WorldWideScience

Sample records for catalytic converters

  1. Catalytic converters in the fireplace

    International Nuclear Information System (INIS)

    Kouki, J.

    1995-01-01

    In addition to selecting the appropriate means of heating and using dry fuel, the amount of harmful emissions contained by flue gases produced by fireplaces can be reduced by technical means. One such option is to use an oxidising catalytic converter. Tests at TTS Institute's Heating Studies Experimental Station have focused on two such converters (dense and coarse) mounted in light-weight iron heating stoves. The ability of the dense catalytic converter to oxidise carbon monoxide gases proved to be good. The concentration of carbon monoxide in the flue gases was reduced by as much as 90 %. Measurements conducted by VTT (Technical Research Centre of Finland) showed that the conversion of other gases, e.g. of methane, was good. The exhaust resistance caused by the dense converter was so great as to necessitate the mounting of a fluegas evacuation fan in the chimney for the purpose of creating sufficient draught. When relying on natural draught, the dense converter requires a chimney of at least 7 metres and a by-pass connection while the fire is being lit. In addition, the converter will have to be constructed to be less dense and this will mean that it's capability to oxidise non-combusted gases will be reduced. The coarse converter did not impair the draught but it's oxidising property was insufficient. With the tests over, the converter was not observed to have become blocked up by impurities

  2. Catalytic Converters Maintain Air Quality in Mines

    Science.gov (United States)

    2014-01-01

    At Langley Research Center, engineers developed a tin-oxide based washcoat to prevent oxygen buildup in carbon dioxide lasers used to detect wind shears. Airflow Catalyst Systems Inc. of Rochester, New York, licensed the technology and then adapted the washcoat for use as a catalytic converter to treat the exhaust from diesel mining equipment.

  3. Effect of inlet cone pipe angle in catalytic converter

    Science.gov (United States)

    Amira Zainal, Nurul; Farhain Azmi, Ezzatul; Arifin Samad, Mohd

    2018-03-01

    The catalytic converter shows significant consequence to improve the performance of the vehicle start from it launched into production. Nowadays, the geometric design of the catalytic converter has become critical to avoid the behavior of backpressure in the exhaust system. The backpressure essentially reduced the performance of vehicles and increased the fuel consumption gradually. Consequently, this study aims to design various models of catalytic converter and optimize the volume of fluid flow inside the catalytic converter by changing the inlet cone pipe angles. Three different geometry angles of the inlet cone pipe of the catalytic converter were assessed. The model is simulated in Solidworks software to determine the optimum geometric design of the catalytic converter. The result showed that by decreasing the divergence angle of inlet cone pipe will upsurge the performance of the catalytic converter.

  4. Platinum recovery from used auto catalytic converters in electrorefining process

    Directory of Open Access Journals (Sweden)

    A. Fornalczyk

    2013-04-01

    Full Text Available This paper presents possibility of removing platinum from the used catalytic converters applying copper as a metal collector in pyrometallurgical methods. The catalytic converter carrier was grinded and melted with copper. During the research obtained Cu-Pt alloy was casted as an anode. Such anode was electrically refined in order to recover platinum. Obtained results were discussed.

  5. Use of Electrically Heated Metal Catalytic Converter in Cold Starting ...

    African Journals Online (AJOL)

    The easiest way to preheat the converter is to use electric resistance heaters. The electrical systems on most cars provide enough energy or power to heat the catalytic converter fast enough. So, in this research the main converter remains its usual position, whereas the heated catalyst is placed close to the exhaust manifold ...

  6. Flow in axisymmetric expansion in a catalytic converter

    DEFF Research Database (Denmark)

    Gotfredsen, Erik; Meyer, Knud Erik

    The flow in an axisymmetric expansion (circular diffusor) is used in many different engineering applications, such as heat exchangers, catalytic converters and filters. These applications require a relatively uniform flow at the inlet. To minimise the pressure loss, an ideal solution would...... for a specific local flow rate and a non-uniform inflow to the catalyst will severely reduce the efficiency of the process. Since each ship will have a unique design the flow system, it is desirable to be able to design the system using Computational Fluid Dynamics (CFD). However, CFD fails to predict flow......-scaled model of the catalytic converter is constructed, see figure 1. The experiments are performed at laboratory conditions, with lower pressure, temperature and velocity than the full-scale catalytic converter. The Reynolds number based on the velocity in the inlet pipe and the diameter of the converter...

  7. Advanced Catalytic Converter in Gasoline Enginer Emission Control: A Review

    Directory of Open Access Journals (Sweden)

    Leman A.M.

    2017-01-01

    Full Text Available Exhaust emission from automobile source has become a major contributor to the air pollution and environmental problem. Catalytic converter is found to be one of the most effective tools to reduce the overwhelming exhaust pollutants in our environment. The development of sustainable catalytic converter still remains a critical issue due to the stringent exhaust emission regulations. Another issue such as price and availability of the precious metal were also forced the automotive industry to investigate the alternatives for producing a better replacement for the material used in catalytic converter. This paper aims at reviewing the present development and improvement on the catalytic converter used on the reduction of exhaust emission in order to meet the regulations and market demand. The use of new catalyst such as to replace the noble metal material of Platinum (Pt, Palladium (Pd and Rhodium (Rh has been reviewed. Material such as zeolite, nickel oxide and metal oxide has been found to effectively reduce the emission than the commercial converter. The preparation method of the catalyst has also evolved through the years as it is to ensure a good characteristic of a good monolith catalyst. Ultrasonic treatment with combination of electroplating technique, citrate method and Plasma Electrolytic Oxidation (PEO has been found as the latest novel preparation method on producing an effective catalyst in reducing the exhaust emission.

  8. Converting sugars to sugar alcohols by aqueous phase catalytic hydrogenation

    Science.gov (United States)

    Elliott, Douglas C [Richland, WA; Werpy, Todd A [West Richland, WA; Wang, Yong [Richland, WA; Frye, Jr., John G.

    2003-05-27

    The present invention provides a method of converting sugars to their corresponding sugar alcohols by catalytic hydrogenation in the aqueous phase. It has been found that surprisingly superior results can be obtained by utilizing a relatively low temperature (less than 120.degree. C.), selected hydrogenation conditions, and a hydrothermally stable catalyst. These results include excellent sugar conversion to the desired sugar alcohol, in combination with long life under hydrothermal conditions.

  9. The use of Phoenics in the design of catalytic converters

    Energy Technology Data Exchange (ETDEWEB)

    Luoma, M. [Kemira Metalkat Oy, Oulu (Finland); Smith, A.G. [S and C Thermofluids Ltd, Bath (United Kingdom)

    1996-12-31

    Manufacturers of automotive catalytic converters are constrained to design a system which is mechanically reliable, puts low back pressure on the engine, has adequate conversion performance, is low cost and of minimum size. In recent years, computational fluid dynamics (CFD) has been widely examined as a means of predicting the performance of catalytic converters to aid with the design process. Kemira Metalkat and S and C Thermofluids have put together and developed a number of existing CFD techniques in order to create a tool which is integrated within the design process. PHOENICS is used in the heart of the system in order to produce predictions of transient (light-off) and steady state catalyst performance. Grid generation tools have been provided to allow simplified and rapid geometry definition with suitable integration (via FEMGEN) within other parts of the catalyst design process. Simplified input techniques have been provided along with associated translators to create specification of the model for PHOENICS. Post-processing software has been provided through FEMVIEW to allow visualisation of catalyst monolith variables and transient performance animation. The whole system is controlled via a menu. The system have been use to study the effects of the catalyst design parameters on the converter performance. The results obtained using the system have so far been more qualitative than quantitative. However, validation studies have been carried out to check pressure drop prediction. A new model for the pressure drop over a metallic monolith has been developed. (author)

  10. Simulation on Toxic Gases in Vehicle Exhaust Equipped with Modified Catalytic Converter : A Review

    Directory of Open Access Journals (Sweden)

    Leman A.M.

    2016-01-01

    Full Text Available Air pollution and global warming is a major issue nowadays. One of the main contributors to be the emission of harmful gases produced by vehicle exhausts lines. The harmful gases like NOx, CO, unburned HC and particulate matter increases the global warming, so catalytic converter plays a vital role in reducing harmful gases. Catalytic converters are used on most vehicles on the road today. This research deals with the gas emission flow in the catalytic converter involving the heat transfer, velocity flow, back pressure and others chemical reaction in the modified catalytic converter by using FeCrAl as a substrate that is treated using the ultrasonic bath and electroplating techniques. The objective of this study is to obtain a quantitative description of the gas emission in the catalytic converter system of automobile exhaust gas using ANSYS Software. The description of the gas emission in the catalytic converter system of automobile exhaust gas using ANSYS Software was simulated in this research in order to provide better efficiency and ease the reusability of the catalytic converter by comparing experimental data with software analysing data. The result will be expected to demonstrate a good approximation of gas emission in the modified catalytic converter simulation data compared to experimental data in order to verify the effectiveness of modified catalytic converter. Therefore studies on simulation of flow through the modified catalytic converter are very important to increase the accuracy of the obtained emission result.

  11. Possibilities Of Metals Extracton From Spent Metallic Automotive Catalytic Converters By Using Biometallurgical Method

    Directory of Open Access Journals (Sweden)

    Willner J.

    2015-09-01

    Full Text Available The main task of automotive catalytic converters is reducing the amount of harmful components of exhaust gases. Metallic catalytic converters are an alternative to standard ceramic catalytic converters. Metallic carriers are usually made from FeCrAl steel, which is covered by a layer of Precious Group Metals (PGMs acting as a catalyst. There are many methods used for recovery of platinum from ceramic carriers in the world, but the issue of platinum and other metals recovery from metallic carriers is poorly described. The article presents results of preliminary experiments of metals biooxidation (Fe, Cr and Al from spent catalytic converters with metallic carrier, using bacteria of the Acidithiobacillus genus.

  12. The influence of platinum washing-out time on its recovery from used auto catalytic converters

    Directory of Open Access Journals (Sweden)

    A. Fornalczyk

    2014-07-01

    Full Text Available The used catalytic converters contain small amounts of precious metals. Recovery of these metals is essential for environmental and economic reasons. This work presents a method of Platinum Group Metals (PGM recovery from auto catalytic converters in which they are washed out by a liquid metal. The magneto-hydro-dynamic pump was used to force circulation of liquid metal under the influence of electromagnetic fields The influence of process time on platinum recovery was also carried out.

  13. I.C. Engine emission reduction by copper oxide catalytic converter

    Science.gov (United States)

    Venkatesan, S. P.; Shubham Uday, Desai; Karan Hemant, Borana; Rajarshi Kushwanth Goud, Kagita; Lakshmana Kumar, G.; Pavan Kumar, K.

    2017-05-01

    The toxic gases emitted from diesel engines are more than petrol engines. Predicting the use of diesel engines, even more in future, this system is developed and can be used to minimize the harmful gases. Toxic gases include NOX, CO, HC and Smoke which are harmful to the atmosphere as well as to the human beings. The main aim of this work is to fabricate system, where the level of intensity of toxic gases is controlled through chemical reaction to more agreeable level. This system acts itself as an exhaust system; hence there is no needs to fit separate the silencer. The whole assembly is fitted in the exhaust pipe from engine. In this work, catalytic converter with copper oxide as a catalyst, by replacing noble catalysts such as platinum, palladium and rhodium is fabricated and fitted in the engine exhaust. With and without catalytic converter, the experimentations are carried out at different loads such as 0%, 25%, 50%, 75%, and 100% of maximum rated load. From the experimental results it is found that the maximum reduction is 32%, 61% and 21% for HC, NOx and CO respectively at 100% of maximum rated load when compared to that of without catalytic converter. This catalytic converter system is cash effective and more economical than the existing catalytic converter.

  14. A comparative evaluation on the emission characteristics of ceramic and metallic catalytic converter in internal combustion engine

    Science.gov (United States)

    Leman, A. M.; Jajuli, Afiqah; Rahman, Fakhrurrazi; Feriyanto, Dafit; Zakaria, Supaat

    2017-09-01

    Enforcement of a stricter regulation on exhaust emission by many countries has led to utilization of catalytic converter to reduce the harmful pollutant emission. Ceramic and metallic catalytic converters are the most common type of catalytic converter used. The purpose of this study is to evaluate the performance of the ceramic and metallic catalytic converter on its conversion efficiency using experimental measurement. Both catalysts were placed on a modified exhaust system equipped with a Mitshubishi 4G93 single cylinder petrol engine that was tested on an eddy current dynamometer under steady state conditions for several engine speeds. The experimental results show that the metallic catalytic converter reduced a higher percentage of CO up to 98.6% reduction emissions while ceramic catalytic converter had a better reduction efficiency of HC up to 85.4% and 87.2% reduction of NOx.

  15. Real life experimental determination of platinum group metals content in automotive catalytic converters

    Science.gov (United States)

    Yakoumis, I.; Moschovi, A. M.; Giannopoulou, I.; Panias, D.

    2018-03-01

    The real life experimental protocol for the preparation of spent automobile catalyst samples for elemental analysis is thoroughly described in the following study. Collection, sorting and dismantling, homogenization and sample preparation for X-Ray fluorescence spectroscopy and Atomic Adsorption Spectroscopy combined with Inductive coupled plasma mass spectrometry are discussed in detail for both ceramic and metallic spent catalysts. The concentrations of Platinum Group Metals (PGMs) in spent catalytic converters are presented based on typical consignments of recycled converters (more than 45,000 pieces) from the Greek Market. The conclusions clearly denoted commercial metallic catalytic foil contains higher PGMs loading than ceramic honeycombs. On the other hand, the total PGMs loading in spent ceramic catalytic converters has been found higher than the corresponding value for the metallic ones.

  16. Modelling and Simulation of Packed Bed Catalytic Converter for Oxidation of Soot in Diesel Powered Vehicles Flue Gas

    Directory of Open Access Journals (Sweden)

    Mohammad Nasikin

    2010-10-01

    Full Text Available Diesel vehicle is used in Indonesia in very big number. This vehicle exhausts pollutants especially diesel soot that can be reduces by using a catalytic converter to convert the soot to CO2. To obtain the optimal dimension of catalytic converter it is needed a model that can represent the profile of soot weight, temperature and pressure along the catalytic converter. In this study, a model is developed for packed bed catalytic converter in an adiabatic condition based on a kinetic study that has been  reported previously. Calculation of developed equations in this model uses Polymath 5.X solver with Range Kutta Method. The simulation result shows that temperature profile along catalytic converter increases with the decrease of soot weight,  while pressure profile decreases. The increase of soot weight in entering gas increases the needed converter length. On the other hand, the increase of catalyst diameter does not affect to soot weight along converter and temperature profile, but results a less pressure drop. For 2.500 c diesel engine, packed bed catalytic converter with ellipse's cross sectional of 14,5X7,5 cm diagonal and 0,8 cm catalyst particle diameter, needs 4,1 cm length.

  17. Experimental investigation on emission reduction in neem oil biodiesel using selective catalytic reduction and catalytic converter techniques.

    Science.gov (United States)

    Viswanathan, Karthickeyan

    2018-03-01

    In the present study, non-edible seed oil namely raw neem oil was converted into biodiesel using transesterification process. In the experimentation, two biodiesel blends were prepared namely B25 (25% neem oil methyl ester with 75% of diesel) and B50 (50% neem oil methyl ester with 50% diesel). Urea-based selective catalytic reduction (SCR) technique with catalytic converter (CC) was fixed in the exhaust tail pipe of the engine for the reduction of engine exhaust emissions. Initially, the engine was operated with diesel as a working fluid and followed by refilling of biodiesel blends B25 and B50 to obtain the baseline readings without SCR and CC. Then, the same procedure was repeated with SCR and CC technique for emission reduction measurement in diesel, B25 and B50 sample. The experimental results revealed that the B25 blend showed higher break thermal efficiency (BTE) and exhaust gas temperature (EGT) with lower break-specific fuel consumption (BSFC) than B50 blend at all loads. On comparing with biodiesel blends, diesel experiences increased BTE of 31.9% with reduced BSFC of 0.29 kg/kWh at full load. A notable emission reduction was noticed for all test fuels in SCR and CC setup. At full load, B25 showed lower carbon monoxide (CO) of 0.09% volume, hydrocarbon (HC) of 24 ppm, and smoke of 14 HSU and oxides of nitrogen (NOx) of 735 ppm than diesel and B50 in SCR and CC setup. On the whole, the engine with SCR and CC setup showed better performance and emission characteristics than standard engine operation.

  18. Catalytic converters for exhaust emission control of commercial equipment powered by internal combustion engines.

    Science.gov (United States)

    Cohn, J G

    1975-04-01

    The development of PTX, monolithic catalytic exhaust purifiers, is outlined, and their first use for exhaust emissions control of commercial equipment is described. The main use of PTX converters is on forklift trucks. The purification achievable with PTX-equipped fork-lift trucks under various operational conditions is discussed, and examples from the field are given. During more than ten years of operation, no adverse health effects have been reported, and PTX-equipped internal combustion engines appear safe for use in confined areas.

  19. The effect of oxygen storage capacity on the dynamic characteristics of an automotive catalytic converter

    International Nuclear Information System (INIS)

    Shamim, Tariq

    2008-01-01

    Automotive catalytic converters, which are employed to reduce engine exhaust emissions, are subjected to highly transient conditions during a typical driving cycle. These transient conditions arise from changes in driving mode, the hysteresis and flow lags of the feedback control system, and result in fluctuations of air-fuel ratio, exhaust gas flow rates and temperatures. The catalyst performance is also strongly influenced by the oxygen storage capacity. This paper presents a computational investigation of the effect of oxygen storage capacity on the dynamic behavior of an automotive catalytic converter subjected to modulations in exhaust gases. The modulations are generated by forcing the temporal variations in exhaust gases air-fuel ratio, gas flow rates and temperatures. The study employs a single-channel based, one-dimensional, non-adiabatic model. The results show that the imposed modulations cause a significant departure in the catalyst behavior from its steady behavior, and the oxygen storage capacity plays an important role in determining the catalyst's response to the imposed modulations. Modulations and oxygen storage capacity are found to have relatively greater influence on the catalyst's performance near stoichiometric conditions

  20. Evaluation of on-board diagnosis methods for three-way catalytic converters.

    Science.gov (United States)

    Tsinoglou, Dimitrios N; Koltsakis, Grigorios C; Samaras, Zissis C

    2002-12-01

    On-board diagnosis (OBD) aims at detecting malfunctions of emission-related components of road vehicles. It is required by legislation in United States and the European Union, as it is considered to be beneficial for the reduction of vehicle-related air pollution. On-board diagnosis of the catalytic converter is a challenging task, as it relies on indirect assessments of catalyst activity. Several methods have been proposed for catalyst diagnosis, presenting a varying degree of correlation between the quantities used as OBD indexes and the actual tailpipe emissions. This paper evaluates two methods, with the support of mathematical modeling; in the first one, which is commonly used by vehicle manufacturers, malfunction detection relies on the oxygen storage properties of the catalyst, while in the second, detection relies on the heat released by the chemical reactions in the catalyst. Both are found to be sufficient for the diagnosis of catalytic converters for current legislation requirements. However, the thermal method presents higher sensitivity to low levels of catalyst deactivation and could therefore be more suitable for diagnosis of future, ultra-low-emitting vehicles.

  1. Novel techniques for the synthesis of three-way catalytic converter support materials

    Science.gov (United States)

    Anyaba, Prince Nwabueze

    Current automobiles use catalytic converters, consisting of noble metals on an oxide support, to convert noxious engine exhaust pollutants into less harmful species. The development of mesoporous oxide supports with optimal pore geometries could enable these devises to decrease in size and weight and significantly reduce the metal loadings required to achieve optimal performance. Thus, in this work, I investigated a wide range of techniques for the synthesis of mesoporous oxides to determine if they could be adapted to ceria-zirconia-yttria mixed oxide (CZY) systems, which are the industry standard for the optimal oxide support for catalytic converter applications. Additionally, I compared and critically evaluated the catalytic performance of the CZY mixed oxides, which were synthesized from the various templating techniques. The catalytic performance test was broken up into two: catalyst activity test which was determined based on the light-off temperatures at which 50% conversion of the reacting species have been converted; and resistance to surface area loss under accelerated aging at heating rate of 20°C/min form 700 to 1000°C, with the final temperature being held fixed for 4 h. To date, the most cost effective methods for preparing mesoporous materials are via techniques that employ templates or structure directing agents. These templates can be divided into two groups: endo-templates (i.e., soft templates, such as surfactants, dendrimers, and block copolymers) and exo-templates (i.e., hard templates, such as porous carbons and resins). The soft templating techniques generally involve both sol-gel and templating methods, while the hard templates required no sol-gel chemistry to achieve the desired templating effect. The precursors for ceria, zirconia, and yttria used were cerium (III) nitrate hexahydrate, zirconyl nitrate, and yttrium nitrate hexahydrate, respectively. The mesoporous CZY materials that were synthesized had surface area values that were

  2. Emission Treatment towards Cold Start and Back Pressure in Internal Combustion Engine against Performance of Catalytic Converter: A Review

    Directory of Open Access Journals (Sweden)

    Leman A.M.

    2017-01-01

    Full Text Available Nowadays, regulation for the vehicles emissions has becoming more stringent in order to reduce the effect of pollutant gases that was being released by the vehicles exhaust. The development of catalytic converter is to resolve the pollution emission aspect. There are lots of improvements done by the researchers towards improving catalytic converter, yet there are still key issues which give negative impact to the environment. One of the problems that are being concern by among of researchers is the cold-start and back pressure problems that usually occur in the composition of catalytic converter. Presented here is a review of cold-starts and back pressure problems together with several alternatives taken by not affecting the performance of vehicles engine and fuel consumption. The review also includes alternative system development and selection of materials to resolve these problems.

  3. Emerging airborne contaminants in India: Platinum Group Elements from catalytic converters in motor vehicles

    International Nuclear Information System (INIS)

    Sen, Indra S.; Mitra, Arijeet; Peucker-Ehrenbrink, Bernhard; Rothenberg, Sarah E.; Tripathi, Sachchida Nand; Bizimis, Michael

    2016-01-01

    Platinum Group Element (PGE) pollution on the Indian subcontinent is a growing concern because vehicle sales in India have rapidly increased over the last decade, and it is well known that automobile catalytic converters are one of the major source of anthropogenic PGE in the environment. Despite the rapid growth of the Indian automobile industry, the sources and magnitude of PGE contamination in Indian airborne particles are unknown. In this study we report PGE and mercury (Hg) concentrations, as well as osmium isotope ratios ( 187 Os/ 188 Os) of airborne particles (PM 10 ) collected in Kanpur, a large industrial city in India. We estimate that 61 ± 22%, 32 ± 24%, and 7 ± 3% of the total Os fraction are derived from eroding upper continental crust, catalytic converters fitted in the exhaust system of motor vehicles, and fossil fuel combustion, respectively. Only one sample had a ten times higher (∼76%) than average contribution from fossil fuel. Unlike Os, Pt is predominantly (84 ± 10%) derived from anthropogenic sources. Platinum Group Element and Hg concentrations are not well correlated. However, the highest concentration of particulate Hg corresponds to the most radiogenic 187 Os/ 188 Os isotope ratios (4.6). Our results further indicated that PGE/Ir ratios could be successfully used to quantify the relative proportions of natural and anthropogenic PGE sources in aerosol samples. Since PGE and Hg data on Indian environmental samples are scarce, this study provides an interpretive framework that calls for additional assessments of PGE and Hg concentrations in environmental samples from India. - Highlights: • Platinum Group Element Pollution is a growing concern in Asia. • Osmium isotopes as tracers of PGE sources is proposed. • Platinum Group Element pollution in India.

  4. Evaluation and development of measurement components for a catalytic converter test system

    Energy Technology Data Exchange (ETDEWEB)

    Chan, A.K.

    1997-08-01

    The purpose of this research and development project was to evaluate and configure the components of a test system designed for the analysis of full-scale vehicle-aged automobile catalytic converters. The components tested included an exhaust gas analyzer for measuring hydrocarbon, CO, CO{sub 2} and O{sub 2} contents and a chemiluminescence detector (CLD) for measuring NO{sub x}, as well as thermocouples and pressure meters. A software package (TestPoint vers.2.Ob, Capital Equipment) was used to develop a computer-based data sampling and acquisition interface with the components and sensors connected to the test system. Tests of the Sun MGA-1200, a non-dispersive infrared (NDIR) analyzer, with CO, CO{sub 2} and various hydrocarbons (propane and octane) revealed sensitivity to large pressure changes (greater than 500 mbar). There was no significant cross-sensitivity between the gases except for the slight response of the hydrocarbon (HC) register to water vapor and CO. However, the low range of HC(5-30 vppm) expected in car exhaust after the converter means any cross-sensitivity could have an effect on the measurement, depending on measurement conditions. Tests of the EcoPhysics CLD 700 NO{sub x} meter also indicated sensitivity to pressure. An executable TestPoint run-time application was created to allow near real-time monitoring of the test system using a desktop computer. Nine channels of analog data are fed to a desktop computer via an A/D board and seven exhaust gas parameters through an RS-232C interface with the MGA-1200 23 refs, 32 figs, 10 tabs. Examination paper

  5. Emission reduction from a diesel engine fueled by pine oil biofuel using SCR and catalytic converter

    Science.gov (United States)

    Vallinayagam, R.; Vedharaj, S.; Yang, W. M.; Saravanan, C. G.; Lee, P. S.; Chua, K. J. E.; Chou, S. K.

    2013-12-01

    In this work, we propose pine oil biofuel, a renewable fuel obtained from the resins of pine tree, as a potential substitute fuel for a diesel engine. Pine oil is endowed with enhanced physical and thermal properties such as lower viscosity and boiling point, which enhances the atomization and fuel/air mixing process. However, the lower cetane number of the pine oil hinders its direct use in diesel engine and hence, it is blended in suitable proportions with diesel so that the ignition assistance could be provided by higher cetane diesel. Since lower cetane fuels are prone to more NOX formation, SCR (selective catalyst reduction), using urea as reducing agent, along with a CC (catalytic converter) has been implemented in the exhaust pipe. From the experimental study, the BTE (brake thermal efficiency) was observed to be increased as the composition of pine oil increases in the blend, with B50 (50% pine oil and 50% diesel) showing 7.5% increase over diesel at full load condition. The major emissions such as smoke, CO, HC and NOX were reduced by 70.1%, 67.5%, 58.6% and 15.2%, respectively, than diesel. Further, the average emissions of B50 with SCR and CC assembly were observed to be reduced, signifying the positive impact of pine oil biofuel on atmospheric environment. In the combustion characteristics front, peak heat release rate and maximum in-cylinder pressure were observed to be higher with longer ignition delay.

  6. Molecular and catalytic properties of angiotensin converting enzyme-I from bovine seminal plasma.

    Science.gov (United States)

    Sharma, M; Singh, U S

    1988-07-01

    Angiotensin converting enzyme [EC 3.4.15.1] was shown to exist in two distinct forms in bovine seminal plasma. The higher molecular weight form of the enzyme (angiotensin convering enzyme I) was purified to homogeneity by Sephadex G-200 gel filtration, and DEAE-Sepharose, blue Sepharose, and concanavalin A-Sepharose column chromatography. Final recovery of the enzyme was 9.0. The molecular weight of the enzyme was estimated to be 8 x 10(5) by the gel filtration method. A value of 4.6 x 10(5) was obtained for the reduced and denatured enzyme by dodecylsulfate polyacrylamide gel electrophoresis. The Stokes' radius, diffusion coefficient, and intrinsic viscosity of the purified enzyme were determined to be 95 A, 2.3 x 10(-7) cm2/s, and 6.76 ml/g. The enzyme had a specific activity of 105.12 mumol/min/mg protein for hippurylhistidylleucine. The Km value for hippurylhistidylleucine was found to be 20 mM. Studies with EDTA suggest that metal ions which are tightly bound are required for its activity. The enzyme was inhibited by some heavy metal ions but did not required sulfhydryl groups for its activity. Trypsin treatment of the urea-denatured enzyme produced a catalytically active fragment with an Mr of 30,000. Chemical hydrolysis of the native enzyme did not produce any active fragment.

  7. Oxidative destruction of biomolecules by gasoline engine exhaust products and detoxifying effects of the three-way catalytic converter.

    Science.gov (United States)

    Blaurock, B; Hippeli, S; Metz, N; Elstner, E F

    1992-01-01

    Aqueous solutions of engine exhaust condensation products were derived from cars powered by diesel or four-stroke gasoline engines (with and without three-way catalytic converter). The cars were operated on a static test platform. Samples of the different exhaust solutions accumulated in a Grimmer-type distillation trap (VDI 3872) during standard test programs (Federal Test Procedure) were incubated with important biomolecules. As indicators of reactive oxygen species or oxidative destruction, ascorbic acid, cysteine, glutathione, serum albumin, the enzymes glycerinaldehyde phosphate dehydrogenase and xanthine oxidase, and the oxygen free-radical indicator keto-methylthiobutyrate were used. During and after the incubations, oxygen activation (consumption) and oxidative destruction were determined. Comparison of the oxidative activities of the different types of exhaust condensates clearly showed that the exhaust condensate derived from the four-stroke car equipped with a three-way catalytic converter exhibited by far the lowest oxidative and destructive power.

  8. Gate-to-Gate Life Cycle Assessment for Determining Carbon Footprint of Catalytic Converter Assembly Process

    Directory of Open Access Journals (Sweden)

    A. N. Mustfizul Karim

    2017-03-01

    Full Text Available With the pursuit of embracing the circular economy, having upward trend in vehicle sales and environmental concern, sustainability has become an imperative part of the global automotive manufacturing strategies. One of the tactics to achieve this sustainable goal is to conserve and enhance the resource base by salvaging the embedded values from end-of-life product and for which, the remanufacturing can be considered as one of the most prominent epitome. Even though many of the auto parts like engine, transmissions, starters, alternators and etc. have been assessed for remanufacturability since last few decades, being a major component of a car body the Catalytic Converter (CC still remains unfocused in literature. However, to examine the remanufacturability of CC, a comprehensive study for assessing its economic, social, and environmental impact is inevitable. Therefore, with an underlying aim of designing the remanufacturable CC, in this endeavour an attempt has made to evaluate the environmental impact of its welding operations by means of energy consumption through gate-to-gate life cycle assessment. Real life data are collected from a Local Malaysian CC manufacturer. The obtained results show that the welding section has a carbon footprint of 0.203 kgCO2e/unit with major emission coming from the plasma arc welding. In addition to that, it is also observed that the value of carbon footprint is not only sensitive to the emission factor and processing time, but also it is responsive to the nature of the processing operations. Certainly, this observation will motivate to change the product design from the prospect of remanufacturing.

