations to evaluate the performance of the grating accelerator structure. However, this work approximates the grating as an infinite structure and does not accurately model a

  8. Gratings for synchrotron and FEL beamlines: a project for the manufacture of ultra-precise gratings at Helmholtz Zentrum Berlin.

    Science.gov (United States)

    Siewert, F; Löchel, B; Buchheim, J; Eggenstein, F; Firsov, A; Gwalt, G; Kutz, O; Lemke, St; Nelles, B; Rudolph, I; Schäfers, F; Seliger, T; Senf, F; Sokolov, A; Waberski, Ch; Wolf, J; Zeschke, T; Zizak, I; Follath, R; Arnold, T; Frost, F; Pietag, F; Erko, A

    2018-01-01

    Blazed gratings are of dedicated interest for the monochromatization of synchrotron radiation when a high photon flux is required, such as, for example, in resonant inelastic X-ray scattering experiments or when the use of laminar gratings is excluded due to too high flux densities and expected damage, for example at free-electron laser beamlines. Their availability became a bottleneck since the decommissioning of the grating manufacture facility at Carl Zeiss in Oberkochen. To resolve this situation a new technological laboratory was established at the Helmholtz Zentrum Berlin, including instrumentation from Carl Zeiss. Besides the upgraded ZEISS equipment, an advanced grating production line has been developed, including a new ultra-precise ruling machine, ion etching technology as well as laser interference lithography. While the old ZEISS ruling machine GTM-6 allows ruling for a grating length up to 170 mm, the new GTM-24 will have the capacity for 600 mm (24 inch) gratings with groove densities between 50 lines mm -1 and 1200 lines mm -1 . A new ion etching machine with a scanning radiofrequency excited ion beam (HF) source allows gratings to be etched into substrates of up to 500 mm length. For a final at-wavelength characterization, a new reflectometer at a new Optics beamline at the BESSY-II storage ring is under operation. This paper reports on the status of the grating fabrication, the measured quality of fabricated items by ex situ and in situ metrology, and future development goals.

  9. Recording of long-period gratings in special single-mode fibers by a CO2 laser

    International Nuclear Information System (INIS)

    Cisarovsky, Petr; Dunovsky, Jiri; Kolarik, Ladislav; Todorov, Filip; Kasik, Ivan; Matejec, Vlastimil

    2006-01-01

    The paper deals with the fabrication of long-period gratings (LPG) in special optical fibers with an inverted parabolic-index profile of the cladding by periodically exposing the fibers to radiation of a high-power CO 2 laser. Details on the fiber fabrication and preparation of LPGs with a period of about 1 mm in the fibers are presented. The fabricated LPGs were evaluated on the basis of their transmission spectra determined by measuring the output spectral density of the fiber with the LPGs. It is shown that the position of the band and its strength depend on the laser beam velocity, beam power and the interaction time of radiation with the fiber

  10. 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.

  11. 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.

  12. 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.

  13. An analysis on LPG storage capability and rotation periods in Southern China; Analyse de la capacite de stockage des LPG et des frequences de rotation des navires dans le Sud de la Chine

    Energy Technology Data Exchange (ETDEWEB)

    Yuankai, L. [Shenzhen Gas Corporation Ltd (China)

    2000-07-01

    The rapidly improving infrastructure and fast growing economic strengths of cities along the Pearl River in southern China is key to the soaring LPG consumption, and also provided great potential for further development In both LPG and LNG businesses in view of a population of 70 million with a only a 40% gas coverage. The existing local pressurized storage tanks lag behind the demand, but planed and projected refrigerating storage facilities and pressurized storage tanks far exceed the future demands by the next decade. To avoid redundancy and excess density, measures has been proposed of West and East evacuation by way of rivers and reopening of railways to ship LPG from south to North regions. It is advisable to keep in mind the following points in making further investments in LPG facilities: rotation periods should be strictly observed, Full play should be brought to the local storage terminals, Economic sustainability and market saturation should be given full consideration, Complementability of LPG storage facilities and LNG receiving Terminals. (author)

  14. Photonic Hilbert transformers based on laterally apodized integrated waveguide Bragg gratings on a SOI wafer.

    Science.gov (United States)

    Bazargani, Hamed Pishvai; Burla, Maurizio; Chrostowski, Lukas; Azaña, José

    2016-11-01

    We experimentally demonstrate high-performance integer and fractional-order photonic Hilbert transformers based on laterally apodized Bragg gratings in a silicon-on-insulator technology platform. The sub-millimeter-long gratings have been fabricated using single-etch electron beam lithography, and the resulting HT devices offer operation bandwidths approaching the THz range, with time-bandwidth products between 10 and 20.

  15. Proposal and design of phase-modulated fiber gratings in transmission for pulse shaping.

    Science.gov (United States)

    Preciado, Miguel A; Shu, Xuewen; Sugden, Kate

    2013-01-01

    An approach to pulse shaping using a phase-modulated fiber Bragg grating (FBG) in transmission is proposed and designed. We show that phase-modulated FBGs can provide transmission responses suitable for pulse shaping applications, offering important technological feasibility benefits, since the coupling strength remains basically uniform in the grating. Moreover, this approach retains the substantial advantages of FBGs in transmission, such as optimum energy efficiency, no requirement for an optical circulator, and robustness against fabrication errors.

  16. 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

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. CONVERSION OF DIESEL ENGINE INTO SPARK IGNITION ENGINE TO WORK WITH CNG AND LPG FUELS FOR MEETING NEW EMISSION NORMS

    Directory of Open Access Journals (Sweden)

    Syed Kaleemuddin

    2010-01-01

    Full Text Available Fluctuating fuel prices and associated pollution problems of largely exploited petroleum liquid fuel has stimulated the research on abundantly available gaseous fuels to keep the mobility industry intact. In the present work an air cooled diesel engine was modified suitably into a spark ignition engine incorporating electronic ignition and variable speed dependant spark timing to accommodate both LPG and CNG as fuels. Engine was optimized for stoichiometric operation on engine dynamometer. Materials of a few intricate engine components were replaced to suit LPG and CNG application. Ignition timing was mapped to work with gaseous fuels for different speeds. Compensation was done for recovering volumetric efficiency when operated with CNG by introducing more volume of air through resonator. Ignition timing was observed to be the pertinent parameter in achieving good performance with gaseous fuels under consideration. Performance and emission tests were carried out on engine dynamometer and chassis dynamometer. Under wide open throttle and at rated speed condition, it was observed that the peak pressure with LPG was lying between diesel fuel and CNG fuel operation due to slow burning nature of gaseous fuels. As compression ratio was maintained same for LPG and CNG fuel operation, low CO emissions were observed with LPG where as HC + NOx emissions were lower with CNG fuel operation. Chassis dynamometer based emission tests yielded lower CO2 levels with CNG operation.

  2. KAJIAN TEKNIS DAN EKONOMIS PENGGUNAAN DUAL FUEL SYSTEM (LPG-SOLAR PADA MESIN DIESEL KAPAL NELAYAN TRADISIONAL

    Directory of Open Access Journals (Sweden)

    Imam Pujo Mulyatno

    2013-06-01

    Full Text Available Pengembangan bahan bakar alternatif dalam rangka mengurangi ketergantungan terhadap bahan bakar minyak (BBM, telah menjadi agenda penting  pemerintah. Penggunaan LPG (Liquefied Petrolium Gas pada mesin diesel kapal nelayan tradisional didasarkan pada keberhasilan penggunaan LPG pada kendaraan-kendaraan darat. Penggunaan LPG pada mesin diesel dilakukan secara dual fuel. Penelitian dual fuel system pada mesin diesel kapal nelayan tradisional bertujuan untuk mengetahui pengaruh penggunaan bahan bakar dual fuel terhadap kinerja mesin dan sistem penggeraknya, meliputi konsumsi bahan bakar, daya, kecepatan kapal, serta efisiensi pada sistem penggerak kapal. Penelitian dilakukan dengan menggunakan DongFeng ZS-1100 dengan tiga putaran mesin yang berbeda yaitu 1000rpm, 1250 rpm dan 1500 rpm. Berdasarkan hasil penelitian ini, penggunaan LPG secara dual fuel mampu menggantikan konsumsi solar hingga 71% dari konsumsi solar seluruhnya selama satu jam. Komposisi LPG yang dihasilkan mencapai lebih dari 60%  dari total pemakaian bahan bakar saat dual fuel. Kecepatan dan jarak tempuh saat menggunakan solar seluruhnya mencapai 5% lebih tinggi dibandingkan dual fuel. Daya dan torsi saat menggunakan dual fuel mencapai 9,8 % lebih tinggi dibandingkan solar seluruhnya. Penggunaan dual fuel mampu mengurangi biaya operasional penangkapan ikan hingga 24,6%, namun dengan waktu tempuh 1,3% lebih lama dari solar seluruhnya. Efisiensi propulsi solar seluruhnya 6% lebih besar dibandingkan efisiensi propulsi dual fuel.

  3. AT on Buried LPG Tanks Over 13 m3: An Innovative and Practical Solution

    Science.gov (United States)

    Di Fratta, Crescenzo; Ferraro, Antonio; Tscheliesnig, Peter; Lackner, Gerald; Correggia, Vincenzo; Altamura, Nicola

    In Italy, since 2005, techniques based on Acoustic Emission have been introduced for testing of underground LPG tanks up to 13 m3, according to the European standard EN 12818:2004. The testing procedure for these tanks plans to install one or more pairs of sensors inside the "dome" suited for the access to the valves and fittings of the tank, directly on the accessible metal shell. This methodology is not applicable for the underground LPG buried tanks, where it is necessary to install a larger number of AE sensors, in order to cover at 100% the whole tank shell, even at very deep positions. Already in 2004, the European standard EN 12820 (Appendix C - Informative)give the possibility to use Acoustic Emission testing of LPG underground or buried tanks with a capacity exceeding 13 m3, but no technique was specified for the application. In 2008, TÜV AUSTRIA ITALIA - BLU SOLUTIONS srl - Italian company of TÜV AUSTRIA Group - has developed a technique to get access at tank shell, where tank capacity is greater than 13 m3 and its' diameter greater than 3,5 m. This methodology was fully in comply with the provisions of the European Standard EN 12819:2010, becoming an innovative solution widely appreciated and is used in Italy since this time. Currently, large companies and petrochemical plants, at the occurrence of the tank's requalification, have engaged TÜV AUSTRIA ITALIA - BLU SOLUTIONS to install such permanent predispositions, which allow access to the tank shell - test object - with diameters from 4 to 8 m. Through this access, you can install the AE sensors needed to cover at 100% the tank surface and then to perform AE test. In an economic crisis period, this technique is proving a valid and practically applicable answer, in order to reduce inspection costs and downtime by offering a technically advanced solution (AT), increasing the safety of the involved operators, protecting natural resources and the environment.

  4. 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...

  5. Effect of initialization time on application potentiality of a ZnO thin film based LPG sensor

    Directory of Open Access Journals (Sweden)

    Parta Mitra

    2009-09-01

    Full Text Available A prototype electronic LPG (Liquid Petroleum Gas sensor based on zinc oxide (ZnO film has been fabricated. The objective of the present work was to investigate the importance of initialization time (also called warm-up time on the application potentiality of the ZnO based alarm. The role of sensor geometry on initialization time is presented. The electronic circuitry of the prototype LPG device alarm is discussed. It is shown that that the initialization time depends on the switch off time (or the time for which the sensor was kept idle. The resistive mode sensors can be fixed at 40% LEL (Lower Explosive Limit of LPG for safe operation.

  6. The cost-effectiveness of a steel tube or a buffer zone for mitigating blast effects on a building spanning an underpass with transport of LPG

    NARCIS (Netherlands)

    Suddle, S.I.; Weerheijm, J.; Berg, A.C. van den

    2010-01-01

    The use of space is being intensified near and above transport routes of hazardous materials. In The Netherlands, some buildings are even realized above infrastructure with transport of hazardous materials like LPG. An accident with an LPG-tank may result in a BLEVE, causing injuries and large

  7. Relations between retail market and distribution in LPG range: analyzing the cooperation and alliances

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Alves

    2009-05-01

    Full Text Available This work aims to proceed with the evaluation of relationship between retail market and distribution in liquefied petroleum gas range (LPG, according to Network Theory. This is an exploratory research, with qualitative characteristic, about the dynamics of cooperation relations. The results, although could not be considered as conclusive, by reason of the study of only one case, shows that an alliance with relationship problems and competition, between point-of-sale and resale, probably will be dissolved as soon as the retailer become a reseller.

  8. Karakterisasi Sensor Gas Lpg (Liquefied Petroleum Gas) Dari Bahan Komposit Semikonduktor Tio2(cuo)

    OpenAIRE

    Dewi, Ratna Sari; -, Elvaswer

    2015-01-01

    The Liquefied Petroleum Gas (LPG's) sensor in the form of composite has been characterized. The steps of manufacturing processes are the mixing of materials, calcinations at 500ºC for 4 hours, blended, compacted and sintered at 700ºC for 4 hours. The sensor was tested at room temperature through current (I)-voltage (V) characteristics, sensitivity, and conductivity. Based on measurement I-V characteristic it's known that sample with 10% addition of CuO have sensitivity of 10 at 10 volt vol...

  9. The analysis of risks at LPG depots: a tool for decision makers

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1993-10-01

    At the Tokyo congress of the World LPG Forum, Mr Patrick Mayras, Technical Director at Butagaz, presented a study on the probability of the occurrence of a major accident which this company has undertaken with Cremer Warner on its storage and filling site in Montereau, together with the key prevention principles which have resulted from this study and which have been applied to all their installations. The study shows that the probability of a BLEVE is 1 in a thousand million years per sphere or, for the 60 storage sites belonging to Butagaz, that the probability of a BLEVE in its installations is 1 every 16 million years. If every company in the profession had this level of standards on an international scale, the probability of a BLEVE occurring in the world would be, again according to Butagaz calculations, of the order of 1 every 100.000 years or, at a really conservative estimate, of the order of 1 every 10.000 years (based on: one storage site for 10.000 t sold/year). This report was received with a great deal of interest in Tokyo and it is certain that this probability-based approach will constitute hence-forth a reference both on a national and an international scale. As Mr Mayras underlined at the end of his presentation, although a zero risk does not exist, there is a socially acceptable risk which is used implicitly by governmental authorities for certain human or industrial activities for certain human or industrial activities which have an accident occurrence probability which is much higher than that run by LPG storage sites. Conversely, the determinist and calculated approach applied in France presents a high cost to society due to the freezing of all land around the sites. The probability-based approach, which can be systematized to all LPG professionals, could, therefore, allow for a relaxation of the constraints weighing on the environment of storage sites and could place LPG on an equal footing with other types of energy. (Abstract Truncated)

  10. Feasibility study of a hybrid plants (photovoltaic–LPG generator system for rural electrification

    Directory of Open Access Journals (Sweden)

    Adouane Mabrouk

    2016-01-01

    Full Text Available The present study investigates the possibility of using a stand-alone photovoltaic/LPG (liquid petroleum gas generator hybrid power system for low-cost electricity production which can satisfy the energy load requirements of a typical remote and isolated rural area. In this context, the optimal dimensions to improve the technical and economical performances of the hybrid system are determined according to the load energy requirements. The proposed system's installation and operating costs are simulated using the Hybrid Optimization Model for Electric Renewable (HOMER, the solar radiation and the system components costs as inputs; and then compared with those of other supply options such as diesel generation.

  11. p-PEDOT:PSS as a heterojunction partner with n-ZnO for detection of LPG at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Ladhe, R.D. [Thin Film and Nano Science Laboratory, Department of Physics, School of Physical Sciences, North Maharashtra University, Jalgaon 425 001 (M.S.) (India); Gurav, K.V. [Department of Materials Science and Engineering, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Pawar, S.M. [Solar Cell Laboratory, LG Components R and D Center, 1271, Sa-Dong, Sanggrok-gu, Ansan-si, Gyeonggi-do 426-791 (Korea, Republic of); Kim, J.H. [Department of Materials Science and Engineering, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Sankapal, B.R., E-mail: brsankapal@rediffmail.com [Thin Film and Nano Science Laboratory, Department of Physics, School of Physical Sciences, North Maharashtra University, Jalgaon 425 001 (M.S.) (India)

    2012-02-25

    Highlights: Black-Right-Pointing-Pointer Formation of heterojunction n-ZnO and p-PEDOT:PSS at room temperature (27 Degree-Sign C). Black-Right-Pointing-Pointer Use of this heterojunction as room temperature LPG sensor. Black-Right-Pointing-Pointer Remarkable gas response with good stability of the sensing device. Black-Right-Pointing-Pointer Use of heterojunction could offer cost-effective LPG sensor that is ecological-friendly. Black-Right-Pointing-Pointer The mass production using scalable room temperature chemical deposition process. - Abstract: Investigation towards the performance of room temperature (27 Degree-Sign C) liquefied petroleum gas (LPG) sensor based on the heterojunction between p-PEDOT:PSS and n-type ZnO is reported. The junction was developed by using chemically deposited ZnO film on to fluorine doped tin oxide (FTO) coated glass substrate followed by coating of thin slurry layer of PEDOT:PSS by using spin coating technique. Both these methods are simple, inexpensive and suitable for large area applications. Different characterization techniques were used to characterize structural, surface morphological and compositional of the material deposited. LPG sensing behavior of the heterojunction was studied at room temperature along with the stability studies. At room temperature, the heterojunction showed 58.8% sensitivity upon exposure to 1000 ppm of LPG with good response and recovery time like 225 s and 190 s, respectively. Furthermore, the LPG sensor reported is cost-effective, user friendly, and easy to fabricate using low cost chemical methods at room temperature.

  12. 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...

  13. 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%.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Fiber design and realization of point-by-point written fiber Bragg gratings in polymer optical fibers

    DEFF Research Database (Denmark)

    Stefani, Alessio; Stecher, Matthias; Town, Graham E.

    2012-01-01

    the gratings make the point-by-point grating writing technique very interesting and would appear to be able to fill this technological gap. On the other end this technique is hardly applicable for microstructured fibers because of the writing beam being scattered by the air-holes. We report on the design...... and because they allow to tune the guiding parameters by modifying the microstructure. Now a days the only technique used to write gratings in such fibers is the phase mask technique with UV light illumination. Despite the good results that have been obtained, a limited flexibility on the grating design...... and the very long times required for the writing of FBGs raise some questions about the possibility of exporting POF FBGs and the sensors based on them from the laboratory bench to the mass production market. The possibility of arbitrary design of fiber Bragg gratings and the very short time required to write...

  19. Flame stability and emission characteristics of turbulent LPG IDF in a backstep burner

    Energy Technology Data Exchange (ETDEWEB)

    S. Mahesh; D.P. Mishra [Indian Institute of Technology, Kanpur (India). Combustion Laboratory, Department of Aerospace Engineering

    2008-09-15

    The stability characteristics and emissions from turbulent LPG inverse diffusion flame (IDF) in a backstep burner are reported in this paper. The blow-off velocity of turbulent LPG IDF is observed to increase monotonically with fuel jet velocity. In contrast to normal diffusion flames (NDF), the flame in the present IDF burner gets blown out without getting lifted-off from the burner surface. The soot free length fraction, SFLF, defined as the ratio of visible premixing length, H{sub p}, to visible flame length, H{sub f}, is used for qualitative estimation of soot reduction in this IDF burner. The SFLF is found to increase with central air jet velocity indicating the occurrence of extended premixing zone in the vicinity of flame base. Interestingly, the soot free length fraction (SFLF) is found to be correlated well with the newly devised parameter, global momentum ratio. The peak value of EINOX happens to occur closer to stoichiometric overall equivalence ratio. 16 refs., 9 figs.

  20. The risks of Bobtail truck LPG (Liquefied Petroleum Gases) distribution in urban areas

    Energy Technology Data Exchange (ETDEWEB)

    Leal, Cesar A. [Det Norske Veritas (DNV), Oslo (Norway)], e-mail: cesar.leal@dnv.com

    2008-07-01

    The use of 'Bobtail' trucks (6 and 9 ton) for distribution of Liquefied Petroleum Gas (LPG) in Brazilian cities represents a new and mobile source of risk. In this paper, it will be presented a discussion about some of the possible accident scenarios that can occur with this kind of vehicle, with emphasis on the possible consequences (BLEVE/fireball). The goal is to spread information and call attention of Government Authorities and gas distribution companies, as well as the general public, about this source of risk. In the case of a 9 ton fireball, fatalities could be expected up to 176 m, according to TNO models. Collapse of the tank engulfed in fire is expected in 10 to 20 minutes, a too short time interval for the arrival of a fire brigade and control of the situation. Suggestions are presented for the use of insulating coating in the tanks capable of withstanding an external fire for two hours without collapsing and the realization of a risk study for estimation of the impact of the use of insulation in terms of risk reduction for the population and a comparison of risks associated to the two forms of LPG distribution. (author)

  1. Investigating the effects of LPG on spark ignition engine combustion and performance

    International Nuclear Information System (INIS)

    Bayraktar, Hakan; Durgun, Orhan

    2005-01-01

    A quasi-dimensional spark ignition (SI) engine cycle model is used to predict the cycle, performance and exhaust emissions of an automotive engine for the cases of using gasoline and LPG. Governing equations of the mathematical model mainly consist of first order ordinary differential equations derived for cylinder pressure and temperature. Combustion is simulated as a turbulent flame propagation process and during this process, two different thermodynamic regions consisting of unburned gases and burned gases that are separated by the flame front are considered. A computer code for the cycle model has been prepared to perform numerical calculations over a range of engine speeds and fuel-air equivalence ratios. In the computations performed at different engine speeds, the same fuel-air equivalence ratios are selected for each fuel to make realistic comparisons from the fuel economy and fuel consumption points of view. Comparisons show that if LPG fueled SI engines are operated at the same conditions with those of gasoline fueled SI engines, significant improvements in exhaust emissions can be achieved. However, variations in various engine performance parameters and the effects on the engine structural elements are not promising

  2. Mode group specific amplification length in an asymmetric LPG assisted few-mode EDFA

    Science.gov (United States)

    Rastogi, Vipul; Gaur, Ankita; Aschieri, Pierre; Dussardier, Bernard

    2017-01-01

    This article presents a scheme for few-mode EDFA, which allows to choose independent amplification lengths for different mode groups. The EDF is a dual concentric core fiber, where the central core is connected to the line FMF and the ring core is doped with erbium to provide amplification. The modes of FMF are launched into the central core of the EDF, are converted into ring modes using LPG for amplification and then converted back into central core modes using another LPG. The distance between the LPGs determines the amplification length. The amplification length, can thus, be chosen for a given mode group. We demonstrate the working of this concept by choosing LP11 and LP21 mode groups of the FMF and show that a suitable choice of amplification lengths for the two mode groups can tailor the differential modal gain (DMG) to any desired value. We demonstrate achieving zero DMG among all the mode of LP11 and LP21 mode groups using this concept while having gain in excess of 20 dB. The study should be useful for optical fiber communication system employing space-division multiplexing (SDM).

  3. Large-area full field x-ray differential phase-contrast imaging using 2D tiled gratings

    Science.gov (United States)

    Schröter, Tobias J.; Koch, Frieder J.; Kunka, Danays; Meyer, Pascal; Tietze, Sabrina; Engelhardt, Sabine; Zuber, Marcus; Baumbach, Tilo; Willer, Konstantin; Birnbacher, Lorenz; Prade, Friedrich; Pfeiffer, Franz; Reichert, Klaus-Martin; Hofmann, Andreas; Mohr, Jürgen

    2017-06-01

    Grating-based x-ray differential phase-contrast imaging (DPCI) is capable of acquiring information based on phase-shift and dark-field signal, in addition to conventional x-ray absorption-contrast. Thus DPCI gives an advantage to investigate composite materials with component wise similar absorption properties like soft tissues. Due to technological challenges in fabricating high quality gratings over a large extent, the field of view (FoV) of the imaging systems is limited to a grating area of a couple of square centimeters. For many imaging applications (e.g. in medicine), however, a FoV that ranges over several ten centimeters is needed. In this manuscript we propose to create large area gratings of theoretically any extent by assembling a number of individual grating tiles. We discuss the precision needed for alignment of each microstructure tile in order to reduce image artifacts and to preserve minimum 90% of the sensitivity obtainable with a monolithic grating. To achieve a reliable high precision alignment a semiautomatic assembly system consisting of a laser autocollimator, a digital microscope and a force sensor together with positioning devices was built. The setup was used to tile a first four times four analyzer grating with a size of 200 mm  ×  200 mm together with a two times two phase grating. First imaging results prove the applicability and quality of the tiling concept.

  4. Using a cover layer to improve the damage resistance of gold-coated gratings induced by a picosecond pulsed laser

    Science.gov (United States)

    Xia, Zhilin; Wu, Yihan; Kong, Fanyu; Jin, Yunxia

    2018-04-01

    The chirped pulse amplification (CPA) technology is the main approach to achieve high-intensity short-pulse laser. Diffraction gratings are good candidates for stretching and compressing laser pulses in CPA. In this paper, a kind of gold-coated grating has been prepared and its laser damage experiment has been performed. The results reflect that the gratings laser damage was dominated by thermal ablation due to gold films or inclusions absorption and involved the deformation or eruption of the gold film. Based on these damage phenomena, a method of using a cover layer to prevent gold films from deforming and erupting has been adopted to improve the gold-coated gratings laser damage threshold. Since the addition of a cover layer changes the gratings diffraction efficiency, the gratings structure has been re-optimized. Furthermore, according to the calculated thermal stress distributions in gratings with optimized structures, the cover layer was demonstrated to be helpful for improving the gratings laser damage resistance if it is thick enough.

  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. X-ray verification of an optically-aligned off-plane grating module

    Science.gov (United States)

    Donovan, Benjamin; McEntaffer, Randall; Tutt, James; DeRoo, Casey; Allured, Ryan; Gaskin, Jessica; Kolodziejczak, Jeffery

    2017-08-01

    The next generation of X-ray spectrometer missions are baselined to have order-of-magnitude improvements in both spectral resolving power and effective area when compared to existing X-ray spectrometer missions. Off-plane X-ray reflection gratings are capable of achieving high resolution and high diffraction efficiencies over the entire X-ray bandpass, making them an ideal technology to implement on these future missions. To achieve the high effective area desired while maintaining high spectral resolution, many off-plane gratings must be precisely aligned such that their diffraction arcs overlap at the focal plane. Methods are under development to align a number of these gratings into a grating module using optical metrology techniques in support of the Off-plane Grating Rocket Experiment (OGRE), a suborbital rocket payload scheduled to launch in late 2018. X-ray testing was performed on an aligned grating module at the Straylight Test Facility (SLTF) at NASA Marshall Space Flight Center (MSFC) to assess the current alignment methodology and its ability to meet the desired performance of OGRE. We report on the results from the test campaign at MSFC, as well as plans for future development.

  7. Room temperature LPG resistive sensor based on the use of a few-layer graphene/SnO2 nanocomposite.

    Science.gov (United States)

    Goutham, Solleti; Bykkam, Satish; Sadasivuni, Kishor Kumar; Kumar, Devarai Santhosh; Ahmadipour, Mohsen; Ahmad, Zainal Arifin; Rao, Kalagadda Venkateswara

    2017-12-20

    A nanocomposite consisting of a few layers of graphene (FLG) and tin dioxide (SnO 2 ) was prepared by ultrasound-assisted synthesis. The uniform SnO 2 nanoparticles (NPs) on the FLG were characterized by X-ray diffraction in terms of lattice and phase structure. The functional groups present in the composite were analyzed by FTIR. Electron microscopy (HR-TEM and FE-SEM) was used to study the morphology. The effect of the fraction of FLG present in the nanocomposite was investigated. Sensitivity, selectivity and reproducibility towards resistive sensing of liquid propane gas (LPG) was characterized by the I-V method. The sensor with 1% of FLG on SnO 2 operated at a typical voltage of 1 V performs best in giving a rapid and sensitive response even at 27 °C. This proves that the operating temperature of such sensors can be drastically decreased which is in contrast to conventional metal oxide LPG sensors. Graphical abstract Schematic of a room temperature gas sensor for liquefied petroleum gas (LPG). It is based on the use of a few-layered graphene (1 wt%)/SnO 2 nanocomposite that was deposited on an interdigitated electrode (IDEs). A sensing mechanism for LPG detection has been established.

  8. 78 FR 42889 - Pipeline Safety: Reminder of Requirements for Utility LP-Gas and LPG Pipeline Systems

    Science.gov (United States)

    2013-07-18

    ... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration 49 CFR Part 192 [Docket No. PHMSA-2013-0097] Pipeline Safety: Reminder of Requirements for Utility LP-Gas and LPG Pipeline Systems AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA), DOT. ACTION...

  9. Risk assessment of liquefied petroleum gas (LPG storage tanks in the process industries using the Bowtie technique

    Directory of Open Access Journals (Sweden)

    Mostafa Mirzaei aliabadi

    2016-09-01

    Full Text Available Introduction: LPG storage tanks contain of large volumes of flammable and pressurized gases. Release of these fluids can lead to disastrous accidents such BLEVE, fiery explosion. Therefore, identifying the causes, consequences, probabilities and scenarios of accidents using Bowtie technique, that is combination of Fault Tree Analyses (FTA and Event Tree Analyses (ETA, is imperative and the purpose of this study. Methods: The hazards of the mentioned in Tehran Refinery LPG tanks were identified by Fault Tree Analyses and the consequences of the top event were predicted by Event Tree Analyses. Then probabilities of the events were calculated and the accident route, from causes phase to consequences phase, was drawn by Bowtie diagram. Results: In total, 21 events and 11 minimal cut sets with their occurrence probabilities and importance measure were determined at the left side of the Bowtie diagram. Also 9 consequences and scenarios of the top event were determined at the right side of the diagram. The occurrence probability of the top event (LPG release of spherical tanks was calculated 3.45×10-2. Conclusion: All factors involved in the occurrence of accidents and their consequences are showed in the Bowtie diagram. According to the obtained data, failure of cathodic protection systems and instrumentation, and overflow of tanks are included as important defects of the LPG tanks. Due to the high probability of the consequences, preventing systems such as cooling systems and Fire stop systems are required for installing in the studied unit to reduce the consequences of accidents.