  9. A Comparative Life Cycle Assessment of Recycling the Platinum Group Metals from Automobile Catalytic Converter: An Australian Perspective

    Science.gov (United States)

    Ghodrat, Maryam; Rhamdhani, M. Akbar; Sharafi, Pezhman; Samali, Bijan

    2017-12-01

    This study provides a comparison between environmental impacts of the recovery of platinum group metals (PGMs) from the end-of-life catalytic converters by hydrometallurgical and pyrometallurgical methods. A gate to grave life cycle assessment of a typical three-way catalytic converter manufactured for an Australian passenger car was carried out using GaBi professional environmental package. Recovery rates, as well as qualities, quantities, losses, and fugitive emissions for all materials and elements used in both methods were calculated based on the developed flowsheets. A life cycle impact assessment was then made by carrying out a mass balance calculation. Inventory data show that the hydrometallurgical route for recycling of the platinum group metals out of catalytic converter scrap has lower impacts on the environment compared with the pyrometallurgical method. In terms of emission effects, the hydrometallurgical process was found to be highly advantageous since it causes insignificant emissions to air, sea water, and fresh water. It is also found that the hydrometallurgical route performs comparatively superior in terms of acidification, eutrophication, fossil depletion, and human toxicity. The obtained results are applicable only to the Australian setting.

  10. Reduction of NOx Emission of a Diesel Engine with a Multiple Injection Pump by SCR Catalytic Converter

    Directory of Open Access Journals (Sweden)

    Vít Marek

    2016-01-01

    Full Text Available This paper deals with reduction of NOx-emission of a diesel engine with multiple injection pump by SCR catalytic converter. Main aim of the measurement was the detection of SCR catalyst converter efficiency. Tests were realized at the Research and Development workplace of Zetor Tractor a.s. Used engine was equipped with a multiple injection pump with electromagnetic regulator of a fuel charge. During the experiment selective catalytic reduction and diesel particulate filter were used as an after treatment of harmful pollutants reduction. Testing cycle of the eight-point test was chosen and Non-Road Steady Cycle (NRSC was maintained according to 97/68/EC directive. Results confirmed the dependencies between temperatures of SCR catalyst and exhaust gases and the volume of exhaust gases on efficiency of SCR catalyst. During the operation load of the engine, selective catalytic reduction reached efficiency over 90 %. Used after treatment system is suitable for reduction of harmful pollutants according to the Tier 4f norm.

  11. Thermal Catalytic Syngas Cleanup for High-Efficiency Waste-to-Energy Converters

    Science.gov (United States)

    2015-12-01

    need SVOC semivolatile organic compound TCLP toxicity characteristic leaching procedure TQG tactical quiet generator TRICON triple container VOC...prototype thermal catalytic syngas-cleaning circuit . A schematic of the system is shown in Figure 8, with photographs of the system in Figures 9 and 10...the gasifier in Figure 8 is a combustor that was used to preheat the catalytic cleanup circuit at start-up by burning the raw syngas and sending the

  12. Comparison of catalytic converter performance in internal combustion engine fueled with Ron 95 and Ron 97 gasoline

    Science.gov (United States)

    Leman, A. M.; Rahman, Fakhrurrazi; Jajuli, Afiqah; Feriyanto, Dafit; Zakaria, Supaat

    2017-09-01

    Generating ideal stability between engine performance, fuel consumption and emission is one of the main challenges in the automotive industry. The characteristics of engine combustion and creation of emission might simply change with different types of operating parameters. This study aims in investigating the relationship between two types of fuels on the performance and exhaust emission of internal combustion engine using ceramic and metallic catalytic converters. Experimental tests were performed on Mitsubishi 4G93 engine by applying several ranges of engine speeds to determine the conversion of pollutant gases released by the engine. The obtained results specify that the usage of RON 97 equipped with metallic converters might increase the conversion percentage of 1.31% for CO and 126 ppm of HC gases. The metallic converters can perform higher conversion compared to ceramic because in the high space velocities, metallic has higher surface geometry area and higher amount of transverse Peclet number (Pi). Ceramic converters achieved conversion at 2496 ppm of NOx gas, which is higher than the metallic converter.

  13. Thermal and catalytic ASVAHL processes under hydrogen pressure for converting heavy crudes and conventional residues

    Energy Technology Data Exchange (ETDEWEB)

    Peries, J.P.; Quignard, A.; Farjon, C.; Laborde, M.

    This article describes the comparative performances of thermal ASVAHL processes (TERVAHL T, TERVAHL H, TERVAHL HC) and catalytic ASVAHL processes (HYVAHL F, HYVAHL C) for two types of processing: (1) degasolined Boscan crude (basis of studies for transportation feasibility), and (2) Safaniya vacuum residue (basis of studies for residue refining). The results reveal the importance of the amount of fixed hydrogen, which affects the conversion obtained and the quality of the residues. The introduction of a TERVAHL HC soluble catalyst or one in catalytic suspension (catalytic hydrovisbreaking) or the use of a supported catalyst (HYVAHL hydrotreatment) enhances the activation of hydrogen. The combination of cracking, polycondensation and hydrogen reactions together with the operating conditions (temperatures, residence time and pressure) are what will define the conversion limits for a given stability of residues.

  14. The Performance of Chrome-Coated Copper as Metallic Catalytic Converter to Reduce Exhaust Gas Emissions from Spark-Ignition Engine

    Science.gov (United States)

    Warju; Harto, S. P.; Soenarto

    2018-01-01

    One of the automotive technologies to reduce exhaust gas emissions from the spark-ignition engine (SIE) is by using a catalytic converter. The aims of this research are firstly to conduct a metallic catalytic converter, secondly to find out to what extend chrome-coated copper plate (Cu+Cr) as a catalyst is efficient. To measure the concentration of carbon monoxide (CO) and hydrocarbon (HC) on the frame there are two conditions required. First is when the standard condition, and second is when Cu+Cr metallic catalytic converter is applied using exhaust gas analyzer. Exhaust gas emissions from SIE are measured by using SNI 19-7118.1-2005. The testing of CO and HC emissions were conducted with variable speed to find the trend of exhaust gas emissions from idle speed to high speed. This experiment results in the fact that the use of Cu+Cr metallic catalytic converter can reduce the production of CO and HC of a four-stroke gasoline engine. The reduction of CO and HC emission are 95,35% and 79,28%. Using active metal catalyst in form of metallic catalytic converter, it is gained an optimum effective surface of a catalyst which finally is able to decrease the amount of CO and HC emission significantly in every spinning happened in the engine. Finally, this technology can be applied to the spark ignition engine both car and motorcycle to support blue sky program in Indonesia.

  15. Catalytic Converter Developed By Washcoat Of γ-Alumina On Nickel Oxide (Nio Catalyst In FeCrAl Substrate For Exhaust Emission Control : A Review

    Directory of Open Access Journals (Sweden)

    Leman A.M.

    2016-01-01

    Full Text Available Automobile exhaust emission control is one of the trending issues in automobile research field. The existing catalytic converter using the noble metals of platinum (Pt, palladium (Pd and rhodium (Rd recently were in limited supply and higher in cost. There is a need for the automotive industry to produce ultra-low emitting vehicles at a reasonable cost. The objective of this study is to investigate the effectiveness of methods of fabrication of modified catalytic converter by approaching FeCrAl as a substrate which treated using ultrasonic bath technique to improve the exhaust emission control. The modified catalytic converter preparation will involve the ultrasonic bath process of FeCrAl foil which has fabricated as metallic monolith coated by γ-Al2O3 powder. Nickel as catalyst material will be prepared using electroplating process. The oxidation test will be conducted using a tube and automatic furnace in temperature of 1100°C for 100 hours. Mitsubishi 4G93 1800cc Petrol E.F.I with a multi -gas analyzer equipped with a hydraulic dynamometer will be used for emission measurements of HC, CO, and NOx in varying speed and load for both conditions with and without catalytic converter. The result will expect the γ-Al2O3 as the washcoat material that fully embedded to FeCrAl substrate with the combination of ultrasonic and electroplating technique will effectively convert the CO, NOx and HC to CO2, NO2 and H2O which means that catalytic converter is effective to improve exhaust emission control of diesel engine. The FeCrAl substrate as a metallic catalytic converter which coated by γ-Al2O3 using ultrasonic and nickelelectroplating technique may improve the exhaust emission control.

  16. Selective catalytic reduction converter design: The effect of ammonia nonuniformity at inlet

    International Nuclear Information System (INIS)

    Paramadayalan, Thiyagarajan; Pant, Atul

    2013-01-01

    A three-dimensional CFD model of SCR converter with detailed chemistry is developed. The model is used to study the effects of radial variation in inlet ammonia profile on SCR emission performance at different temperatures. The model shows that radial variation in inlet ammonia concentration affects the SCR performance in the operating range of 200-400 .deg. C. In automotive SCR systems, ammonia is non-uniformly distributed due to evaporation/reaction of injected urea, and using a 1D model or a 3D model with flat ammonia profile at inlet for these conditions can result in erroneous emission prediction. The 3D SCR model is also used to study the effect of converter design parameters like inlet cone angle and monolith cell density on the SCR performance for a non-uniform ammonia concentration profile at the inlet. The performance of SCR is evaluated using DeNO x efficiency and ammonia slip

  17. Catalytic

    Directory of Open Access Journals (Sweden)

    S.A. Hanafi

    2014-03-01

    Full Text Available A series of dealuminated Y-zeolites impregnated by 0.5 wt% Pt catalysts promoted by different amounts of Ni, Pd or Cr (0.3 and 0.6 wt% were prepared and characterized as hydrocracking catalysts. The physicochemical and structural characterization of the solid catalysts were investigated and reported through N2 physisorption, XRD, TGA-DSC, FT-IR and TEM techniques. Solid catalysts surface acidities were investigated through FT-IR spectroscopy aided by pyridine adsorption. The solid catalytic activities were evaluated through hydroconversion of n-hexane and n-heptane employing micro-catalytic pulse technique directly connected to a gas chromatograph analyzer. The thermal stability of the solids was also investigated up to 800 °C. Crystallinity studies using the XRD technique of all modified samples proved analogous to the parent Y-zeolite, exhibiting nearly an amorphous and microcrystalline character of the second metal oxides. Disclosure of bimetallic catalysts crystalline characterization, through XRD, was not viable. The nitrogen adsorption–desorption isotherms for all samples concluded type I adsorption isotherms, without any hysteresis loop, indicating that the entire pore system is composed of micropores. TEM micrographs of the solid catalysts demonstrate well-dispersed Pt, Ni and Cr nanoparticles having sizes of 2–4 nm and 7–8 nm, respectively. The catalytic activity results indicate that the bimetallic (0.5Pt–0.3Cr/D18H–Y catalyst is the most active towards n-hexane and n-heptane isomerization while (0.5Pt–0.6Ni/D18H–Y catalyst can be designed as most suitable as a cracking catalyst.

  18. Diffusion and Bonding Mechanism of Protective γ-Al2O3 on FeCrAl Foil for Metallic Three-Way Catalytic Converter

    Directory of Open Access Journals (Sweden)

    Feriyanto Dafit

    2017-01-01

    Full Text Available High pollutant level contributed by mobile sources/land transportation that become main problems for the human health. Improving exhaust emission system by improving catalytic converter properties is one of the most effective way to produce healthy air in our environment. It is conducted by two methods i.e. ultrasonic during electroplating (UBDEL and electroplating process (EL which are not fully investigated yet as catalytic converter coating process. UBDEL is conducted using sulphamate types electrolyte solution, Frequency of 35 kHz, current of 1.28A, Voltage of 12 V, and various time of 15, 30, 45, 60 and 75 minutes. Meanwhile El method is conducted using parameters of current of 1.28A, Voltage of 12 V, stirrer speed of 60 rpm and various time of 15, 30, 45, 60 and 75 minutes. Fully γ-Al2O3 bonding to the FeCrAl substrate is shown by UBDEL 75 minutes samples proved by SEM images and Ra and Rq are 4.01 μm and 5.64 μm, respectively. Ni present on the FeCrAl substrate as other protective layer generated by Ni electroplating process that will improve thermal stability of FeCrAl at high temperature of 1000 °C. From the results, can summarized that UBDEL technique is promoted as an effective catalytic converter coating technique.

  19. Influence of fuel properties, nitrogen oxides, and exhaust treatment by an oxidation catalytic converter on the mutagenicity of diesel engine emissions.

    Science.gov (United States)

    Bünger, Jürgen; Krahl, Jürgen; Weigel, Andreas; Schröder, Olaf; Brüning, Thomas; Müller, Michael; Hallier, Ernst; Westphal, Götz

    2006-08-01

    Particle emissions of diesel engines (DEP) content polycyclic aromatic hydrocarbons (PAH) these compounds cause a strong mutagenicity of solvent extracts of DEP. We investigated the influence of fuel properties, nitrogen oxides (NO( x )), and an oxidation catalytic converter (OCC) on the mutagenic effects of DEP. The engine was fuelled with common diesel fuel (DF), low-sulphur diesel fuel (LSDF), rapeseed oil methyl ester (RME), and soybean oil methyl ester (SME) and run at five different load modes in two series with and without installation of an OCC in the exhaust pipe. Particles from the cooled and diluted exhaust were sampled onto glass fibre filters and extracted with dichloromethane in a soxhlet apparatus. The mutagenicity of the extracts was tested using the Salmonella typhimurium/mammalian microsome assay with tester strains TA98 and TA100. Without OCC the number of revertant colonies was lower in extracts of LSDF than in extracts of DF. The lowest numbers of revertant colonies were induced by the plant oil derived fuels. In three load modes, operation with the OCC led to a reduction of the mutagenicity. However, direct mutagenic effects under heavy duty conditions (load mode A) were significantly increased for RME (TA98, TA100) and SME (TA98). A consistent but not significant increase in direct mutagenicity was observed for DF and LSDF at load mode A, and for DF at idling (load mode E) when emissions were treated with the OCC. These results raise concern over the use of oxidation catalytic converters with diesel engines. We hypothesise that the OCC increases formation of direct acting mutagens under certain conditions by the reaction of NO( x ) with PAH resulting in the formation of nitrated-PAH. Most of these compounds are powerful direct acting mutagens.

  20. Electrochemical behaviour of metal hexacyanoferrate converted to metal hydroxide films immobilized on indium tin oxide electrodes-Catalytic ability towards alcohol oxidation in alkaline medium

    International Nuclear Information System (INIS)

    Ganesh, V.; Latha Maheswari, D.; Berchmans, Sheela

    2011-01-01

    Graphical abstract: - Abstract: In this work, we demonstrate a simple method to modify indium tin oxide (ITO) electrodes in order to perform electro-catalytic oxidation of alcohols in alkaline medium. Metal hexacyanoferrate (MHCF) films such as nickel hexacyanoferrate (NiHCF) and copper hexacyanoferrate (CuHCF) were successfully immobilized on ITO electrodes using an electrochemical method. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were employed to characterize the structural and morphological aspects of MHCF films. Cyclic voltammetry (CV) was used to study the redox properties and to determine the surface coverage of these films on ITO electrodes. Electrochemical potential cycling was carried out in alkaline medium in order to alter the chemical structure of these films and convert to their corresponding metal hydroxide films. SEM and XPS were performed to analyze the structure and morphology of metal hydroxide modified electrodes. Electro-catalytic oxidation ability of these films towards methanol and ethanol in alkaline medium was investigated using CV. From these studies we found that metal hydroxide modified electrodes show a better catalytic performance and good stability for methanol oxidation along with the alleviation of CO poisoning effect. We have obtained an anodic oxidation current density of ∼82 mA cm -2 for methanol oxidation, which is at least 10 fold higher than that of any metal hydroxide modified electrodes reported till date. The onset potential for methanol oxidation is lowered by ∼200 mV compared to other chemically modified electrodes reported. A plausible mechanism was proposed for the alcohol oxidation based on the redox properties of these modified electrodes. The methodology adapted in this work does not contain costlier noble metals like platinum and ruthenium and is economically viable.

  1. Evaluation of an EMITEC resistively heated metal monolith catalytic converter on two M100 neat methanol-fueled vehicles

    Science.gov (United States)

    Piotrowski, Gregory K.; Schaefer, Ronald M.

    1992-12-01

    The report describes the evaluation of a resistively heated catalyst system on two different methanol fueled vehicles. The EMITEC catalyst consisted of a compact resistively heated metal monolith in front of a larger conventional main converter. The EMITEC catalyst was evaluated on two neat methanol-fueled vehicles, a 1981 Volkswagen Rabbit and a 1988 Toyota Corolla. Emission testing was conducted over the Federal Test Procedure (FTP) CVS-75 test cycle. The emissions of primary interest were cold start methanol (unburned fuel), carbon monoxide, and formaldehyde.

  2. Oxidative leaching process with cupric ion in hydrochloric acid media for recovery of Pd and Rh from spent catalytic converters

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, C.A., E-mail: carlos.nogueira@lneg.pt [Laboratório Nacional de Energia e Geologia, I.P., Campus do Lumiar, 1649-038 Lisboa (Portugal); Paiva, A.P., E-mail: appaiva@fc.ul.pt [Centro de Química e Bioquímica, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa (Portugal); Oliveira, P.C. [Laboratório Nacional de Energia e Geologia, I.P., Campus do Lumiar, 1649-038 Lisboa (Portugal); Costa, M.C., E-mail: mcorada@ualg.pt [Centro de Ciências do Mar, Departamento de Química e Farmácia, Faculdade de Ciências e de Tecnologia, Campus de Gambelas, 8005-139 Faro (Portugal); Costa, A.M. Rosa da, E-mail: amcosta@ualg.pt [Centro de Investigação em Química do Algarve, Departamento de Química e Farmácia, Faculdade de Ciências e de Tecnologia, Campus de Gambelas, 8005-139 Faro (Portugal)

    2014-08-15

    Highlights: • A new leaching process based on Cu{sup 2+}/HCl media for recovering Pd and Rh from spent autocatalytic converters is presented. • Palladium and rhodium were efficiently leached, with attained maximum yields of 95% and 86%, respectively. • Temperature, time, and HCl and Cu{sup 2+} concentrations were found to be significant factors in the leaching of Pd and Rh. - Abstract: The recycling of platinum-group metals from wastes such as autocatalytic converters is getting growing attention due to the scarcity of these precious metals and the market pressure originated by increase of demand in current and emerging applications. Hydrometallurgical treatment of such wastes is an alternative way to the most usual pyrometallurgical processes based on smelter operations. This paper focuses on the development of a leaching process using cupric chloride as oxidising agent, in HCl media, for recovery of palladium and rhodium from a spent catalyst. The chloride media allows the adequate conditions for oxidising and solubilising the metals, as demonstrated by equilibrium calculations based on thermodynamic data. The experimental study of the leaching process revealed that Pd solubilisation is clearly easier than that of Rh. The factors temperature, time, and HCl and Cu{sup 2+} concentrations were significant regarding Pd and Rh leaching, the latter requiring higher factor values to achieve the same results. Leaching yields of 95% Pd and 86% Rh were achieved under optimised conditions (T = 80 °C, t = 4 h, [HCl] = 6 M, [Cu{sup 2+}] = 0.3 M)

  3. Pyrolysis of marine biomass to produce bio-oil and its upgrading using a novel multi-metal catalyst prepared from the spent car catalytic converter.

    Science.gov (United States)

    Sabegh, Mahzad Yaghmaei; Norouzi, Omid; Jafarian, Sajedeh; Khosh, Akram Ghanbari; Tavasoli, Ahmad

    2018-02-01

    In order to reduce the economic and environmental consequences caused by spent car catalyst, we herein report for the first time a novel promising multi-metal catalyst prepared from spent car catalytic converters to upgrade the pyrolysis bio-oils. The physico-chemical properties of prepared catalyst were characterized by XRD, EDS, FESEM, and FT-IR analyses. The thermal stability of the multi-metal catalyst was studied with TGA. To investigate the activity of the catalyst, Conversion of Cladophora glomerata (C. glomerata) into bio-products was carried out via a fixed bed reactor with and without catalyst at the temperature of 500°C. Although the catalyst didn't catalyze the gasification reaction, bio-oil was upgraded over the catalyst. The main effect of the catalyst on the bio-oil components is deoxygenating of nitrogen compounds and promotion the ketonization reaction, which converts acid to ketone and declines the corrosive nature of bio-oil. Copyright © 2017. Published by Elsevier Ltd.

  4. Oxidative leaching process with cupric ion in hydrochloric acid media for recovery of Pd and Rh from spent catalytic converters.

    Science.gov (United States)

    Nogueira, C A; Paiva, A P; Oliveira, P C; Costa, M C; da Costa, A M Rosa

    2014-08-15

    The recycling of platinum-group metals from wastes such as autocatalytic converters is getting growing attention due to the scarcity of these precious metals and the market pressure originated by increase of demand in current and emerging applications. Hydrometallurgical treatment of such wastes is an alternative way to the most usual pyrometallurgical processes based on smelter operations. This paper focuses on the development of a leaching process using cupric chloride as oxidising agent, in HCl media, for recovery of palladium and rhodium from a spent catalyst. The chloride media allows the adequate conditions for oxidising and solubilising the metals, as demonstrated by equilibrium calculations based on thermodynamic data. The experimental study of the leaching process revealed that Pd solubilisation is clearly easier than that of Rh. The factors temperature, time, and HCl and Cu(2+) concentrations were significant regarding Pd and Rh leaching, the latter requiring higher factor values to achieve the same results. Leaching yields of 95% Pd and 86% Rh were achieved under optimised conditions (T = 80 °C, t = 4h, [HCl] = 6M, [Cu(2+)] = 0.3M). Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Platinum from automotive catalytic converters: environmental health evaluation based on recent data on exposure and effects; Platin aus Automobilabgaskatalysatoren: Umweltmedizinische Bewertung auf Basis neuer Expositions- und Wirkungsdaten

    Energy Technology Data Exchange (ETDEWEB)

    Rosner, G. [Consulting-Buero Toxikologie - Umwelt, Merzhausen/Freiburg (Germany); Artelt, S. [Bayern Innovativ Gesellschaft fuer Innovation und Wissenstransfer mbH, Nuernberg (Germany); Mangelsdorf, I. [Fraunhofer-Institut fuer Toxikologie und Aerosolforschung (ITA), Hannover (Germany); Merget, R. [Berufsgenossenschaftliches Forschungsinstitut fuer Arbeitsmedizin (BGFA), Bochum (Germany)

    1998-12-01

    We estimated ambient air concentrations of platinum by applying dispersion models as well as recent emission factors that have been derived from engine test bench experiments with three-way, monolith-type catalytic converters. Predicted concentrations in various exposure scenarios range from 4 pg/m{sup 3} (street canyon, typical conditions) up to 112 pg/m{sup 3} (express-motorway, severe conditions). These values agree well with the few measurements of platinum ambient air concentrations. Platinum is emitted from catalytic converters in very small amounts (ng/km range) and is mainly in the oxidation state 0 (elemental platinum). The nanocrystalline platinum particles are attached to {mu}m-sized aluminum oxide particles. Whether free ultrafine platinum particles may be emitted and result in biological effects has not been studied sufficiently. Hence, risk assessment can only be based on the respiratory sensitizing effects of halogenated platinum salts, although this can be considered a very sensitive endpoint. The presence of such compounds in the soluble fraction ({<=}1%) of the total platinum emissions as well as their secondary formation from platinum particles cannot principally be excluded. Our risk assessment is based on recent occupational studies in a catalytic converter production plant, from which a conservative, no effect level (NOEL) of 1.5 ng/cm{sup 3} can be derived for soluble platinum. In a (reasonable) worst case approach we assume that halogenated platinum salts comprise 1% (0.1%) of the total platinum emissions. Applying an unsafety factor of 10 to account for inter-individual variability, a guidance value of 150 (15) ng/m{sup 3} is derived for catalyst-borne platinum. The exposure to platinum in ambient air as measured or predicted is at least two orders of magnitude below this `critical` range. (orig.) [Deutsch] In einer differenzierten Aktualisierung frueherer Expositionsabschaetzungen werden anhand von Ausbreitungsmodellen und aktuellen

  6. Nano sponge Mn₂O ₃ as a new adsorbent for the preconcentration of Pd(II) and Rh(III) ions in sea water, wastewater, rock, street sediment and catalytic converter samples prior to FAAS determinations.

    Science.gov (United States)

    Yavuz, Emre; Tokalıoğlu, Serife; Sahan, Halil; Patat, Saban

    2014-10-01

    In this study, a nano sponge Mn2O3 adsorbent was synthesized and was used for the first time. Various parameters affecting the recovery values of Pd(II) and Rh(III) were examined. The tolerance limits (≥ 90 %) for both Pd(II) and Rh(III) ions were found to be 75,000 mg L(-1) Na(I), 75,000 mg L(-1) K(I), 50,000 mg L(-1) Mg(II) and 50,000 mg L(-1) Ca(II). A 30s contact time was enough for both adsorption and elution. A preconcentration factor of 100 was obtained by using 100mg of the nano sponge Mn2O3. The reusability of the adsorbent was 120 times. Adsorption capacities for Pd(II) and Rh(III) were found to be 42 and 6.2 mg g(-1), respectively. The detection limits were 1.0 µg L(-1) for Pd(II) and 0.37 µg L(-1) for Rh(III) and the relative standard deviations (RSD, %) were found to be ≤ 2.5%. The method was validated by analyzing the standard reference material, SRM 2556 (Used Auto Catalyst Pellets) and spiked real samples. The optimized method was applied for the preconcentration of Pd(II) and Rh(III) ions in water (sea water and wastewater), rock, street sediment and catalytic converter samples. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Measuring the effects of platinum from catalytic converter equipped vehicles by means of plant indicators (food and fodder plants); Wirkungsmessungen von Platin aus katalysatorbetriebenen Kraftfahrzeugen mit pflanzlichen Bioindikatoren (Nahrungs- und Futterpflanzen)

    Energy Technology Data Exchange (ETDEWEB)

    Maier-Reiter, W.; Sommer, B. [TUEV Energie und Umwelt GmbH, Filderstadt (Germany). Niederlassung Stuttgart

    1997-12-31

    The essential aim of the present R and D project, titled ``Measuring the effects of platinum from catalytic converter equipped vehicles by means of plant indicators - food and fodder plants (VPT 02)``, was to obtain first orienting results on the potential effects of platinum pollution on plants by means of short-time, high-dose exposure experiments. The most important effect criterion in assessing potential hazards to humans and animals via the food chain, beside any outwardly visible changes (reaction), was the analytical detection of platinum accumulation in the plants. The project was also intended as a first contribution to the ecotoxicology of platinum, in particular the behaviour of metallic platinum and water-soluble platinum compounds in the soil-plant system. [Deutsch] Die wesentliche Zielsetzung des F and E-Vorhabens `Wirkungsmessungen von Platin und Platinverbindungen mit pflanzlichen Bioindikatoren - Nahrungs- und Futterpflanzen (VPT 02)` war es, im Rahmen von Kurzzeit-Belastungsexperimenten im hohen Dosisbereich erste orientierende Ergebnisse zu den moeglichen Auswirkungen von Platin-Belastungen auf Pflanzen abzuleiten. Neben aeusserlich sichtbaren Veraenderungen der Pflanzen (Reaktion) wurde als Wirkungskriterium insbesondere die chemisch-analytisch erfassbare Platin-Anreicherung in den Pflanzen (Akkumulation) betrachtet, die eine Abschaetzung moeglicher Gefaehrdungen von Mensch und Tier ueber die Nahrungskette ermoeglicht. Zudem sollte ein erster Beitrag zur Oekotoxikologie des Platins, insbesondere zum Verhalten von metallischem Platin und wasserloeslichen Platinverbindungen im System Boden-Pflanzen, erarbeitet werden. (orig.)

  8. Diesel Catalytic Converters As Emission Control Devices

    International Nuclear Information System (INIS)

    El Banna, S.; El Deen, O.N.

    2004-01-01

    Internal combustion engines are devices that generate work from combustion reactions. Combustion products under high pressure produce work by expansion through a turbine or piston. The combustion reactions inside these engines are not necessarily neutralizing or complete and air pollutants are produced. There are three major types of internal combustion engine(l) in use today: I) the spark ignition engine, which is used primarily in automobiles; 2) the diesel engine, which is used in large vehicles and industrial systems where cycle efficiency offers advantages over the more compact and lighter-weight spark ignition engine and; 3) the gas turbine, which is used in aircraft due to its high power/weight ratio and is also used for stationary power generation. Each of these types of engine is an important source of atmospheric pollutants. Automobiles are the one of the major source of carbon monoxide, unburned hydrocarbons, and nitrogen oxides. Probably more than any other combustion system, the design of automobile engines is now being guided by requirements to reduce emissions of these pollutants. While substantial progress has been made in emission reduction, automobiles remain important sources of air pollutants

  9. Discussion of risks of platinum resources based on a function orientated criticality assessment. Shown by cytostatic drugs and automotive catalytic converters; Diskussion der Risiken der Ressource Platin auf Basis eines um funktionale Faktoren erweiterten Kritikalitaetsassessments. Dargestellt am Beispiel platinhaltiger Zytostatika und Autoabgaskatalysatoren

    Energy Technology Data Exchange (ETDEWEB)

    Thorenz, Andrea; Reller, Armin [University of Augsburg, Chair of Resource Strategy, Environment Science Center, Augsburg (Germany)

    2011-12-15

    The purpose of the study is the enhancement of criticality assessments for resources in order to address function specific factors like dissipation, recycling, bio-activity and toxicity. The developed methodology is applied to platinum-containing cytostatic drugs and automotive catalytic converters. Methods: The study is methodically based on an analysis of resource specific factors like exploration rates, reserves-to-production ratio and regional distribution of exploration areas as well as on the investigation of product/functional depending factors like recycling rates, dissipation rates, bio-diversity and toxicity. Taking into account that economic and ecological risks may occur at any stage of the supply, consumption and dissipation processes, the whole life cycles of the two analyzed products (cytostatic drugs and automotive catalytic converters) are considered. As an approach to reduce potential economic and ecological risks the study is especially focused on recycling strategies. In order to get a better understanding of platinum as an essential resource for the development of our society the history and the cultural impact of the term ''resource'' are introduced. The availability of platinum is crucial for several products of our modern society. Areas of application are e.g. jewellery, automotive catalytic converters, investments (coins, bars), computers, mobile devices, fertilizers and cytostatic drugs. Economic risks are caused by limited sources and dynamic demand of new application areas like fuel cells and drugs. Platinum-containing drugs are used for the treatment of several kinds of cancer such as testicular, breast, colon and prostate. Currently the pharmaceutical industry requires 6,9 tons per year (3 percent of the total demand of platinum). Due to the improvement of medical standards and the ageing society, especially in developing countries, the demand of platinum-containing drugs will rise significantly. The dissipation of

  10. Data Converter

    NARCIS (Netherlands)

    Schinkel, Daniel

    2006-01-01

    A data converter comprises a discrete-time sigma delta modulator e.g. for driving a Class-D power amplifier. The low-pass filter of the sigma delta modulator is modified by adding a suitably positioned pole to lower the oscillation frequency (limit cycle) of the sigma delta modulator in order to

  11. Data Converter

    NARCIS (Netherlands)

    Schinkel, Daniel

    2005-01-01

    A data converter comprises a discrete-time sigma delta modulator e.g. for driving a Class-D power amplifier. The low-pass filter of the sigma delta modulator is modified by adding a suitably positioned pole to lower the oscillation frequency (limit cycle) of the sigma delta modulator in order to

  12. Data Converter

    NARCIS (Netherlands)

    Schinkel, Daniel; Nuijten, Petrus A.C.M.