  10. Fast-LPG Sensors at Room Temperature by α-Fe2O3/CNT Nanocomposite Thin Films

    Directory of Open Access Journals (Sweden)

    B. Chaitongrat

    2018-01-01

    Full Text Available We present performance of a room temperature LPG sensor based on α-Fe2O3/CNT (carbon nanotube nanocomposite films. The nanocomposite film was fabricated via the metallic Fe catalyst particle on CNTs in which both the catalyst particles and the CNT were simultaneously synthesized by chemical vapor deposition (CVD synthesis and were subsequently annealed in air to create α-Fe2O3. These methods are simple, inexpensive, and suitable for large-scale production. The structure, surface morphologies, and LPG response of nanocomposite films were investigated. Raman spectroscopy and XPS analysis showed the formation of α-Fe2O3 on small CNTs (SWNTs. Morphological analysis using FE-SEM and AFM revealed the formation of the porous surface along with roughness surface. Additionally, the sensing performance of α-Fe2O3/CNTs showed that it could detect LPG concentration at lower value than 25% of LEL with response/recovery time of less than 30 seconds at room temperature. These results suggest that the α-Fe2O3/CNTs films are challenging materials for monitoring LPG operating at room temperature.

  11. Use of CFD for calculation of dispersion of LPG along rail transport routes situated above or below ground level

    NARCIS (Netherlands)

    Trijssenaar-Buhre, I.J.M.; Reinders, J.E.A.

    2010-01-01

    The use and transport of dangerous substances may pose a risk to people present in the vicinity. Well known examples of dangerous substances are the very toxic chemical chlorine and the extremely flammable Liquefied Petroleum Gas (LPG). The adverse effects of accidental releases of such materials

  12. 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.

  13. 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.

  14. 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.}

  15. 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.

  16. 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.

  17. Detecting Liquefied Petroleum Gas (LPG) at Room Temperature Using ZnSnO3/ZnO Nanowire Piezo-Nanogenerator as Self-Powered Gas Sensor.

    Science.gov (United States)

    Fu, Yongming; Nie, Yuxin; Zhao, Yayu; Wang, Penglei; Xing, Lili; Zhang, Yan; Xue, Xinyu

    2015-05-20

    High sensitivity, selectivity, and reliability have been achieved from ZnSnO3/ZnO nanowire (NW) piezo-nanogenerator (NG) as self-powered gas sensor (SPGS) for detecting liquefied petroleum gas (LPG) at room temperature (RT). After being exposed to 8000 ppm LPG, the output piezo-voltage of ZnSnO3/ZnO NW SPGS under compressive deformation is 0.089 V, much smaller than that in air ambience (0.533 V). The sensitivity of the SPGS against 8000 ppm LPG is up to 83.23, and the low limit of detection is 600 ppm. The SPGS has lower sensitivity against H2S, H2, ethanol, methanol and saturated water vapor than LPG, indicating good selectivity for detecting LPG. After two months, the decline of the sensing performance is less than 6%. Such piezo-LPG sensing at RT can be ascribed to the new piezo-surface coupling effect of ZnSnO3/ZnO nanocomposites. The practical application of the device driven by human motion has also been simply demonstrated. This work provides a novel approach to fabricate RT-LPG sensors and promotes the development of self-powered sensing system.

  18. 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.

  19. 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).

  20. 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.

  1. Arc-Induced Long Period Gratings from Standard to Polarization-Maintaining and Photonic Crystal Fibers

    Directory of Open Access Journals (Sweden)

    Flavio Esposito

    2018-03-01

    Full Text Available In this work, we report about our recent results concerning the fabrication of Long Period Grating (LPG sensors in several optical fibers, through the Electric Arc Discharge (EAD technique. In particular, the following silica fibers with both different dopants and geometrical structures are considered: standard Ge-doped, photosensitive B/Ge codoped, P-doped, pure-silica core with F-doped cladding, Panda type Polarization-maintaining, and Hollow core Photonic crystal fiber. An adaptive platform was developed and the appropriate “recipe” was identified for each fiber, in terms of both arc discharge parameters and setup arrangement, for manufacturing LPGs with strong and narrow attenuation bands, low insertion losses, and short length. As the fabricated devices have appealing features from the application point of view, the sensitivity characteristics towards changes in different external perturbations (i.e., surrounding refractive index, temperature, and strain are investigated and compared, highlighting the effects of different fiber composition and structure.

  2. 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....

  3. 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.

  4. 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

  5. Tuning properties of long-period gratings by plasma post-processing of their diamond-like carbon nano-overlays

    Science.gov (United States)

    Smietana, M.; Koba, M.; Mikulic, P.; Bock, W. J.

    2014-11-01

    This work presents an application of reactive ion etching (RIE) for effective tuning of spectral response and the refractive index (RI) sensitivity of diamond-like carbon (DLC) nano-coated long-period gratings (LPGs). When oxygen plasma is applied the technique allows for an efficient and well controlled etching of hard and chemically resistant DLC films deposited on optical fibers. We show that optical properties of DLC, especially its refractive index, strongly depend on thickness of the film when it is thinner than 150 nm. The effect of DLC nano-coating deposition and etching on spectral properties of the LPGs is discussed. We have correlated the DLC properties with the shift of the LPG resonance wavelength and have found that both deposition and etching processes took place less effectively than on the electrode when the LPG sample was held above the electrode in the plasma reactor. An advantage of plasma-based etching is a capability for post-processing of the nano-coated structures with a good precision, as well as cleaning the samples and their re-coating according to requested needs. Moreover, the application of RIE allows for post-fabrication tuning of RI sensitivity of the DLC nano-coated LPGs.

  6. Tuning properties of long-period gratings by plasma post-processing of their diamond-like carbon nano-overlays

    International Nuclear Information System (INIS)

    Smietana, M; Koba, M; Mikulic, P; Bock, W J

    2014-01-01

    This work presents an application of reactive ion etching (RIE) for effective tuning of spectral response and the refractive index (RI) sensitivity of diamond-like carbon (DLC) nano-coated long-period gratings (LPGs). When oxygen plasma is applied the technique allows for an efficient and well controlled etching of hard and chemically resistant DLC films deposited on optical fibers. We show that optical properties of DLC, especially its refractive index, strongly depend on thickness of the film when it is thinner than 150 nm. The effect of DLC nano-coating deposition and etching on spectral properties of the LPGs is discussed. We have correlated the DLC properties with the shift of the LPG resonance wavelength and have found that both deposition and etching processes took place less effectively than on the electrode when the LPG sample was held above the electrode in the plasma reactor. An advantage of plasma-based etching is a capability for post-processing of the nano-coated structures with a good precision, as well as cleaning the samples and their re-coating according to requested needs. Moreover, the application of RIE allows for post-fabrication tuning of RI sensitivity of the DLC nano-coated LPGs. (paper)

  7. LPG ammonia and nitrogen dioxide gas sensing properties of nanostructured polypyrrole thin film

    Science.gov (United States)

    Bagul, Sagar B.; Upadhye, Deepak S.; Sharma, Ramphal

    2016-05-01

    Nanostructured Polypyrrole thin film was synthesized by easy and economic chemical oxidative polymerization technique on glass at room temperature. The prepared thin film of Polypyrrole was characterized by optical absorbance study by UV-visible spectroscopy and electrical study by I-V measurement system. The optical absorbance spectrum of Polypyrrole shows two fundamental peaks in region of 420 and 890 nm, which confirms the formation of Polypyrrole on glass substrate. The I-V graph of nanostructured Polypyrrole represents the Ohmic nature. Furthermore, the thin film of Polypyrrole was investigated by Scanning electron microscopy for surface morphology study. The SEM micrograph represents spherical nanostructured morphology of Polypyrrole on glass substrate. In order to investigate gas sensing properties, 100 ppm of LPG, Ammonia and Nitrogen Dioxide were injected in the gas chamber and magnitude of resistance has been recorded as a function of time in second. It was observed that nanostructured Polypyrrole thin film shows good sensing behavior at room temperature.

  8. Chemically designed Pt/PPy nano-composite for effective LPG gas sensor.

    Science.gov (United States)

    Gaikwad, Namrata; Bhanoth, Sreenu; More, Priyesh V; Jain, G H; Khanna, P K

    2014-03-07

    Simultaneous in situ reduction of hexachloroplatinic acid by the amine group in the pyrrole monomer and oxidation of pyrrole to form polypyrrole (PPy) was examined. The reactions were performed at various temperatures to understand the degree of reduction of platinum precursor as well as doping of polypyrrole with Pt(II) chloro-complex. Spectroscopic images revealed different morphologies for the Pt/PPy nano-composite prepared at various temperatures. The as-prepared Pt/PPy nano-composite samples were tested for their ability to sense liquefied petroleum gas (LPG) which resulted in excellent sensing at relatively low temperature. The porous nature and ohmic contact between the PPy and platinum nanoparticles makes the as-prepared Pt/PPy nano-composite highly useful for sensors as well as electronic applications.

  9. Effect of Baffles on the Sloshing in Road Tankers Carrying LPG: A Comparative Numerical Study

    Directory of Open Access Journals (Sweden)

    J. L. Bautista-Jacobo

    2015-01-01

    Full Text Available This work presents a comparative numerical study of the effect of using baffles, and its design, on the behavior of sloshing in a partially filled road tanker carrying LPG. Navier-Stokes equations and standard k-ε turbulence model are used to simulate fluid movement; the Volume of Fluid (VOF method is used to track the liquid-gas interface. Velocity distributions, sloshing stabilization times, and contours of turbulent kinetic energy, which are of high importance in choosing the best design of baffles, are shown. The results show sloshing stabilization times of 22 and 21 s for road tankers with cross-shaped (Type I and X-shaped (Type II baffles, respectively, finding lower values of turbulent kinetic energy for Type II design, being, therefore, the best design of baffles for damping of sloshing and vehicle control among studied ones.

  10. Numerical Modeling of a Jet Ignition Direct Injection (JI DI LPG Engine

    Directory of Open Access Journals (Sweden)

    Albert Boretti

    2017-01-01

    Full Text Available The paper presents indirectly validated simulations of the operation of a LPG engine fitted with Direct Injection (DI and Jet Ignition (JI. It is demonstrated that the engine may have diesel like efficiencies and load control by quantity of fuel injected.  As the liquid propane quickly evaporates after injection in the main chamber, the main chamber mixture may be much closer to stoichiometry than a diesel for a better specific power at low engine speeds. This design also works at the high engine speeds impossible for the diesel, as combustion within the main chamber is controlled by the turbulent mixing rather than the vaporization and diffusion processes of the injected fuel of the diesel. 

  11. 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.

  12. 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.

  13. Real time NO emissions measurement during cold start in LPG SI engine

    International Nuclear Information System (INIS)

    Li, Gong; Liu, Zhimin; Li, Zhilong; Qiu, Dongping; Li, Liguang

    2007-01-01

    To identify combustion occurrence is very important. Traditionally, cylinder pressure has been used as a criterion of combustion occurrence, but it can be unreliable when identifying lean mixture combustion (there is little difference in the cylinder pressure trace between the firing cycle and motoring cycles at the lean combustion limit). This is particularly important for fuels like LPG, which have a good capacity for lean combustion. In this study, a fast response NO detector, CambustionfNOx400, based on the chemiluminescence method, was used to measure real time NO emissions in order to evaluate the technique as a criterion for establishing combustion occurrence. At the same time, this paper presents an investigation of the characteristics of real time NO emissions of the first firing cycle during cold start in a LPG SI engine to determine the optimal excess air factor of the first firing cycle, and the cylinder pressure and crank shaft speed of the engine were measured and recorded. Test results show that the excess air ratio directly influences the cylinder pressure, engine speed and NO emissions of the first firing cycle. As the excess air coefficient is reduced from the lean misfiring limit, NO emissions increase quickly, then reduce quickly and then reduce slowly. NO emissions generally increase with peak cylinder pressure, even at constant excess air coefficient. Real time NO emissions can be used to identify cylinder combustion and misfire occurrence during engine cranking, even at the dilute combustion limit, and real time NO emission can be used to understand the combustion and misfire occurrence. (author)

  14. Ferrite thin films: Synthesis, characterization and gas sensing properties towards LPG

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Pratibha; Godbole, R.V. [Department of Physics, Abasaheb Garware College, Karve Road, Pune 411 004 (India); Phase, D.M. [UGC-DAE CSR Centre, Indore (India); Chikate, R.C. [Department of Chemistry, Abasaheb Garware College, Karve Road, Pune 411 004 (India); Bhagwat, Sunita, E-mail: smb.agc@gmail.com [Department of Physics, Abasaheb Garware College, Karve Road, Pune 411 004 (India)

    2015-01-15

    Nanocrystalline (Co, Cu, Ni, Zn) ferrite thin films have been deposited onto the Si (100) and alumina substrates by spray pyrolysis deposition technique. Respective metal chlorides and iron chloride were used as precursors. The structural properties of (Co, Cu, Ni, Zn) ferrite thin films were investigated by X-ray diffraction (XRD) technique which confirms polycrystalline nature and single phase spinel structure. The surface morphology was studied using scanning electron microscopy (SEM) which reveals spherical morphology for these films except NiFe{sub 2}O{sub 4} films that exhibit petal like structure. The optical transmittance and reflectance measurements were recorded using a double beam spectrophotometer. The optical studies reveal that the transition is direct band gap energy. The VSM analyzes reveal the predominant ferrimagnetic nature for CuFe{sub 2}O{sub 4} films. The gas sensing properties towards Liquid Petroleum Gas (LPG) revealed that ZnFe{sub 2}O{sub 4} films are sensitive at lower temperature while NiFe{sub 2}O{sub 4} films show steep rise at higher temperature. - Highlights: • (Co, Cu, Ni, Zn) ferrite thin films are synthesized by simple spray pyrolysis technique. • Homogenization of substituent within ferrite structure. • CuFe{sub 2}O{sub 4} film exhibits predominantly ferrimagnetic nature. • LPG sensing at lower temperature for ZnFe{sub 2}O{sub 4} film. • High sensitivity for NiFe{sub 2}O{sub 4} film at higher temperature due to defects created in the structure.

  15. 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.

  16. 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.

  17. Development of pulse laser processing for mounting fiber Bragg grating

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Aikihko; Shimada, Yukihiro; Yonemoto, Yukihiro; Suzuki, Hirokazu; Ishibashi, Hisayoshi [Quantum Beam Science Directorate, Japan Atomic Energy Agency, 8-1-7 Umebidai Kidugawa Kyoto 619-0215 (Japan); Applied Laser Technology Institute, Tsuruga Head Office, Japan Atomic Energy Agency, 65-20 Kizaki Tsuruga Fukui 914-8585 (Japan); Technical Research and Development Institute, Kumagai Gumi Co., Ltd., 2-1 Tsukudo, Shinjuku Tokyo 162-8557 (Japan)

    2012-07-11

    Pulse laser processing has been developed for the application of industrial plants in monitoring and maintenance. Surface cleaning by nano-second laser ablation was demonstrated for decontamination of oxide layers of Cr contained steel. Direct writing by femtosecond processing induced a Bragg grating in optical fiber to make it a seismic sensor for structural health monitoring. Adhesive cement was used to fix the seismic sensor on the surface of reactor coolant pipe material. Pulse laser processing and its related technologies were presented to overcome the severe accidents of nuclear power plants.

  18. Structural Health Monitoring of Bridges with Fiber Bragg Grating Sensors

    Directory of Open Access Journals (Sweden)

    Francisco Navarro-Henríquez

    2014-11-01

    Systems with fiber optic sensors FBG (Fiber Bragg Grating are consolidated in the Structural Health Monitoring (SMH of bridges, Nondestructive Testing (NDT static and dynamic measurements of deformation, displacement, deflection, temperature and vibration. This article provides a brief introduction to the technology and the fundamentals of fiber optic sensors, also present comparative advantages over its traditional counterpart is presented. Their characteristics are described and measurement graphics are presented as an application example of the FBG sensors. Finally, some key aspects to consider for proper use in the field are mentioned.

  19. Component-wise exergy and energy analysis of vapor compression refrigeration system using mixture of R134a and LPG as refrigerant

    Science.gov (United States)

    Gill, Jatinder; Singh, Jagdev

    2017-11-01

    In this work, the experimental examination was carried out using a mixture of R134a and LPG refrigerant (consisting of R134a and LPG in a proportion of 28:72 by weight) as a replacement for R134a in a vapor compression refrigeration system. Exergy and energy tests were carried out at different evaporator and condenser temperatures with controlled environmental conditions. The results showed that the exergy destruction in the compressor, condenser, evaporator, and a capillary tube of the R134a / LPG refrigeration system was found lower by approximately 11.13-3.41%, 2.24-3.43%, 12.02-13.47% and 1.54-5.61% respectively. The compressor exhibits the highest level of destruction, accompanied by a condenser, an evaporator and a capillary tube in refrigeration systems. The refrigeration capacity, COP and power consumption of the compressor of the R134a /LPG refrigeration system were detected higher and lower compared to the R134a refrigeration system by about 7.04-11.41%, 15.1-17.82%, and 3.83-8.08% respectively. Also, the miscibility of R134a and LPG blend with mineral oil discovered good. The R134a and LPG refrigerant mixture proposed in this study perform superior to R134a from component-wise exergy and energy analyses under similar experimental conditions.

  20. Component-wise exergy and energy analysis of vapor compression refrigeration system using mixture of R134a and LPG as refrigerant

    Science.gov (United States)

    Gill, Jatinder; Singh, Jagdev

    2018-05-01

    In this work, the experimental examination was carried out using a mixture of R134a and LPG refrigerant (consisting of R134a and LPG in a proportion of 28:72 by weight) as a replacement for R134a in a vapor compression refrigeration system. Exergy and energy tests were carried out at different evaporator and condenser temperatures with controlled environmental conditions. The results showed that the exergy destruction in the compressor, condenser, evaporator, and a capillary tube of the R134a / LPG refrigeration system was found lower by approximately 11.13-3.41%, 2.24-3.43%, 12.02-13.47% and 1.54-5.61% respectively. The compressor exhibits the highest level of destruction, accompanied by a condenser, an evaporator and a capillary tube in refrigeration systems. The refrigeration capacity, COP and power consumption of the compressor of the R134a /LPG refrigeration system were detected higher and lower compared to the R134a refrigeration system by about 7.04-11.41%, 15.1-17.82%, and 3.83-8.08% respectively. Also, the miscibility of R134a and LPG blend with mineral oil discovered good. The R134a and LPG refrigerant mixture proposed in this study perform superior to R134a from component-wise exergy and energy analyses under similar experimental conditions.

  1. Energy and exergy analysis of LPG (liquefied petroleum gas) as a drop in replacement for R134a in domestic refrigerators

    International Nuclear Information System (INIS)

    El-Morsi, Mohamed

    2015-01-01

    This study presents a comparison of energetic and exergetic performance of a vapour compression refrigeration system using pure HC (hydrocarbon) refrigerants. In this study, three different pure HCs propane (R290), butane (R600) and commercial LPG (liquefied petroleum gas) are used in the theoretical analysis. R134a is also used in the analysis as a reference refrigerant. The evaporator temperature ranges from −30 to 0 °C while the condenser ranges from 30 to 50 °C. MATLAB software is used for solving the thermodynamic equations, while the thermo-physical properties are calculated using REFPROP software. The results show that R600 has the highest COP c and exergetic efficiency, while LPG has the lowest. When compared to R134a, the COP c for R134a is higher than that for LPG by 10%. Also, the exergetic efficiency is higher by 5%. However, LPG has the advantage of being not expensive, available in large amounts and zero ozone depletion potential and low global warming potential. - Highlights: • The results show that R600 has the highest COP c & exergy efficiency, and the lowest irreversibility. • LPG has the lowest COP c & exergy efficiency, and the highest irreversibility. • Compared to R134a, LPG has a lower COP c and exergy efficiency by an average of 10% and 5%, respectively

  2. 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.

  3. 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.

  4. CST simulations of THz Smith–Purcell radiation from a lamellar grating with vacuum gaps

    International Nuclear Information System (INIS)

    Lekomtsev, K.; Karataev, P.; Tishchenko, A.A.; Urakawa, J.

    2015-01-01

    Smith–Purcell radiation (SPR) from a lamellar grating with vacuum gaps was calculated using Computer Simulation Technology (CST) Particle In Cell (PIC) solver. The shapes of the radiation distributions were compared with those of Resonant Diffraction Radiation theory. Study of calculation domain meshing was performed. Influence of a transverse bunch size on the calculation accuracy and an SPR intensity distribution was investigated. Dependencies of the SPR yield on Lorentz factor and grating strip depth were calculated and compared with previously reported theoretical and experimental studies

  5. Compact beam splitters with deep gratings for miniature photonic integrated circuits: design and implementation aspects.

    Science.gov (United States)

    Chen, Chin-Hui; Klamkin, Jonathan; Nicholes, Steven C; Johansson, Leif A; Bowers, John E; Coldren, Larry A

    2009-09-01

    We present an extensive study of an ultracompact grating-based beam splitter suitable for photonic integrated circuits (PICs) that have stringent density requirements. The 10 microm long beam splitter exhibits equal splitting, low insertion loss, and also provides a high extinction ratio in an integrated coherent balanced receiver. We further present the design strategies for avoiding mode distortion in the beam splitter and discuss optimization of the widths of the detectors to improve insertion loss and extinction ratio of the coherent receiver circuit. In our study, we show that the grating-based beam splitter is a competitive technology having low fabrication complexity for ultracompact PICs.

  6. Polarization-independent high-index contrast grating and its fabrication tolerances

    DEFF Research Database (Denmark)

    Ikeda, Kazuhiro; Takeuchi, Kazuma; Takayose, Kentaro

    2013-01-01

    also investigated the fabrication tolerances of the structure and found that, assuming careful optimizations of electron beam lithography for the precise grating width and dry-etching for the vertical sidewall, the suggested polarization-independent HCG can be fabricated using standard technologies.......A polarization-independent, high-index contrast grating (HCG) with a single layer of cross stripes allowing simple fabrication is proposed. Since the cross stripes structure can be suspended in air by selectively wet-etching the layer below, all the layers can be grown at once when implemented...

  7. Comparing modelling techniques when designing VPH gratings for BigBOSS

    Science.gov (United States)

    Poppett, Claire; Edelstein, Jerry; Lampton, Michael; Jelinsky, Patrick; Arns, James

    2012-09-01

    BigBOSS is a Stage IV Dark Energy instrument based on the Baryon Acoustic Oscillations (BAO) and Red Shift Distortions (RSD) techniques using spectroscopic data of 20 million ELG and LRG galaxies at 0.5VPH) gratings have been identified as a key technology which will enable the efficiency requirement to be met, however it is important to be able to accurately predict their performance. In this paper we quantitatively compare different modelling techniques in order to assess the parameter space over which they are more capable of accurately predicting measured performance. Finally we present baseline parameters for grating designs that are most suitable for the BigBOSS instrument.

  8. Analysis of Engine Parameters at Using Diesel-LPG and Diesel-CNG Mixture in Compression-ignition Engine

    Directory of Open Access Journals (Sweden)

    Michal Jukl

    2014-01-01

    Full Text Available This work is aimed on influence of diesel engine parameters that is used with mixture of gas and diesel fuel. The first part of the article describes diesel fuel systems where small part of diesel fuel is replaced by LPG or CNG fuel. These systems are often called as Diesel-Gas systems. Next part of the article focuses on tested car and measurement equipment. Measurement was performed by common-rail diesel engine in Fiat Doblň. Tests were carried out in laboratories of the Department of Engineering and Automobile Transport at the Mendel University in Brno. They were observed changes between emissions of used fuels – diesel without addition of gas, diesel + LPG and diesel + CNG mixture. It was found that that the addition of gas had positive effect on the performance parameters and emissions.

  9. Theoretical and experimental investigations on the performance of dual fuel diesel engine with hydrogen and LPG as secondary fuels

    Energy Technology Data Exchange (ETDEWEB)

    Lata, D.B.; Misra, Ashok [Department of Mechanical Engineering, Birla Institute of Technology, Mesra, Ranchi 835215 (India)

    2010-11-15

    The mathematical models to predict pressure, net heat release rate, mean gas temperature, and brake thermal efficiency for dual fuel diesel engine operated on hydrogen, LPG and mixture of LPG and hydrogen as secondary fuels are developed. In these models emphasis have been given on spray mixing characteristics, flame propagation, equilibrium combustion products and in-cylinder processes, which were computed using empirical equations and compared with experimental results. This combustion model predicts results which are in close agreement with the results of experiments conducted on a multi cylinder turbocharged, intercooled gen-set diesel engine. The predictions are also in close agreement with the results on single cylinder diesel engine obtained by other researchers. A reasonable agreement between the predicted and experimental results reveals that the presented model gives quantitatively and qualitatively realistic prediction of in-cylinder processes and engine performances during combustion. (author)

  10. A study on damage effect from boiling liquid expanding vapor explosion(Believe) of LPG charging facility

    Energy Technology Data Exchange (ETDEWEB)

    Roh, Sam Kew; Ham, Eun Gu [Dept. of Architectural Engineering, Kwangwoon University (Korea); Kim, Tae Hwan [Automation System Research Institute, Seoul (Korea)

    1999-12-01

    The LPG refueling station's explosion at Bucheon city was a major accident which with rare frequency of occurrence and large damage effect. Therefore, to prevent similar accident in the future from LPG charging stations which located in urban area. It needs to identify the damage effects of such facilities by comparing theoretically quantities risk and actual damage. The BLEVE effects from the accident showed similar damage effect in case of heat flux, however, the overpressure level reflected at the reduced distance by 15%. The structure damage to the near by area showed comparatively large heat radiation damage to the concrete structure strength and shape changes through heat flux while the overpressure effect was small. 13 refs., 4 figs., 4 tabs.

  11. 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.

  12. Nonresidential buildings energy consumption survey: 1979 consumption and expenditures. Part 2. Steam, fuel oil, LPG, and all fuels

    Energy Technology Data Exchange (ETDEWEB)

    Patinkin, L.

    1983-12-01

    This report presents data on square footage and on total energy consumption and expenditures for commercial buildings in the contiguous United States. Also included are detailed consumption and expenditures tables for fuel oil or kerosene, liquid petroleum gas (LPG), and purchased steam. Commercial buildings include all nonresidential buildings with the exception of those where industrial activities occupy more of the total square footage than any other type of activity. 7 figures, 23 tables.

  13. A high spatial resolution distributed optical fiber grating sensing system based on OFDR

    Science.gov (United States)

    Dong, Ke; Xiong, Yuchuan; Wen, Hongqiao; Tong, Xinlin; Zhang, Cui; Deng, Chengwei

    2017-10-01

    A distributed optical fiber grating sensing system with large capacity and high spatial resolution is presented. Since highdensity identical weak grating array was utilized as sensing fiber, the multiplexing number was greatly increased, meanwhile, optical frequency domain reflectometry (OFDR) technology was used to implement high resolution distributed sensing system. In order to eliminate the nonlinear effect of tunable light source, a windowed FFT algorithm based on cubic spline interpolation was applied. The feasibility of the algorithm was experimentally testified, ultimately, the spatial resolution of system can reach mm-level. The influence of the crosstalk signal in the grating array on the OFDR system was analyzed. A method that a long enough delay fiber was added before the first FBG to remove crosstalk signal was proposed. The experiment was verified using an optical fiber with 113 uniform Bragg gratings at an interval of 10cm whose reflectivity are less than 1%. It demonstrates that crosstalk signal and measurement signal can be completely separated in the distance domain after adding a long enough delay fiber. Finally, the temperature experiment of distributed grating sensing system was carried out. The results display that each raster's center wavelength in the fiber link is independent of each other and the center wavelength drift has a good linear relationship with the temperature. The sensitivity of linear fitting is equal to 11.1pm/°C.

  14. Microstructural and Mechanical Properties of Welded High Strength Steel Plate Using SMAW and SAW Method for LPG Storage Tanks

    Science.gov (United States)

    Winarto, Winarto; Riastuti, Rini; Kumeidi, Nur

    2018-03-01

    Indonesian government policy to convert energy consumption for domestic household from kerosene to liquefied petroleum gas (LPG) may lead to the increasing demand for LPG storage tank. LPG storage tank with a large capacity generally used the HSLA steel material of ASTM A516 Grade 70 joined by SMAW or combination between SMAW and SAW method. The heat input can affect the microstructure and mechanical properties of the weld area. The input heat is proportional to the welding current and the arc voltage, but inversely proportional to its welding speed. The result shows that the combination of SMAW-SAW process yield the lower hardness in the HAZ and the fusion zone compared to the singe SMAW process. PWHT mainly applied to reduce residual stress of welded joint. The result shows that PWHT can reduce the hardness in the HAZ and the fusion zone in comparing with the singe SMAW process. The microstructure of weld joint shows a coarser structure in the combined welding process (SMAW-SAW) comparing with the single welding process (SMAW).

  15. Experimental and analytical investigation of thermal coating effectiveness for 3 m{sup 3} LPG tanks engulfed by fire

    Energy Technology Data Exchange (ETDEWEB)

    Landucci, Gabriele [CONPRICI - Dipartimento di Ingegneria Chimica, Chimica Industriale e Scienza dei Materiali, Universita degli Studi di Pisa, via Diotisalvi n.2, 56126 Pisa (Italy); Molag, Menso; Reinders, Johan [Nederlandse Organisatie voor toegepast-natuurwetenschappelijk onderzoek TNO, Laan van Westenenk 501, P.O. Box 342, 7300 AH Apeldoorn (Netherlands); Cozzani, Valerio [CONPRICI - Dipartimento di Ingegneria Chimica, Mineraria e delle Tecnologie Ambientali, Alma Mater Studiorum, Universita di Bologna, via Terracini n.28, 40131 Bologna (Italy)], E-mail: valerio.cozzani@unibo.it

    2009-01-30

    Two large-scale diesel pool fire engulfment tests were carried out on LPG tanks protected with intumescing materials to test the effectiveness of thermal coatings in the prevention of hot BLEVE accidental scenarios in the road and rail transport of LPG. A specific test protocol was defined to enhance reproducibility of experimental tests. The geometrical characteristics of the test tanks were selected in order to obtain shell stresses similar to those present in full-size road tankers complying to ADR standards. In order to better understand the stress distribution on the vessel and to identify underlying complicating phenomena, a finite element model was also developed to better analyze the experimental data. A non-homogeneous and time-dependent effectiveness of the fire protection given by the intumescing coating was evidenced both by finite element simulations and by the analysis of the coating after the tests. The results of the fire tests pointed out that the coating assured an effective protection of the tanks, consistently increasing the expected time to failure. The data obtained suggest that the introduction of fire protection coatings may be a viable route to improve the safety of the LPG distribution chain.