    2005-01-01

    A data converter comprises a discrete- time sigma delta modulator e.g. for driving a Class-D power amplifier. The low-pass filter of the sigma delta modulator is modified by adding a suitably positioned pole to lower the oscillation frequency (limit cycle) of the sigma delta modulator in order to

  13. Hydrogen converters

    International Nuclear Information System (INIS)

    Mondino, Angel V.

    2003-01-01

    The National Atomic Energy Commission of Argentina developed a process of 99 Mo production from fission, based on irradiation of uranium aluminide targets with thermal neutrons in the RA-3 reactor of the Ezeiza Atomic Centre. These targets are afterwards dissolved in an alkaline solution, with the consequent liberation of hydrogen as the main gaseous residue. This work deals with the use of a first model of metallic converter and a later prototype of glass converter at laboratory scale, adjusted to the requirements and conditions of the specific redox process. Oxidized copper wires were used, which were reduced to elementary copper at 400 C degrees and then regenerated by oxidation with hot air. Details of the bed structure and the operation conditions are also provided. The equipment required for the assembling in cells is minimal and, taking into account the operation final temperature and the purge with nitrogen, the procedure is totally safe. Finally, the results are extrapolated for the design of a converter to be used in a hot cell. (author)

  14. Ray converter

    International Nuclear Information System (INIS)

    Reiss, K.H.

    1976-01-01

    In a radiographic system a converter is used for changing image forming intensity distribution in a bundle of penetrating rays into a flow of electrically charged particles by electrodes located in a gas space and partly latticed (grids) which lie at potentials stepped from cathode to anode. The invention is particularly characterized by the provision of at least two grids extending between and parallel to the cathode and the anode. The electrical field which lies between two electrodes lies at least between the grids located closest to the cathode being to the extent of between 1 and 10 percent, in the average preferably 3 percent below the electrical break down field in the gas in a homogeneous electrical field

  15. Dispersion of Pt, Pd and Rh produced by catalytic converters into the roadside and urban environment. Element speciation study; Dispersion dans l'environnement routier et urbain de Pt, Pd, et Rh emis par les pots d'echappement catalytiques. Etude de la speciation des elements

    Energy Technology Data Exchange (ETDEWEB)

    Amosse, J.; Delbos, V. [Centre National de la Recherche Scientifique (CNRS), Lab. de Geodynamique des Chaines Alpines, LGCA, UMR 5025, 38 - Grenoble (France)

    2002-09-01

    This study highlights the dispersion into the French urban environment of platinum group elements (PGEs) used in catalytic converters. Differences were observed between Pt and Rh on the one hand, and Pd on the other one. One experiment, consisting in passing the corrosive gas emissions from engines over the metals heated to 1000 deg. C, showed that Pd was severely corroded by nitrogen oxides. It was concluded that Pd is emitted in nitrate form. Hydrolysis of this nitrate form leads to the formation of soluble species. In situ pH and E{sub h} measurements in the soils concerned confirm this theory when the results are compared with the Pd species predominance diagram. (authors)

  16. Catalytic devices

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ming; Zhang, Xiang

    2018-01-23

    This disclosure provides systems, methods, and apparatus related to catalytic devices. In one aspect, a device includes a substrate, an electrically insulating layer disposed on the substrate, a layer of material disposed on the electrically insulating layer, and a catalyst disposed on the layer of material. The substrate comprises an electrically conductive material. The substrate and the layer of material are electrically coupled to one another and configured to have a voltage applied across them.

  17. Zeolitic catalytic conversion of alcohols to hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Narula, Chaitanya K.; Davison, Brian H.; Keller, Martin

    2018-04-10

    A method for converting an alcohol to a hydrocarbon, the method comprising contacting said alcohol with a metal-loaded zeolite catalyst at a temperature of at least 100.degree. C. and up to 550.degree. C., wherein said alcohol can be produced by a fermentation process, said metal is a positively-charged metal ion, and said metal-loaded zeolite catalyst is catalytically active for converting said alcohol to said hydrocarbon.

  18. Zeolitic catalytic conversion of alochols to hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Narula, Chaitanya K.; Davison, Brian H.; Keller, Martin

    2017-01-03

    A method for converting an alcohol to a hydrocarbon, the method comprising contacting said alcohol with a metal-loaded zeolite catalyst at a temperature of at least 100.degree. C. and up to 550.degree. C., wherein said alcohol can be produced by a fermentation process, said metal is a positively-charged metal ion, and said metal-loaded zeolite catalyst is catalytically active for converting said alcohol to said hydrocarbon.

  19. Catalytic Membrane Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Boyle, T.J.; Brinker, C.J.; Gardner, T.J.; Hughes, R.C.; Sault, A.G.

    1998-12-01

    The proposed "catalytic membrane sensor" (CMS) was developed to generate a device which would selectively identify a specific reagent in a complex mixture of gases. This was to be accomplished by modifying an existing Hz sensor with a series of thin films. Through selectively sieving the desired component from a complex mixture and identifying it by decomposing it into Hz (and other by-products), a Hz sensor could then be used to detect the presence of the select component. The proposed "sandwich-type" modifications involved the deposition of a catalyst layered between two size selective sol-gel layers on a Pd/Ni resistive Hz sensor. The role of the catalyst was to convert organic materials to Hz and organic by-products. The role of the membraneo was to impart both chemical specificity by molecukir sieving of the analyte and converted product streams, as well as controlling access to the underlying Pd/Ni sensor. Ultimately, an array of these CMS elements encompassing different catalysts and membranes were to be developed which would enable improved selectivity and specificity from a compiex mixture of organic gases via pattern recognition methodologies. We have successfully generated a CMS device by a series of spin-coat deposited methods; however, it was determined that the high temperature required to activate the catalyst, destroys the sensor.

  20. Catalytic production of biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Theilgaard Madsen, A.

    2011-07-01

    The focus of this thesis is the catalytic production of diesel from biomass, especially emphasising catalytic conversion of waste vegetable oils and fats. In chapter 1 an introduction to biofuels and a review on different catalytic methods for diesel production from biomass is given. Two of these methods have been used industrially for a number of years already, namely the transesterification (and esterification) of oils and fats with methanol to form fatty acid methyl esters (FAME), and the hydrodeoxygenation (HDO) of fats and oils to form straight-chain alkanes. Other possible routes to diesel include upgrading and deoxygenation of pyrolysis oils or aqueous sludge wastes, condensations and reductions of sugars in aqueous phase (aqueous-phase reforming, APR) for monofunctional hydrocarbons, and gasification of any type of biomass followed by Fischer-Tropsch-synthesis for alkane biofuels. These methods have not yet been industrialised, but may be more promising due to the larger abundance of their potential feedstocks, especially waste feedstocks. Chapter 2 deals with formation of FAME from waste fats and oils. A range of acidic catalysts were tested in a model fat mixture of methanol, lauric acid and trioctanoin. Sulphonic acid-functionalised ionic liquids showed extremely fast convertion of lauric acid to methyl laurate, and trioctanoate was converted to methyl octanoate within 24 h. A catalyst based on a sulphonated carbon-matrix made by pyrolysing (or carbonising) carbohydrates, so-called sulphonated pyrolysed sucrose (SPS), was optimised further. No systematic dependency on pyrolysis and sulphonation conditions could be obtained, however, with respect to esterification activity, but high activity was obtained in the model fat mixture. SPS impregnated on opel-cell Al{sub 2}O{sub 3} and microporous SiO{sub 2} (ISPS) was much less active in the esterification than the original SPS powder due to low loading and thereby low number of strongly acidic sites on the

  1. Wavelength converter technology

    DEFF Research Database (Denmark)

    Kloch, Allan; Hansen, Peter Bukhave; Poulsen, Henrik Nørskov

    1999-01-01

    Wavelength conversion is important since it ensures full flexibility of the WDM network layer. Progress in optical wavelength converter technology is reviewed with emphasis on all-optical wavelength converter types based on semiconductor optical amplifiers.......Wavelength conversion is important since it ensures full flexibility of the WDM network layer. Progress in optical wavelength converter technology is reviewed with emphasis on all-optical wavelength converter types based on semiconductor optical amplifiers....

  2. Wavelength converter technology

    DEFF Research Database (Denmark)

    Kloch, Allan; Hansen, Peter Bukhave; Poulsen, Henrik Nørskov

    1999-01-01

    Wavelength conversion is important since it ensures full flexibility of the WDM network layer. Progress in optical wavelength converter technology is reviewed with emphasis on air-optical wavelength converter types based on semiconductor optical amplifiers.......Wavelength conversion is important since it ensures full flexibility of the WDM network layer. Progress in optical wavelength converter technology is reviewed with emphasis on air-optical wavelength converter types based on semiconductor optical amplifiers....

  3. Technologies for converter topologies

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yan; Zhang, Haiyu

    2017-02-28

    In some embodiments of the disclosed inverter topologies, an inverter may include a full bridge LLC resonant converter, a first boost converter, and a second boost converter. In such embodiments, the first and second boost converters operate in an interleaved manner. In other disclosed embodiments, the inverter may include a half-bridge inverter circuit, a resonant circuit, a capacitor divider circuit, and a transformer.

  4. Molecular catalytic coal liquid conversion

    Energy Technology Data Exchange (ETDEWEB)

    Stock, L.M.; Yang, Shiyong [Univ. of Chicago, IL (United States)

    1995-12-31

    This research, which is relevant to the development of new catalytic systems for the improvement of the quality of coal liquids by the addition of dihydrogen, is divided into two tasks. Task 1 centers on the activation of dihydrogen by molecular basic reagents such as hydroxide ion to convert it into a reactive adduct (OH{center_dot}H{sub 2}){sup {minus}} that can reduce organic molecules. Such species should be robust withstanding severe conditions and chemical poisons. Task 2 is focused on an entirely different approach that exploits molecular catalysts, derived from organometallic compounds that are capable of reducing monocyclic aromatic compounds under very mild conditions. Accomplishments and conclusions are discussed.

  5. Catalytic Combustion of Ethyl Acetate

    OpenAIRE

    ÖZÇELİK, Tuğba GÜRMEN; ATALAY, Süheyda; ALPAY, Erden

    2014-01-01

    The catalytic combustion of ethyl acetate over prepared metal oxide catalysts was investigated. CeO, Co2O3, Mn2O3, Cr2O3, and CeO-Co2O3 catalysts were prepared on monolith supports and they were tested. Before conducting the catalyst experiments, we searched for the homogeneous gas phase combustion reaction of ethyl acetate. According to the homogeneous phase experimental results, 45% of ethyl acetate was converted at the maximum reactor temperature tested (350 °C). All the prepare...

  6. Monitoring of Basic Parameters for Selective Catalytic Reduction System Used in an Agricultural Tractor

    Directory of Open Access Journals (Sweden)

    Antonín Skřivánek

    2014-01-01

    Full Text Available Presented paper describes monitoring of basic parameters for selective catalytic reduction (SCR system used in an agricultural tractor. SCR systems are used to reduce emissions of nitrogen oxides (NOx produced by combustion of fuel. The usage of SCR catalytic converters entails certain disadvantages in the use of reducing agent and the necessity of suitable operating conditions to achieve optimum efficiency of the catalytic converter. This paper aims to predict consumption of AdBlue depending on the temperature of SCR catalytic converter, which reflects the engine load and monitoring the effectiveness of SCR catalytic converter when operating a tractor engine with a maximum dose of fuel. To fulfill those aims, the measurements have been performed on the Case Puma 185 CVX agricultural tractor. As the measurement results indicate, the lowest NOx emissions correspond to high consumption of AdBlue. Other studies imply that the catalytic converter operates at optimal operating temperature and with the highest efficiency of NOx emission reduction. The effectiveness of NOx emission reduction is thus affected not only by quantity of injected reagent but also by catalytic converter thermal load. Further measurement results indicate that the lowest amount of emissions of NOx (and the highest efficiency rate is achieved by catalytic converter in a range in which the engine operates with the highest engine efficiency.

  7. Josephson stroboscopic converters. Review

    International Nuclear Information System (INIS)

    Askerzade, I.N.

    2006-01-01

    One reviews studies dealing with the Josephson stroboscopic converters. One analyzed dynamic properties of the Josephson junctions serving as sensitive comparators in converters. One elaborates a theory to evaluate time resolution and sensitivity of the Josephson comparators. One derived analytical formulae for the limiting characteristics of superconductors of strobe-converters. One discusses peculiar features of strobe-converters on the basis of high-temperature superconductors. Evaluations show feasibility of designing of strobe-converters with subpicosecond time resolution and nanoampere sensitivity [ru

  8. The photoelectric displacement converter

    Science.gov (United States)

    Dragoner, Valeriu V.

    2005-02-01

    In the article are examined questions of constructing photoelectric displacement converter satisfying demands that are stated above. Converter has channels of approximate and precise readings. The approximate reading may be accomplished either by the method of reading from a code mask or by the method of the consecutive calculation of optical scale gaps number. Phase interpolator of mouar strips" gaps is determined as a precise measuring. It is shown mathematical model of converter that allow evaluating errors and operating speed of conversion.

  9. Interleaved power converter

    Science.gov (United States)

    Zhu, Lizhi

    2007-11-13

    A power converter architecture interleaves full bridge converters to alleviate thermal management problems in high current applications, and may, for example, double the output power capability while reducing parts count and costs. For example, one phase of a three phase inverter is shared between two transformers, which provide power to a rectifier such as a current doubler rectifier to provide two full bridge DC/DC converters with three rather than four high voltage inverter legs.

  10. Power converters definitions, classification and converter topologies

    CERN Document Server

    Bordry, Frederick

    2006-01-01

    This paper introduces power conversion principles and defines the terminology. The concepts of sources and switches are defined and classified. From the basic laws of source interconnections, a generic method of power converter synthesis is presented. Some examples illustrate this systematic method. Finally, the notions of commutation cell and soft commutation are introduced and discussed.

  11. Catalytic conversion of alcohols to hydrocarbons with low benzene content

    Energy Technology Data Exchange (ETDEWEB)

    Narula, Chaitanya K.; Davison, Brian H.; Keller, Martin

    2016-03-08

    A method for converting an alcohol to a hydrocarbon fraction having a lowered benzene content, the method comprising: converting said alcohol to a hydrocarbon fraction by contacting said alcohol, under conditions suitable for converting said alcohol to said hydrocarbon fraction, with a metal-loaded zeolite catalyst catalytically active for converting said alcohol to said hydrocarbon fraction, and contacting said hydrocarbon fraction with a benzene alkylation catalyst, under conditions suitable for alkylating benzene, to form alkylated benzene product in said hydrocarbon fraction. Also described is a catalyst composition useful in the method, comprising a mixture of (i) a metal-loaded zeolite catalyst catalytically active for converting said alcohol to said hydrocarbon, and (ii) a benzene alkylation catalyst, in which (i) and (ii) may be in a mixed or separated state. A reactor for housing the catalyst and conducting the reaction is also described.

  12. Catalytic conversion of alcohols to hydrocarbons with low benzene content

    Energy Technology Data Exchange (ETDEWEB)

    Narula, Chaitanya K.; Davison, Brian H.; Keller, Martin

    2016-09-06

    A method for converting an alcohol to a hydrocarbon fraction having a lowered benzene content, the method comprising: converting said alcohol to a hydrocarbon fraction by contacting said alcohol, under conditions suitable for converting said alcohol to said hydrocarbon fraction, with a metal-loaded zeolite catalyst catalytically active for converting said alcohol to said hydrocarbon fraction, and contacting said hydrocarbon fraction with a benzene alkylation catalyst, under conditions suitable for alkylating benzene, to form alkylated benzene product in said hydrocarbon fraction. Also described is a catalyst composition useful in the method, comprising a mixture of (i) a metal-loaded zeolite catalyst catalytically active for converting said alcohol to said hydrocarbon, and (ii) a benzene alkylation catalyst, in which (i) and (ii) may be in a mixed or separated state. A reactor for housing the catalyst and conducting the reaction is also described.

  13. Porous media for catalytic renewable energy conversion

    Science.gov (United States)

    Hotz, Nico

    2012-05-01

    A novel flow-based method is presented to place catalytic nanoparticles into a reactor by sol-gelation of a porous ceramic consisting of copper-based nanoparticles, silica sand, ceramic binder, and a gelation agent. This method allows for the placement of a liquid precursor containing the catalyst into the final reactor geometry without the need of impregnating or coating of a substrate with the catalytic material. The so generated foam-like porous ceramic shows properties highly appropriate for use as catalytic reactor material, e.g., reasonable pressure drop due to its porosity, high thermal and catalytic stability, and excellent catalytic behavior. The catalytic activity of micro-reactors containing this foam-like ceramic is tested in terms of their ability to convert alcoholic biofuel (e.g. methanol) to a hydrogen-rich gas mixture with low concentrations of carbon monoxide (up to 75% hydrogen content and less than 0.2% CO, for the case of methanol). This gas mixture is subsequently used in a low-temperature fuel cell, converting the hydrogen directly to electricity. A low concentration of CO is crucial to avoid poisoning of the fuel cell catalyst. Since conventional Polymer Electrolyte Membrane (PEM) fuel cells require CO concentrations far below 100 ppm and since most methods to reduce the mole fraction of CO (such as Preferential Oxidation or PROX) have CO conversions of up to 99%, the alcohol fuel reformer has to achieve initial CO mole fractions significantly below 1%. The catalyst and the porous ceramic reactor of the present study can successfully fulfill this requirement.

  14. Advanced dcdc converters

    CERN Document Server

    Luo, Fang Lin

    2003-01-01

    DC/DC conversion techniques have undergone rapid development in recent decades. With the pioneering work of these authors, DC/DC converters have now moved into their sixth generation. This book offers a concise, practical presentation of DC/DC converters, summarizing the spectrum of conversion tecnologies and presentingmany new ideas and more than 100 new topologies. Nowhere else in the literature are DC/DC converters so logically sorted and systematically introduced, and nowhere else can readers find detailed information on prototype topologies that represent a major contribution to modern power engineering. More than 320 figures, 60 tables, and 500 formulae facilitate understand and provide precise data.

  15. Improving Power Converter Reliability

    DEFF Research Database (Denmark)

    Ghimire, Pramod; de Vega, Angel Ruiz; Beczkowski, Szymon

    2014-01-01

    The real-time junction temperature monitoring of a high-power insulated-gate bipolar transistor (IGBT) module is important to increase the overall reliability of power converters for industrial applications. This article proposes a new method to measure the on-state collector?emitter voltage...... of a high-power IGBT module during converter operation, which may play a vital role in improving the reliability of the power converters. The measured voltage is used to estimate the module average junction temperature of the high and low-voltage side of a half-bridge IGBT separately in every fundamental...

  16. Thermionic photovoltaic energy converter

    Science.gov (United States)

    Chubb, D. L. (Inventor)

    1985-01-01

    A thermionic photovoltaic energy conversion device comprises a thermionic diode mounted within a hollow tubular photovoltaic converter. The thermionic diode maintains a cesium discharge for producing excited atoms that emit line radiation in the wavelength region of 850 nm to 890 nm. The photovoltaic converter is a silicon or gallium arsenide photovoltaic cell having bandgap energies in this same wavelength region for optimum cell efficiency.

  17. Catalytic Oligopeptide Synthesis.

    Science.gov (United States)

    Liu, Zijian; Noda, Hidetoshi; Shibasaki, Masakatsu; Kumagai, Naoya

    2018-02-02

    Waste-free catalytic assembly of α-amino acids is fueled by a multiboron catalyst that features a characteristic B 3 NO 2 heterocycle, providing a versatile catalytic protocol wherein functionalized natural α-amino acid units are accommodated and commonly used protecting groups are tolerated. The facile dehydrative conditions eliminate the use of engineered peptide coupling reagents, exemplifying a greener catalytic alternative for peptide coupling. The catalysis is sufficiently robust to enable pentapeptide synthesis, constructing all four amide bond linkages in a catalytic fashion.

  18. Method for recovering catalytic elements from fuel cell membrane electrode assemblies

    Science.gov (United States)

    Shore, Lawrence [Edison, NJ; Matlin, Ramail [Berkeley Heights, NJ; Heinz, Robert [Ludwigshafen, DE

    2012-06-26

    A method for recovering catalytic elements from a fuel cell membrane electrode assembly is provided. The method includes converting the membrane electrode assembly into a particulate material, wetting the particulate material, forming a slurry comprising the wetted particulate material and an acid leachate adapted to dissolve at least one of the catalytic elements into a soluble catalytic element salt, separating the slurry into a depleted particulate material and a supernatant containing the catalytic element salt, and washing the depleted particulate material to remove any catalytic element salt retained within pores in the depleted particulate material.

  19. Catalytic conversion of light alkanes

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, J.E.

    1992-06-30

    The second Quarterly Report of 1992 on the Catalytic Conversion of Light Alkanes reviews the work done between April 1, 1992 and June 31, 1992 on the Cooperative Agreement. The mission of this work is to devise a new catalyst which can be used in a simple economic process to convert the light alkanes in natural gas to oxygenate products that can either be used as clean-burning, high octane liquid fuels, as fuel components or as precursors to liquid hydrocarbon uwspomdon fuel. During the past quarter we have continued to design, prepare, characterize and test novel catalysts for the mild selective reaction of light hydrocarbons with air or oxygen to produce alcohols directly. These catalysts are designed to form active metal oxo (MO) species and to be uniquely active for the homolytic cleavage of the carbon-hydrogen bonds in light alkanes producing intermediates which can form alcohols. We continue to investigate three molecular environments for the active catalytic species that we are trying to generate: electron-deficient macrocycles (PHASE I), polyoxometallates (PHASE II), and regular oxidic lattices including zeolites and related structures as well as other molecular surface structures having metal oxo groups (PHASE I).

  20. Novel Catalytic Reactor for CO2 Reduction via Sabatier Process, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Precision Combustion, Inc. (PCI) proposes to develop a novel, efficient, and lightweight catalytic Sabatier CO2 methanation unit, capable of converting a mixture of...

  1. Power converter design optimization

    Science.gov (United States)

    Yu, Y.; Lee, F. C. Y.; Triner, J. E.

    1977-01-01

    Utilizing the demonstrated capability of nonlinear programming algorithms, a practical design optimization approach for power converters is established to conceive a design to meet all power-circuit performance requirements and concurrently optimize a defined quantity such as weight or losses. In addition, to facilitate a cost-effective design, the computer-aided approach provides a means to readily assess (1) the weight-efficiency tradeoff, (2) impacts of converter requirements and component characteristics on a given design, and (3) optimum power system configurations.

  2. Angiotensin-converting enzyme

    DEFF Research Database (Denmark)

    Sørensen, P G; Rømer, F K; Cortes, D

    1984-01-01

    In order to evaluate bleomycin-associated lung damage in humans, lung function parameters and serum levels of the endothelial-bound angiotensin-converting enzyme (ACE) were determined by serial measurements in 11 patients who were treated for testicular cancer. None developed clinical or radiolog......In order to evaluate bleomycin-associated lung damage in humans, lung function parameters and serum levels of the endothelial-bound angiotensin-converting enzyme (ACE) were determined by serial measurements in 11 patients who were treated for testicular cancer. None developed clinical...

  3. An Electromagnetic Beam Converter

    DEFF Research Database (Denmark)

    2009-01-01

    The present invention relates to an electromagnetic beam converter and a method for conversion of an input beam of electromagnetic radiation having a bell shaped intensity profile a(x,y) into an output beam having a prescribed target intensity profile l(x',y') based on a further development...

  4. Definition of Power Converters

    CERN Document Server

    Bordry, F

    2015-01-01

    The paper is intended to introduce power conversion principles and to define common terms in the domain. The concept s of sources and switches are defined and classified. From the basic laws of source interconnections, a generic method of power converter synthesis is presented. Some examples illustrate this systematic method. Finally, the commutation cell and soft commuta tion are introduced and discussedd.

  5. SSG Wave Energy Converter

    DEFF Research Database (Denmark)

    Margheritini, Lucia; Vicinanza, Diego; Frigaard, Peter

    2008-01-01

    The SSG (Sea Slot-cone Generator) is a wave energy converter of the overtopping type. The structure consists of a number of reservoirs one on the top of each others above the mean water level, in which the water of incoming waves is stored temporary. In each reservoir, expressively designed low h...

  6. Converting the reset

    NARCIS (Netherlands)

    J.K. Hoogland (Jiri); C.D.D. Neumann; D. Bloch

    2001-01-01

    textabstractWe give a simple algorithm to incorporate the effects of resets in convertible bond prices, without having to add an extra factor to take into account the value of the reset. Furthermore we show that the effect of a notice period, and additional make-whole features, can be treated in a

  7. The Convertible Arbitrage Strategy Analyzed

    NARCIS (Netherlands)

    Loncarski, I.; Ter Horst, J.R.; Veld, C.H.

    2006-01-01

    This paper analyzes convertible bond arbitrage on the Canadian market for the period 1998 to 2004.Convertible bond arbitrage is the combination of a long position in convertible bonds and a short position in the underlying stocks. Convertible arbitrage has been one of the most successful strategies

  8. In-Situ Catalytic Fast Pyrolysis Technology Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Biddy, M.; Dutta, A.; Jones, S.; Meyer, A.

    2013-03-01

    This technology pathway case investigates converting woody biomass using in-situ catalytic fast pyrolysis followed by upgrading to gasoline-, diesel-, and jet-range hydrocarbon blendstocks. Technical barriers and key research needs that should be pursued for this pathway to be competitive with petroleum-derived blendstocks have been identified.

  9. Catalytic distillation process

    Science.gov (United States)

    Smith, L.A. Jr.

    1982-06-22

    A method is described for conducting chemical reactions and fractionation of the reaction mixture comprising feeding reactants to a distillation column reactor into a feed zone and concurrently contacting the reactants with a fixed bed catalytic packing to concurrently carry out the reaction and fractionate the reaction mixture. For example, a method for preparing methyl tertiary butyl ether in high purity from a mixed feed stream of isobutene and normal butene comprising feeding the mixed feed stream to a distillation column reactor into a feed zone at the lower end of a distillation reaction zone, and methanol into the upper end of said distillation reaction zone, which is packed with a properly supported cationic ion exchange resin, contacting the C[sub 4] feed and methanol with the catalytic distillation packing to react methanol and isobutene, and concurrently fractionating the ether from the column below the catalytic zone and removing normal butene overhead above the catalytic zone.

  10. Catalytic Functions of Standards

    NARCIS (Netherlands)

    K. Blind (Knut)

    2009-01-01

    textabstractThe three different areas and the examples have illustrated several catalytic functions of standards for innovation. First, the standardisation process reduces the time to market of inventions, research results and innovative technologies. Second, standards themselves promote the

  11. Microprocessor controlled static converter

    Directory of Open Access Journals (Sweden)

    Stefan Szabo

    2005-10-01

    Full Text Available This paper wants to demonstrate a way of implementing a microcontroller into an DC motor speed control loop. The static power converter is a fully controlled rectifier bridge, using standard SCR's. The bridge's control signals are supplied by the microcontroller and are phase-angle or burst types. The automation loop contains a software PI-style regulator. All the experimental results shows that this aproach is flexibile enough to be used on a large scale.

  12. Catalytic distillation structure

    Science.gov (United States)

    Smith, L.A. Jr.

    1984-04-17

    Catalytic distillation structure is described for use in reaction distillation columns, and provides reaction sites and distillation structure consisting of a catalyst component and a resilient component intimately associated therewith. The resilient component has at least about 70 volume % open space and is present with the catalyst component in an amount such that the catalytic distillation structure consists of at least 10 volume % open space. 10 figs.

  13. Combined hydrothermal liquefaction and catalytic hydrothermal gasification system and process for conversion of biomass feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, Douglas C.; Neuenschwander, Gary G.; Hart, Todd R.

    2017-09-12

    A combined hydrothermal liquefaction (HTL) and catalytic hydrothermal gasification (CHG) system and process are described that convert various biomass-containing sources into separable bio-oils and aqueous effluents that contain residual organics. Bio-oils may be converted to useful bio-based fuels and other chemical feedstocks. Residual organics in HTL aqueous effluents may be gasified and converted into medium-BTU product gases and directly used for process heating or to provide energy.

  14. Resonant power converters

    CERN Document Server

    Kazimierczuk, Marian K

    2012-01-01

    This book is devoted to resonant energy conversion in power electronics. It is a practical, systematic guide to the analysis and design of various dc-dc resonant inverters, high-frequency rectifiers, and dc-dc resonant converters that are building blocks of many of today's high-frequency energy processors. Designed to function as both a superior senior-to-graduate level textbook for electrical engineering courses and a valuable professional reference for practicing engineers, it provides students and engineers with a solid grasp of existing high-frequency technology, while acquainting them wit

  15. Cycloidal Wave Energy Converter

    Energy Technology Data Exchange (ETDEWEB)

    Stefan G. Siegel, Ph.D.