  16. A study on the criterions of lean burn limit for an LPG EFI engine. Paper no. IGEC-1-140

    International Nuclear Information System (INIS)

    Li, L.; Wang, Z.; Xiao, Z.; Wang, H.; Deng, B.; Su, Y.

    2005-01-01

    Based on electronic low-pressure gaseous injection, the comparing analysis of several methods for the criterions of lean burn limit in an LPG engine is presented. Experiments are carried out in a single cylinder, four-stroke, water-cooled, 125cc engine with electronic LPG injection. According to the analysis of multi-parameters in and out cylinder, it shows that variation coefficient of indicated pressure which is the classical judgment of lean burn limit, the HC emission, HC emission rising gradient, the misfiring rate and the variation coefficient of the crank angle of the maximum combustion pressure can be as the criterions for lean burn limit. For the test engine, 15% as variation coefficient of indicative mean pressure, 500 x 10 -6 as HC emission, 2000 x 10 -6 as HC emission rising ratio, 1% as misfiring rate and 50% as variation coefficient of the crank angle of the maximum combustion pressure can be as the judgment criterions of LPG lean burn limits. (author)

  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. The tragedy of San Juanico--the most severe LPG disaster in history.

    Science.gov (United States)

    Arturson, G

    1987-04-01

    During the early morning of Monday, 19 November 1984, one of the largest disasters in industrial history occurred in the Mexico City Area, causing the greatest rescue effort to assist population in an emergency ever undertaken. The tragic catastrophe started in a large LPG (Liquid Petroleum Gas) storage and distribution centre in San Juan Ixhuatepec, 20 km north of Mexico City. The facilities, owned by the Pemex State Oil Company, consisted of six spherical storage tanks (four with a volume of 1600 m3 and two with a volume of 2400 m3) and 48 horizontal cylindrical bullet tanks of different sizes. At the time of the disaster the storage tanks contained 11,000 m3 of a mixture of propane and butane. The inhabitants of San Juan Ixhuatepec numbered about 40,000, and a further 60,000 lived in the hills surrounding the village. The majority were poor country people living in one-story houses constructed of concrete pillars filled in with bricks and with roofs of iron sheets. The disaster started due to LPG leakage, probably a pipe leakage or rupture due to excess pressure. A vapour cloud built up and was slowly moved by the north-east wind towards the ground-placed flare pit located in the western part of the plant. The vapour cloud was ignited around 5:40 a.m. and was followed by an extensive fire at the plant area. The first explosion was registered on the seismograph at the University of Mexico at 05 h 44 min 52 s and was followed by a dozen explosions within the next hour, some of them of BLEVE type (Boiling Liquid Expanding Vapour Explosion) due to rupture of one or more storage tanks. Two of the explosions had an intensity of 0.5 on the Richter scale. Unburned and burning gas entered the houses south of the plant area and set fire to everything. Blast waves from the explosions not only destroyed a number of houses but also shifted several cylindrical tanks from their supports and added more gas to the fire. The smaller spheres and some of the cylinders exploded and

  19. 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)

  20. 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

  1. Sequential interrogation of multiple FBG sensors using LPG modulation and an artificial neural network

    International Nuclear Information System (INIS)

    Basu, Mainak; Ghorai, S K

    2015-01-01

    Interrogating multiple fiber Bragg gratings (FBG) requires highly sensitive spectrum scanning equipment such as optical spectrum analyzers, tunable filters, acousto-optic tunable filters etc, which are expensive, bulky and time consuming. In this paper, we present a new approach for multiple FBG sensor interrogation using long-period gratings and an artificial neural network. The reflection spectra of the multiplexed FBGs are modulated by two long period gratings separately and the modulated optical intensities were detected by two photodetectors. The outputs of the detectors are then used as input in a previously trained artificial neural network to interrogate the FBG sensors. Simulations have been performed to determine the strain and wavelength shift using two and four sensors. The interrogation system has also been demonstrated experimentally for two sensors using simply supported beams in the range of 0–350 μstrain. The proposed interrogation scheme has been found to identify the perturbed FBG, and to determine strain and wavelength shift with reasonable accuracy. (paper)

  2. 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.

  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. Thermodynamic modeling of LPG combustion in dual-fuel engines; Modelisation thermodynamique de la combustion du GPL dans les moteurs dual-fuel

    Energy Technology Data Exchange (ETDEWEB)

    Bilcan, A.; Le Corre, O.; Tazerout, M. [Ecole des Mines de Nantes, 44 (France); Ramesh, A. [Indian Institute of Technology Madras (India)

    2002-07-01

    Dual-fuel engines are modified diesel engines burning simultaneously two fuels inside the cylinder: a gaseous one, called the primary fuel and a liquid one, called the pilot fuel. The thermal efficiency of the dual-fuel engine and of the diesel engine are comparable; the level of emissions is lower compared to the diesel one. This article presents a new procedure for the combustion modeling in a LPG-diesel dual-fuel engine. The procedures deals with the ignition delay period and with the rate of heat release inside the cylinder. This procedure is validated using experimental data issued front a collaboration with the Indian Institute of Technology from Madras, India. The used engine is a single-cylinder one, air-cooled. The pilot fuel is direct injected inside the cylinder The engine was run at constant load and with different diesel substitutions, i.e. for different air to fuel ratios of the primary fuel-air mixture. The general error of the procedure is below 10%. (authors)

  8. POLA PENGELUARAN, PERSEPSI, DAN KEPUASAN KELUARGA TERHADAP PERUBAHAN PENGGUNAAN ENERGI DARI MINYAK TANAH KE LPG

    Directory of Open Access Journals (Sweden)

    Megawati Simanjuntak

    2009-08-01

    Full Text Available The objectives of this research were to analyze the expenses pattern, perception, and satisfaction level of families among fuel conversion. This research was conducted in two villages, namely Cikarawang Village and Situ Gede Village, District of Bogor on October 2008. Total sample were 30 households consisted of fifteen samples in each village that chosen purposively. The average of expenses of families per month for buying fuel, after the fuel conversion program had been conducted tend to decreased from IDR 96.500,00 per month to IDR 58.800,00 per month after the program or saved the family expenses for IDR 37.700,00 per month. Most of respondents stated agreed that conversion program could decreased the family expenses. The gas gave more advantage compared to kerosene, accepted gas as replacement of kerosene, and there was no force in conducting the conversion program. The satisfaction level showed that, respondents felt saver using kerosene and viewed from the cost to buy fuel, few respondents felt heavy for the gas price. Otherwise, the using of LPG was felt more efisien in time, cleaner, and more practice than kerosene.

  9. Modeling the release, spreading, and burning of LNG, LPG, and gasoline on water

    International Nuclear Information System (INIS)

    Johnson, David W.; Cornwell, John B.

    2007-01-01

    Current interest in the shipment of liquefied natural gas (LNG) has renewed the debate about the safety of shipping large volumes of flammable fuels. The size of a spreading pool following a release of LNG from an LNG tank ship has been the subject of numerous papers and studies dating back to the mid-1970s. Several papers have presented idealized views of how the LNG would be released and spread across a quiescent water surface. There is a considerable amount of publicly available material describing these idealized releases, but little discussion of how other flammable fuels would behave if released from similar sized ships. The purpose of this paper is to determine whether the models currently available from the United States Federal Energy Regulatory Commission (FERC) can be used to simulate the release, spreading, vaporization, and pool fire impacts for materials other than LNG, and if so, identify which material-specific parameters are required. The review of the basic equations and principles in FERC's LNG release, spreading, and burning models did not reveal a critical fault that would prevent their use in evaluating the consequences of other flammable fluid releases. With the correct physical data, the models can be used with the same level of confidence for materials such as LPG and gasoline as they are for LNG

  10. Operation and management of United Central Piping LPG supply stations in Shenzhen

    Energy Technology Data Exchange (ETDEWEB)

    Lai Yankai

    1997-11-01

    Shenzhen has based its city gas development project on the eventual conversion to natural gas supply by way of central piping LPG supply stations. To fully exploit the potential gas supply capability of every central piping station and cut down the total running cost, we have been connecting the existing supply stations and their piping system into a network, which not only provided a more reliable gas supply performance, but can greatly simplify the evacuation of gas stations from the ever-expanding downtown areas to suburbs. Through this way, the periodic gas stock held by individual stations can be transferred to storage terminal or stations of enough holding capability; the supplying distance has been much lengthened and the gas volume held in the piping system increased; gas supply covered by small stations has been shifted to new and large stations. By linking these stations, we are able to provide pipeline LP gas supply for a large area, and in the same time lay down the pipeline infrastructure for the upcoming LNG supply so that an easy conversion to LNG supply can be secured as soon as the projected LNG terminal is put to service. (au)

  11. Experimental studies of flame stability and emission characteristics of simple LPG jet diffusion flame

    Energy Technology Data Exchange (ETDEWEB)

    D.Y. Kiran; D.P. Mishra [Indian Institute of Technology Kanpur, Kanpur (India). Combustion Laboratory, Department of Aerospace Engineering

    2007-07-15

    In the present study, experiments were carried out to measure the lift-off height, H{sub L}; flame length, L{sub f} and blow-off velocity for a simple LPG (liquefied petroleum gas) jet diffusion flames. It is observed that lift-off height is proportional to the fuel exit velocity, U{sub f}. A semi-empirical correlation between lift-off height and global strain rate, U{sub f}/D{sub f} is proposed. Two regimes identified either as buoyancy or momentum dominated were characterized by Froude number, Fr. For momentum dominated jet diffusion flames, L{sub f}/D{sub f} remains almost constant and therefore is independent of the Froude number. The NOx emissions, expressed in terms of emission index, EINOx is found to decrease with U{sub f}. This decreasing trend is consistent with the concept that increasing jet velocity reduces the residence time as reported in the literature. The present data is also compared with the available data of propane gas and found to be in good agreement well particularly in trend wise. Besides these data, EINOx scaling law is also reported in the present study. 20 refs., 8 figs.

  12. Experimental investigation of laminar LPG-H{sub 2} jet diffusion flame with preheated reactants

    Energy Technology Data Exchange (ETDEWEB)

    D.P. Mishra; P. Kumar [Indian Institute of Technology, Kanpur (India). Combustion Laboratory, Department of Aerospace Engineering

    2008-10-15

    This paper presents an experimental investigation of the effect of H{sub 2} addition on flame length, soot free length fraction (SFLF), flame radiant fraction, gas temperature and emission level in LPG-H{sub 2} composite fuel jet diffusion flame for two preheated cases namely, (i) preheated air and (ii) preheated air and fuel. Results show that the H{sub 2} addition leads to a reduction in flame length which may be caused due to an increased gas temperature. Besides this, the flame length is also observed to be reduced with increasing reactants temperature. The soot free length fraction (SFLF) increases as H{sub 2} is added to fuel stream. This might have been caused by decrease in the C/H ratio in the flame and is favorable to attenuate PAH formation rate. Interestingly, the SFLF is observed to be reduced with increasing reactants temperature that may be due to reduction in induction period of soot formation caused by enhanced flame temperature. Moreover, the decreased radiant heat fraction with hydrogen addition is pertinent with the reduction in soot concentration level. The reduction in NOx emission level with H{sub 2} addition to the fuel stream is also observed. On the contrary, NOx emission level is found to be enhanced significantly with reactant temperature that can be attributed to the increase in thermal NOx through Zeldovich mechanism. 31 refs., 4 figs., 2 tabs.

  13. A heterogeneous fleet vehicle routing model for solving the LPG distribution problem: A case study

    International Nuclear Information System (INIS)

    Onut, S; Kamber, M R; Altay, G

    2014-01-01

    Vehicle Routing Problem (VRP) is an important management problem in the field of distribution and logistics. In VRPs, routes from a distribution point to geographically distributed points are designed with minimum cost and considering customer demands. All points should be visited only once and by one vehicle in one route. Total demand in one route should not exceed the capacity of the vehicle that assigned to that route. VRPs are varied due to real life constraints related to vehicle types, number of depots, transportation conditions and time periods, etc. Heterogeneous fleet vehicle routing problem is a kind of VRP that vehicles have different capacity and costs. There are two types of vehicles in our problem. In this study, it is used the real world data and obtained from a company that operates in LPG sector in Turkey. An optimization model is established for planning daily routes and assigned vehicles. The model is solved by GAMS and optimal solution is found in a reasonable time

  14. A heterogeneous fleet vehicle routing model for solving the LPG distribution problem: A case study

    Science.gov (United States)

    Onut, S.; Kamber, M. R.; Altay, G.

    2014-03-01

    Vehicle Routing Problem (VRP) is an important management problem in the field of distribution and logistics. In VRPs, routes from a distribution point to geographically distributed points are designed with minimum cost and considering customer demands. All points should be visited only once and by one vehicle in one route. Total demand in one route should not exceed the capacity of the vehicle that assigned to that route. VRPs are varied due to real life constraints related to vehicle types, number of depots, transportation conditions and time periods, etc. Heterogeneous fleet vehicle routing problem is a kind of VRP that vehicles have different capacity and costs. There are two types of vehicles in our problem. In this study, it is used the real world data and obtained from a company that operates in LPG sector in Turkey. An optimization model is established for planning daily routes and assigned vehicles. The model is solved by GAMS and optimal solution is found in a reasonable time.