    2012-11-30

    This program allowed further advancing the development of a novel type of wave energy converter, a Cycloidal Wave Energy Converter or CycWEC. A CycWEC consists of one or more hydrofoils rotating around a central shaft, and operates fully submerged beneath the water surface. It operates under feedback control sensing the incoming waves, and converts wave power to shaft power directly without any intermediate power take off system. Previous research consisting of numerical simulations and two dimensional small 1:300 scale wave flume experiments had indicated wave cancellation efficiencies beyond 95%. The present work was centered on construction and testing of a 1:10 scale model and conducting two testing campaigns in a three dimensional wave basin. These experiments allowed for the first time for direct measurement of electrical power generated as well as the interaction of the CycWEC in a three dimensional environment. The Atargis team successfully conducted two testing campaigns at the Texas A&M Offshore Technology Research Center and was able to demonstrate electricity generation. In addition, three dimensional wave diffraction results show the ability to achieve wave focusing, thus increasing the amount of wave power that can be extracted beyond what was expected from earlier two dimensional investigations. Numerical results showed wave cancellation efficiencies for irregular waves to be on par with results for regular waves over a wide range of wave lengths. Using the results from previous simulations and experiments a full scale prototype was designed and its performance in a North Atlantic wave climate of average 30kW/m of wave crest was estimated. A full scale WEC with a blade span of 150m will deliver a design power of 5MW at an estimated levelized cost of energy (LCOE) in the range of 10-17 US cents per kWh. Based on the new results achieved in the 1:10 scale experiments these estimates appear conservative and the likely performance at full scale will

  16. X-Y Converter Family

    DEFF Research Database (Denmark)

    Bhaskar, Mahajan Sagar; Sanjeevikumar, Padmanaban; Wheeler, Patrick

    2016-01-01

    system, high voltage automotive applications and industrial drives. Compared to the traditional boost converter and existing recent converters, the proposed XY converter family has the ability to provide a higher output voltage by using less number of power devices and reactive components. Other distinct......A New breed of a buck boost converter, named as the XY converter family is proposed in this article. In the XY family, 16 topologies are presented which are highly suitable for renewable energy applications which require a high ratio of DC-DC converter; such as a photovoltaic multilevel inverter...... features of the XY converter family are i) Single control switch ii) Provide negative output voltage iii) Non-isolated topologies iv) High conversion ratio without making the use of high duty cycle and v) modular structure. XY family is compared with the recent high step-up converters and the detailed...

  17. An Experimental Study of Flow and Thermal Transient Response in a Race-Track Monolith Catalytic Converter Etude expérimentale de l'écoulement et de la réponse thermique en régime transitoire dans un pot catalytique muni d'un monolithe de forme ovale

    Directory of Open Access Journals (Sweden)

    Leclerc J. P.

    2006-11-01

    Full Text Available A model for the pressure drop was proposed and compared to experimental results. Global flow characteristics and velocity distribution were studied from residence time distribution measurements in a race-trackmonolith. Significant dead volumes were detected and the velocity distribution was determined. The effect of flow-rate, inlet tube diameter and flow deflector was investigated. Study of the time evolution of outlet temperature and temperature distribution in a monolith coated or not with catalyst makes it possible to determine the thermal characteristics of heat-up. The influence of flow rate, velocity distribution and developing laminar flow regime in the channel were qualitatively estimated. Theses results allow one to determine the hydrodynamic and thermal behavior of the catalytic converter and to propose reliable and realistic assumptions for subsequent modeling. Chaque année, un véhicule de moyenne cylindrée rejette dans l'atmosphère 240 kg de monoxyde de carbone, 40 kg d'oxyde d'azote et 77 kg d'hydrocarbures [1]. Si le moteur propre semble être la meilleure solution pour l'avenir, le pot catalytique est aujourd'hui la seule solution envisageable. Le fonctionnement du pot catalytique est satisfaisant lorsque la voiture roule à une vitesse constante. Cependant, il n'en est pas de même lors du démarrage à froid pendant lequel de nombreux problèmes subsistent, comme le montre la figure 1. Plusieurs modèles ont été développés afin de comprendre et d'améliorer les performances du pot catalytique [2, 3, 11, 12 et 13]. Cependant, suivant les hypothèses faites, ces modèles fournissent des résultats plus ou moins contradictoires. Une étude expérimentale a donc été effectuée afin de mieux cerner les processus qui gouvernent le fonctionnement du pot catalytique et de proposer des hypothèses réalistes pour la modélisation. Un modèle d'estimation de la perte de charge a été proposé et comparé aux résultats exp

  18. Steam reformer with catalytic combustor

    Science.gov (United States)

    Voecks, Gerald E. (Inventor)

    1990-01-01

    A steam reformer is disclosed having an annular steam reforming catalyst bed formed by concentric cylinders and having a catalytic combustor located at the center of the innermost cylinder. Fuel is fed into the interior of the catalytic combustor and air is directed at the top of the combustor, creating a catalytic reaction which provides sufficient heat so as to maintain the catalytic reaction in the steam reforming catalyst bed. Alternatively, air is fed into the interior of the catalytic combustor and a fuel mixture is directed at the top. The catalytic combustor provides enhanced radiant and convective heat transfer to the reformer catalyst bed.

  19. Manufacturing method of photoelectric converter

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, Shunpei; Suzuki, Kunio; Fukada, Takeshi; Kanehana, Mikio

    1987-06-25

    This is a photoelectric converter wherein a photoelectromotive force is generated by utilizing the shorter wavelength side by the 1st converter and by utilizing the longer wavelength side by the 2nd converter; as a whole, wider wavelength range of light can be converted into electricity. In the 1st. converter, an electrode on the side of semi-incident surface is made transparent as well as an electrode equipped on the back of a non-mono-crystalline semiconductor. Light which passed this is introduced into the 2nd converter to generate an electromotive force. This invention especially relates with a method of forming this 2nd converter. In preparing I-type non-mono-crystalline semiconductor among the semiconductors having PIN junction, PCVD method is used by means of ECR (Electron Cyclotron Resonance) by using a hydrogen- or halogen- added Si-semiconductor instead of using expensive Ge, etc, which are common in the conventional method. (3 figs)

  20. Power converters for ITER

    CERN Document Server

    Benfatto, I

    2006-01-01

    The International Thermonuclear Experimental Reactor (ITER) is a thermonuclear fusion experiment designed to provide long deuterium– tritium burning plasma operation. After a short description of ITER objectives, the main design parameters and the construction schedule, the paper describes the electrical characteristics of the French 400 kV grid at Cadarache: the European site proposed for ITER. Moreover, the paper describes the main requirements and features of the power converters designed for the ITER coil and additional heating power supplies, characterized by a total installed power of about 1.8 GVA, modular design with basic units up to 90 MVA continuous duty, dc currents up to 68 kA, and voltages from 1 kV to 1 MV dc.

  1. Unity power factor converter

    Science.gov (United States)

    Wester, Gene W. (Inventor)

    1980-01-01

    A unity power factor converter capable of effecting either inversion (dc-to-dc) or rectification (ac-to-dc), and capable of providing bilateral power control from a DC source (or load) through an AC transmission line to a DC load (or source) for power flow in either direction, is comprised of comparators for comparing the AC current i with an AC signal i.sub.ref (or its phase inversion) derived from the AC ports to generate control signals to operate a switch control circuit for high speed switching to shape the AC current waveform to a sine waveform, and synchronize it in phase and frequency with the AC voltage at the AC ports, by selectively switching the connections to a series inductor as required to increase or decrease the current i.

  2. Bidirectional DC/DC Converter

    Science.gov (United States)

    Pedersen, F.

    2008-09-01

    The presented bidirectional DC/DC converter design concept is a further development of an already existing converter used for low battery voltage operation.For low battery voltage operation a high efficient low parts count DC/DC converter was developed, and used in a satellite for the battery charge and battery discharge function.The converter consists in a bidirectional, non regulating DC/DC converter connected to a discharge regulating Buck converter and a charge regulating Buck converter.The Bidirectional non regulating DC/DC converter performs with relatively high efficiency even at relatively high currents, which here means up to 35Amps.This performance was obtained through the use of power MOSFET's with on- resistances of only a few mille Ohms connected to a special transformer allowing paralleling several transistor stages on the low voltage side of the transformer. The design is patent protected. Synchronous rectification leads to high efficiency at the low battery voltages considered, which was in the range 2,7- 4,3 Volt DC.The converter performs with low switching losses as zero voltage zero current switching is implemented in all switching positions of the converter.Now, the drive power needed, to switch a relatively large number of low Ohm , hence high drive capacitance, power MOSFET's using conventional drive techniques would limit the overall conversion efficiency.Therefore a resonant drive consuming considerable less power than a conventional drive circuit was implemented in the converter.To the originally built and patent protected bidirectional non regulating DC/DC converter, is added the functionality of regulation.Hereby the need for additional converter stages in form of a Charge Buck regulator and a Discharge Buck regulator is eliminated.The bidirectional DC/DC converter can be used in connection with batteries, motors, etc, where the bidirectional feature, simple design and high performance may be useful.

  3. Hydrocarbon conversion with an attenuated superactive multimetallic catalytic composite

    International Nuclear Information System (INIS)

    Antos, G.J.

    1981-01-01

    Hydrocarbons are converted by contacting them at hydrocarbon conversion conditions with a novel attenuated superactive multimetallic catalytic composite comprising a combination of a catalytically effective amount of a pyrolyzed rhenium carbonyl component with a porous carrier material containing a uniform dispersion of catalytically effective amounts of a platinum group component, which is maintained in the elemental metallic state during the incorporation and pyrolysis of the rhenium carbonyl component, and of an iron component. In a highly preferred embodiment, this novel catalytic composite also contains a catalytically effective amount of a halogen component. The platinum group component, pyrolyzed rhenium carbonyl component, iron component and optional halogen component are preferably present in the multimetallic catalytic composite in amounts, calculated on an elemental basis, corresponding to about 0.01 to about 2 wt. % platinum group metal, about 0.01 to about 5 wt. % rhenium, about 0.005 to about 4 wt. % iron and about 0.1 to about 5 wt. % halogen. A key feature associated with the preparation of the subject catalytic composite is reaction of a rhenium carbonyl complex with a porous carrier material containing a uniform dispersion of an iron component and of a platinum group component maintained in the elemental state, whereby the interaction of the rhenium moiety with the platinum group moiety is maximized due to the platinophilic (i.e., platinum-seeking) propensities of the carbon monoxide ligands associated with the rhenium reagent. A specific example of the type of hydrocarbon conversion process disclosed herein is a process for the catalytic reforming of a low octane gasoline fraction wherein the gasoline fraction and a hydrogen stream are contacted with the attenuated superactive multimetallic catalytic composite at reforming conditions

  4. CATALYTIC KINETIC SPECTROPHOTOMETRIC DETERMINATION ...

    African Journals Online (AJOL)

    Preferred Customer

    acetylchlorophosphonazo(CPApA) by hydrogen peroxide in 0.10 M phosphoric acid. A novel catalytic kinetic-spectrophotometric method is proposed for the determination of copper based on this principle. Copper(II) can be determined spectrophotometrically ...

  5. CATALYTIC KINETIC SPECTROPHOTOMETRIC DETERMINATION ...

    African Journals Online (AJOL)

    Based on the property that in 0.12 M sulfuric acid medium titanium(IV) catalyzes the discoloring reaction of DBS-arsenazo oxidized by potassium bromate, a new catalytic kinetic spectrophotometric method for the determination of trace titanium (IV) was developed. The linear range of the determination of titanium is

  6. Advanced power electronics converters PWM converters processing AC voltages

    CERN Document Server

    dos Santos, Euzeli

    2014-01-01

    This book covers power electronics, in depth, by presenting the basic principles and application details, which can be used both as a textbook and reference book.  Introduces a new method to present power electronics converters called Power Blocks Geometry. Applicable for courses focusing on power electronics, power electronics converters, and advanced power converters. Offers a comprehensive set of simulation results to help understand the circuits presented throughout the book

  7. Mono-, bi-, and tri-metallic Ni-based catalysts for the catalytic hydrotreatment of pyrolysis liquids

    NARCIS (Netherlands)

    Yin, Wang; Venderbosch, Robbie H.; He, Songbo; Bykova, Maria V.; Khromova, Sofia A.; Yakovlev, Vadim A.; Heeres, Hero J.

    Catalytic hydrotreatment is a promising technology to convert pyrolysis liquids into intermediates with improved properties. Here, we report a catalyst screening study on the catalytic hydrotreatment of pyrolysis liquids using bi- and tri-metallic nickel-based catalysts in a batch autoclave (initial

  8. Integrated power electronic converters and digital control

    CERN Document Server

    Emadi, Ali; Nie, Zhong

    2009-01-01

    Non-isolated DC-DC ConvertersBuck ConverterBoost ConverterBuck-Boost ConverterIsolated DC-DC ConvertersFlyback ConverterForward ConverterPush-Pull ConverterFull-Bridge ConverterHalf-Bridge ConverterPower Factor CorrectionConcept of PFCGeneral Classification of PFC CircuitsHigh Switching Frequency Topologies for PFCApplication of PFC in Advanced Motor DrivesIntegrated Switched-Mode Power ConvertersSwitched-Mode Power SuppliesThe Concept of Integrated ConverterDefinition of Integrated Switched-Mode Power Supplies (ISMPS)Boost-Type Integrated TopologiesGeneral Structure of Boost-Type Integrated T

  9. Nanostructure Neutron Converter Layer Development

    Science.gov (United States)

    Park, Cheol (Inventor); Sauti, Godfrey (Inventor); Kang, Jin Ho (Inventor); Lowther, Sharon E. (Inventor); Thibeault, Sheila A. (Inventor); Bryant, Robert G. (Inventor)

    2016-01-01

    Methods for making a neutron converter layer are provided. The various embodiment methods enable the formation of a single layer neutron converter material. The single layer neutron converter material formed according to the various embodiments may have a high neutron absorption cross section, tailored resistivity providing a good electric field penetration with submicron particles, and a high secondary electron emission coefficient. In an embodiment method a neutron converter layer may be formed by sequential supercritical fluid metallization of a porous nanostructure aerogel or polyimide film. In another embodiment method a neutron converter layer may be formed by simultaneous supercritical fluid metallization of a porous nanostructure aerogel or polyimide film. In a further embodiment method a neutron converter layer may be formed by in-situ metalized aerogel nanostructure development.

  10. Impedance source power electronic converters

    CERN Document Server

    Liu, Yushan; Ge, Baoming; Blaabjerg, Frede; Ellabban, Omar; Loh, Poh Chiang

    2016-01-01

    Impedance Source Power Electronic Converters brings together state of the art knowledge and cutting edge techniques in various stages of research related to the ever more popular impedance source converters/inverters. Significant research efforts are underway to develop commercially viable and technically feasible, efficient and reliable power converters for renewable energy, electric transportation and for various industrial applications. This book provides a detailed understanding of the concepts, designs, controls, and application demonstrations of the impedance source converters/inverters. Key features: Comprehensive analysis of the impedance source converter/inverter topologies, including typical topologies and derived topologies. Fully explains the design and control techniques of impedance source converters/inverters, including hardware design and control parameter design for corresponding control methods. Presents the latest power conversion solutions that aim to advance the role of pow...

  11. Impedance Source Power Electronic Converters

    DEFF Research Database (Denmark)

    Liu, Yushan; Abu-Rub, Haitham; Ge, Baoming

    Impedance Source Power Electronic Converters brings together state of the art knowledge and cutting edge techniques in various stages of research related to the ever more popular impedance source converters/inverters. Significant research efforts are underway to develop commercially viable...... and technically feasible, efficient and reliable power converters for renewable energy, electric transportation and for various industrial applications. This book provides a detailed understanding of the concepts, designs, controls, and application demonstrations of the impedance source converters/inverters. Key...... features: Comprehensive analysis of the impedance source converter/inverter topologies, including typical topologies and derived topologies. Fully explains the design and control techniques of impedance source converters/inverters, including hardware design and control parameter design for corresponding...

  12. Noise exposure in convertible automobiles.

    Science.gov (United States)

    Mikulec, A A; Lukens, S B; Jackson, L E; Deyoung, M N

    2011-02-01

    To quantify the noise exposure received while driving a convertible automobile with the top open, compared with the top closed. Five different convertible automobiles were driven, with the top both closed and open, and noise levels measured. The cars were tested at speeds of 88.5, 104.6 and 120.7 km/h. When driving with the convertible top open, the mean noise exposure ranged from 85.3 dB at 88.5 km/h to 89.9 dB at 120.7 km/h. At the tested speeds, noise exposure increased by an average of 12.4-14.6 dB after opening the convertible top. Driving convertible automobiles at speeds exceeding 88.5 km/h, with the top open, may result in noise exposure levels exceeding recommended limits, especially when driving with the convertible top open for prolonged periods.

  13. Advanced converter reactors

    International Nuclear Information System (INIS)

    Kasten, P.R.

    1979-01-01

    Advanced converter reactors (ACRs) of primary US interest are those which can be commercialized within about 20 years, and are: Advanced Light-Water Reactors, Spectral-Shift-Control Reactors, Heavy-Water Reactors (CANDU type), and High-Temperature Gas-Cooled Reactors. These reactors can operate on uranium, thorium, or uranium-thorium fuel cycles, but have the greatest fuel utilization on thorium type cycles. The water reactors tend to operate more economically on uranium cycles, while the HTGR is more economical on thorium cycles. Thus, the HTGR had the greatest practical potential for improving fuel utilization. If the US has 3.4 to 4 million tons U 3 O 8 at reasonable costs, ACRs can make important contributions to maintaining a high nuclear power level for many decades; further, they work well with fast breeder reactors in the long term under symbiotic fueling conditions. Primary nuclear data needs of ACRs are integral measurements of reactivity coefficients and resonance absorption integrals

  14. Les procédés ASVAHL thermiques et catalytiques sous pression d'hydrogène pour la conversion des bruts lourds et des résidus de bruts classiques Thermal and Catalytic Asvahl Processes under Hydrogen Pressure for Converting Heavy Crudes and Conventional Residues

    Directory of Open Access Journals (Sweden)

    Peries J. P.

    2006-11-01

    Full Text Available Cet article décrit les performances comparées des procédés ASVAHL thermiques (TERVAHL T, TERVAHL H, TERVAHL HC et catalytiques (HYVAHL F, HYVAHL C dans deux cas de traitement: - brut désessencié Boscan (base des études objectif Transport; - résidu sous vide Safaniya (base des études Raffinage de résidu. A travers ces résultats, l'importance de la quantité d'hydrogène fixée est mise en évidence. Elle joue sur la conversion obtenue et sur la qualité des résidus. L'introduction de catalyseur soluble ou en suspension catalytique TERVAHL HC (hydroviscoréduction catalytique ou l'utilisation d'un catalyseur supporté (hydrotraiternent HYVAHL favorisent l'activation de l'hydrogène. C'est la combinaison des réactions de craquage, de polycondensation et d'hydrogénation, et les conditions opératoires (températures, temps de séjour et pression qui définiront les limites de la conversion pour une stabilité donnée des résidus. This article describes the comparative performances of thermal ASVAHL processes (TERVAHL T, TERVAHL H, TERVAHL HQ and catalytic ASVAHL processes (HYVAHL F, HYVAHL C for two types of processing: (1 degasolined Boscan crude (basis of studies for transportation feasibility, and (2 Safaniya vacuum residue (basis of studies for residue refining. The results reveal the importance of the amount of fixed hydrogen, which affects the conversion obtained and the quality of the residues. The introduction of a TERVAHL HC soluble catalyst or one in catalytic suspension (catalytic hydrovisbreaking or the use of a supported catalyst (HYVAHL hydrotreatment enhances the activation of hydrogen. The combination of cracking, polycondensation and hydrogen reactions together with the operating conditions (temperatures, residence time and pressure are what will define the conversion limits for a given stability of residues.

  15. Catalytic thermal barrier coatings

    Science.gov (United States)

    Kulkarni, Anand A.; Campbell, Christian X.; Subramanian, Ramesh

    2009-06-02

    A catalyst element (30) for high temperature applications such as a gas turbine engine. The catalyst element includes a metal substrate such as a tube (32) having a layer of ceramic thermal barrier coating material (34) disposed on the substrate for thermally insulating the metal substrate from a high temperature fuel/air mixture. The ceramic thermal barrier coating material is formed of a crystal structure populated with base elements but with selected sites of the crystal structure being populated by substitute ions selected to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a higher rate than would the base compound without the ionic substitutions. Precious metal crystallites may be disposed within the crystal structure to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a lower light-off temperature than would the ceramic thermal barrier coating material without the precious metal crystallites.

  16. Catalytic partial oxidation of methanol and ethanol for hydrogen generation.

    Science.gov (United States)

    Hohn, Keith L; Lin, Yu-Chuan

    2009-01-01

    Hydrogen-powered fuel cell vehicles feature high energy efficiency and minor environmental impact. Liquid fuels are ideal hydrogen carriers, which can catalytically be converted into syngas or hydrogen to power vehicles. Among the potential liquid fuels, alcohols have several advantages. The hydrogen/carbon ratio is higher than that of other liquid hydrocarbons or oxygenates, especially in the case of methanol. In addition, alcohols can be derived from renewable biomass resources. Catalytic partial oxidation of methanol or ethanol offers immense potential for onboard hydrogen generation due to its rapid reaction rate and exothermic nature. These benefits stimulate a burgeoning research community in catalyst design, reaction engineering, and mechanistic investigation. The purpose of this Minireview is to provide insight into syngas and hydrogen production from methanol and ethanol partial oxidation, particularly highlighting catalytic chemistry.

  17. Catalytic upgrading of butyric acid towards fine chemicals and biofuels.

    Science.gov (United States)

    Sjöblom, Magnus; Matsakas, Leonidas; Christakopoulos, Paul; Rova, Ulrika

    2016-04-01

    Fermentation-based production of butyric acid is robust and efficient. Modern catalytic technologies make it possible to convert butyric acid to important fine chemicals and biofuels. Here, current chemocatalytic and biocatalytic conversion methods are reviewed with a focus on upgrading butyric acid to 1-butanol or butyl-butyrate. Supported Ruthenium- and Platinum-based catalyst and lipase exhibit important activities which can pave the way for more sustainable process concepts for the production of green fuels and chemicals. © FEMS 2016.

  18. Catalytic upgrading of butyric acid towards fine chemicals and biofuels

    OpenAIRE

    Sj?blom, Magnus; Matsakas, Leonidas; Christakopoulos, Paul; Rova, Ulrika

    2016-01-01

    Fermentation-based production of butyric acid is robust and efficient. Modern catalytic technologies make it possible to convert butyric acid to important fine chemicals and biofuels. Here, current chemocatalytic and biocatalytic conversion methods are reviewed with a focus on upgrading butyric acid to 1-butanol or butyl-butyrate. Supported Ruthenium- and Platinum-based catalyst and lipase exhibit important activities which can pave the way for more sustainable process concepts for the produc...

  19. Investigation of the Flow Characteristics in a Catalytic Muffler with Perforated Inlet Cone

    OpenAIRE

    Gyo Woo Lee; Man Young Kim

    2014-01-01

    Emission regulations for diesel engines are being strengthened and it is impossible to meet the standards without exhaust after-treatment systems. Lack of the space in many diesel vehicles, however, make it difficult to design and install stand-alone catalytic converters such as DOC, DPF, and SCR in the vehicle exhaust systems. Accordingly, those have been installed inside the muffler to save the space, and referred to the catalytic muffler. However, that has complex internal structure with p...

  20. Advanced DC/DC converters

    CERN Document Server

    Luo, Fang Lin

    2003-01-01

    DC/DC conversion techniques have undergone rapid development in recent decades. With the pioneering work of these authors, DC/DC converters have now moved into their sixth generation. This book offers a concise, practical presentation of DC/DC converters, summarizing the spectrum of conversion tecnologies and presentingmany new ideas and more than 100 new topologies. Nowhere else in the literature are DC/DC converters so logically sorted and systematically introduced, and nowhere else can readers find detailed information on prototype topologies that represent a major contribution to modern power engineering. More than 320 figures, 60 tables, and 500 formulae facilitate understand and provide precise data.

  1. Catalytic reforming methods

    Science.gov (United States)

    Tadd, Andrew R; Schwank, Johannes

    2013-05-14

    A catalytic reforming method is disclosed herein. The method includes sequentially supplying a plurality of feedstocks of variable compositions to a reformer. The method further includes adding a respective predetermined co-reactant to each of the plurality of feedstocks to obtain a substantially constant output from the reformer for the plurality of feedstocks. The respective predetermined co-reactant is based on a C/H/O atomic composition for a respective one of the plurality of feedstocks and a predetermined C/H/O atomic composition for the substantially constant output.

  2. An Artificial Biomimetic Catalysis Converting CO2 to Green Fuels

    Science.gov (United States)

    Li, Caihong; Wang, Zhiming

    2017-09-01

    Researchers devote to design catalytic systems with higher activity, selectivity, and stability ideally based on cheap and earth-abundant elements to reduce CO2 to value-added hydrocarbon fuels under mild conditions driven by visible light. This may offer profound inspirations on that. A bi-functional molecular iron catalyst designed could not only catalyze two-electron reduction from CO2 to CO but also further convert CO to CH4 with a high selectivity of 82% stably over several days.

  3. Processes for converting lignocellulosics to reduced acid pyrolysis oil

    Science.gov (United States)

    Kocal, Joseph Anthony; Brandvold, Timothy A

    2015-01-06

    Processes for producing reduced acid lignocellulosic-derived pyrolysis oil are provided. In a process, lignocellulosic material is fed to a heating zone. A basic solid catalyst is delivered to the heating zone. The lignocellulosic material is pyrolyzed in the presence of the basic solid catalyst in the heating zone to create pyrolysis gases. The oxygen in the pyrolysis gases is catalytically converted to separable species in the heating zone. The pyrolysis gases are removed from the heating zone and are liquefied to form the reduced acid lignocellulosic-derived pyrolysis oil.

  4. Lignin Valorization using Heterogenous Catalytic Oxidation

    DEFF Research Database (Denmark)

    Melián Rodríguez, Mayra; Shunmugavel, Saravanamurugan; Kegnæs, Søren

    The research interests in biomass conversion to fuels and chemicals has increased significantly in the last decade in view of current problems such as global warming, high oil prices, food crisis and other geopolitical scenarios. Many different reactions and processes to convert biomass into high......-value products and fuels have been proposed in the literature, giving special attention to the conversion of lignocellulosic biomass, which does not compete with food resources and is widely available as a low cost feedstock 1. Lignocellulose biomass is a complex material composed of three main fractions...... be obtained 2. Heiko Lange et al., has reported that the catalytic oxidation products of lignin and lignin model compounds range from aromatic aldehyde and carboxylic acid and they must be originate form oxidation of side chain. The products we obtained in these reactions are based on the severity...

  5. Wind/water energy converter

    Science.gov (United States)

    Paulkovich, J.

    1979-01-01

    Device will convert wind, water, tidal or wave energy into electrical or mechanical energy. Is comprised of windmill-like paddles or blades synchronously geared to orient themselves to wind direction for optimum energy extraction.

  6. Matrix Converter in Hybrid Drives

    Czech Academy of Sciences Publication Activity Database

    Lettl, Jiří; Flígl, S.

    -, č. 3 (2004), s. 77-80 ISSN 0204-3599 Institutional research plan: CEZ:AV0Z2057903 Keywords : matrix converter * hybrid drive * electric power splitting Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  7. Catalytic combustion in small wood burning appliances

    Energy Technology Data Exchange (ETDEWEB)

    Oravainen, H. [VTT Energy, Jyvaeskylae (Finland)

    1996-12-31

    There is over a million hand fired small heating appliances in Finland where about 5,4 million cubic meters of wood fuel is used. Combustion in such heating appliances is a batch-type process. In early stages of combustion when volatiles are burned, the formation of carbon monoxide (CO) and other combustible gases are difficult to avoid when using fuels that have high volatile matter content. Harmful emissions are formed mostly after each fuel adding but also during char burnout period. When the CO-content in flue gases is, say over 0.5 %, also other harmful emissions will be formed. Methane (CH{sub 4}) and other hydrocarbons are released and the amount of polycyclic aromatic hydrocarbons (PAH)-compounds can be remarkable. Some PAH-compounds are very carcinogenic. It has been estimated that in Finland even more than 90 % of hydrocarbon and PAH emissions are due to small scale wood combustion. Emissions from transportation is excluded from these figures. That is why wood combustion has a net effect on greenhouse gas phenomena. For example carbon monoxide emissions from small scale wood combustion are two fold compared to that of energy production in power plants. Methane emission is of the same order as emission from transportation and seven fold compared with those of energy production. Emissions from small heating appliances can be reduced by developing the combustion techniques, but also by using other means, for example catalytic converters. In certain stages of the batch combustion, temperature is not high enough, gas mixing is not good enough and residence time is too short for complete combustion. When placed to a suitable place inside a heating appliance, a catalytic converter can oxidize unburned gases in the flue gas into compounds that are not harmful to the environment. (3 refs.)

  8. Novel Catalytic Membrane Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Stuart Nemser, PhD

    2010-10-01

    There are many industrial catalytic organic reversible reactions with amines or alcohols that have water as one of the products. Many of these reactions are homogeneously catalyzed. In all cases removal of water facilitates the reaction and produces more of the desired chemical product. By shifting the reaction to right we produce more chemical product with little or no additional capital investment. Many of these reactions can also relate to bioprocesses. Given the large number of water-organic compound separations achievable and the ability of the Compact Membrane Systems, Inc. (CMS) perfluoro membranes to withstand these harsh operating conditions, this is an ideal demonstration system for the water-of-reaction removal using a membrane reactor. Enhanced reaction synthesis is consistent with the DOE objective to lower the energy intensity of U.S. industry 25% by 2017 in accord with the Energy Policy Act of 2005 and to improve the United States manufacturing competitiveness. The objective of this program is to develop the platform technology for enhancing homogeneous catalytic chemical syntheses.

  9. Boron nitride converted carbon fiber

    Science.gov (United States)

    Rousseas, Michael; Mickelson, William; Zettl, Alexander K.

    2016-04-05

    This disclosure provides systems, methods, and apparatus related to boron nitride converted carbon fiber. In one aspect, a method may include the operations of providing boron oxide and carbon fiber, heating the boron oxide to melt the boron oxide and heating the carbon fiber, mixing a nitrogen-containing gas with boron oxide vapor from molten boron oxide, and converting at least a portion of the carbon fiber to boron nitride.

  10. Current status of converter steelmaking

    Energy Technology Data Exchange (ETDEWEB)

    Oghbasialasie, H.; Holappa, L.

    1995-12-31

    This literature work is mainly focusing on the mechanisms of modern converter steelmaking and related with the evaluation of converter technology applied during the last decades and further to the future. The history of steelmaking has been briefly reviewed from bloomeries and early-steelmaking processes to the progress of modern converter process. The pneumatic converter processes were developed in the 1850`s and thereafter the basis for the rapid growth of steel industries was established for the next 100 years. The world production of steel has not continuously grown but fluctuating quite much. It reached 723 Mt in 1994. The production is believed to grow the forecast for the year 2003 being approximately 800 Mt. Electric arc furnace production is estimated to reach 280 Mt by 2003, and BOFIOH will reach 520 Mt by 2003. The current status of the converter steelmaking process is briefly described both on its theoretical bases and practical technological progresses. Developments which significantly improve the process are briefly discussed. Several more recent developments such as combined oxygen blowing process, increased scrap melting, post combustion and hot metal pretreatment are discussed. The future progress will be in further development of these process characteristics as well as in eventual emerging of the continuous converter process. (author)

  11. Radiolabelled substrates for angiotensin converting enzyme

    International Nuclear Information System (INIS)

    Chung, A.Y.; Ryan, J.W.; Ryan, J.P.; Ryan, U.S.

    1986-01-01

    Six [3H]benzoyl-tripeptides were prepared and tested as substrates for angiotensin converting enzyme. Each was prepared first as its [4-iodo]-benzoyl-analog, and an atom of 3H per molecule was introduced by catalytic dehalogenation in 3H2-gas. Kinetic parameters were measured at 37 degrees C using as buffer 0.05 M Hepes, pH 8.0 containing 0.1 M NaCl and 0.6 M Na2SO4. When the substrates were used at concentrations far below their respective Km values, fractional rates of substrate utilization per unit time for constant enzyme concentration were direct function of respective second order rate constants (Kc/Km). Although absolute values of Kc/Km differed for human enzyme as opposed to rabbit enzyme, relative values of Kc/Km were virtually identical. Similarly, relative rates of substrates utilization during passage through lungs of anesthetized rats were similar to relative values of Kc/Km measured in vitro. Thus, there is now a range of ACE substrates usable, in vitro and in vivo, under conditions of first order enzyme kinetics, conditions under which values of V/Km and Ki can be measured directly

  12. Catalytic Antibodies: Concept and Promise

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 11. Catalytic Antibodies: Concept and Promise. Desirazu N Rao Bharath Wootla. General Article Volume 12 Issue ... Keywords. Catalytic antibodies; abzymes; hybridome technology; Diels– Alder reaction; Michaelis– Menten kinetics; Factor VIII.

  13. Catalytic interface erosion

    International Nuclear Information System (INIS)

    Meng, H.; Cohen, E.G.D.

    1995-01-01

    We study interface erosion processes: catalytic erosions. We present two cases. (1) The erosion of a completely occupied lattice by one single moving particle starting from somewhere inside the lattice, considering deterministic as well as probabilistic erosion rules. In the latter case, the eroded regions appear to have interfaces with continuously tunable fractal dimensions. (2) The kinetic roughening of an initially flat surface, where ballistic or diffusion-limited particles, which remain intact themselves, erode the surface coming from the outside, using the same erosion rules as in (1). Many features resembling realistic interfaces, for example, islands and inlets, are generated. The dependence of the surface width on the system size is due to both the erosion mechanism and the way particles move before reaching the surface

  14. Catalytic detritiation of water

    International Nuclear Information System (INIS)

    Rogers, M.L.; Lamberger, P.H.; Ellis, R.E.; Mills, T.K.

    1977-01-01

    A pilot-scale system has been used at Mound Laboratory to investigate the catalytic detritiation of water. A hydrophobic, precious metal catalyst is used to promote the exchange of tritium between liquid water and gaseous hydrogen at 60 0 C. Two columns are used, each 7.5 m long by 2.5 cm ID and packed with catalyst. Water flow is 5-10 cm 3 /min and countercurrent hydrogen flow is 9,000-12,000 cm 3 /min. The equipment, except for the columns, is housed in an inert atmosphere glovebox and is computer controlled. The hydrogen is obtained by electrolysis of a portion of the water stream. Enriched gaseous tritium is withdrawn for further enrichment. A description of the system is included along with an outline of its operation. Recent experimental data are discussed

  15. Converter Monitoring Unit for Retrofit of Wind Power Converters

    DEFF Research Database (Denmark)

    Rannestad, Bjorn; Maarbjerg, Anders Eggert; Frederiksen, Kristian

    2018-01-01

    A Converter Monitoring Unit (CMU), which will enable condition monitoring of wind turbine converters is presented in this paper. Reducing the cost of corrective maintenance by means of condition monitoring is a way of lowering Operation & Maintenance (O&M) costs for wind turbine systems....... The CMU must be able to detect a broad range of failure modes related to Insulated Gate Bipolar Transistor (IGBT) power modules and associated gate drives. IGBT collector-emitter on-state voltage (vceon) and current (ic) is sampled in the CMU and used for detection of emerging failures. A new method...

  16. Hydrogen peroxide catalytic decomposition

    Science.gov (United States)

    Parrish, Clyde F. (Inventor)

    2010-01-01

    Nitric oxide in a gaseous stream is converted to nitrogen dioxide using oxidizing species generated through the use of concentrated hydrogen peroxide fed as a monopropellant into a catalyzed thruster assembly. The hydrogen peroxide is preferably stored at stable concentration levels, i.e., approximately 50%-70% by volume, and may be increased in concentration in a continuous process preceding decomposition in the thruster assembly. The exhaust of the thruster assembly, rich in hydroxyl and/or hydroperoxy radicals, may be fed into a stream containing oxidizable components, such as nitric oxide, to facilitate their oxidation.

  17. Catalytic extraction processing of contaminated scrap metal

    International Nuclear Information System (INIS)

    Griffin, T.P.; Johnston, J.E.

    1994-01-01

    The contract was conceived to establish the commercial capability of Catalytic Extraction Processing (CEP) to treat contaminated scrap metal in the DOE inventory. In so doing, Molten Metal Technology, Inc. (MMT), pursued the following objectives: demonstration of the recycling of ferrous and non-ferrous metals--to establish that radioactively contaminated scrap metal can be converted to high-grade, ferrous and non-ferrous alloys which can be reused by DOE or reintroduced into commerce; immobilize radionuclides--that CEP will concentrate the radionuclides in a dense vitreous phase, minimize secondary waste generation and stabilize and reduce waste volume; destroy hazardous organics--that CEP will convert hazardous organics to valuable industrial gases, which can be used as feed gases for chemical synthesis or as an energy source; recovery volatile heavy metals--that CEP's off-gas treatment system will capture volatile heavy metals, such as mercury and lead; and establish that CEP is economical for processing contaminated scrap metal in the DOE inventory--that CEP is a more cost-effective and, complete treatment and recycling technology than competing technologies for processing contaminated scrap. The process and its performance are described

  18. Catalytic Combustion of Gasified Waste

    Energy Technology Data Exchange (ETDEWEB)

    Kusar, Henrik

    2003-09-01

    This thesis concerns catalytic combustion for gas turbine application using a low heating-value (LHV) gas, derived from gasified waste. The main research in catalytic combustion focuses on methane as fuel, but an increasing interest is directed towards catalytic combustion of LHV fuels. This thesis shows that it is possible to catalytically combust a LHV gas and to oxidize fuel-bound nitrogen (NH{sub 3}) directly into N{sub 2} without forming NO{sub x} The first part of the thesis gives a background to the system. It defines waste, shortly describes gasification and more thoroughly catalytic combustion. The second part of the present thesis, paper I, concerns the development and testing of potential catalysts for catalytic combustion of LHV gases. The objective of this work was to investigate the possibility to use a stable metal oxide instead of noble metals as ignition catalyst and at the same time reduce the formation of NO{sub x} In paper II pilot-scale tests were carried out to prove the potential of catalytic combustion using real gasified waste and to compare with the results obtained in laboratory scale using a synthetic gas simulating gasified waste. In paper III, selective catalytic oxidation for decreasing the NO{sub x} formation from fuel-bound nitrogen was examined using two different approaches: fuel-lean and fuel-rich conditions. Finally, the last part of the thesis deals with deactivation of catalysts. The various deactivation processes which may affect high-temperature catalytic combustion are reviewed in paper IV. In paper V the poisoning effect of low amounts of sulfur was studied; various metal oxides as well as supported palladium and platinum catalysts were used as catalysts for combustion of a synthetic gas. In conclusion, with the results obtained in this thesis it would be possible to compose a working catalytic system for gas turbine application using a LHV gas.

  19. Modeling of asymmetrical boost converters

    Directory of Open Access Journals (Sweden)

    Eliana Isabel Arango Zuluaga

    2014-01-01

    Full Text Available The asymmetrical interleaved dual boost (AIDB is a fifth-order DC/DC converter designed to interface photovoltaic (PV panels. The AIDB produces small current harmonics to the PV panels, reducing the power losses caused by the converter operation. Moreover, the AIDB provides a large voltage conversion ratio, which is required to step-up the PV voltage to the large dc-link voltage used in grid-connected inverters. To reject irradiance and load disturbances, the AIDB must be operated in a closed-loop and a dynamic model is required. Given that the AIDB converter operates in Discontinuous Conduction Mode (DCM, classical modeling approaches based on Continuous Conduction Mode (CCM are not valid. Moreover, classical DCM modeling techniques are not suitable for the AIDB converter. Therefore, this paper develops a novel mathematical model for the AIDB converter, which is suitable for control-pur-poses. The proposed model is based on the calculation of a diode current that is typically disregarded. Moreover, because the traditional correction to the second duty cycle reported in literature is not effective, a new equation is designed. The model accuracy is contrasted with circuital simulations in time and frequency domains, obtaining satisfactory results. Finally, the usefulness of the model in control applications is illustrated with an application example.

  20. Simplified design of data converters

    CERN Document Server

    Lenk, John

    1997-01-01

    Simplified Design of Data Converters shows how to design and experiment with data converters, both analog-to-digital and digital to analog. The design approach here is the same one used in all of John Lenk's best-selling books on simplified and practical design. Throughout the book, design problems start with guidelines for selecting all components on a trial-value basis, assuming a specific design goal and set of conditions. Then, using the guideline values in experimental circuits, the desired results are produced by varying the experimental component values, if needed.If you are a w

  1. Catalytic Mechanism and Mode of Action of the Periplasmic Alginate Epimerase AlgG

    NARCIS (Netherlands)

    Wolfram, Francis; Kitova, Elena N.; Robinson, Howard; Walvoort, Marthe T. C.; Codee, Jeroen D. C.; Klassen, John S.; Howell, P. Lynne

    2014-01-01

    Background: The alginate epimerase AlgG converts mannuronate to its C5 epimer guluronate at the polymer level. Results: The structure of Pseudomonas syringae AlgG has been determined, and the protein has been functionally characterized. Conclusion: His(319) acts as the catalytic base, whereas

  2. Single-Pass Catalytic Conversion of Syngas into Olefins via Methanol.

    Science.gov (United States)

    Olsbye, Unni

    2016-06-20

    All together now: Combination in a single reactor of the catalysts for converting syngas into methanol and methanol into olefins was recently reported by Cheng et al. This approach considerably simplifies the catalytic conversion of natural gas. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. AC-DC PFC Converter Using Combination of Flyback Converter and Full-bridge DC-DC Converter

    Directory of Open Access Journals (Sweden)

    Moh. Zaenal Efendi

    2014-06-01

    Full Text Available This paper presents a combination of power factor correction converter using Flyback converter and Full-bridge dc-dc converter in series connection. Flyback converter is operated in discontinuous conduction mode so that it can serve as a power factor correction converter and meanwhile Full-bridge dc-dc converter is used for dc regulator. This converter system is designed to produce a 86 Volt of output voltage and 2 A of output current. Both simulation and experiment results show that the power factor of this converter achieves up to 0.99 and meets harmonic standard of IEC61000-3-2. Keywords: Flyback Converter, Full-bridge DC-DC Converter, Power Factor Correction.

  4. Catalytic cracking with deasphalted oil

    Energy Technology Data Exchange (ETDEWEB)

    Beaton, W.I.; Taylor, J.L.; Peck, L.B.; Mosby, J.F.

    1990-07-10

    This patent describes a catalytic cracking process. It comprises: hydrotreating resid; thereafter deasphalting the hydrotreated resid to produce substantially deasphalted oil; catalytically cracking the hydrotreated oil in a catalytic cracking unit in the presence of a cracking catalyst to produce upgraded oil leaving coked catalyst; and regenerating the coked catalyst in the presence of a combustion-supporting gas comprising excess molecular oxygen in an amount greater than the stoichiometric amount required for substantially completely combusting the coke on the catalyst to carbon dioxide.

  5. Charge-pump voltage converter

    Science.gov (United States)

    Brainard, John P [Albuquerque, NM; Christenson, Todd R [Albuquerque, NM

    2009-11-03

    A charge-pump voltage converter for converting a low voltage provided by a low-voltage source to a higher voltage. Charge is inductively generated on a transfer rotor electrode during its transit past an inductor stator electrode and subsequently transferred by the rotating rotor to a collector stator electrode for storage or use. Repetition of the charge transfer process leads to a build-up of voltage on a charge-receiving device. Connection of multiple charge-pump voltage converters in series can generate higher voltages, and connection of multiple charge-pump voltage converters in parallel can generate higher currents. Microelectromechanical (MEMS) embodiments of this invention provide a small and compact high-voltage (several hundred V) voltage source starting with a few-V initial voltage source. The microscale size of many embodiments of this invention make it ideally suited for MEMS- and other micro-applications where integration of the voltage or charge source in a small package is highly desirable.

  6. Reliability of Wave Energy Converters

    DEFF Research Database (Denmark)

    Ambühl, Simon

    There are many different working principles for wave energy converters (WECs) which are used to produce electricity from waves. In order for WECs tobecome successful and more competitive to other renewable electricity sources,the consideration of the structural reliability of WECs is essential.St...

  7. Advanced Thermionic Converter Technology Program

    Science.gov (United States)

    Luke, James R.

    2003-01-01

    A thermionic energy converter (TEC) is a direct energy conversion device, which converts heat to electricity with no moving parts. Thermionic converters are well suited to space nuclear power systems because of their high power density, high heat rejection temperature, and immunity to radiation. Several recent advances in thermionic energy conversion technology have greatly improved the efficiency of these devices. A research program was undertaken to independently confirm these advances, and to extend them to converters with practical geometry. The recent development of a stable cesium/oxygen vapor source has led to a significant improvement in performance. The addition of a small amount of oxygen to the cesium vapor can increase the emission current by a factor of three or more. The beneficial effects of oxygen are stable and reproducible. A TEC with a cold seal has been invented, which greatly simplifies construction, operation, and maintenance of the TEC. Electron reflection from the collector has been shown to reduce the performance of TEC's. Reflection suppressing materials were produced and tested. One sample showed evidence of reflection suppression, increasing the average output voltage by 0.16 V. Another sample did not. Research in this area is ongoing.

  8. Catalytic cracking of lignites

    Energy Technology Data Exchange (ETDEWEB)

    Seitz, M.; Nowak, S.; Naegler, T.; Zimmermann, J. [Hochschule Merseburg (Germany); Welscher, J.; Schwieger, W. [Erlangen-Nuernberg Univ. (Germany); Hahn, T. [Halle-Wittenberg Univ., Halle (Germany)

    2013-11-01

    A most important factor for the chemical industry is the availability of cheap raw materials. As the oil price of crude oil is rising alternative feedstocks like coal are coming into focus. This work, the catalytic cracking of lignite is part of the alliance ibi (innovative Braunkohlenintegration) to use lignite as a raw material to produce chemicals. With this new one step process without an input of external hydrogen, mostly propylene, butenes and aromatics and char are formed. The product yield depends on manifold process parameters. The use of acid catalysts (zeolites like MFI) shows the highest amount of the desired products. Hydrogen rich lignites with a molar H/C ratio of > 1 are to be favoured. Due to primary cracking and secondary reactions the ratio between catalyst and lignite, temperature and residence time are the most important parameter to control the product distribution. Experiments at 500 C in a discontinuous rotary kiln reactor show yields up to 32 wt-% of hydrocarbons per lignite (maf - moisture and ash free) and 43 wt-% char, which can be gasified. Particularly, the yields of propylene and butenes as main products can be enhanced four times to about 8 wt-% by the use of catalysts while the tar yield decreases. In order to develop this innovative process catalyst systems fixed on beads were developed for an easy separation and regeneration of the used catalyst from the formed char. (orig.)

  9. Catalytic gasification of automotive shredder residues with hydrogen generation

    Science.gov (United States)

    Lin, Kuen-Song; Chowdhury, Sujan; Wang, Ze-Ping

    Hydrogen is a clean and new energy carrier to generate power through the Proton exchange membrane fuel cell (PEMFC) system. Hydrogen can be effectively turned out through the catalytic gasification of organic material such as automotive shredder residues (ASR). The main objective of this manuscript is to present an analysis of the catalytic gasification of ASR for the generation of high-purity hydrogen in a lab-scale fixed-bed downdraft gasifier using 15 wt.% NiO/Al 2O 3 catalysts at 760-900 K. In the catalytic gasification process, reduction of Ni(II) catalyst into Ni(0) has been confirmed through XANES spectra and consequently EXAFS data shows that the central Ni atoms have Ni-O and Ni-Ni bonds with bond distances of 2.03 ± 0.05 and 2.46 ± 0.05 Å, respectively. ASR is partially oxidized and ultimately converts into hydrogen rich syngas (CO and H 2) and increases of the reaction temperature are favored the generation of hydrogen with decomposition of the CO. As well, approximately 220 kg h -1 of ASR would be catalytically gasified at 760-900 K and 46.2 atm with the reactor volume 0.27 m 3 to obtain approximately 3.42 × 10 5 kcal h -1 of thermal energy during over 87% syngas generation with the generation of 100 kW electric powers.

  10. Catalytic pyrolysis of lignocellulosic biomass

    NARCIS (Netherlands)

    Seshan, Kulathuiyer; Sa, Jacinto

    2014-01-01

    This chapter reports on the latest developments of biomass catalytic pyrolysis for the production of fuels. The primary focus is on the role of catalysts in the process, namely, their influence in the liquefaction of lignocellulosic biomass.

  11. Catalytic Cracking of Used Palm Oil using Composite Zeolite

    International Nuclear Information System (INIS)

    Chang, W.H.; Tye, C.T.

    2013-01-01

    The rapid expansion of human society implies greater energy demand and environmental issues. In face of depletion energy resources, research is being carried out widely in order to convert the plant oil into biofuel. In this research, the production of liquid biofuels via catalytic cracking of used palm oil in the presence of composite zeolite was studied. The performance of composite zeolite of different properties in the reaction has been evaluated. The catalytic cracking reactions were carried out in a batch reactor at reaction temperature of 350 degree Celsius for an hour. In the present study, adjusting the ratio of meso porous coating to microporous zeolite and magnesium loading on composite zeolite catalyst were found to be able to increase the gasoline fraction and overall conversion of the reaction. (author)

  12. Parametric study of laser photovoltaic energy converters

    Science.gov (United States)

    Walker, G. H.; Heinbockel, J. H.

    1987-01-01

    Photovoltaic converters are of interest for converting laser power to electrical power in a space-based laser power system. This paper describes a model for photovoltaic laser converters and the application of this model to a neodymium laser silicon photovoltaic converter system. A parametric study which defines the sensitivity of the photovoltaic parameters is described. An optimized silicon photovoltaic converter has an efficiency greater than 50 percent for 1000 W/sq cm of neodymium laser radiation.

  13. Trash-to-Gas: Converting Space Trash into Useful Products

    Science.gov (United States)

    Caraccio, Anne J.; Hintze, Paul E.

    2013-01-01

    NASA's Logistical Reduction and Repurposing (LRR) project is a collaborative effort in which NASA is determined to reduce total logistical mass through reduction, reuse and recycling of various wastes and components of long duration space missions and habitats. LRR is focusing on four distinct advanced areas of study: Advanced Clothing System, Logistics-to-Living, Heat Melt Compactor and Trash to Supply Gas (TtSG). The objective of TtSG is to develop technologies that convert material waste, human waste and food waste into high-value products. High-value products include life support oxygen and water, rocket fuels, raw material production feedstocks, and other energy sources. There are multiple pathways for converting waste to products involving single or multi-step processes. This paper discusses thermal oxidation methods of converting waste to methane. Different wastes, including food, food packaging, Maximum Absorbent Garments (MAGs), human waste simulants, and cotton washcloths have been evaluated in a thermal degradation reactor under conditions promoting pyrolysis, gasification or incineration. The goal was to evaluate the degradation processes at varying temperatures and ramp cycles and to maximize production of desirable products and minimize high molecular weight hydrocarbon (tar) production. Catalytic cracking was also evaluated to minimize tar production. The quantities of CO2, CO, CH4, and H2O were measured under the different thermal degradation conditions. The conversion efficiencies of these products were used to determine the best methods for producing desired products.

  14. Trash to Gas: Converting Space Trash into Useful Products

    Science.gov (United States)

    Nur, Mononita

    2013-01-01

    NASA's Logistical Reduction and Repurposing (LRR) project is a collaborative effort in which NASA is determined to reduce total logistical mass through reduction, reuse and recycling of various wastes and components of long duration space missions and habitats. LRR is focusing on four distinct advanced areas of study: Advanced Clothing System, Logistics-to-Living, Heat Melt Compactor and Trash to Supply Gas (TtSG). The objective of TtSG is to develop technologies that convert material waste, human waste and food waste into high-value products. High-value products include life support oxygen and water, rocket fuels, raw material production feedstocks, and other energy sources. There are multiple pathways for converting waste to products involving single or multi-step processes. This paper discusses thermal oxidation methods of converting waste to methane. Different wastes, including food, food packaging, Maximum Absorbent Garments (MAGs), human waste simulants, and cotton washcloths have been evaluated in a thermal degradation reactor under conditions promoting pyrolysis, gasification or incineration. The goal was to evaluate the degradation processes at varying temperatures and ramp cycles and to maximize production of desirable products and minimize high molecular weight hydrocarbon (tar) production. Catalytic cracking was also evaluated to minimize tar production. The quantities of C02, CO, CH4, and H20 were measured under the different thermal degradation conditions. The conversion efficiencies of these products were used to determine the best methods for producing desired products.

  15. Understanding the mechanism of catalytic fast pyrolysis by unveiling reactive intermediates in heterogeneous catalysis

    Science.gov (United States)

    Hemberger, Patrick; Custodis, Victoria B. F.; Bodi, Andras; Gerber, Thomas; van Bokhoven, Jeroen A.

    2017-06-01

    Catalytic fast pyrolysis is a promising way to convert lignin into fine chemicals and fuels, but current approaches lack selectivity and yield unsatisfactory conversion. Understanding the pyrolysis reaction mechanism at the molecular level may help to make this sustainable process more economic. Reactive intermediates are responsible for product branching and hold the key to unveiling these mechanisms, but are notoriously difficult to detect isomer-selectively. Here, we investigate the catalytic pyrolysis of guaiacol, a lignin model compound, using photoelectron photoion coincidence spectroscopy with synchrotron radiation, which allows for isomer-selective detection of reactive intermediates. In combination with ambient pressure pyrolysis, we identify fulvenone as the central reactive intermediate, generated by catalytic demethylation to catechol and subsequent dehydration. The fulvenone ketene is responsible for the phenol formation. This technique may open unique opportunities for isomer-resolved probing in catalysis, and holds the potential for achieving a mechanistic understanding of complex, real-life catalytic processes.

  16. Understanding the mechanism of catalytic fast pyrolysis by unveiling reactive intermediates in heterogeneous catalysis

    Science.gov (United States)

    Hemberger, Patrick; Custodis, Victoria B. F.; Bodi, Andras; Gerber, Thomas; van Bokhoven, Jeroen A.

    2017-01-01

    Catalytic fast pyrolysis is a promising way to convert lignin into fine chemicals and fuels, but current approaches lack selectivity and yield unsatisfactory conversion. Understanding the pyrolysis reaction mechanism at the molecular level may help to make this sustainable process more economic. Reactive intermediates are responsible for product branching and hold the key to unveiling these mechanisms, but are notoriously difficult to detect isomer-selectively. Here, we investigate the catalytic pyrolysis of guaiacol, a lignin model compound, using photoelectron photoion coincidence spectroscopy with synchrotron radiation, which allows for isomer-selective detection of reactive intermediates. In combination with ambient pressure pyrolysis, we identify fulvenone as the central reactive intermediate, generated by catalytic demethylation to catechol and subsequent dehydration. The fulvenone ketene is responsible for the phenol formation. This technique may open unique opportunities for isomer-resolved probing in catalysis, and holds the potential for achieving a mechanistic understanding of complex, real-life catalytic processes. PMID:28660882

  17. Photoelectric converter; Koden henkan soshi

    Energy Technology Data Exchange (ETDEWEB)

    Sawayama, I.

    1995-04-07

    The conventional solar cell module wherein plural photovoltaic elements formed on a metal substrate are connected and coated by weatherproof and translucent resin has defects such as pinholes, and separation because moisture infiltrating from the outside causes dissolution of such conductive matrix as silver in the collecting electrode. This invention relates to a photoelectric converter which has little decrease in the output under the environment of light irradiation, wherein a photoelectric converting semiconductor, a transparent conductive layer on the above-mentioned semiconductor, and conductive member containing water repellent fine powder grains on this transparent conductive layer are laminated successively. Polytetrafluoroethylene, polydimethyl siloxane, polyethylene, and nylon are desirable to be employed as the water repellent fine powder grains. The fine powder grains are mixed with conductive filler and binder to produce conductive paste, pattern-applied by a screen printing machine, and subjected to thermal treatment to form a conductive member. 3 figs., 1 tab.

  18. Photoelectric converters with quantum coherence

    Science.gov (United States)

    Su, Shan-He; Sun, Chang-Pu; Li, Sheng-Wen; Chen, Jin-Can

    2016-05-01

    Photon impingement is capable of liberating electrons in electronic devices and driving the electron flux from the lower chemical potential to higher chemical potential. Previous studies hinted that the thermodynamic efficiency of a nanosized photoelectric converter at maximum power is bounded by the Curzon-Ahlborn efficiency ηCA. In this study, we apply quantum effects to design a photoelectric converter based on a three-level quantum dot (QD) interacting with fermionic baths and photons. We show that, by adopting a pair of suitable degenerate states, quantum coherences induced by the couplings of QDs to sunlight and fermion baths can coexist steadily in nanoelectronic systems. Our analysis indicates that the efficiency at maximum power is no longer limited to ηCA through manipulation of carefully controlled quantum coherences.

  19. Radiated EMI from power converters

    Directory of Open Access Journals (Sweden)

    Arnautovski-Toševa Vesna

    2005-01-01

    Full Text Available With the continuous increase of switching frequency together with the ongoing trend to higher complexity and functionality, power converters as a part of electronic systems have raised more and more electromagnetic energy pollution to the local system environment. In the same time, stringent demands are imposed on the designers of new circuits that electromagnetic interference (EMI has to be suppressed at its source before it is allowed to propagate into other circuits and systems. In this paper, the authors present a full-wave numerical method for calculation and simulation of electromagnetic field radiated by power converter circuitry. The main objective is to analyze the layout geometry in order to obtain competitive PCB layout that will enable suitably attenuated level of the radiated electric field to safe level. By this it would be possible to ensure reliable operation of the sensitive electronic components in the proximity.

  20. Biomass compounds converted to gasoline

    Energy Technology Data Exchange (ETDEWEB)

    1979-10-08

    It is claimed that corn, castor, and jojoba oils as well as Hevea latex can be converted in high yields to gasoline by passage over zeolite catalysts at 450 degrees to 500 degrees centigrade. Gasoline yields are 60% from corn oil (essentially tristearin), compared with 50% yields from methanol. Latex depolymerizes before conversion. Fat and oil molecules adopt conformations that enable them to enter zeolite interstices, resulting in high yields of C6 to C9 aromatics.

  1. Status of advanced bremsstrahlung converters

    International Nuclear Information System (INIS)

    Halbleib, J.A.

    1980-01-01

    This paper is an attempt to review the somewhat ill-defined area of advanced converter research in a more or less chronological fashion. Section 2 reviews the early B/sub z/ work that was motivated by the CASINO project. More recent work makes liberal use of technology from ICF research using REBs is discussed in Sec. 3. Section 4 discusses possible directions for future research, some of which are being actively pursued at Sandia National Laboratories (SNL) and elsewhere

  2. Computerized simulation of converter process

    Energy Technology Data Exchange (ETDEWEB)

    Jalkanen, H.; Suomi, M.L.; Wallgren, M. [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Metallurgy

    1996-12-31

    Converter process is essentially an oxidising refining process aiming in addition to (1) the primary refining action, decarburisation of high carbon iron melt, also to (2) maximal elimination of impurity elements, especially silicon, phosphorus and sulphur, (3) melting of substantial amounts of scrap using the extra heat released in oxidation reactions and (4) to exact final steel temperature control, optimal for further treatments. `Quantitative modelling of such a complex non-stationary chemical process as oxygen converting necessitates extensive formulation of chemical and thermal evolution of the process in connection with the technological properties of the reactor and the process control measures. A comprehensive converter simulation program like CONSIM-3. 1 and its preceding versions that is based on the theoretical and practical knowledge on the process can be used for (1) educating specialists and smelter personnel, (2) planning of the blowing programs, (3) developing and testing of process control systems and after some elaboration and restructuring (4) it can be integrated to static or dynamic process control systems. (orig.) SULA 2 Research Programme; 10 refs.

  3. Development of a Compact Matrix Converter

    Directory of Open Access Journals (Sweden)

    J. Bauer

    2009-01-01

    Full Text Available This paper deals with the development of a matrix converter. Matrix converters belong to the category of direct frequency converters. A converter does not contain DC-link and the output voltage is provided by direct switching of voltage from the input phases. This is enabled by 9 bidirectional switches, which are provided by anti-serial connection of 18 IGBT transistors. The absence of a DC-link is great advantage of the matrix converter, but it also increases the requirements on the converter control. For this reason a new prototype of a matrix converter is being developed with sophisticated modern components (FPGA, Power PC equipped in the control part of the converter. The converter will be used for testing new control algorithms and commutation methods. 

  4. Simulation Results of Double Forward Converter

    Directory of Open Access Journals (Sweden)

    P. Vijaya KUMAR

    2009-12-01

    Full Text Available This work aims to find a better forward converter for DC to DC conversion.Simulation of double forward converter in SMPS system is discussed in this paper. Aforward converter with RCD snubber to synchronous rectifier and/or to current doubleris also discussed. The evolution of the forward converter is first reviewed in a tutorialfashion. Performance parameters are discussed including operating principle, voltageconversion ratio, efficiency, device stress, small-signal dynamics, noise and EMI. Itscircuit operation and its performance characteristics of the forward converter with RCDsnubber and double forward converter are described and the simulation results arepresented.