  15. Investigation of soot formation and temperature field in laminar diffusion flames of LPG-air mixture

    Energy Technology Data Exchange (ETDEWEB)

    Shahad, Haroun A.K.; Mohammed, Yassar K.A. [Babylon Univ., Dept. of Mechanical Engineering, Babylon (Israel)

    2000-11-01

    Soot formation and burnout were studied at atmospheric pressure in co-flowing, axisymmetric buoyant laminar diffusion flames and double flames of liquefied petroleum gases (LPG)-air mixtures. In diffusion flames, two different fuel flow rates were examined. In double flames, three different primary air flow rates were examined. A soot sampling probe and a thermocouple were used to measure the local soot mass concentration and flame temperature, respectively. Flame residence time was predicted using a uniformly accelerated motion model as function of axial distance of the flame. The increase of primary air flow rate was found to suppress the energy transfer from the annular region, at which the soot is produced, to the flame axis. The time required to initiate soot formation at the flame axis becomes longer as the primary air is increased. The trend rate of soot formation was found to be similar along the flame axis in all tested diffusion flames. The increase of primary air by 10% of the stoichiometric air requirement of the fuel results in a 70% reduction in maximum soot concentration. The final exhaust of soot, which is determined by the net effect of soot formation and burnout, is much lower in double flames than that in diffusion flames. (Author)

  16. Providing cleaner energy access in Indonesia through the megaproject of kerosene conversion to LPG

    International Nuclear Information System (INIS)

    Budya, Hanung; Yasir Arofat, Muhammad

    2011-01-01

    In 2007 Indonesia undertook a massive energy program to convert its primary cooking fuel from kerosene to LPG in more than 50 million households. This megaproject, to be completed in late 2011, provided an improved household cooking fuel, with its associated benefits in user costs, cleanliness, convenience, and environment, and reduced the government's huge subsidy for petroleum fuels. Presented from the perspective of Pertamina, Indonesia's sole NOC, and the program implementer, this paper describes the background of the fuels situation, the planning stages, including the preparatory analytical work, targeted market surveys and tests, and the subsequent building of the financial, technical, and institutional models for carrying out the program on an expeditious schedule. It presents the project's major execution steps, results of the program to date, and the unique institutional roles of each party, including the activities and benefits for the government, Pertamina, the public, the industry, and the crucial agents in the fuel supply chains. Finally there is a retrospective policy analysis and a discussion of key factors and challenges in the execution of Indonesia's largest-ever energy initiative to provide improved cooking fuel.

  17. The Study on the Quantitative Analysis in LPG Tank's Fire and Explosion

    Energy Technology Data Exchange (ETDEWEB)

    Bae, S.J.; Kim, B.J. [Department of chemical Engineering, Soongsil University, Seoul (Korea)

    1999-04-01

    Chemical plant's fire and explosion does not only damage to the chemical plants themselves but also damage to people in or near of the accident spot and the neighborhood of chemical plant. For that reason, Chemical process safety management has become important. One of safety management methods is called 'the quantitative analysis', which is used to reduce and prevent the accident. The results of the quantitative analysis could be used to arrange the equipments, evaluate the minimum safety distance, prepare the safety equipments. In this study we make the computer program to make easy to do quantitative analysis of the accident. The output of the computer program is the magnitude of fire(pool fire and fireball) and explosion (UVCE and BLEVE) effects. We used the thermal radiation as a measure of fire magnitude and used the overpressure as a measure of explosion magnitude. In case of BLEVE, the fly distance of fragment can be evaluated. Also probit analysis was done in every case. As the case study, Buchun LPG explosion accident in Korea was analysed by the program developed. The simulation results showed that the permissible distance was 800m and probit analysis showed that 1st degree burn, 2nd degree burn, and death distances are 450, 280, 260m, respectively. the simulation results showed the good agreement with the result from SAFER PROGRAM made by DuPont. 13 refs., 4 figs., 2 tabs.

  18. LPG ammonia and nitrogen dioxide gas sensing properties of nanostructured polypyrrole thin film

    Energy Technology Data Exchange (ETDEWEB)

    Bagul, Sagar B., E-mail: nano.sbbagul@gmail.com; Upadhye, Deepak S.; Sharma, Ramphal, E-mail: rps.phy@gmail.com [Thin Film and Nanotechnology Laboratory, Department of Nanotechnology, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad (India)

    2016-05-06

    Nanostructured Polypyrrole thin film was synthesized by easy and economic chemical oxidative polymerization technique on glass at room temperature. The prepared thin film of Polypyrrole was characterized by optical absorbance study by UV-visible spectroscopy and electrical study by I-V measurement system. The optical absorbance spectrum of Polypyrrole shows two fundamental peaks in region of 420 and 890 nm, which confirms the formation of Polypyrrole on glass substrate. The I-V graph of nanostructured Polypyrrole represents the Ohmic nature. Furthermore, the thin film of Polypyrrole was investigated by Scanning electron microscopy for surface morphology study. The SEM micrograph represents spherical nanostructured morphology of Polypyrrole on glass substrate. In order to investigate gas sensing properties, 100 ppm of LPG, Ammonia and Nitrogen Dioxide were injected in the gas chamber and magnitude of resistance has been recorded as a function of time in second. It was observed that nanostructured Polypyrrole thin film shows good sensing behavior at room temperature.

  19. Opportunities and Challenges for Petroleum and LPG Markets in Sub-Saharan Africa

    International Nuclear Information System (INIS)

    Matthews, William G.

    2014-01-01

    Petroleum products are the lifeblood of the economies of all Sub-Saharan African countries. They are key fuels used in road transport and power generation. Households use kerosene and liquefied petroleum gas (LPG) for lighting and cooking. In this era of high oil prices, if the product is state-subsidized, the government budget bears the brunt of price increases. If the price changes are passed through to consumers, the household budgets are impacted directly. The countries most vulnerable to oil price shocks are the low-income oil importers which are disproportionately concentrated in Sub-Saharan Africa. End user prices are affected by several factors: market size and economies of scale, mode of product transport, controlled pricing, protection of inefficient domestic suppliers, degree of competition, clear and stable legal framework, effective monitoring and disclosure of industry statistics. This paper is based on two recent studies of the oil sectors of several countries in Sub-Saharan Africa which posed the following questions: Is each stage in the supply chain, from import of crude oil or refined products to retail, efficiently run and are the efficiency gains passed on to end-users? If not, what are the potential causes and possible means of remedying the problems? - Highlights: • Examines comparative efficiencies of oil product supply chains in twelve sub-Saharan countries. • Identifies areas for improvement towards “best practice”. • Objective is to reduce differential between international reference prices and consumer prices

  20. Development of a 2kWe LPG fuel processor for PEFC

    International Nuclear Information System (INIS)

    Cipiti, F.; Pino, L.; Vita, A.; Cordaro, M.; Lagana, M.; Recupero, V.

    2004-01-01

    The successful development of Polymer Electrolyte Fuel Cells (PEFC's) for stationary and/or transportation purposes is strictly dependent on the choice of a proper fuel processor. This paper covers the in progress activities performed at CNR-ITAE on the development of a 2 kWequivalent hydrogen generator unit, (under testing) feed by LPG (propane). The main issues that should be satisfied by the hydrogen generator will be high fuel conversion, stable performance for repeated start-up and shut-down cycles, capability to process different hydrocarbons, etc. The actual unit, is constituted by an autothermal reactor (ATR) with a proprietary CNR/ITAE catalyst, an intermediate water gas shift (ITS) and a CO preferential oxidation (PROX) reactors containing commercial catalysts; the system includes heat exchangers, manual and automatic valves, pressure regulators and transducers, flow meters and ancillaries. External heating is supplied only during the start-up; on regime operations the global heat balance is smoothly exothermic. The main objectives of the experimental tests are: evaluation of reactors and system performance (in steady state and in transient response), identification of main operating limits of the reactors, to validate heat and mass balance. Preliminary results, for the 2 kW prototype, are presented. (author)

  1. Using Geographic Information System - GIS - for pipeline management: case of Urucu-Coari LPG pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Furquim, Maysa P.O. [ESTEIO Engenharia e Aerolevantamentos S.A, Curitiba, PR (Brazil)

    2009-07-01

    This technical paper seeks to demonstrate the stages run during the GIS - Geographic Information System accomplishment as for the follow-up of a pipeline work. The GLPDUTO (LPG Pipeline) Urucu-Coari work shall be the focus of this paper. The main challenges in the compilation of data generated in the work site will be presented, as well the importance for the definition of which data should be relevant, so that the construction company and PETROBRAS could follow up its evolution. The GIS development has been performed since January 2007 and should be finished by the first semester of 2009. The following stages for GIS definition for the work management will be presented: brief history of the project - project conception, purpose, structure implemented and accomplishment expectations; survey data in loco - raw data obtained directly during the carrying out of the work and generated in the project and implantation stage; treated data - data resulting from raw data, but already treated as for the GIS environment; routines developed - specific tools created for the consolidation of the data to be manipulated on GIS in an optimized and functional way; result presented - GIS in its final conception, developed and input with the routines and data regarding the project. (author)

  2. 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.

  3. 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...

  4. 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.

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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

  10. 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.

  11. 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…

  12. [INVITED] Tilted fiber grating mechanical and biochemical sensors

    Science.gov (United States)

    Guo, Tuan; Liu, Fu; Guan, Bai-Ou; Albert, Jacques

    2016-04-01

    The tilted fiber Bragg grating (TFBG) is a new kind of fiber-optic sensor that possesses all the advantages of well-established Bragg grating technology in addition to being able to excite cladding modes resonantly. This device opens up a multitude of opportunities for single-point sensing in hard-to-reach spaces with very controllable cross-sensitivities, absolute and relative measurements of various parameters, and an extreme sensitivity to materials external to the fiber without requiring the fiber to be etched or tapered. Over the past five years, our research group has been developing multimodal fiber-optic sensors based on TFBG in various shapes and forms, always keeping the device itself simple to fabricate and compatible with low-cost manufacturing. This paper presents a brief review of the principle, fabrication, characterization, and implementation of TFBGs, followed by our progress in TFBG sensors for mechanical and biochemical applications, including one-dimensional TFBG vibroscopes, accelerometers and micro-displacement sensors; two-dimensional TFBG vector vibroscopes and vector rotation sensors; reflective TFBG refractometers with in-fiber and fiber-to-fiber configurations; polarimetric and plasmonic TFBG biochemical sensors for in-situ detection of cell, protein and glucose.

  13. Research on robot navigation vision sensor based on grating projection stereo vision

    Science.gov (United States)

    Zhang, Xiaoling; Luo, Yinsheng; Lin, Yuchi; Zhu, Lei

    2016-10-01

    A novel visual navigation method based on grating projection stereo vision for mobile robot in dark environment is proposed. This method is combining with grating projection profilometry of plane structured light and stereo vision technology. It can be employed to realize obstacle detection, SLAM (Simultaneous Localization and Mapping) and vision odometry for mobile robot navigation in dark environment without the image match in stereo vision technology and without phase unwrapping in the grating projection profilometry. First, we research the new vision sensor theoretical, and build geometric and mathematical model of the grating projection stereo vision system. Second, the computational method of 3D coordinates of space obstacle in the robot's visual field is studied, and then the obstacles in the field is located accurately. The result of simulation experiment and analysis shows that this research is useful to break the current autonomous navigation problem of mobile robot in dark environment, and to provide the theoretical basis and exploration direction for further study on navigation of space exploring robot in the dark and without GPS environment.

  14. 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.

  15. 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

  16. 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.

  17. Development of a Novel Spectrophotometer for Biochemical Analyzer Based on Volume Holography Transmissive Grating and Linear CCD

    International Nuclear Information System (INIS)

    Ren Zhong; Liu Guodong; Huang Zhen; Zeng Lvming; Dai Longmin

    2011-01-01

    The classical surface-embossed plane and concave grating are usually used as the diffraction grating in some spectrophotometers. But the minute cracks are produced on the surface of the gratings' grooves, which leads to generate the stray-light and decrease the efficiency of instrument. Therefore, a novel custom-built spectrophotometer for BCA is developed in this paper. Meanwhile, the volume holography transmissive (VHT) grating is used as the diffraction grating in this spectrophotometer. Additionally, a high resolution CCD and data acquisition (DAQ) card with combined the virtual software platform based on LabVIEW are used to design the spectral acquisition and analysis system. Experimental results show that the spectral range and the diffraction efficiency of the spectrophotometer for BCA are greatly increased. The spectral range of the spectrophotometer for BCA can reach 300-1000 nm, its wavelength resolution can reach 1nm. And, it uses the back-splitting-light technology and multi-channel parallel analysis. Compared with other same types, this spectrophotometer has many advantages, such as, higher efficiency, simpler algorithm, higher accuracy, cheaper cost and fewer stray-light and higher imaging quality, etc. Therefore, this spectrophotometer for BCA based on VHT grating will has the greatly potential values in the fields of the biochemical or medical research.

  18. 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.

  19. 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.

  20. Miniature fiber Bragg grating sensor interrogator (FBG-Transceiver) system

    Science.gov (United States)

    Mendoza, Edgar A.; Kempen, Cornelia; Lopatin, Craig

    2007-04-01

    This paper describes recent progress conducted towards the development of a miniature fiber Bragg grating sensor interrogator (FBG-Transceiver TM) system based on multi-channel integrated optic sensor (InOSense TM) microchip technology. The hybrid InOSense TM microchip technology enables the integration of all of the functionalities, both passive and active, of conventional bench top FBG sensor interrogator systems, packaged in a miniaturized, low power operation, 2-cm x 5-cm package suitable for the long-term structural health monitoring in applications where size, weight, and power are critical for operation. The FBG-Transceiver system uses active optoelectronic components monolithically integrated to the InOSense TM microchip, a microprocessor controlled signal processing electronics board capable of processing the FBG sensors signals related to stress-strain and temperature as well as vibration and acoustics. The FBG-Transceiver TM system represents a new, reliable, highly robust technology that can be used to accurately monitor the status of an array of distributed fiber optic Bragg grating sensors installed in critical infrastructures. Its miniature package, low power operation, and state-of-the-art data communications architecture, all at a very affordable price makes it a very attractive solution for a large number of SHM/NDI applications in aerospace, naval and maritime industry, civil structures like bridges, buildings and dams, the oil and chemical industry, and for homeland security applications. The miniature, cost-efficient FBG-Transceiver TM system is poised to revolutionize the field of structural health monitoring and nondestructive inspection market. The sponsor of this program is NAVAIR under a DOD SBIR contract.

  1. 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

  2. Effects of N2 gas on preheated laminar LPG jet diffusion flame

    International Nuclear Information System (INIS)

    Mishra, D.P.; Kumar, P.

    2010-01-01

    This paper presents an experimental investigation of the inert gas effect on flame length, NO x and soot free length fraction (SFLF) in a laminar LPG diffusion flame. Besides this, flame radiant fraction and temperature are also measured to explain observed NO x emission and SFLF. The inert is added to both air and fuel stream at each base line condition by maintaining a constant mass flow rate in each stream. Results indicate that inert addition leads to a significant enhancement in flame length for air-diluted stream than fuel-diluted stream. However, the flame length is observed to reduce with increasing reactant temperature. It is also observed that the SFLF increases with addition of N 2 for fuel-diluted stream. In contrast, SFLF remains almost constant when N 2 is added to air stream. The decrease in fuel concentration and gas temperature caused by inert addition leads to reduction in soot volume fraction and hence enhances SFLF. Interestingly, the SFLF reduces with increasing reactant temperature, due to reduction in induction period of soot formation caused by enhanced flame temperature. Besides this, the reduction in NO x emission level with inert addition is also observed. For all the three cases, the air dilution proved to be much efficient in reducing NO x emission level as compared to fuel dilution. This can be attributed to the differences in reduced gas temperature and residence time between air and fuel-diluted streams. On the contrary, NO x emission level enhances significantly with increasing reactant temperature as a result of increase in thermal NO x through Zeldovich mechanism.