  5. Catalytic bioreactors and methods of using same

    Science.gov (United States)

    Worden, Robert Mark; Liu, Yangmu Chloe

    2017-07-25

    Various embodiments provide a bioreactor for producing a bioproduct comprising one or more catalytically active zones located in a housing and adapted to keep two incompatible gaseous reactants separated when in a gas phase, wherein each of the one or more catalytically active zones may comprise a catalytic component retainer and a catalytic component retained within and/or thereon. Each of the catalytically active zones may additionally or alternatively comprise a liquid medium located on either side of the catalytic component retainer. Catalytic component may include a microbial cell culture located within and/or on the catalytic component retainer, a suspended catalytic component suspended in the liquid medium, or a combination thereof. Methods of using various embodiments of the bioreactor to produce a bioproduct, such as isobutanol, are also provided.

  6. Auxiliary resonant DC tank converter

    Science.gov (United States)

    Peng, Fang Z.

    2000-01-01

    An auxiliary resonant dc tank (ARDCT) converter is provided for achieving soft-switching in a power converter. An ARDCT circuit is coupled directly across a dc bus to the inverter to generate a resonant dc bus voltage, including upper and lower resonant capacitors connected in series as a resonant leg, first and second dc tank capacitors connected in series as a tank leg, and an auxiliary resonant circuit comprising a series combination of a resonant inductor and a pair of auxiliary switching devices. The ARDCT circuit further includes first clamping means for holding the resonant dc bus voltage to the dc tank voltage of the tank leg, and second clamping means for clamping the resonant dc bus voltage to zero during a resonant period. The ARDCT circuit resonantly brings the dc bus voltage to zero in order to provide a zero-voltage switching opportunity for the inverter, then quickly rebounds the dc bus voltage back to the dc tank voltage after the inverter changes state. The auxiliary switching devices are turned on and off under zero-current conditions. The ARDCT circuit only absorbs ripples of the inverter dc bus current, thus having less current stress. In addition, since the ARDCT circuit is coupled in parallel with the dc power supply and the inverter for merely assisting soft-switching of the inverter without participating in real dc power transmission and power conversion, malfunction and failure of the tank circuit will not affect the functional operation of the inverter; thus a highly reliable converter system is expected.

  7. Converting pest insects into food

    DEFF Research Database (Denmark)

    Offenberg, Hans Joachim; Wiwatwittaya, Decha

    2010-01-01

    Canopy dwelling weaver ants (Oecophylla spp.) are used to control a variety of pests in a number of tropical tree crops. What is less familiar is the existence of commercial markets where these ants and their brood are sold for (i) human consumption, (ii) pet food or (iii) traditional medicine...... by pest insects, problematic pests are converted into food and additional earnings. To assess the profitability of providing additional food for the ants, O. smaragdina food conversion efficiency (ECI) was estimated in the laboratory. This estimate suggests the feeding of weaver ants in ant farms...

  8. Power Converters and Power Quality

    CERN Document Server

    Kahle, K

    2015-01-01

    This paper discusses the subject of power quality for power converters. The first part gives an overview of most of the common disturbances and power quality issues in electrical networks for particle accelerators, and explains their consequences for accelerator operation. The propagation of asymmetrical network disturbances into a network is analysed. Quantitative parameters for network disturbances in a typical network are presented, and immunity levels for users’ electrical equipment are proposed. The second part of this paper discusses the technologies and strategies used in particle accelerator networks for power quality improvement . Particular focus is given to networks supplying loads with cycling active and reactive power

  9. High-Performance Data Converters

    DEFF Research Database (Denmark)

    Steensgaard-Madsen, Jesper

    Novel techniques for multi-bit oversampled data conversion are described. State-of-the-art oversampled data converters are analyzed, leading to the conclusion that their performance is limited mainly by low-resolution signal representation. To increase the resolution, high-performance, high......, because that requires a high-resolution loop quantizer which introduces only a small delay. Generally, it is not acceptable to design the loop quantizer as a high-resolution flash quantizer because they require a large chip area and high power consumption. Pipeline techniques are proposed to circumvent...

  10. Power electronics converters and regulators

    CERN Document Server

    Dokić, Branko L

    2015-01-01

    This book is the result of the extensive experience the authors gained through their year-long occupation at the Faculty of Electrical Engineering at the University of Banja Luka. Starting at the fundamental basics of electrical engineering, the book guides the reader into this field and covers all the relevant types of converters and regulators. Understanding is enhanced by the given examples, exercises and solutions. Thus this book can be used as a textbook for students, for self-study or as a reference book for professionals.

  11. Electromechanical converters for electric vehicles

    Science.gov (United States)

    Ambros, T.; Burduniuc, M.; Deaconu, S. I.; Rujanschi, N.

    2018-01-01

    The paper presents the analysis of various constructive schemes of synchronous electromechanical converters with permanent magnets fixed on the rotor and asynchronous with the short-circuit rotor. Various electrical stator winding schemes have also been compared, demonstrating the efficiency of copper utilization in toroidal windings. The electromagnetic calculus of the axial machine has particularities compared to the cylindrical machine, in the paper is presented the method of correlating the geometry of the cylindrical and axial machines. In this case the method and recommendations used in the design of such machines may be used.

  12. Power electronic converters without electrolytic capacitors

    OpenAIRE

    Van den Bossche, Alex; Haddad, Salim; Mordjaoui, Mourad

    2017-01-01

    Power electronic converters may have a quite long lifetime, but some applications such as converters for automotive and photovoltaic could even desire a longer life. One of the elements to increase the lifetime of converters is to avoid electrolytic capacitors, They can be replaced by metalized film capacitors or ceramic capacitors. A lot of converter types can be re-designed to use them, but it influences the way of designing, as a lower capacitance value is used. Electrolytic capacitors are...

  13. OAM mode converter in twisted fibers

    DEFF Research Database (Denmark)

    Usuga Castaneda, Mario A.; Beltran-Mejia, Felipe; Cordeiro, Cristiano

    2014-01-01

    We analyze the case of an OAM mode converter based on a twisted fiber, through finite element simulations where we exploit an equivalence between geometric and material transformations. The obtained converter has potential applications in MDM. © 2014 OSA.......We analyze the case of an OAM mode converter based on a twisted fiber, through finite element simulations where we exploit an equivalence between geometric and material transformations. The obtained converter has potential applications in MDM. © 2014 OSA....

  14. Catalytic Decoupling of Quantum Information

    DEFF Research Database (Denmark)

    Majenz, Christian; Berta, Mario; Dupuis, Frédéric

    2017-01-01

    The decoupling technique is a fundamental tool in quantum information theory with applications ranging from quantum thermodynamics to quantum many body physics to the study of black hole radiation. In this work we introduce the notion of catalytic decoupling, that is, decoupling in the presence...... of an uncorrelated ancilla system. This removes a restriction on the standard notion of decoupling, which becomes important for structureless resources, and yields a tight characterization in terms of the max-mutual information. Catalytic decoupling naturally unifies various tasks like the erasure of correlations...

  15. Catalytic activity of Au nanoparticles

    DEFF Research Database (Denmark)

    Larsen, Britt Hvolbæk; Janssens, Ton V.W.; Clausen, Bjerne

    2007-01-01

    Au is usually viewed as an inert metal, but surprisingly it has been found that Au nanoparticles less than 3–5 nm in diameter are catalytically active for several chemical reactions. We discuss the origin of this effect, focusing on the way in which the chemical activity of Au may change with par......Au is usually viewed as an inert metal, but surprisingly it has been found that Au nanoparticles less than 3–5 nm in diameter are catalytically active for several chemical reactions. We discuss the origin of this effect, focusing on the way in which the chemical activity of Au may change...

  16. Catalytic pyrolysis using UZM-39 aluminosilicate zeolite

    Science.gov (United States)

    Nicholas, Christpher P; Boldingh, Edwin P

    2013-12-17

    A new family of coherently grown composites of TUN and IMF zeotypes has been synthesized and show to be effective catalysts for catalytic pyrolysis of biomass. These zeolites are represented by the empirical formula. Na.sub.nM.sub.m.sup.n+R.sub.rQ.sub.qAl.sub1-xE.sub.xSi.sub.yO.s- ub.z where M represents zinc or a metal or metals from Group 1, Group 2, Group 3 or the lanthanide series of the periodic table, R is an A,.OMEGA.-dihalosubstituted paraffin such as 1,4-dibromobutane, Q is a neutral amine containing 5 or fewer carbon atoms such as 1-methylpyrrolidine and E is a framework element such as gallium. The process involves contacting a carbonaceous biomass feedstock with UZM-39 at pyrolysis conditions to produce pyrolysis gases comprising hydrocarbons. The catalyst catalyzes a deoxygenation reaction converting oxygenated hyrdocarbons into hydrocarbons removing the oxygen as carbon oxides and water. A portion of the pyrolysis gases is condensed to produce low oxygen biomass-derived pyrolysis oil.

  17. Hybrid thermionic-photovoltaic converter

    Energy Technology Data Exchange (ETDEWEB)

    Datas, A. [Instituto de Energía Solar, Universidad Politécnica de Madrid, 28040 Madrid (Spain)

    2016-04-04

    A conceptual device for the direct conversion of heat into electricity is presented. This concept hybridizes thermionic (TI) and thermophotovoltaic (TPV) energy conversion in a single thermionic-photovoltaic (TIPV) solid-state device. This device transforms into electricity both the electron and photon fluxes emitted by an incandescent surface. This letter presents an idealized analysis of this device in order to determine its theoretical potential. According to this analysis, the key advantage of this converter, with respect to either TPV or TI, is the higher power density in an extended temperature range. For low temperatures, TIPV performs like TPV due to the negligible electron flux. On the contrary, for high temperatures, TIPV performs like TI due to the great enhancement of the electron flux, which overshadows the photon flux contribution. At the intermediate temperatures, ∼1650 K in the case of this particular study, I show that the power density potential of TIPV converter is twice as great as that of TPV and TI. The greatest impact concerns applications in which the temperature varies in a relatively wide range, for which averaged power density enhancement above 500% is attainable.

  18. 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.

  19. Development and test of a new catalytic converter for natural gas ...

    Indian Academy of Sciences (India)

    immobile. However, the recent studies show that the application of these materials have been extensively increased in vehicle exhaust catalyst, industry, jewelerys, anticancer drug, in dentistry as alloy that cause their anthropogenic emission and spread in the environment. Platinum content of road dusts can be soluble and ...

  20. Effective Diffusivities and Pore-Transport Characteristics of Washcoated Ceramic Monolith for Automotive Catalytic Converter

    Czech Academy of Sciences Publication Activity Database

    Starý, T.; Šolcová, Olga; Schneider, Petr; Marek, M.

    2006-01-01

    Roč. 61, č. 18 (2006), s. 5934-5943 ISSN 0009-2509 R&D Projects: GA ČR(CZ) GA104/05/2616; GA AV ČR(CZ) IAA4072404 Institutional research plan: CEZ:AV0Z40720504 Keywords : effective diffusivity * monolith catalyst * chromatography Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.629, year: 2006

  1. Development and test of a new catalytic converter for natural gas ...

    Indian Academy of Sciences (India)

    3Department of Chemical Engineering, University of Technology Mara, Malaysia. 4Department of Electrical Engineering .... been extensively increased in vehicle exhaust catalyst, industry, jewelerys, anticancer drug, in dentistry as alloy that cause their ..... The Gurneng Hotel, Penang, Malaysia. Masakazu Anpo 2000 Use of ...

  2. Analysis of Platinum Content in Used Auto Catalytic Converter Carriers and the Possibility of its Recovery

    Directory of Open Access Journals (Sweden)

    Saternus M.

    2014-06-01

    Full Text Available Obecnie każdy wyprodukowany samochód musi być wyposażony w katalizator, w którym metale szlachetne takie jak platyna, pallad czy rod pełnią funkcje katalityczne. Czas życia katalizatorów jest ograniczony, zatem zostają one zastąpione nowymi, a stare stanowią ważne źródło platynowców. Zużyte katalizatory samochodowe przerabiane są hydrometalurgicznie lub pirometalurgicznie. Jednakże pierwszym etapem takiego przerobu powinna być analiza chemiczna. W pracy analizie na zawartość platyny poddano kilka różnych nośników katalitycznych pochodzących z różnych samochodów. Do tego celu posłużył elektronowy mikroskop skaningowy. Przedstawiono strukturę analizowanych nośników katalitycznych, ich analizę chemiczną jak również wykresy EDS (Energy Dispersive Spectrum. Przeprowadzono dyskusję wyników i możliwych metod odzysku platyny.

  3. Biogasoline Production from Palm Oil Via Catalytic Hydrocracking over Gamma-Alumina Catalyst

    OpenAIRE

    Anondho Wijanarko; Dadi Mawardi; Mohammad Nasikin

    2010-01-01

    Bio gasoline conversion from palm oil is an alternative energy resources method which can be substituted fossil fuel base energy utilization. Previous research resulted that palm oil can be converted into hydrocarbon by catalytic cracking reaction with γ-alumina catalyst. In this research, catalytic cracking reaction of palm oil by γ-alumina catalyst is done in  a stirrer batch reactor with the oil/catalyst weight ratio variation of 100:1, 75:1, and 50:1; at suhue variation of 260 to 340...

  4. Catalytic Gasification of Lignocellulosic Biomass

    NARCIS (Netherlands)

    Chodimella, Pramod; Seshan, Kulathuiyer; Schlaf, Marcel; Zhang, Z. Conrad

    2015-01-01

    Gasification of lignocellulosic biomass has attracted substantial current research interest. Various possible routes to convert biomass to fuels have been explored. In the present chapter, an overview of the gasification processes and their possible products are discussed. Gasification of solid

  5. Engineering reactors for catalytic reactions

    Indian Academy of Sciences (India)

    ... improvements in reactor performance. In this article, application of recent (and not so recent) developments in engineering reactors for catalytic reactions is discussed. Some examples where performance enhancement was realized by catalyst design, appropriate choice of reactor, better injection and dispersion strategies ...

  6. Catalytic properties of niobium compounds

    International Nuclear Information System (INIS)

    Tanabe, K.; Iizuka, T.

    1983-04-01

    The catalytic activity and selectivity of niobium compounds including oxides, salts, organometallic compounds and others are outlined. The application of these compounds as catalysts to diversified reactions is reported. The nature and action of niobium catalysts are characteristic and sometimes anomalous, suggesting the necessity of basic research and the potential use as catalysts for important processes in the chemical industry. (Author) [pt

  7. Catalytic carboxyester hydrolysis by diaminodiphenols

    Indian Academy of Sciences (India)

    Administrator

    Two diaminodiphenols, 1 and 2, have been examined as catalysts for the hydrolysis of 4- nitrophenyl acetate (NA) and 4-nitrophenylphosphate (NP) in aqueous-acetonitrile (25% acetonitrile v/v) media at 35ºC, I = 1·0 mol dm–3. The compound 1 enhances the hydrolysis rate of NA more than 105 times. Its catalytic efficiency ...

  8. Engineering reactors for catalytic reactions

    Indian Academy of Sciences (India)

    on selectivity can make substantial impact on process viability and economics. Extensive studies have been conducted to establish sound basis for design and engineering of reactors for practising such catalytic reactions and for realizing improvements in reactor performance. In this article, application of recent (and not so ...

  9. Manufacturing method of photoelectric converter

    Energy Technology Data Exchange (ETDEWEB)

    Toda, Koji; Niwa, Yasuo

    1987-06-24

    In a method of making a thin film for a photoelectric converter by a method to form an electroconductive layer by burning a mixture of lead oxide and chromic oxide, thickness of the film was limited and the poreless uniform film was not obtainable. The intransparency of the film gave low conversion efficiency only. This invention enabled to obtain a transparent film wherein an oxide (containing lead and chrome) is used as a target to form, in vacuum, a thin film of the oxide, and then this thin film is heat-treated in an atmosphere at least containing lead. Thin transparent film was obtained enhancing the conversion efficiency. High quality and high reliability are ensured because a poreless uniform film can be obtained. Cost was reduced because mass-production was made possible by the use of a vacuum technique. (5 figs)

  10. Efficiency of Capacitively Loaded Converters

    DEFF Research Database (Denmark)

    Andersen, Thomas; Huang, Lina; Andersen, Michael A. E.

    2012-01-01

    is introduced as a definition of efficiency. The calculated and measured efficiency curves for charging DEAP actuator, polypropylene film capacitor and X7R MLCC are provided and compared. The attention has to be paid for the voltage dependent capacitive load, like X7R MLCC, when evaluating the charging......This paper explores the characteristic of capacitance versus voltage for dielectric electro active polymer (DEAP) actuator, 2kV polypropylene film capacitor as well as 3kV X7R multi layer ceramic capacitor (MLCC) at the beginning. An energy efficiency for capacitively loaded converters...... polypropylene film capacitor can be the equivalent capacitive load. Because of the voltage dependent characteristic, X7R MLCC cannot be used to replace the DEAP actuator. However, this type of capacitor can be used to substitute the capacitive actuator with voltage dependent property at the development phase....

  11. Catalytic ozonation of sulfamethoxazole by composite iron-manganese silicate oxide: cooperation mechanism between adsorption and catalytic reaction.

    Science.gov (United States)

    Gao, Guoying; Kang, Jing; Shen, Jimin; Chen, Zhonglin; Chu, Wei

    2016-11-01

    A systematic investigation of the cooperation mechanism between adsorption and catalytic reaction during the catalytic ozonation of sulfamethoxazole (SMX) by composite iron-manganese silicate oxide (FMSO) was carried out in this work. Results showed that the total organic carbon (TOC) removal increased significantly from 27 % (sole-ozonation) to 79.8 % (FMSO catalytic ozonation). The presence of FMSO in the ozonation process effectively enhanced the ozone utilization efficiency and accelerated the transformation of ozone into hydroxyl radicals. The latter result was verified by the indirect method, using NaHSO 3 as the reductor, and the direct electron spin resonance (ESR) determination technology. The adsorption of SMX on FMSO was minimal (1.8 %). However, ozone rapidly converted SMX into various intermediates, which was exhibited by the much higher adsorption affinity on the surface of FMSO than that of SMX. The accumulation of various intermediates on the FMSO surface also increased their contact probability with the ·OH radicals generated by the ozone decomposition. The continuous interaction of intermediates with ·OH radicals could further promote the benign cycling of the release of adsorption sites and the succeeding adsorption/decomposition of ozone and intermediates on FMSO. This could be another reason for the higher and faster TOC removal rate.

  12. Catalytic Conversion of Renewable Resources into Bulk and Fine Chemicals.

    Science.gov (United States)

    de Vries, Johannes G

    2016-12-01

    Several strategies can be chosen to convert renewable resources into chemicals. In this account, I exemplify the route that starts with so-called platform chemicals; these are relatively simple chemicals that can be produced in high yield, directly from renewable resources, either via fermentation or via chemical routes. They can be converted into the existing bulk chemicals in a very efficient manner using multistep catalytic conversions. Two examples are given of the conversion of sugars into nylon intermediates. 5-Hydroxymethylfurfural (HMF) can be prepared in good yield from fructose. Two hydrogenation steps convert HMF into 1,6-hexanediol. Oppenauer oxidation converts this product into caprolactone, which in the past, has been converted into caprolactam in a large-scale industrial process by reaction with ammonia. An even more interesting platform chemical is levulinic acid (LA), which can be obtained directly from lignocellulose in good yield by treatment with dilute sulfuric acid at 200°C. Hydrogenation converts LA into gamma-valerolactone, which is ring-opened and esterified in a gas-phase process to a mixture of isomeric methyl pentenoates in excellent selectivity. In a remarkable selective palladium-catalysed isomerising methoxycarbonylation, this mixture is converted in to dimethyl adipate, which is finally hydrolysed to adipic acid. Overall selectivities of both processes are extremely high. The conversion of lignin into chemicals is a much more complicated task in view of the complex nature of lignin. It was discovered that breakage of the most prevalent β-O-4 bond in lignin occurs not only via the well-documented C3 pathway, but also via a C2 pathway, leading to the formation of highly reactive phenylacetaldehydes. These compounds went largely unnoticed as they immediately recondense on lignin. We have now found that it is possible to prevent this by converting these aldehydes in a tandem reaction, as they are formed. For this purpose, we have used

  13. In situ catalytic hydrogenation of model compounds and biomass-derived phenolic compounds for bio-oil upgrading

    Science.gov (United States)

    Junfeng Feng; Zhongzhi Yang; Chung-yun Hse; Qiuli Su; Kui Wang; Jianchun Jiang; Junming Xu

    2017-01-01

    The renewable phenolic compounds produced by directional liquefaction of biomass are a mixture of complete fragments decomposed from native lignin. These compounds are unstable and difficult to use directly as biofuel. Here, we report an efficient in situ catalytic hydrogenation method that can convert phenolic compounds into saturated cyclohexanes. The process has...

  14. Integrated Laser and Electron Microscopy Correlates Structure of Fluid Catalytic Cracking Particles to Brønsted Acidity

    NARCIS (Netherlands)

    Karreman, M.A.|info:eu-repo/dai/nl/315886528; Buurmans, I.L.C.|info:eu-repo/dai/nl/31406592X; Geus, J|info:eu-repo/dai/nl/412538024; Agronskaia, A.V.|info:eu-repo/dai/nl/183239830; Ruiz Martinez, J.|info:eu-repo/dai/nl/341386405; Gerritsen, H.C.|info:eu-repo/dai/nl/071548777; Weckhuysen, B.M.|info:eu-repo/dai/nl/285484397

    2012-01-01

    Fluid catalytic cracking (FCC) is the main industrial process used worldwide to convert crude oil fractions into fuels and important base chemicals, such as light olefins.[1] This is achieved by using micron-sized spherical catalyst particles of complex composition. Zeolitic material, usually

  15. Simultaneous fast pyrolysis and catalytic upgrading of lignin to obtain a marine diesel fuel

    DEFF Research Database (Denmark)

    Zhou, Guofeng

    The topic of this Ph.D. project is to convert lignin, a by-product from a 2nd generation bio-ethanol plant, into a marine diesel fuel by fast pyrolysis followed with catalytic upgrading of the pyrolysis vapor. Lignin, a major component of lignocellulosic biomass, is underutilized in the 2nd...... generation bio-ethanol plants. Shipping industry on the other hand is looking for clean alternative fuels in order to meet stricter fuel quality and emission standards. To convert lignin into a renewable marine diesel fuel will both accelerate the development of modern bio-refinery and transfer the marine...

  16. Three-phase AC-AC power converters based on matrix converter topology matrix-reactance frequency converters concept

    CERN Document Server

    Szczesniak, Pawel

    2013-01-01

    AC voltage frequency changes is one of the most important functions of solid state power converters. The most desirable features in frequency converters are the ability to generate load voltages with arbitrary amplitude and frequency, sinusoidal currents and voltages waveforms; the possibility of providing unity power factor for any load; and, finally, a simple and compact power circuit. Over the past decades, a number of different frequency converter topologies have appeared in the literature, but only the converters with either a voltage or current DC link are commonly used in industrial app

  17. Incorporation of catalytic dehydrogenation into fischer-tropsch synthesis to significantly reduce carbon dioxide emissions

    Science.gov (United States)

    Huffman, Gerald P.

    2012-11-13

    A new method of producing liquid transportation fuels from coal and other hydrocarbons that significantly reduces carbon dioxide emissions by combining Fischer-Tropsch synthesis with catalytic dehydrogenation is claimed. Catalytic dehydrogenation (CDH) of the gaseous products (C1-C4) of Fischer-Tropsch synthesis (FTS) can produce large quantities of hydrogen while converting the carbon to multi-walled carbon nanotubes (MWCNT). Incorporation of CDH into a FTS-CDH plant converting coal to liquid fuels can eliminate all or most of the CO.sub.2 emissions from the water-gas shift (WGS) reaction that is currently used to elevate the H.sub.2 level of coal-derived syngas for FTS. Additionally, the FTS-CDH process saves large amounts of water used by the WGS reaction and produces a valuable by-product, MWCNT.

  18. Loss of collectrin, an angiotensin-converting enzyme 2 homolog, uncouples endothelial nitric oxide synthase and causes hypertension and vascular dysfunction

    DEFF Research Database (Denmark)

    Cechova, Sylvia; Zeng, Qing; Billaud, Marie

    2013-01-01

    Collectrin is an orphan member of the renin-angiotensin system and is a homolog of angiotensin-converting enzyme 2, sharing ≈50% sequence identity. Unlike angiotensin-converting enzyme 2, collectrin lacks any catalytic domain. Collectrin has been shown to function as a chaperone of amino acid tra...... transporters. In rodents, the renal expression of collectrin is increased after subtotal nephrectomy and during high-salt feeding, raising the question of whether collectrin has any direct role in blood pressure regulation....

  19. Vapor Phase Catalytic Ammonia Reduction

    Science.gov (United States)

    Flynn, Michael T.; Harper, Lynn D. (Technical Monitor)

    1994-01-01

    This paper discusses the development of a Vapor Phase Catalytic Ammonia Reduction (VPCAR) teststand and the results of an experimental program designed to evaluate the potential of the technology as a water purification process. In the experimental program the technology is evaluated based upon product water purity, water recovery rate, and power consumption. The experimental work demonstrates that the technology produces high purity product water and attains high water recovery rates at a relatively high specific power consumption. The experimental program was conducted in 3 phases. In phase I an Igepon(TM) soap and water mixture was used to evaluate the performance of an innovative Wiped-Film Rotating-Disk evaporator and associated demister. In phase II a phenol-water solution was used to evaluate the performance of the high temperature catalytic oxidation reactor. In phase III a urine analog was used to evaluate the performance of the combined distillation/oxidation functions of the processor.

  20. Radiation-Tolerant DC-DC Converters

    Science.gov (United States)

    Skutt, Glenn; Sable, Dan; Leslie, Leonard; Graham, Shawn

    2012-01-01

    A document discusses power converters suitable for space use that meet the DSCC MIL-PRF-38534 Appendix G radiation hardness level P classification. A method for qualifying commercially produced electronic parts for DC-DC converters per the Defense Supply Center Columbus (DSCC) radiation hardened assurance requirements was developed. Development and compliance testing of standard hybrid converters suitable for space use were completed for missions with total dose radiation requirements of up to 30 kRad. This innovation provides the same overall performance as standard hybrid converters, but includes assurance of radiation- tolerant design through components and design compliance testing. This availability of design-certified radiation-tolerant converters can significantly reduce total cost and delivery time for power converters for space applications that fit the appropriate DSCC classification (30 kRad).

  1. Reliability of Power Electronic Converter Systems

    DEFF Research Database (Denmark)

    electronic converter systems; anomaly detection and remaining-life prediction for power electronics; reliability of DC-link capacitors in power electronic converters; reliability of power electronics packaging; modeling for life-time prediction of power semiconductor modules; minimization of DC......-tolerant adjustable speed drive systems; mission profile oriented reliability design in wind turbine and photovoltaic systems; reliability of power conversion systems in photovoltaic applications; power supplies for computers; and high-power converters. Reliability of Power Electronic Converter Systems is essential......The main aims of power electronic converter systems (PECS) are to control, convert, and condition electrical power flow from one form to another through the use of solid-state electronics. This book outlines current research into the scientific modeling, experimentation, and remedial measures...

  2. Inorganic membranes and catalytic reactors

    OpenAIRE

    Rangel, Maria do Carmo

    1997-01-01

    Membrane reactors are reviewed with emphasis in their applications in catalysis field. The basic principles of these systems are presented as well as a historical development. The several kinds of catalytic membranes and their preparations are discussed including the problems, needs and challenges to be solved in order to use these reactors in commercial processes. Some applications of inorganic membrane reactors are also shown. It was concluded that these systems have a great potential for i...

  3. Formation of ZSM-22 zeolite catalytic particles by fusion of elementary nanorods.

    Science.gov (United States)

    Hayasaka, Kazuaki; Liang, Duoduo; Huybrechts, Ward; De Waele, Bart R; Houthoofd, Kristof J; Eloy, Pierre; Gaigneaux, Eric M; van Tendeloo, Gustaaf; Thybaut, Joris W; Marin, Guy B; Denayer, Joeri F M; Baron, Gino V; Jacobs, Pierre A; Kirschhock, Christine E A; Martens, Johan A

    2007-01-01

    An ZSM-22 aluminosilicate zeolite was synthesized using the hydrothermal gel method at 150 degrees C. Products obtained after different synthesis times were characterized using various techniques and catalytic testing. Massive formation of ZSM-22 nanocrystals occurs after only a short synthesis time, appearing as isolated rods with a cross section of 12+/-4 nm. Nanorods have aluminum enriched at their external surface. Later in the crystallization process nanorods align and fuse sideways, whereby the external surface is systematically converted into an internal micropore surface. The formation of aluminum bearing micropores by the joining of nanorod surfaces is responsible for the enhanced catalytic activity. For this, the zeolite synthesis of nanoscale crystallites is ineffective for enhancing catalytic activity.

  4. Gadolinium sheet converter for neutron radiography

    Energy Technology Data Exchange (ETDEWEB)

    Lima, C.T.S. [Laboratorio de Neutrongrafia em Tempo Real (LNRTR/PEN/COPPE), Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21941-972 Rio de Janeiro, RJ (Brazil); Crispim, V.R. [Laboratorio de Neutrongrafia em Tempo Real (LNRTR/PEN/COPPE), Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21941-972 Rio de Janeiro, RJ (Brazil); PEN/COPPE-DNC/Escola Politecnica CT, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21941-972 Rio de Janeiro, RJ (Brazil)], E-mail: verginia@con.ufrj.br; Santos, W.M.S. [Laboratorio de Colisao Atomica e Molecular (LACAM/IF), Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68528, 21941-972 Rio de Janeiro, RJ (Brazil)

    2007-12-15

    This work describes a methodology developed for the confection of gadolinium sheet converter for neutron radiography using the gadolinium chloride (GdCl{sub 3}) as material converter. Though manufactured at a relatively low cost, they are as good as the sheet converter on the market. Here, we present neutron radiography of the penetrameter, the edge spread function, the modulation transfer function and characteristic curves for each set sheet-AA400 Kodak film.

  5. Ocean floor mounting of wave energy converters

    Science.gov (United States)

    Siegel, Stefan G

    2015-01-20

    A system for mounting a set of wave energy converters in the ocean includes a pole attached to a floor of an ocean and a slider mounted on the pole in a manner that permits the slider to move vertically along the pole and rotate about the pole. The wave energy converters can then be mounted on the slider to allow adjustment of the depth and orientation of the wave energy converters.