  3. Effects of N{sub 2} gas on preheated laminar LPG jet diffusion flame

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, D.P.; Kumar, P. [Department of Aerospace Engineering, Indian Institute of Technology, Kanpur 208 016 (India)

    2010-11-15

    This paper presents an experimental investigation of the inert gas effect on flame length, NO{sub x} and soot free length fraction (SFLF) in a laminar LPG diffusion flame. Besides this, flame radiant fraction and temperature are also measured to explain observed NO{sub x} emission and SFLF. The inert is added to both air and fuel stream at each base line condition by maintaining a constant mass flow rate in each stream. Results indicate that inert addition leads to a significant enhancement in flame length for air-diluted stream than fuel-diluted stream. However, the flame length is observed to reduce with increasing reactant temperature. It is also observed that the SFLF increases with addition of N{sub 2} for fuel-diluted stream. In contrast, SFLF remains almost constant when N{sub 2} is added to air stream. The decrease in fuel concentration and gas temperature caused by inert addition leads to reduction in soot volume fraction and hence enhances SFLF. Interestingly, the SFLF reduces with increasing reactant temperature, due to reduction in induction period of soot formation caused by enhanced flame temperature. Besides this, the reduction in NO{sub x} emission level with inert addition is also observed. For all the three cases, the air dilution proved to be much efficient in reducing NO{sub x} emission level as compared to fuel dilution. This can be attributed to the differences in reduced gas temperature and residence time between air and fuel-diluted streams. On the contrary, NO{sub x} emission level enhances significantly with increasing reactant temperature as a result of increase in thermal NO{sub x} through Zeldovich mechanism. (author)

  4. Characterization of bluff-body stabilized LPG jet diffusion flame with N{sub 2} dilution

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, P.; Mishra, D.P. [Combustion Lab, Department of Aerospace Engineering, Indian Institute of Technology, Kanpur, Uttar Pradesh 208 016 (India)

    2008-10-15

    Measurements of several parameters like flame length, soot free length fraction (SFLF), radiant fraction, gas temperature and emission levels are performed in coaxial LPG jet diffusion flame to provide an insight into the effect of lip thickness and inert addition on flame characteristics. The present measurements reveal that the visible flame length is found to be reduced with increase in lip thickness. In contrast, the flame length for all lip thicknesses gets enhanced by inert addition to the fuel stream, which can be attributed to the reduced diffusivity of the mixture gases. The SFLF is seen to be enhanced with N{sub 2} addition due to decrease in the fuel concentration and flame temperature. However, the SFLF is reduced with increasing lip thickness of the bluff-body which is caused due to the reduction in induction period of soot formation. For all lip thickness, the NO{sub x} emission level is observed to be attenuated with inert (N{sub 2}) addition, which can be ascribed to reduction in residence time of gas mixture. Besides this, NO{sub x} emission level is enhanced with increasing lip thickness. The emission index of CO is found to be increased with nitrogen addition; in contrast, the EICO{sub 2} is seen to be reduced, for all lip thickness. This can be attributed to attrition in residence time with inert addition that tends to inhibit the conversion of CO to CO{sub 2}. Moreover, EICO is also observed to be attenuated while EICO{sub 2} gets enhanced, with increasing lip thickness which might be due to the increased residence time of mixture gases. (author)

  5. Characterization of bluff-body stabilized LPG jet diffusion flame with N2 dilution

    International Nuclear Information System (INIS)

    Kumar, P.; Mishra, D.P.

    2008-01-01

    Measurements of several parameters like flame length, soot free length fraction (SFLF), radiant fraction, gas temperature and emission levels are performed in coaxial LPG jet diffusion flame to provide an insight into the effect of lip thickness and inert addition on flame characteristics. The present measurements reveal that the visible flame length is found to be reduced with increase in lip thickness. In contrast, the flame length for all lip thicknesses gets enhanced by inert addition to the fuel stream, which can be attributed to the reduced diffusivity of the mixture gases. The SFLF is seen to be enhanced with N 2 addition due to decrease in the fuel concentration and flame temperature. However, the SFLF is reduced with increasing lip thickness of the bluff-body which is caused due to the reduction in induction period of soot formation. For all lip thickness, the NO x emission level is observed to be attenuated with inert (N 2 ) addition, which can be ascribed to reduction in residence time of gas mixture. Besides this, NO x emission level is enhanced with increasing lip thickness. The emission index of CO is found to be increased with nitrogen addition; in contrast, the EICO 2 is seen to be reduced, for all lip thickness. This can be attributed to attrition in residence time with inert addition that tends to inhibit the conversion of CO to CO 2 . Moreover, EICO is also observed to be attenuated while EICO 2 gets enhanced, with increasing lip thickness which might be due to the increased residence time of mixture gases

  6. Modeling the potential health benefits of lower household air pollution after a hypothetical liquified petroleum gas (LPG) cookstove intervention.

    Science.gov (United States)

    Steenland, Kyle; Pillarisetti, Ajay; Kirby, Miles; Peel, Jennifer; Clark, Maggie; Checkley, Will; Chang, Howard H; Clasen, Thomas

    2018-02-01

    Improved biomass and advanced fuel cookstoves can lower household air pollution (HAP), but levels of fine particulate matter (PM 2.5 ) often remain above the World Health Organization (WHO) recommended interim target of 35μg/m 3 . Based on existing literature, we first estimate a range of likely levels of personal PM 2.5 before and after a liquefied petroleum gas (LPG) intervention. Using simulations reflecting uncertainty in both the exposure estimates and exposure-response coefficients, we estimate corresponding expected health benefits for systolic blood pressure (SBP) in adults, birthweight, and pneumonia incidence among children LPG stove intervention would decrease personal PM 2.5 exposure from approximately 270μg/m 3 to approximately 70μg/m 3 , due to likely continued use of traditional open-fire stoves. We estimate that this decrease would lead to a 5.5mmHg lower SBP among women over age 50, a 338g higher birthweight, and a 37% lower incidence of severe childhood pneumonia. We estimate that decreased SBP, if sustained, would result in a 5%-10% decrease in mortality for women over age 50. We estimate that higher birthweight would reduce infant mortality by 4 to 11 deaths per 1000 births; for comparison, the current global infant mortality rate is 32/1000 live births. Reduced exposure is estimated to prevent approximately 29 cases of severe pneumonia per year per 1000 children under 2, avoiding approximately 2-3 deaths/1000 per year. However, there are large uncertainties around all these estimates due to uncertainty in both exposure estimates and in exposure-response coefficients; all health effect estimates include the null value of no benefit. An LPG stove intervention, while not likely to lower exposure to the WHO interim target level, is still likely to offer important health benefits. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Influence of film thickness and Fe doping on LPG sensing properties of Mn3O4 thin film grown by SILAR method

    Science.gov (United States)

    Belkhedkar, M. R.; Ubale, A. U.

    2018-05-01

    Nanocrystalline Fe doped and undoped Mn3O4 thin films have been deposited by Successive Ionic Layer Adsorption and Reaction (SILAR) method onto glass substrates using MnCl2 and NaOH as cationic and anionic precursors. The grazing incidence X-ray diffraction (GIXRD) and field emission scanning electron microscopy (FESEM)) have been carried out to analyze structural and surface morphological properties of the films. The LPG sensing performance of Mn3O4thin films have been studied by varying temperature, concentration of LPG, thickness of the film and doping percentage of Fe. The LPG response of the Mn3O4thin films were found to be enhances with film thickness and decreases with increased Fe doping (0 to 8 wt. %) at 573 K temperature.

  8. 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.

  9. 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.

  10. 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...

  11. 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

  12. Laser-driven grating linac

    International Nuclear Information System (INIS)

    Palmer, R.B.

    1982-01-01

    I would like to consider a 50 TeV on 50 TeV collider. Even a hadron machine with such an energy seems unrealistic with current technology. Magnetic fields higher than 10 Tesla are difficult and at this field the circumference would be 120 km. I conclude that only a high gradient Linac could be practical and that one should aim for 10 GeV/meter so as to keep the total length down to the order ot 10 km. Currently it is only plausible to obtain such fields using the very high energy densities produced by lasers. The luminosity is another issue. I aim for 10 33 to 10 34 but I am conscious that higher luminosities than even these are really desired, especially for an e + e - machine. I tend to assume that the machine is an e + e - machine but it will also accept hadrons

  13. 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

  14. Grate monitoring systems, state of the art; Metoder foer rosteroevervakning, dagslaegesbestaemning

    Energy Technology Data Exchange (ETDEWEB)

    Blom, Elisabet [Aaf Processdesign AB, Linkoeping (Sweden)

    2001-01-01

    During a number of years research and development projects have been made to present methods of monitoring the grate in a grate fired boiler. The monitoring is interesting in order to be able to increase efficiency, increase burn-out of ash, improve the status of emissions, improve transportation of ash and fuel through the furnace, reduce costs for operation and maintenance, handle greater loads etc. Improvement of the combustion has been concentrated to the development of the gas phase combustion. In the past few years the computer development has progressed rapidly and the use of optical monitoring methods have been made possible for monitoring grates. To analyse state of the art of optical grate monitoring systems three different methods have been used, literature search, inquiry where plant owners were asked if they have used grate monitoring systems and if so what experiences they have, and interviews with scientists and users. The inquiry investigation was made during spring 2000 and supplemented with a few known users of grate monitoring systems in august 2000. The interviews were made during august 2000. The methods which have been examined are: Video monitoring; Computer vision; IR-pyrometry; IR-camera technology; Laser measuring methods; Acoustic pyrometry. The survey showed that video monitoring is useful to monitor the fuel bed and an aid to the operators. A good cooling and cleansing system is essential to make the system reliable. If the system is aided with computer vision the computer will show numbers which can be used in the control system. These have been tried at a couple of sites but the system is still being developed and no sites uses this function fully automated. Infrared measurements have been tried in number of research projects. The IR-pyrometer technique is good for measuring temperature but the reliability is too low for some of the users. IR-cameras are used in several waste incineration plants to control the combustion. The systems

  15. Visualizing Magnetic domain of Electric Steel using Grating Interferometer at NG6 of NIST

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Ju; Oh, Oh Sung; Lee, Se Ho; Kim, Dae Seung; Lee, Seung Wook [Pusan National University, Busan (Korea, Republic of); Kim, Jong Yul [KAERI, Daejeon (Korea, Republic of); Kwon, Oh Yeoul [Pohang Iron and Steel Company, Pohang (Korea, Republic of); Hussey, D. S.; Jacobson, D. L.; Lamannad, J. M. [NIST, Gaithersburg (United States)

    2016-05-15

    The Grating Interferometer is one of new imaging techniques provides improved contrast images, Phase Contrast Image and Dark-Field Image, which have never been seen before by conventional radiography. Neutron Dark-Field Imaging (NDFI) suggests new approach for material science providing the scattering image caused by the micro-structure of object. We attracted to the application of NDFI for material science, the electric steel which produce magnetic scattering information especially. In this study, we developed 1 dimensional gratings using gadox filling method to make the Talbot-Lau Interferometer (TLI). The experiment was conducted at cold neutron imaging facility NG6 of National Institute of Standards and Technologies, NIST. We confirmed that the 3 order Talbot-Lau type of neutron grating interferometer which is composed of gratings made by gadox filling method is well operated at cold neutron imaging beamline. NDFI is definitely powerful visualizing tool for material science, especially magnetic materials. In further study, we will research electric steel more in realistic conditions when it is worked as a component of electric motor.

  16. Development of the auto gas and LPG-powered vehicle sector in Turkey: A statistical case study of the sector for Bursa

    International Nuclear Information System (INIS)

    Karamangil, M. Ihsan

    2007-01-01

    In this paper, the development of LPG-powered vehicle sector in Turkey and the policies applied by the Turkish Government as well as the total fleet of LPG-powered vehicles in Bursa province, which is assumed as typical district to represent whole Turkey, are analyzed. We also tried to point out economical losses and applicational problems caused by wrong energy and environmental policies in Turkey. We aimed to focus a guiding light on the newly developing auto gas markets in different countries through the problems resulting from the fast growth of the sector and the experiences in Turkish application

  17. 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.

  18. 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

  19. 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.

  20. 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)

  1. Synthesis of nano-structured tin oxide thin films with faster response to LPG and ammonia by spray pyrolysis

    Science.gov (United States)

    PrasannaKumari, K.; Thomas, Boben

    2018-01-01

    Nanostructured SnO2 thin film have been efficiently fabricated by spray pyrolysis using atomizers of different types. The structure and morphology of as-prepared samples are investigated by techniques such as x-ray diffraction, and field-emission scanning electron microscopy. Significant morphological changes are observed in films by modifying the precursor atomization as a result of change of spray device. The optical characterization indicates that change in atomization, affects the absorbance and the band gap, following the varied crystallite size. Gas sensing investigations on ultrasonically prepared tin oxide films show NH3 response at operating temperatures lower down to 50 °C. For 1000 ppm of LPG the response at 350 °C for air blast atomizer film is about 99%, with short response and recovery times. The photoluminescence emmision spectra reveal the correlation between atomization process and the quantity of oxygen vacancies present in the samples. The favorable size reduction in microstructure with good crystallinity with slight change in lattice properties suggest their scope in gas sensing applications. On the basis of these characterizations, the mechanism of LPG and NH3 gas sensing of nanostructured SnO2 thin films has been proposed.

  2. Characterization of performance-emission indices of a diesel engine using ANFIS operating in dual-fuel mode with LPG

    Science.gov (United States)

    Chakraborty, Amitav; Roy, Sumit; Banerjee, Rahul

    2018-03-01

    This experimental work highlights the inherent capability of an adaptive-neuro fuzzy inference system (ANFIS) based model to act as a robust system identification tool (SIT) in prognosticating the performance and emission parameters of an existing diesel engine running of diesel-LPG dual fuel mode. The developed model proved its adeptness by successfully harnessing the effects of the input parameters of load, injection duration and LPG energy share on output parameters of BSFCEQ, BTE, NOX, SOOT, CO and HC. Successive evaluation of the ANFIS model, revealed high levels of resemblance with the already forecasted ANN results for the same input parameters and it was evident that similar to ANN, ANFIS also has the innate ability to act as a robust SIT. The ANFIS predicted data harmonized the experimental data with high overall accuracy. The correlation coefficient (R) values are stretched in between 0.99207 to 0.999988. The mean absolute percentage error (MAPE) tallies were recorded in the range of 0.02-0.173% with the root mean square errors (RMSE) in acceptable margins. Hence the developed model is capable of emulating the actual engine parameters with commendable ranges of accuracy, which in turn would act as a robust prediction platform in the future domains of optimization.

  3. Structural, Morphological, and LPG Sensing Properties of Al-Doped ZnO Thin Film Prepared by SILAR

    Directory of Open Access Journals (Sweden)

    Shampa Mondal

    2013-01-01

    Full Text Available Undoped and aluminum doped zinc oxide (AZO thin films were deposited on glass substrates by successive ion layer adsorption and reaction (SILAR technique from ammonium zincate complex. The thin films are characterized by X-ray diffraction (XRD and scanning electron microscopy (SEM for their structural and morphological studies. Both undoped and Al-doped film show strong preferred c-axis orientation. The texture coefficient (TC of the film along (002 direction increases due to Al incorporation. SEM micrograph shows round shaped particles for pure ZnO. However AZO films show particles with off spherical shape and compact interconnected grains. Sensitivity of the film in presence of 80% LEL (lower explosive limit of LPG increases with temperature and is maximum at 325°C. Significantly high sensitivity of 87% with reasonably fast response was observed for 1% Al-doped ZnO (AZO film in presence of 1.6 vol% LPG at 325°C.