  6. Commutation Processes in Multiresonant ZVS Bridge Converter

    Directory of Open Access Journals (Sweden)

    Miroslaw Luft

    2008-01-01

    Full Text Available The analysis of the multiresonant ZVS DC/DC bridge converter is presented. The control system of the converter is basedon the method of frequency control at the constant time of transistor turn-off with a phase shift. The operation of the circuit is givenand the operating range of the converter is defined where ZVS switching operation is assured. Control characteristics are given andthe converter’s efficiency is defined. The circuit’s operation is analysed on the basis of results of the converter simulation tests using Simplorer programme.

  7. Modelling of procecces in catalytic recombiners

    International Nuclear Information System (INIS)

    Boehm, J.

    2007-01-01

    In order to achieve a high degree of safety in nuclear power plants and prevent possible accident scenarios, their consequences are calculated and analysed with numeric codes. One of the most important part of nuclear safety research of hazardous incidents are development and validation of these numeric models, which are implemented into accident codes. The severe hydrogen release during a core meltdown is one of the considered scenario of performed accident analyses. One of the most important measure for the elimination of the hydrogen is catalytic recombiners. Converting the hydrogen with the atmospheric oxygen to water vapor in an exothermic reaction will prevent possible detonation of the hydrogen/air atmosphere. Within the dissertation the recombiner simulation REKO-DIREKT was developed and validated by an extensive experimental database. The performance of recombiners with regard to the conversion of the hydrogen and the temperature development is modelled. The REKO-DIREKT program is unique and has made significant revolution in research of hydrogen safety. For the first time it has been possible to show the performance of the recombiner so great in detail by using REKO-DIREKT. In the future engineers of nuclear power plants will have opportunity to have precise forecasts about the process of the possible accidents with hydrogen release. Also with presence of water vapor or with oxygen depletion which are included in the model. The major discussion of the hydrogen ignition at hot catalyst steel plates can be evaluated in the future with REKO-DIREKT more reliably than the existing used models. (orig.)

  8. Advanced treatment of biologically pretreated coal gasification wastewater by a novel integration of heterogeneous catalytic ozonation and biological process.

    Science.gov (United States)

    Zhuang, Haifeng; Han, Hongjun; Jia, Shengyong; Hou, Baolin; Zhao, Qian

    2014-08-01

    Advanced treatment of biologically pretreated coal gasification wastewater (CGW) was investigated employing heterogeneous catalytic ozonation integrated with anoxic moving bed biofilm reactor (ANMBBR) and biological aerated filter (BAF) process. The results indicated that catalytic ozonation with the prepared catalyst (i.e. MnOx/SBAC, sewage sludge was converted into sludge based activated carbon (SBAC) which loaded manganese oxides) significantly enhanced performance of pollutants removal by generated hydroxyl radicals. The effluent of catalytic ozonation process was more biodegradable and less toxic than that in ozonation alone. Meanwhile, ANMBBR-BAF showed efficient capacity of pollutants removal in treatment of the effluent of catalytic ozonation at a shorter reaction time, allowing the discharge limits to be met. Therefore, the integrated process with efficient, economical and sustainable advantages was suitable for advanced treatment of real biologically pretreated CGW. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Time-Interleaved Analog to Digital Converters

    NARCIS (Netherlands)

    Louwsma, S.M.; van Tuijl, Adrianus Johannes Maria; Nauta, Bram

    2010-01-01

    This book describes the research carried out by our PhD student Simon Louwsma at the University of Twente, The Netherlands in the field of high-speed Analogto- Digital (AD) converters. AD converters are crucial circuits for modern systems where information is stored or processed in digital form. Due

  10. Present trends in HVDC converter station design

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, Lennart; Asplund, Gunnar; Bjorklund, Hans; Flisberg, Gunnar [ABB Power Systems AB, Ludvika (Sweden)

    1994-12-31

    HVDC converter station technology has developed rapidly to satisfy increasing requirements during past 10 - 15 years, but there has not been any dramatic changes since thyristor valves were introduced in the mid 70s. This paper describes some recent and expected future developments, that will substantiality change and simplify future converter stations. (author) 4 refs., 7 figs.

  11. Modelling and Control of Grid converter

    DEFF Research Database (Denmark)

    Teodorescu, Remus; Blaabjerg, Frede; Iov, Florin

    The present report describes the work done in the Phase 1a during the research project "Modelling and Control of Grid Converter". The developed models for the plant and different control strategies for the grid converter are presented in detail. Simulation results under different operating...

  12. Controller for a wave energy converter

    Science.gov (United States)

    Wilson, David G.; Bull, Diana L.; Robinett, III, Rush D.

    2015-09-22

    A wave energy converter (WEC) is described, the WEC including a power take off (PTO) that converts relative motion of bodies of the WEC into electrical energy. A controller controls operation of the PTO, causing the PTO to act as a motor to widen a wave frequency spectrum that is usable to generate electrical energy.

  13. Utilization of Nonlinear Converters for Audio Amplification

    DEFF Research Database (Denmark)

    Iversen, Niels; Birch, Thomas; Knott, Arnold

    2012-01-01

    . The introduction of non-linear converters for audio amplication defeats this limitation. A Cuk converter, designed to deliver an AC peak output voltage twice the supply voltage, is presented in this paper. A 3V prototype has been developed to prove the concept. The prototype shows that it is possible to achieve...

  14. Front converter lenses for smart phones

    Science.gov (United States)

    Reiley, Daniel J.; O'Neil, Patrick

    2017-11-01

    Front converters for the iPhone 6, from six different vendors, are examined in detail. Telephoto, wide angle, and fisheye converters are examined. System performance is measured, and the measured lens designs are presented. Great variety is found in both design type and performance; little correlation is found between performance and design type.

  15. Switched-mode converters (one quadrant)

    CERN Document Server

    Barrade, P

    2006-01-01

    Switched-mode converters are DC/DC converters that supply DC loads with a regulated output voltage, and protection against overcurrents and short circuits. These converters are generally fed from an AC network via a transformer and a conventional diode rectifier. Switched-mode converters (one quadrant) are non-reversible converters that allow the feeding of a DC load with unipolar voltage and current. The switched-mode converters presented in this contribution are classified into two families. The first is dedicated to the basic topologies of DC/DC converters, generally used for low- to mid-power applications. As such structures enable only hard commutation processes, the main drawback of such topologies is high commutation losses. A typical multichannel evolution is presented that allows an interesting decrease in these losses. Deduced from this direct DC/DC converter, an evolution is also presented that allows the integration of a transformer into the buck and the buck–boost structure. This enables an int...

  16. Modeling and Simulation of Matrix Converter

    DEFF Research Database (Denmark)

    Liu, Fu-rong; Klumpner, Christian; Blaabjerg, Frede

    2005-01-01

    This paper discusses the modeling and simulation of matrix converter. Two models of matrix converter are presented: one is based on indirect space vector modulation and the other is based on power balance equation. The basis of these two models is• given and the process on modeling is introduced...

  17. A novel converter topology for TEM applications

    Indian Academy of Sciences (India)

    and energy levels of the TEM system, require special type of excitation technique. Power converters for such non-standard requirements are not reported in the literature, particularly for TEM applications. This paper introduces TEM systems to the reader and presents the requirements for excitation. A converter topology.

  18. Multilevel converters for 10 MW Wind Turbines

    DEFF Research Database (Denmark)

    Ma, Ke; Blaabjerg, Frede

    2011-01-01

    Several promising multi-level converter configurations for 10 MW Wind Turbines both with direct drive and one-stage gear box drive using Permanent Magnet Synchronous Generator (PMSG) are proposed, designed and compared. Reliability is a crucial indicator for large scale wind power converters...

  19. A novel converter topology for TEM applications

    Indian Academy of Sciences (India)

    Power converters for such non-standard requirements are not reported in the literature, particularly for TEM applications. This paper introduces TEM systems to the reader and presents the requirements for excitation. A converter topology to meet the requirements, it's analysis, control and performance are presented. Among ...

  20. Feasibility of converting lactic acid to ethanol in food waste fermentation by immobilized lactate oxidase

    International Nuclear Information System (INIS)

    Ma, Hong-zhi; Xing, Yi; Yu, Miao; Wang, Qunhui

    2014-01-01

    Highlights: • Residue lactic acid in food waste could be converted to pyruvic acid. • Calcium alginate immobilized the lactate oxidase with high pH and thermal stability. • Immobilized enzyme could convert 70% lactic acid to pyruvic acid. • Ethanol yield could be increased by 20% with lactate oxidase added. - Abstract: Adoption of lactic acid bacteria (LAB) into ethanol fermentation from food waste can replace the sterilization process. However, LAB inoculation will convert part of the substrate into lactic acid (LA), not ethanol. This study adopted lactate oxidase to convert the produced LA to pyruvate, and then ethanol fermentation was carried out. The immobilization enzyme was utilized, and corresponding optimum conditions were determined. Results showed that calcium alginate could successfully immobilize the enzyme and improve pH and thermal stability. The optimum pH and temperature were 6.2 and 55 °C, respectively. The utilization of immobilized enzyme with catalytic time of 5 h could convert 70% LA to pyruvate, and the addition of enzyme increased the ethanol yield by 20% more than that of the control. The process could be applied in food waste storage and can help in reducing carbon source consumption

  1. Periodic Control of Power Electronic Converters

    DEFF Research Database (Denmark)

    Zhou, Keliang; Danwei, Wang; Yang, Yongheng

    Advanced power electronic converters convert, control and condition electricity. Power converters require control strategies for periodic signal compensation to assure good power quality and stable power system operation. This comprehensive text presents the most recent internal model principle...... based periodic control technology, which offers the perfect periodic control solution for power electronic conversion. It also provides complete analysis and synthesis methods for periodic control systems, and plenty of practical examples to demonstrate the validity of proposed periodic control...... technology for power converters. It proposes a unified framework for housing periodic control schemes for power converters, and provides a general proportional-integral-derivative control solution to periodic signal compensation in extensive engineering applications. Periodic Control of Power Electronic...

  2. A review of Indirect Matrix Converter Topologies

    Directory of Open Access Journals (Sweden)

    Salem Rahmani

    2015-08-01

    Full Text Available Abstract—Matrix Converter (MC is a modern direct AC/AC electrical power converter without dc-link capacitor. MC is operated in four quadrant, assuring a control of the output voltage, amplitude and frequency. The matrix converter has recently attracted significant attention among researchers and it has become increasing attractive for applications of wind energy conversion, military power supplies, induction motor drives, etc. Recently, different MC topologies have been proposed and developed which have their own advantages and disadvantages. Matrix converter can be classified as direct and indirect structures. The direct one has been elaborated in previous work. In this paper the indirect MCs are reviewed. Different characteristics of the indirect MC topologies are mentioned to show the strengths and weaknesses of such converter topologies.

  3. Switched Mode Four-Quadrant Converters

    CERN Document Server

    Thurel, Y

    2015-01-01

    This paper was originally presented at CAS-2004, and was slightly modified for CAS-2014. It presents a review of the key parameters that impact the design choices for a true four-quadrant power converter, in the range 1-10 kW, mainly based on switching mode converter topology. This paper will first describe the state-of-the-art for this power converter family, giving the drawbacks and advantages of different possible solutions. It will also present practical results obtained from the CERN-designed converter. It will finally give some important tips regarding critical phases like test one, when conducting a project dealing with this type of power converter.

  4. Qualitative model of a plasma photoelectric converter

    Science.gov (United States)

    Gorbunov, N. A.; Flamant, G.

    2009-01-01

    A converter of focused optical radiation into electric current is considered on the basis of the photovoltaic effect in plasmas. The converter model is based on analysis of asymmetric spatial distributions of charge particle number density and ambipolar potential in the photoplasma produced by external optical radiation focused in a heat pipe filled with a mixture of alkali vapor and a heavy inert gas. Energy balance in the plasma photoelectric converter is analyzed. The conditions in which the external radiation energy is effectively absorbed in the converter are indicated. The plasma parameters for which the energy of absorbed optical radiation is mainly spent on sustaining the ambipolar field in the plasma are determined. It is shown that the plasma photoelectric converter makes it possible to attain a high conversion efficiency for focused solar radiation.

  5. A novel power converter for photovoltaic applications

    Science.gov (United States)

    Yuvarajan, S.; Yu, Dachuan; Xu, Shanguang

    A simple and economical power conditioner to convert the power available from solar panels into 60 Hz ac voltage is described. The raw dc voltage from the solar panels is converted to a regulated dc voltage using a boost converter and a large capacitor and the dc output is then converted to 60 Hz ac using a bridge inverter. The ratio between the load current and the short-circuit current of a PV panel at maximum power point is nearly constant for different insolation (light) levels and this property is utilized in designing a simple maximum power point tracking (MPPT) controller. The controller includes a novel arrangement for sensing the short-circuit current without disturbing the operation of the PV panel and implementing MPPT. The switching losses in the inverter are reduced by using snubbers. The results obtained on an experimental converter are presented.

  6. The Simulation of DFIG Grid Side Converter

    Directory of Open Access Journals (Sweden)

    LU Yan-Ling

    2017-02-01

    Full Text Available Firstly,DFIG basic structure of grid side converter was analyzed according to basic principles of voltage converter, and a mathematical model of grid side converter was established in the three-phase stationary coordinate system and the two-phase rotating coordinate system respectively. Then use the grid voltage oriented vector control strategy based On dq coordinate model of the grid side converter and its essential principles and realization scheme were introduced. Finally,SVPWM,Park,control systems and other power electronics model were built in matlab/simulink,converter was simulated based On vector control strategy under rectifier state and inverter state respectively. The simulation results show that the control strategy has a good dynamic response,and by choosing the appropriate inductance,capacitance,the network side current will reach stable state quickly with smooth waveform and small harmonic,while the DC voltage will reach stable value quickly with small overshoot.

  7. Transformer Isolated Buck-Boost Converters

    Directory of Open Access Journals (Sweden)

    Barry W. Williams

    2016-12-01

    Full Text Available Of the single-switch dc-to-dc converters, those with the buck-boost voltage transfer function offer most potential for transformer coupling, hence isolation, at the kilowatt level. This paper highlights the limitations of the traditional magnetic coupled, buck-boost topology. Then four split-capacitor transformer-coupled topologies (specifically the Cuk, sepic, zeta, and a new, converters with a common ac equivalent circuit are explored, that do not temporarily store core magnetic energy as does the traditional isolated buck-boost converter nor have a core dc magnetizing current bias, as with the sepic and zeta transformer coupled topologies. Core dc bias capacitive voltage compensation is a practical design constraint in three of the four topologies, while all four must cater for stray and leakage inductance effects. Simulations and experimental results for the new converter at 408W support the transformer-coupled, single-switch dc-to-dc converter concepts investigated.

  8. Catalytic Organometallic Reactions of Ammonia

    Science.gov (United States)

    Klinkenberg, Jessica L.

    2012-01-01

    Until recently, ammonia had rarely succumbed to catalytic transformations with homogeneous catalysts, and the development of such reactions that are selective for the formation of single products under mild conditions has encountered numerous challenges. However, recently developed catalysts have allowed several classes of reactions to create products with nitrogen-containing functional groups from ammonia. These reactions include hydroaminomethylation, reductive amination, alkylation, allylic substitution, hydroamination, and cross-coupling. This Minireview describes examples of these processes and the factors that control catalyst activity and selectivity. PMID:20857466

  9. Studies of Catalytic Model Systems

    DEFF Research Database (Denmark)

    Holse, Christian

    of the Cu/ZnO nanoparticles is highly relevant to industrial methanol synthesis for which the direct interaction of Cu and ZnO nanocrystals synergistically boost the catalytic activity. The dynamical behavior of the nanoparticles under reducing and oxidizing environments were studied by means of ex situ X...... as the nanoparticles are reduced. The Cu/ZnO nanoparticles are tested on a  µ-reactor platform and prove to be active towards methanol synthesis, making it an excellent model system for further investigations into activity depended morphology changes....

  10. Kinetics of heterogeneous catalytic reactions

    CERN Document Server

    Boudart, Michel

    2014-01-01

    This book is a critical account of the principles of the kinetics of heterogeneous catalytic reactions in the light of recent developments in surface science and catalysis science. Originally published in 1984. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These paperback editions preserve the original texts of these important books while presenting them in durable paperback editions. The goal of the Princeton Legacy Library is to vastly increase acc

  11. Studies of coupled chemical and catalytic coal conversion methods

    Energy Technology Data Exchange (ETDEWEB)

    Stock, L.M.

    1990-01-01

    This report concerns our research on base-catalyzed coal solubilization and a new approach for hydrogen addition. The work on base-catalyzed, chemical solubilization is continuing. this report is focused on the hydrogenation research. Specifically it deals with the use of arene chromium carbonyl complexes as reagents for the addition of dideuterium to coal molecules. In one phase of the work, he has established that the aromatic hydrocarbons in a representative coal liquid can be converted in very good yield to arene chromium carbonyl compounds. In a second phase of the work directly related to our objective of improved methods for catalytic hydrogenation, he has established that the aromatic constituents of the same coal liquid add dideuterium in the presence of added napththalene chromium carbonyl.

  12. Catalytic Hydroisomerization Upgrading of Vegetable Oil-Based Insulating Oil

    Directory of Open Access Journals (Sweden)

    Dieu-Phuong Phan

    2018-03-01

    Full Text Available Due to its high biodegradability, high dielectric strength, and good thermal stability, vegetable oil is under consideration as an alternative transformer fluid for power system equipment, replacing traditional petroleum-based insulating oils. Its main drawbacks are its poor low-temperature properties arising from the crystallization of its long-chain normal paraffins, and its lower oxidative stability arising from its higher concentration of unsaturated fatty acids. Hydroisomerization/isomerization over bifunctional catalysts is considered to be an efficient pathway to upgrade vegetable oil-based insulating oil; this converts saturated/unsaturated long-chain fatty acids to branched isomers. The efficiency of this process depends crucially on the behavior of the catalyst system. This paper extensively reviews recent results on the influence that the metal phase and acidity, the effects of pore channels, and the balance between metal and acid sites have upon the activity and selectivity of catalytic hydroisomerization.

  13. In-Situ Catalytic Fast Pyrolysis Technology Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Biddy, Mary J.; Dutta, Abhijit; Jones, Susanne B.; Meyer, Pimphan A.

    2013-03-31

    In support of the Bioenergy Technologies Office, the National Renewable Energy Laboratory (NREL) and the Pacific Northwest National Laboratory (PNNL) are undertaking studies of biomass conversion technologies to hydrocarbon fuels to identify barriers and target research toward reducing conversion costs. Process designs and preliminary economic estimates for each of these pathway cases were developed using rigorous modeling tools (Aspen Plus and Chemcad). These analyses incorporated the best information available at the time of development, including data from recent pilot and bench-scale demonstrations, collaborative industrial and academic partners, and published literature and patents. This pathway case investigates converting woody biomass using in-situ catalytic fast pyrolysis followed by upgrading to gasoline, diesel, and jet range blendstocks. Technical barriers and key research needs that should be pursued for this pathway to be competitive with petroleum-derived blendstocks have been identified.

  14. Catalytic conversion of methane: Carbon dioxide reforming and oxidative coupling

    KAUST Repository

    Takanabe, Kazuhiro

    2012-01-01

    Natural gas conversion remains one of the essential technologies for current energy needs. This review focuses on the mechanistic aspects of the development of efficient and durable catalysts for two reactions, carbon dioxide reforming and the oxidative coupling of methane. These two reactions have tremendous technological significance for practical application in industry. An understanding of the fundamental aspects and reaction mechanisms of the catalytic reactions reviewed in this study would support the design of industrial catalysts. CO 2 reforming of methane utilizes CO 2, which is often stored in large quantities, to convert as a reactant. Strategies to eliminate carbon deposition, which is the major problem associated with this reaction, are discussed. The oxidative coupling of methane directly produces ethylene in one reactor through a slightly exothermic reaction, potentially minimizing the capital cost of the natural gas conversion process. The focus of discussion in this review will be on the attainable yield of C 2 products by rigorous kinetic analyses.

  15. Catalytic enantioselective Reformatsky reaction with ketones

    NARCIS (Netherlands)

    Fernandez-Ibanez, M. Angeles; Macia, Beatriz; Minnaard, Adriaan J.; Feringa, Ben L.

    2008-01-01

    Chiral tertiary alcohols were obtained with good yields and enantioselectivities via a catalytic Reformatsky reaction with ketones, including the challenging diaryl ketones, using chiral BINOL derivatives.

  16. Underwater noise from a wave energy converter

    DEFF Research Database (Denmark)

    Tougaard, Jakob

    of the absorber type. During recordings the converter was operating close to maximum power output (nominal capacity of 110 kW). During operation the independently operating absorbers float semi-submerged in the water and wave-generated up-and-down motion is converted into hydraulic pressure by means of pistons...... connected to the arms of the absorbers. The hydraulic pressure then in turn drives the generator. A 57 minute sequence of noise from the converter was recorded by a Loggerhead datalogger deployed in 7 m deep water 25 m from the converter. This sequence contained recordings of ambient noise, the converter...... in full operation and start and stop of the converter. Median broad band (10 Hz – 20 kHz) sound pressure level (Leq) was 123 dB re. 1 Pa, irrespective of status of the wave energy converter (stopped, running or starting/stopping). The most pronounced peak in the third-octave spectrum was in the 160 Hz...

  17. Electromagnetic Compatibility of Matrix Converter System

    Directory of Open Access Journals (Sweden)

    S. Fligl

    2006-12-01

    Full Text Available The presented paper deals with matrix converters pulse width modulation strategies design with emphasis on the electromagnetic compatibility. Matrix converters provide an all-silicon solution to the problem of converting AC power from one frequency to another, offering almost all the features required of an ideal static frequency changer. They possess many advantages compared to the conventional voltage or current source inverters. A matrix converter does not require energy storage components as a bulky capacitor or an inductance in the DC-link, and enables the bi-directional power flow between the power supply and load. The most of the contemporary modulation strategies are able to provide practically sinusoidal waveforms of the input and output currents with negligible low order harmonics, and to control the input displacement factor. The perspective of matrix converters regarding EMC in comparison with other types of converters is brightly evident because it is no need to use any equipment for power factor correction and current and voltage harmonics reduction. Such converter with proper control is properly compatible both with the supply mains and with the supplied load. A special digital control system was developed for the realized experimental test bed which makes it possible to achieve greater throughput of the digital control system and its variability.

  18. Selective harmonic control for power converters

    DEFF Research Database (Denmark)

    Zhou, Keliang; Yang, Yongheng; Blaabjerg, Frede

    2014-01-01

    This paper proposes an Internal Model Principle (IMP) based Selective Harmonic Controller (SHC) for power converters. The proposed SHC offers an optimal control solution for power converters to mitigate power harmonics. It makes a good trade-off among cost, complexity and performance. It has high...... accuracy and fast transient response, and it is cost-effective, easy for real-time implementation, and compatible for design rules-of-thumb. An application on a three-phase PWM converter has confirmed the effectiveness of the proposed control scheme in terms of harmonic mitigation....

  19. High-power converters and AC drives

    CERN Document Server

    Wu, Bin

    2017-01-01

    This new edition reflects the recent technological advancements in the MV drive industry, such as advanced multilevel converters and drive configurations. It includes three new chapters, Control of Synchronous Motor Drives, Transformerless MV Drives, and Matrix Converter Fed Drives. In addition, there are extensively revised chapters on Multilevel Voltage Source Inverters and Voltage Source Inverter-Fed Drives. This book includes a systematic analysis on a variety of high-power multilevel converters, illustrates important concepts with simulations and experiments, introduces various megawatt drives produced by world leading drive manufacturers, and addresses practical problems and their mitigations methods.

  20. CAS - CERN Accelerator School: Power Converters

    CERN Document Server

    2015-01-01

    These proceedings collate lectures given at the twenty-eighth specialized course organised by the CERN Accelerator School (CAS). The course was held at the Hotel du Parc, Baden, Switzerland from 7 - 14 May 2014, in collaboration with the Paul Scherrer Institute. Following introductory lectures on accelerators and the requirements on power converters, the course covered components and topologies of the different types of power converters needed for particle accelerators. Issues of design, control and exploitation in a sometimes-hostile environment were addressed. Site visits to ABB and PSI provided an insight into state-of-the-art power converter production and operation, while topical seminars completed the programme.

  1. Reliability of Power Electronic Converter Systems

    DEFF Research Database (Denmark)

    for advancing the reliability, availability, system robustness, and maintainability of PECS at different levels of complexity. Drawing on the experience of an international team of experts, this book explores the reliability of PECS covering topics including an introduction to reliability engineering in power......-tolerant adjustable speed drive systems; mission profile oriented reliability design in wind turbine and photovoltaic systems; reliability of power conversion systems in photovoltaic applications; power supplies for computers; and high-power converters. Reliability of Power Electronic Converter Systems is essential...... reading for researchers, professionals and students working with power electronics and their applications, particularly those specializing in the development and application of power electronic converters and systems....

  2. Power Electronics Converters for Wind Turbine Systems

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Liserre, Marco; Ma, Ke

    2012-01-01

    The steady growth of installed wind power together with the upscaling of the single wind turbine power capability has pushed the research and development of power converters toward full-scale power conversion, lowered cost pr kW, increased power density, and also the need for higher reliability......, in the latter case with attention to series connection and parallel connection either electrical or magnetic ones (multiphase/windings machines/transformers). It is concluded that as the power level increases in wind turbines, medium-voltage power converters will be a dominant power converter configuration...

  3. Synchronous Control of Modular Multilevel Converters

    DEFF Research Database (Denmark)

    Oleschuk, Valentin; Blaabjerg, Frede; Bose, Bimal K.

    2002-01-01

    A novel method of direct synchronous pulsewidth modulation (PWM) is applied for control of modular multilevel converters consisting from three standard triphase inverter modules along with an 0.33 p.u. output transformer. The proposed method provides synchronisation of the voltage waveforms...... for each module and the composed voltage at the output of the converter. Multilevel output voltage of the converter has quarter-wave symmetry during the whole range including the zone of overmodulation. Both continuous and discontinuous versions of synchronous PWM, based on vector approach...

  4. Effects of electric current upon catalytic steam reforming of biomass gasification tar model compounds to syngas

    International Nuclear Information System (INIS)

    Tao, Jun; Lu, Qiang; Dong, Changqing; Du, Xiaoze; Dahlquist, Erik

    2015-01-01

    Highlights: • ECR technique was proposed to convert biomass gasification tar model compounds. • Electric current enhanced the reforming efficiency remarkably. • The highest toluene conversion reached 99.9%. • Ni–CeO 2 /γ-Al 2 O 3 exhibited good stability during the ECR performance. - Abstract: Electrochemical catalytic reforming (ECR) technique, known as electric current enhanced catalytic reforming technique, was proposed to convert the biomass gasification tar into syngas. In this study, Ni–CeO 2 /γ-Al 2 O 3 catalyst was prepared, and toluene was employed as the major feedstock for ECR experiments using a fixed-bed lab-scale setup where thermal electrons could be generated and provided to the catalyst. Several factors, including the electric current intensity, reaction temperature and steam/carbon (S/C) ratio, were investigated to reveal their effects on the conversion of toluene as well as the composition of the gas products. Moreover, toluene, two other tar model compounds (benzene and 1-methylnaphthalene) and real tar (tar-containing wastewater) were subjected to the long period catalytic stability tests. All the used catalysts were analyzed to determine their carbon contents. The results indicated that the presence of electric current enhanced the catalytic performance remarkably. The toluene conversion reached 99.9% under the electric current of 4 A, catalytic temperature of 800 °C and S/C ratio of 3. Stable conversion performances of benzene, 1-methylnaphthalene and tar-containing wastewater were also observed in the ECR process. H 2 and CO were the major gas products, while CO 2 and CH 4 were the minor ones. Due to the promising capability, the ECR technique deserves further investigation and application for efficient tar conversion

  5. State estimation for wave energy converters

    Energy Technology Data Exchange (ETDEWEB)

    Bacelli, Giorgio; Coe, Ryan Geoffrey

    2017-04-01

    This report gives a brief discussion and examples on the topic of state estimation for wave energy converters (WECs). These methods are intended for use to enable real-time closed loop control of WECs.

  6. multilevel buck converter for automotive electrical load

    African Journals Online (AJOL)

    user

    MULTILEVEL BUCK CONVERTER FOR AUTOMOTIVE ELECTRICAL LOAD. E. T. Yabefa1,* and D. Ebregbe2. 1ELECTRICAL DEPARTMENT, BAYELSA STATE COLLEGE OF ARTS & SCIENCE (BYCAS) YENAGOA, BAYELSA STATE NIGERIA. 2ELECTRICAL ENGINEERING DEPARTMENT, NIGER DELTA UNIVERSITY, ...

  7. Reliability of power electronic converter systems

    CERN Document Server

    Chung, Henry Shu-hung; Blaabjerg, Frede; Pecht, Michael

    2016-01-01

    This book outlines current research into the scientific modeling, experimentation, and remedial measures for advancing the reliability, availability, system robustness, and maintainability of Power Electronic Converter Systems (PECS) at different levels of complexity.

  8. A three-port direct current converter

    DEFF Research Database (Denmark)

    2016-01-01

    The three-port direct current converter comprising: at least one input direct current source; at least one storage battery; a primary side circuit; a secondary side circuit; a first single magnetic component shared by the primary side circuit and the secondary side circuit, wherein the primary side...... circuit comprises a connection between the at least one input direct current source and the at least one storage battery, the primary side circuit configured for operating as a buck converter; a second magnetic component serially coupled to the first single magnetic component, wherein the first and second...... magnetic components are configured to perform a voltage step-up, wherein the secondary side circuit comprises a connection between the at least one storage battery and at least one load, the secondary side configured for operating as a tapped boost converter; wherein the three-port direct current converter...

  9. "Forback" Dc-To-Dc Converters

    Science.gov (United States)

    Lukemire, Alan T.

    1992-01-01

    Dc-to-dc power-converter circuits called "forback" resemble circuits of standard configurations called "forward", "flyback", and "Cuk". Circuit employs minor modifications to existing topologies, combines advantages, while eliminating disadvantages, of older circuits.