  4. Performance of the diffraction grating on a bank note: the experience with the Australian Commemorative note

    Science.gov (United States)

    Hardwick, Bruce A.

    1990-04-01

    In January 1988, we at the Note Printing Branch first released to the Reserve Bank a polymer based banknote containing an Optically Variable Device (OVD), a diffraction grating. This banknote was the culmination of many years of Research and Development effort, and represented a very significant departure from conventional banknote technology in many ways. It was a test bed. We are very pleased with its performance.

  5. 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.

  6. 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.

  7. 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...

  8. 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.

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. Photovoltaic dependence of photorefractive grating on the externally applied dc electric field

    Science.gov (United States)

    Maurya, M. K.; Yadav, R. A.

    2013-04-01

    Photovoltaic dependence of photorefractive grating (i.e., space-charge field and phase-shift of the index grating) on the externally applied dc electric field in photovoltaic-photorefractive materials has been investigated. The influence of photovoltaic field (EPhN), diffusion field and carrier concentration ratio r (donor/acceptor impurity concentration ratio) on the space-charge field (SCF) and phase-shift of the index grating in the presence and absence of the externally applied dc electric field have also been studied in details. Our results show that, for a given value of EPhN and r, the magnitude of the SCF and phase-shift of the index grating can be enhanced significantly by employing the lower dc electric field (EONphotovoltaic-photorefractive crystal and higher value of diffusion field (EDN>40). Such an enhancement in the magnitude of the SCF and phase-shift of the index grating are responsible for the strongest beam coupling in photovoltaic-photorefractive materials. This sufficiently strong beam coupling increases the two-beam coupling gain that may be exceed the absorption and reflection losses of the photovoltaic-photorefractive sample, and optical amplification can occur. The higher value of optical amplification in photovoltaic-photorefractive sample is required for the every applications of photorefractive effect so that technology based on the photorefractive effect such as holographic storage devices, optical information processing, acousto-optic tunable filters, gyro-sensors, optical modulators, optical switches, photorefractive-photovoltaic solitons, biomedical applications, and frequency converters could be improved.

  14. Emission Studies in CI Engine using LPG and Palm Kernel Methyl Ester as Fuels and Di-ethyl Ether as an Additive

    Science.gov (United States)

    Dora, Nagaraju; Jothi, T. J. Sarvoththama

    2018-05-01

    The present study investigates the effectiveness of using di-ethyl ether (DEE) as the fuel additive in engine performance and emissions. Experiments are carried out in a single cylinder four stroke diesel engine at constant speed. Two different fuels namely liquefied petroleum gas (LPG) and palm kernel methyl ester (PKME) are used as primary fuels with DEE as the fuel additive. LPG flow rates of 0.6 and 0.8 kg/h are considered, and flow rate of DEE is varied to maintain the constant engine speed. In case of PKME fuel, it is blended with diesel in the latter to the former ratio of 80:20, and DEE is varied in the volumetric proportion of 1 and 2%. Results indicate that for the engine operating in LPG-DEE mode at 0.6 kg/h of LPG, the brake thermal efficiency is lowered by 26%; however, NOx is subsequently reduced by around 30% compared to the engine running with only diesel fuel at 70% load. Similarly, results of PKME blended fuel showed a drastic reduction in the NOx and CO emissions. In these two modes of operation, DEE is observed to be significant fuel additive regarding emissions reduction.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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...

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. Alkali/chloride release during refuse incineration on a grate: Full-scale experimental findings

    DEFF Research Database (Denmark)

    Bøjer, Martin; Jensen, Peter Arendt; Frandsen, Flemming

    2008-01-01

    in waste cause relatively high super heater corrosion rates. The Cl-content in waste is one of the key-factors for volatilisation of alkali and heavy metals in WtE plants. Little is known about the release of Cl, Na, K, Zn, Pb, and S along grate of waste incineration plants. The 26 t h(-1) WtE plant......Waste to energy (WtE) plants are utilised for the production of heat and electricity. However, due to corrosion at super heater surfaces a relatively low 25% of the waste lower heating value can with the present technology be converted to electricity. High contents of Cl, Na, K, Zn, Pb and S...... of the grate near port 3 with a high temperature, that contains relatively low amounts of corrosive elements, and lead to a separate high temperature super heater and thus increase the electrical efficiency....

  10. 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...

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. EFFECT OF INJECTOR OPENING PRESSURE ON PERFORMANCE AND EMISSION OF LPG - METHYL ESTER OF MAHUA OIL DUAL FUEL ENGINE

    Directory of Open Access Journals (Sweden)

    N. Kapilan

    2017-11-01

    Full Text Available One of variables, which affect the performance and emission of dual fuel engine is injection pressure. Hence in the present work, effect of Injector opening pressure on the performance of the engine was studied.  A four stroke single cylinder engine was modified to work in dual fuel mode. Three injector opening pressures (180 bar, 200 bar and 220 bar were considered for the present work. Methyl ester of mahua oil was used as pilot fuel and LPG was used as primary fuel.    From the test results, it was observed that the injector opening pressure of 200 bar results in higher brake thermal efficiency. The higher injector opening pressure results in better atomization and peneatration of methyl ester of mahua oil. The exhaust emissions such as Smoke, unburnt hydro carbon and carbon monoxide of 200 bar is lower than other pressures.

  16. The 2003 guidebook of petroleum, gas and LPG. Every professional and web site in the oil and gas industry

    International Nuclear Information System (INIS)

    Legros, E.

    2003-01-01

    This guidebook is a joint special issue of 'Petrole et Gaz Informations' and 'GPL Actualites' journals. It is a complete and practical information tool which takes stock of: the economical activity during 2001 and 2002 (exploration/production, deep offshore activities, maritime transport and tanker-ships, European refining and new specifications, automotive fuels and future engines, lubricants, maritime transport of liquefied petroleum gas (LPG), storage facilities and capacity, new standards for bitumen binders, natural gas prospects, sustainable development and ethical investment, air pollution abatement etc..); the 2002 economical key-data of oil and gas summarized in an atlas of maps and statistical tables; a list of public organizations and associations, and of oil and gas companies settled in France; a list of companies involved in oil and gas equipments, services and products sorted by sector; and a yearbook of the oil and gas professionals with their corporate and web sites. (J.S.)

  17. Viability of LPG use in low-power outboard engines for reduction in consumption and pollutant emissions

    International Nuclear Information System (INIS)

    Murillo, S.; Miguez, J.L.; Porteiro, J.; Hernandez, J.J.; Lopez-Gonzalez, L.M.

    2003-01-01

    This study presents the viability of the use of liquefied petroleum gases (LPG) dosage systems in order to solve the fuel supply in four-stroke outboard engines in compliance with regulations concerning emissions of immediate application pollutants. Results obtained show an important decrease in specific fuel consumption (nearly 20%) provoking a small power loss (about 5%), with an extra saving when making use of bottled fuel, which does not suffer spills in the bunkers and maintenance operations. Laboratory tests have been carried out on 8 and 15 HP Yamaha outboard engines, obtaining reductions in pollutants (CO, HC and NO x ) of 60% and of 95% for each power, respectively. These trials have been contrasted with tests carried out in the Vigo estuary and the river Milno waterways, both located in the South of Galicia (Spain). (Author)

  18. Experimental and numerical studies of rotating drum grate furnace

    Directory of Open Access Journals (Sweden)

    Basista Grzegorz

    2017-01-01

    Full Text Available Waste material from the meat industry can be taken into account as a biofuel. Studies confirm, that calorific value is higher and ash content is lower comparing to some conventional fuels. EU directives regulate details of thermal disposal of the waste material from the meat industry - especially in range of the process temperature and time of the particle presence in area of the combustion zone. The paper describes design of the rotating drum grate stove, dedicated to thermal disposal of the meat wastes as well as solid biomass (pellet, small bricket, wood chips combustion. Device has been developed in frames of cooperation between AGH University of Science and Technology (Krakow, Poland and producer focused on technologies of energy utilization of biomass in distributed generation. Results of measurements of selected operational parameters performed during startup of the furnace have been presented and discussed. Furthermore, numerical model of the combustion process has been developed to complement experimental results in range of the temperature and oxygen distribution in the area of the combustion chamber. ANSYS CFX solver has been applied to perform simulations including rotational domain related with specifics of operation of the device. Results of numerical modelling and experimental studies have been summarized and compared.

  19. 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.

  20. Polymer coated fiber Bragg grating thermometry for microwave hyperthermia.

    Science.gov (United States)

    Saxena, Indu Fiesler; Hui, Kaleo; Astrahan, Melvin

    2010-09-01

    Measuring tissue temperature distribution during electromagnetically induced hyperthermia (HT) is challenging. High resistance thermistors with nonmetallic leads have been used successfully in commercial HT systems for about three decades. The single 1 mm thick temperature sensing element is mechanically moved to measure tissue temperature distributions. By employing a single thermometry probe containing a fixed linear sensor array temperature, distributions during therapy can be measured with greater ease. While the first attempts to use fiber Bragg grating (FBG) technology to obtain multiple temperature points along a single fiber have been reported, improvement in the detection system's stability were needed for clinical applications. The FBG temperature sensing system described here has a very high temporal stability detection system and an order of magnitude faster readout than commercial systems. It is shown to be suitable for multiple point fiber thermometry during microwave hyperthermia when compared to conventional mechanically scanning probe HT thermometry. A polymer coated fiber Bragg grating (PFBG) technology is described that provides a number of FBG thermometry locations along the length of a single optical fiber. The PFBG probe developed is tested under simulated microwave hyperthermia treatment to a tissue equivalent phantom. Two temperature probes, the multiple PFBG sensor and the Bowman probe, placed symmetrically with respect to a microwave antenna in a tissue phantom are subjected to microwave hyperthermia. Measurements are made at start of HT and 85 min later, when a 6 degrees C increase in temperature is registered by both probes, as is typical in clinical HT therapy. The optical fiber multipoint thermometry probe performs highly stable, real-time thermometry updating each multipoint thermometry scan over a 5 cm length every 2 s. Bowman probe measurements are acquired simultaneously for comparison. In addition, the PFBG sensor's detection

  1. Design and Analysis of Multilayered Waveguide Structure With Metal-Dielectric Gratings for Sensing With Reflection Narrowband Notch Filter

    Directory of Open Access Journals (Sweden)

    Guiju ZHANG

    2015-11-01

    Full Text Available Developments in micro and nanofabrication technologies have led a variety of grating waveguide structures (GWS being proposed and implemented in optics and laser application systems. A new design of multilayered nanostructure double-grating is described for reflection notch filter. Thin metal film and dielectric film are used and designed with one-dimensional composite gratings. The results calculated by rigorous coupled-wave analysis (RCWA present that the thin metal film between substrate and grating can produce significant attenuated reflections and efficiency in a broad reflected spectral range. The behavior of such a reflection filter is evaluated for refractive index sensing, which can be applied inside the integrated waveguide structure while succeeding cycles in measurement. The filter peaks are designed and obtained in a visible range with full width half maximum (FWHM of several nanometers to less than one nanometer. The multilayered structure shows a sensitivity of refractive index of 220nm/RIU as changing the surroundings. The reflection spectra are studied under different periods, depths and duty cycles. The passive structure and its characteristics can achieve practical applications in various fields, such as optical sensing, color filtering, Raman spectroscopy and laser technology.DOI: http://dx.doi.org/10.5755/j01.ms.21.4.9625

  2. 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

  3. 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

  4. 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...

  5. 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...

  6. 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.

  7. Decree 234/003. Is derogate decree 317/987, from the date of entry into force the safe exercise regulation of the packing activities and the distribution of liquefied petroleum gas (LPG) that will dictate the URSEA

    International Nuclear Information System (INIS)

    2003-01-01

    This decree allows the entry into force the safe exercise regulation of the packing activities and the distribution of liquefied petroleum gas (LPG) that will dictate the URSEA (The regulatory unit of energy and water service)

  8. 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.

  9. 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.

  10. 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)

  11. 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.

  12. 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.

  13. 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.

  14. High-energy x-ray grating-based phase-contrast radiography of human anatomy

    Science.gov (United States)

    Horn, Florian; Hauke, Christian; Lachner, Sebastian; Ludwig, Veronika; Pelzer, Georg; Rieger, Jens; Schuster, Max; Seifert, Maria; Wandner, Johannes; Wolf, Andreas; Michel, Thilo; Anton, Gisela

    2016-03-01

    X-ray grating-based phase-contrast Talbot-Lau interferometry is a promising imaging technology that has the potential to raise soft tissue contrast in comparison to conventional attenuation-based imaging. Additionally, it is sensitive to attenuation, refraction and scattering of the radiation and thus provides complementary and otherwise inaccessible information due to the dark-field image, which shows the sub-pixel size granularity of the measured object. Until recent progress the method has been mainly limited to photon energies below 40 keV. Scaling the method to photon energies that are sufficient to pass large and spacious objects represents a challenging task. This is caused by increasing demands regarding the fabrication process of the gratings and the broad spectra that come along with the use of polychromatic X-ray sources operated at high acceleration voltages. We designed a setup that is capable to reach high visibilities in the range from 50 to 120 kV. Therefore, spacious and dense parts of the human body with high attenuation can be measured, such as a human knee. The authors will show investigations on the resulting attenuation, differential phase-contrast and dark-field images. The images experimentally show that X-ray grating-based phase-contrast radiography is feasible with highly absorbing parts of the human body containing massive bones.

  15. 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...

  16. 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...

  17. 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.

  18. 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

  19. 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.

  20. WDM hybrid microoptical transceiver with Bragg volume grating

    Science.gov (United States)

    Jeřábek, Vitezslav; Armas, Julio; Mareš, David; Prajzler, Václav

    2012-02-01

    The paper presents the design, simulation and construction results of the wavelength division multiplex bidirectional transceiver module (WDM transceiver) for the passive optical network (PON) of a fiber to the home (FTTH) topology network. WDM transceiver uses a microoptical hybrid integration technology with volume holographic Bragg grating triplex filter -VHGT and a collimation lenses imagine system for wavelength multiplexing/ demultiplexing. This transmission type VHGT filter has high diffraction angle, very low insertion loses and optical crosstalk, which guide to very good technical parameters of transceiver module. WDM transceiver has been constructed using system of a four micromodules in the new circle topology. The optical micromodule with VHGT filter and collimation and decollimation lenses, two optoelectronics microwave receiver micromodules for receiving download information (internet and digital TV signals) and optoelectronic transmitter micromodule for transmitting upload information. In the paper is presented the optical analysis of the optical imagine system by ray-transfer matrix. We compute and measure VHGT characteristics such as diffraction angle, diffraction efficiency and diffraction crosstalk of the optical system for 1310, 1490 and 1550 nm wavelength radiation. For the design of optoelectronic receiver micromodule was used the low signal electrical equivalent circuit for the dynamic performance signal analysis. In the paper is presented the planar form WDM transceiver with polymer optical waveguides and two stage interference demultiplexing optical filter as well.