  10. Multilevel-clamped multilevel converters (MLC2)

    DEFF Research Database (Denmark)

    Rodriguez, Pedro; Bellar, Maria Dias; Muñoz-Aguliar, Raúl Santiago

    2012-01-01

    This letter introduces a new series of multilevel (ML) converters based on the ML clamping concept. By applying this technique, a ML clamping unit (MCU) conveys additional levels for synthesizing the output waveforms of a diode-clampedML dc– ac power converter. The basic building block of the ML...... clamping scheme is the ML clamping cell, which is composed of a pair of dc sources associated with one single-pole/triple-throw type of switch arrangement. The number of series-connected ML-clamping cells will set the number of levels of the synthesized waveform. By depending on the MCU arrangements......, different converter configurations can be derived, namely, the common clamping and the modular types. Both approaches can be accomplished by employing classical three-level neutral-point-clamped (NPC) technology. Thus, the overall structure of the resultant converter is kept simple, wherein the number...

  11. The Role of Ruthenium in CO2 Capture and Catalytic Conversion to Fuel by Dual Function Materials (DFM)

    OpenAIRE

    Shuoxun Wang; Erik T. Schrunk; Harshit Mahajan; and Robert J. Farrauto

    2017-01-01

    Development of sustainable energy technologies and reduction of carbon dioxide in the atmosphere are the two effective strategies in dealing with current environmental issues. Herein we report a Dual Function Material (DFM) consisting of supported sodium carbonate in intimate contact with dispersed Ru as a promising catalytic solution for combining both approaches. The Ru-Na2CO3 DFM deposited on Al2O3 captures CO2 from a flue gas and catalytically converts it to synthetic natural gas (i.e., m...

  12. Switching power converters medium and high power

    CERN Document Server

    Neacsu, Dorin O

    2013-01-01

    An examination of all of the multidisciplinary aspects of medium- and high-power converter systems, including basic power electronics, digital control and hardware, sensors, analog preprocessing of signals, protection devices and fault management, and pulse-width-modulation (PWM) algorithms, Switching Power Converters: Medium and High Power, Second Edition discusses the actual use of industrial technology and its related subassemblies and components, covering facets of implementation otherwise overlooked by theoretical textbooks. The updated Second Edition contains many new figures, as well as

  13. A new type time-amplitude converter

    International Nuclear Information System (INIS)

    Mou Haiwei; Han Jian; Li Zhongwei

    2004-01-01

    The time-amplitude converter is used mostly in nuclear physics experiments where require fast time measurement, such as the identify of particles, the measurement of excitated life-span and flying time of nucleon, and so on. According to the requirement of experiment, a new type time-amplitude converter composing of IC has been developed. It is precision is 100 ns. It has the merits of stable performance, higher precision and so on. (authors)

  14. AC – AC Converters for UPS

    Directory of Open Access Journals (Sweden)

    Rusalin Lucian R. Păun

    2008-05-01

    Full Text Available This paper propose a new control technique forsingle – phase AC – AC converters used for a on-line UPSwith a good dynamic response, a reduced-partscomponents, a good output characteristic, a good powerfactorcorrection(PFC. This converter no needs anisolation transformer. A power factor correction rectifierand an inverter with the proposed control scheme has beendesigned and simulated using Caspoc2007, validating theconcept.

  15. Resonant Wave Energy Converters: Concept development

    International Nuclear Information System (INIS)

    Arena, Felice; Barbaro, Giuseppe; Fiamma, Vincenzo; Laface, Valentina; Malara, Giovanni; Romolo, Alessandra; Strati, Federica Mara

    2015-01-01

    The Resonant Wave Energy Converter (REWEC) is a device for converting sea wave energy to electrical energy. It belongs to the family of Oscillating Water Columns and is composed by an absorbing chamber connected to the open sea via a vertical duct. The paper gives a holistic view on the concept development of the device, starting from its implementation in the context of submerged breakwaters to the recently developed vertical breakwaters. [it

  16. Heterogeneous catalytic degradation of polyacrylamide solution | Hu ...

    African Journals Online (AJOL)

    Modified with trace metal elements, the catalytic activity of Fe2O3/Al2O3 could be changed greatly. Among various trace metal elements, Fe2O3/Al2O3 catalysts modified with Co and Cu showed great increase on catalytic activity. International Journal of Engineering, Science and Technology, Vol. 2, No. 7, 2010, pp. 110- ...

  17. Catalytic gasification of dry and wet biomass

    NARCIS (Netherlands)

    van Rossum, G.; Potic, B.; Kersten, Sascha R.A.; van Swaaij, Willibrordus Petrus Maria

    2009-01-01

    Catalytic gasification of dry biomass and of wet biomass streams in hot compressed water are reviewed and discussed as potential technologies for the production of synthesis gas, hydrogen- and methane-rich gas. Next to literature data also new experimental results from our laboratory on catalytic

  18. LHC Power Converters: A Precision Game

    CERN Multimedia

    2001-01-01

    The LHC test-bed, String 2, is close to commissioning and one important element to get a first chance to prove what it can do is the power converter system. In String 2 there are 16 converters, in the full LHC there will be almost 1800. This article takes a look at what is so special about the power converters for the LHC. The 13 000 Amps power converters with the watercooled cables going to the String 2 feedboxes. The LHC's superconducting magnets will be the pinnacle of high technology. But to work, they'll need the help of high-precision power converters to supply them with extremely stable DC current. Perfection will be the name of the game, with an accuracy of just 1-2 parts per million (ppm) required. LEP, for the sake of comparison, could live with 10-20 ppm. The LHC's power converters will be very different from those of LEP or the SPS since the new accelerator's magnets are mostly superconducting. That means that they require much higher currents at a lower voltage since superconductors have no re...

  19. Non-catalytic recuperative reformer

    Science.gov (United States)

    Khinkis, Mark J.; Kozlov, Aleksandr P.; Kurek, Harry

    2015-12-22

    A non-catalytic recuperative reformer has a flue gas flow path for conducting hot flue gas from a thermal process and a reforming mixture flow path for conducting a reforming mixture. At least a portion of the reforming mixture flow path is embedded in the flue gas flow path to permit heat transfer from the hot flue gas to the reforming mixture. The reforming mixture flow path contains substantially no material commonly used as a catalyst for reforming hydrocarbon fuel (e.g., nickel oxide, platinum group elements or rhenium), but instead the reforming mixture is reformed into a higher calorific fuel via reactions due to the heat transfer and residence time. In a preferred embodiment, extended surfaces of metal material such as stainless steel or metal alloy that are high in nickel content are included within at least a portion of the reforming mixture flow path.

  20. Electrochemical promotion of catalytic reactions

    Science.gov (United States)

    Imbihl, R.

    2010-05-01

    The electrochemical promotion of heterogeneously catalyzed reactions (EPOC) became feasible through the use of porous metal electrodes interfaced to a solid electrolyte. With the O 2- conducting yttrium stabilized zirconia (YSZ), the Na + conducting β″-Al 2O 3 (β-alumina), and several other types of solid electrolytes the EPOC effect has been demonstrated for about 100 reaction systems in studies conducted mainly in the mbar range. Surface science investigations showed that the physical basis for the EPOC effect lies in the electrochemically induced spillover of oxygen and alkali metal, respectively, onto the surface of the metal electrodes. For the catalytic promotion effect general concepts and mechanistic schemes were proposed but these concepts and schemes are largely speculative. Applying surface analytical tools to EPOC systems the proposed mechanistic schemes can be verified or invalidated. This report summarizes the progress which has been achieved in the mechanistic understanding of the EPOC effect.

  1. Selective catalytic oxidation of ammonia

    Energy Technology Data Exchange (ETDEWEB)

    Leppaelahti, J.; Koljonen, T. [VTT Energy, Espoo (Finland)

    1996-12-31

    In the combustion of fossil fuels, the principal source of nitrogen oxides is nitrogen bound in the fuel structure. In gasification, a large part of fuel nitrogen forms NH{sub 3}, which may form nitrogen oxides during gas combustion. If NH{sub 3} and other nitrogen species could be removed from hot gas, the NO emission could be considerably reduced. However, relatively little attention has been paid to finding new means of removing nitrogen compounds from the hot gasification gas. The possibility of selectively oxidizing NH{sub 3} to N{sub 2} in the hot gasification has been studied at VTT Energy. The largest NH{sub 3} reductions have been achieved by catalytic oxidation on aluminium oxides. (author) (4 refs.)

  2. Diesel engine catalytic combustor system. [aircraft engines

    Science.gov (United States)

    Ream, L. W. (Inventor)

    1984-01-01

    A low compression turbocharged diesel engine is provided in which the turbocharger can be operated independently of the engine to power auxiliary equipment. Fuel and air are burned in a catalytic combustor to drive the turbine wheel of turbine section which is initially caused to rotate by starter motor. By opening a flapper value, compressed air from the blower section is directed to catalytic combustor when it is heated and expanded, serving to drive the turbine wheel and also to heat the catalytic element. To start, engine valve is closed, combustion is terminated in catalytic combustor, and the valve is then opened to utilize air from the blower for the air driven motor. When the engine starts, the constituents in its exhaust gas react in the catalytic element and the heat generated provides additional energy for the turbine section.

  3. The evolution of catalytic function

    Science.gov (United States)

    Maurel, Marie-Christine; Ricard, Jacques

    2006-03-01

    It is very likely that the main driving force of enzyme evolution is the requirement to improve catalytic and regulatory efficiency which results from the intrinsic performance as well as from the spatial and functional organization of enzymes in living cells. Kinetic co-operativity may occur in simple monomeric proteins if they display “slow” conformational transitions, at the cost of catalytic efficiency. Oligomeric enzymes on the other hand can be both efficient and co-operative. We speculate that the main reason for the emergence of co-operative oligomeric enzymes is the need for catalysts that are both cooperative and efficient. As it is not useful for an enzyme to respond to a change of substrate concentration in a complex kinetic way, the emergence of symmetry has its probable origin in a requirement for “functional simplicity”. In a living cell, enzyme are associated with other macromolecules and membranes. The fine tuning of their activity may also be reached through mutations of the microenvironment. Our hypothesis is that these mutations are related to the vectorial transport of molecules, to achieve the hysteresis loops of enzyme reactions generated by the coupling of reaction and diffusion, through the co-operativity brought about by electric interactions between a charged substrate and a membrane, and last but not least, through oscillations. As the physical origins of these effects are very simple and do not require complex molecular devices, it is very likely that the functional advantage generated by the spatial and functional organization of enzyme molecules within the cell have appeared in prebiotic catalysis or very early during the primeval stages of biological evolution. We shall began this paper by presenting the nature of the probable earliest catalysts in the RNA world.

  4. Converting lignin to aromatics: step by step

    NARCIS (Netherlands)

    Strassberger, Z.I.

    2014-01-01

    Lignin, the glue that holds trees together, is the most abundant natural resource of aromatics. In that respect, it is a far more advanced resource than crude oil. This is because lignin already contains the aromatic functional groups. Thus, catalytic conversion of lignin to high-value aromatics is

  5. Directly converting CO2 into a gasoline fuel

    Science.gov (United States)

    Wei, Jian; Ge, Qingjie; Yao, Ruwei; Wen, Zhiyong; Fang, Chuanyan; Guo, Lisheng; Xu, Hengyong; Sun, Jian

    2017-05-01

    The direct production of liquid fuels from CO2 hydrogenation has attracted enormous interest for its significant roles in mitigating CO2 emissions and reducing dependence on petrochemicals. Here we report a highly efficient, stable and multifunctional Na-Fe3O4/HZSM-5 catalyst, which can directly convert CO2 to gasoline-range (C5-C11) hydrocarbons with selectivity up to 78% of all hydrocarbons while only 4% methane at a CO2 conversion of 22% under industrial relevant conditions. It is achieved by a multifunctional catalyst providing three types of active sites (Fe3O4, Fe5C2 and acid sites), which cooperatively catalyse a tandem reaction. More significantly, the appropriate proximity of three types of active sites plays a crucial role in the successive and synergetic catalytic conversion of CO2 to gasoline. The multifunctional catalyst, exhibiting a remarkable stability for 1,000 h on stream, definitely has the potential to be a promising industrial catalyst for CO2 utilization to liquid fuels.

  6. Performance of new generation TWC catalytic systems working under different conditions in order to reduce the emission of a global warming gas: N{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Mac-Beath, I.; Castillo, S.; Camposeco, R.; Moran-Pineda, M. [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico). Programa de Ingenieria Molecular

    2010-07-01

    In this work, three-way catalytic systems (TWC-K, TWC-M and TWC-P) were prepared and tested experimentally in order to analyze N{sub 2}O emissions. Various types and quantities of precious metals (Pt-Pd-Rh), and different mixed oxides (CexBayLazMgwO{sub 2}-Al{sub 2}O{sub 3}) to prepare the supports were used. The catalytic tests were carried out by using common exhaust gases from a gasoline engine under different oxidizing conditions. The TWC catalytic compositions were based on catalytic converters used in retrofitting programs in the Metropolitan Area in Mexico City. Fresh and aged TWC catalytic samples were tested; in both conditions, the catalytic compositions were characterized by BET, TEM-EDS and XRD in order to analyze the efficiency of the catalytic behavior. Due to the fact that the 4{sup th} TWC generation (Pd-Only TWC) has Pd as main active metal, the tested TWC catalytic samples were synthesized by having Pd in a higher proportion with regard to Pt and Rh used as complements with some differences in support composition. (orig.)

  7. Understanding delta-sigma data converters

    CERN Document Server

    Pavan, Shanti; Temes, Gabor C

    2017-01-01

    This new edition introduces novel analysis and design techniques for delta-sigma (ΔΣ) converters in physical and conceptual terms, and includes new chapters that explore developments in the field over the last decade. This book explains the principles and operation of delta-sigma analog-to-digital converters (ADCs) in physical and conceptual terms in accordance with the most recent developments in the field. The interest of ΔΣ converter designers has shifted significantly over the past decade, due to many new applications for data converters at the far ends of the frequency spectrum. Continuous-time delta-sigma A/D converters with GHz clocks, of both lowpass and bandpass types, are required for wireless applications. At the other extreme, multiplexed ADCs with very narrow (sometimes 10 Hz wide) signal bandwidths, but very high accuracy are needed in the interfaces of biomedical and environmental sensors. To reflect the changing eeds of designers, the second edition includes significant new material on bo...

  8. Isolated and soft-switched power converter

    Science.gov (United States)

    Peng, Fang Zheng; Adams, Donald Joe

    2002-01-01

    An isolated and soft-switched power converter is used for DC/DC and DC/DC/AC power conversion. The power converter includes two resonant tank circuits coupled back-to-back through an isolation transformer. Each resonant tank circuit includes a pair of resonant capacitors connected in series as a resonant leg, a pair of tank capacitors connected in series as a tank leg, and a pair of switching devices with anti-parallel clamping diodes coupled in series as resonant switches and clamping devices for the resonant leg. The power converter is well suited for DC/DC and DC/DC/AC power conversion applications in which high-voltage isolation, DC to DC voltage boost, bidirectional power flow, and a minimal number of conventional switching components are important design objectives. For example, the power converter is especially well suited to electric vehicle applications and load-side electric generation and storage systems, and other applications in which these objectives are important. The power converter may be used for many different applications, including electric vehicles, hybrid combustion/electric vehicles, fuel-cell powered vehicles with low-voltage starting, remote power sources utilizing low-voltage DC power sources, such as photovoltaics and others, electric power backup systems, and load-side electric storage and generation systems.

  9. Underwater noise from a wave energy converter

    DEFF Research Database (Denmark)

    Tougaard, Jakob

    in full operation and start and stop of the converter. Median broad band (10 Hz – 20 kHz) sound pressure level (Leq) was 123 dB re. 1 Pa, irrespective of status of the wave energy converter (stopped, running or starting/stopping). The most pronounced peak in the third-octave spectrum was in the 160 Hz...... band during start and stop of the converter, attributed to the hydraulic pump responsible for lifting and lowering the absorbers. Less pronounced, but still statistically significant differences were seen in the bands 125, 160, 200 and 250 Hz when operation and ambient were compared. No statistically...... significant noise above ambient could be detected above the 250 Hz band. The absolute increase in noise above ambient was very small. L50 third-octave levels in the four bands with the converter running were thus only 1-2 dB above ambient L50 levels. The noise recorded 25 m from the wave energy converter...

  10. Catalytic Wittig and aza-Wittig reactions

    Directory of Open Access Journals (Sweden)

    Zhiqi Lao

    2016-11-01

    Full Text Available This review surveys the literature regarding the development of catalytic versions of the Wittig and aza-Wittig reactions. The first section summarizes how arsenic and tellurium-based catalytic Wittig-type reaction systems were developed first due to the relatively easy reduction of the oxides involved. This is followed by a presentation of the current state of the art regarding phosphine-catalyzed Wittig reactions. The second section covers the field of related catalytic aza-Wittig reactions that are catalyzed by both phosphine oxides and phosphines.

  11. Catalytic Wittig and aza-Wittig reactions.

    Science.gov (United States)

    Lao, Zhiqi; Toy, Patrick H

    2016-01-01

    This review surveys the literature regarding the development of catalytic versions of the Wittig and aza-Wittig reactions. The first section summarizes how arsenic and tellurium-based catalytic Wittig-type reaction systems were developed first due to the relatively easy reduction of the oxides involved. This is followed by a presentation of the current state of the art regarding phosphine-catalyzed Wittig reactions. The second section covers the field of related catalytic aza-Wittig reactions that are catalyzed by both phosphine oxides and phosphines.

  12. High Efficiency Reversible Fuel Cell Power Converter

    DEFF Research Database (Denmark)

    Pittini, Riccardo

    to traditional unidirectional fuel cell, bidirectional fuel cells have increased operating voltage and current ranges. These characteristics increase the stresses on dc-dc and dc-ac converters in the electrical system, which require proper design and advanced optimization. This work is part of the PhD project...... entitled "High Efficiency Reversible Fuel Cell Power Converter" and it presents the design of a high efficiency dc-dc converter developed and optimized for bidirectional fuel cell applications. First, a brief overview of fuel cell and energy storage technologies is presented. Different system topologies......The large scale integration of renewable energy sources requires suitable energy storage systems to balance energy production and demand in the electrical grid. Bidirectional fuel cells are an attractive technology for energy storage systems due to the high energy density of fuel. Compared...

  13. Reliability of Power Electronic Converter Systems

    DEFF Research Database (Denmark)

    The main aims of power electronic converter systems (PECS) are to control, convert, and condition electrical power flow from one form to another through the use of solid-state electronics. This book outlines current research into the scientific modeling, experimentation, and remedial measures......-link capacitance in power electronic converter systems; wind turbine systems; smart control strategies for improved reliability of power electronics system; lifetime modelling; power module lifetime test and state monitoring; tools for performance and reliability analysis of power electronics systems; fault...... for advancing the reliability, availability, system robustness, and maintainability of PECS at different levels of complexity. Drawing on the experience of an international team of experts, this book explores the reliability of PECS covering topics including an introduction to reliability engineering in power...

  14. Converters for Distributed Power Generation Systems

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Yang, Yongheng

    2015-01-01

    Power electronics technology has become the enabling technology for the integration of distributed power generation systems (DPGS) such as offshore wind turbine power systems and commercial photovoltaic power plants. Depending on the applications, a vast array of DPGS-based power converter...... topologies has been developed and more are coming into the market in order to achieve an efficient and reliable power conversion from the renewables. In addition, stringent demands from both the distribution system operators and the consumers have been imposed on the renewable-based DPGS. This article...... presents an overview of the power converters for the DPGS, mainly based on wind turbine systems and photovoltaic systems, covering a wide range of applications. Moreover, the modulation schemes and interfacing power filters for the power converters are also exemplified. Finally, the general control...

  15. Measurements of neutron spectrum from uranium converter

    International Nuclear Information System (INIS)

    Ninkovic, M.; Sotic, O.; Marinkovic, S.

    1978-01-01

    The procedure for determination of energetic distribution of neutrons by the multisphere technique is given. The theoretical basis and features of the method are explained. The spectral distribution of neutrons emerging from the neutron converter constructed at the bare reactor assembly RB, has been determined applying the existing computer programme and literature data for the energetic dependence functions of spheres of various diameters. The obtained spectral distribution has a specific maximum in the domain of fast neutrons, justifying thus the reacton for the construction of the converter. The neutron spectrum data obtained and given in this report are very important for the use of the converter in neutron dosimetry and radiation protection, as well as in the radiobiology, shielding, reactor physics etc. (author)

  16. Radioisotope thermionic converters for space applications

    International Nuclear Information System (INIS)

    Miskolczy, G.; Lieb, D.P.

    1990-01-01

    The recent history of radioisotope thermionics is reviewed, with emphasis on the U.S. programs, and the prospects for the future are assessed. In radioisotope thermionic converters the emitter heat is generated by the decay of a radioactive isotope. The thermionic converter emitter is mounted directly on a capsule containing the isotope. The rest of the capsule is generally insulated to reduce thermal loss. The development of isotope-fueled thermionic power systems for space application has been pursued since the late 1950's. The U.S. effort was concentrated on modular systems with alpha emitters as the isotope heat source. In the SNAP-13 program, the heat sources were Cerium isotopes and each module produced about 100 watts. The converters were planar diodes and the capsule was insulated with multi-foil insulation

  17. Reliability of Power Electronic Converter Systems

    DEFF Research Database (Denmark)

    for advancing the reliability, availability, system robustness, and maintainability of PECS at different levels of complexity. Drawing on the experience of an international team of experts, this book explores the reliability of PECS covering topics including an introduction to reliability engineering in power...... electronic converter systems; anomaly detection and remaining-life prediction for power electronics; reliability of DC-link capacitors in power electronic converters; reliability of power electronics packaging; modeling for life-time prediction of power semiconductor modules; minimization of DC......-link capacitance in power electronic converter systems; wind turbine systems; smart control strategies for improved reliability of power electronics system; lifetime modelling; power module lifetime test and state monitoring; tools for performance and reliability analysis of power electronics systems; fault...

  18. Current Mode Data Converters for Sensor Systems

    DEFF Research Database (Denmark)

    Jørgensen, Ivan Herald Holger

    to reduce these. A novel measure called the 'error energy measure' is presented. This measure is very helpful in the design phase as it evaluates the dynamic performance of a DAC without performing long term simulations. A thorough analysis of the stability of 1-bit oversampled data converters is presented......This thesis is mainly concerned with data conversion. Especially data conversion using current mode signal processing is treated.A tutorial chapter introducing D/A conversion is presented. In this chapter the effects that cause static and dynamic nonlinearities are discussed along with methods....... Also, a methodology for designing the feedback filter in oversampled data converters is presented. Finally, the effect of nonideal effects in oversampled converters is investigated.Switched current (SI) technique is briefly presented at the system level and transistor level. A thorough analysis...

  19. Biogasoline Production from Palm Oil Via Catalytic Hydrocracking over Gamma-Alumina Catalyst

    Directory of Open Access Journals (Sweden)

    Anondho Wijanarko

    2010-10-01

    Full Text Available Bio gasoline conversion from palm oil is an alternative energy resources method which can be substituted fossil fuel base energy utilization. Previous research resulted that palm oil can be converted into hydrocarbon by catalytic cracking reaction with γ-alumina catalyst. In this research, catalytic cracking reaction of palm oil by γ-alumina catalyst is done in  a stirrer batch reactor with the oil/catalyst weight ratio variation of 100:1, 75:1, and 50:1; at suhue variation of 260 to 340oC and reaction time variation of 1 to 2 hour. Post cracking reaction, bio gasoline yield could be obtained after 2 steps batch distillation. Physical property test result such as density and viscosity of this cracking reaction product and commercial gasoline tended a closed similarity. According to result of the cracking product's density, viscosity and FTIR, it  can conclude that optimum yield of the palm oil catalytic cracking reaction could be occurred when oil/catalyst weight  ratio 100:1 at 340 oC in 1.5 hour and base on this bio gasoline's FTIR, GC and GC-MS identification results, its  hydrocarbons content was resembled to the commercial  gasoline. This palm oil catalytic cracking reaction shown 11.8% (v/v in yield and 28.0% (v/v in conversion concern to feed palm oil base and produced a 61.0 octane number's biogasoline.

  20. single-phase dc phase dc-ac boost converter ac boost converter

    African Journals Online (AJOL)

    User

    supply (UPS) AC motor drives and other power sup systems, need to step-up the DC input voltage. increase the output voltage level in order requirements, DC-DC boost converter is used provide DC bus voltage for PWM inverters. Hence, conventional design always cascades DC and a separate DC-AC converter.

  1. Efficient modelling of a modular multilevel converter

    DEFF Research Database (Denmark)

    El-Khatib, Walid Ziad; Holbøll, Joachim; Rasmussen, Tonny Wederberg

    2013-01-01

    Looking at the near future, we see that offshore wind penetration into the electrical grid will continue increasing rapidly. Until very recently, the trend has been to place the offshore wind farms close to shore within the reach for transmission using HVAC cables but for larger distances HVDC...... are calculated for the converter. Time-domain simulations on a MMC HVDC test system are performed in the PSCAD/EMTDC software environment based on the new model. The results demonstrate that the modeled MMC-HVDC system with or without converter transformer is able to operate under specific fault conditions....

  2. The Angiotensin-Converting-Enzyme-Induced Angioedema.

    Science.gov (United States)

    Bas, Murat

    2017-02-01

    The bradykinin B2 receptor antagonist icatibant is effective in angiotensin-converting enzyme inhibitor-induced angioedema. The drug is not approved officially for this indication and has to be administered in an emergency situation off-label. Corticosteroids or antihistamines do not seem to work in this condition. The effectiveness of C1-esterase-inhibitor in angiotensin-converting enzyme-induced angioedema must be verified in a double-blind study. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Combination solar photovoltaic heat engine energy converter

    Science.gov (United States)

    Chubb, Donald L.

    1987-01-01

    A combination solar photovoltaic heat engine converter is proposed. Such a system is suitable for either terrestrial or space power applications. The combination system has a higher efficiency than either the photovoltaic array or the heat engine alone can attain. Advantages in concentrator and radiator area and receiver mass of the photovoltaic heat engine system over a heat-engine-only system are estimated. A mass and area comparison between the proposed space station organic Rankine power system and a combination PV-heat engine system is made. The critical problem for the proposed converter is the necessity for high temperature photovoltaic array operation. Estimates of the required photovoltaic temperature are presented.

  4. Solar energy converter using surface plasma waves

    Science.gov (United States)

    Anderson, L. M. (Inventor)

    1984-01-01

    Sunlight is dispersed over a diffraction grating formed on the surface of a conducting film on a substrate. The angular dispersion controls the effective grating period so that a matching spectrum of surface plasmons is excited for parallel processing on the conducting film. The resulting surface plasmons carry energy to an array of inelastic tunnel diodes. This solar energy converter does not require different materials for each frequency band, and sunlight is directly converted to electricity in an efficient manner by extracting more energy from the more energetic photons.

  5. New strategy for optimizing wavelength converter placement

    Science.gov (United States)

    Foo, Y. C.; Chien, S. F.; Low, Andy L. Y.; Teo, C. F.; Lee, Youngseok

    2005-01-01

    This paper proposes a new strategic alternate-path routing to be combined with the particle swarm optimization (PSO) algorithm to better solve the wavelength converters placement problem. The strategic search heuristic is designed to provide network connectivity topologies for the converters to be placed more effectively. The new strategy is applied to the 14-node NSFNET to examine its efficiency in reducing the blocking probability in sparse wavelength conversion network. Computed results show that, when applied to the identical optimization framework, our search method outperforms both the equal-cost multipath routing and traffic-engineering-aware shortest-path routing.

  6. A linear temperature-to-frequency converter

    DEFF Research Database (Denmark)

    Løvborg, Leif

    1965-01-01

    , and that the maximum value of the temperature-frequency coefficient beta in this point is-1/3 alpha, where a is the temperature coefficient of the thermistor at the corresponding temperature. Curves showing the range in which the converter is expected to be linear to within plusmn0.1 degC are given. A laboratory......-built converter having beta = 1.0% degC-1 at 25degC is found to be linear to within plusmn0. 1 degC from 10 to 40degC....

  7. Performance Evaluation of Wave Energy Converters

    DEFF Research Database (Denmark)

    Pecher, Arthur

    . Guidelines for the development of wave energy converters recommend the use of different prototypes, having different sizes, which have to perform tank tests or sea trials. This implicates the need of different testing environment, which shifts from being controllable to uncontrollable with the development...... stages, and results thereby in a need for specific test objectives and procedures for each development stage. This PhD thesis has looked into the different development stages and more specifically in the performance assessment of wave energy converters based on tank testing and sea trials. The objective...

  8. Performance Evaluation of Wave Energy Converters

    DEFF Research Database (Denmark)

    Pecher, Arthur

    . Guidelines for the development of wave energy converters recommend the use of different prototypes, having different sizes, which have to perform tank tests or sea trials. Thisimplicates the need of different testing environment, which shifts from being controllable to uncontrollable with the development...... stages, and results thereby in a need for specific testobjectives and procedures for each development stage. This PhD thesis has looked into the different development stages and more specifically in the performance assessment of wave energy converters based on tank testing and sea trials. The objective...

  9. A Hybrid Catalytic Route to Fuels from Biomass Syngas

    Energy Technology Data Exchange (ETDEWEB)

    Harmon, Laurel [LanzaTech, Inc.; Hallen, Richard [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lilga, Michael [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Heijstra, Bjorn [LanzaTech, Inc.; Palou-Rivera, Ignasi [LanzaTech, Inc.; Handler, Robert [Michigan Technological Univ., Houghton, MI (United States)

    2017-12-31

    LanzaTech partnered with the Pacific Northwest National Laboratory (PNNL), Imperium Aviation Fuels, InEnTec, Orochem Technologies, the University of Delaware, Michigan Technological University, the National Renewable Energy Laboratory, and The Boeing Company, to develop a cost-effective hybrid conversion technology for catalytic upgrading of biomass-derived syngas to sustainable alternative jet fuel (SAJF) meeting the price, quality and environmental requirements of the aviation industry. Alternative “synthetic paraffinic kerosene” (SPK) blendstock produced from syngas via “Fischer-Tropsch” (F-T) or from lipids via “hydroprocessing of esters and fatty acids” (HEFA) are currently being used in commercial jet fuel blends containing at least 50% petroleum-based fuel. This project developed an alternative route to SAJF from ethanol, a type of “alcohol to jet” (ATJ) SPK. The project objective was to demonstrate a pathway that combines syngas fermentation to ethanol with catalytic upgrading of ethanol to sustainable alternative jet fuel and shows attractive overall system economics to drive down the price of biomass-derived jet fuel. The hybrid pathway was to be demonstrated on three biomass feedstocks: corn stover, woody biomass, and third biomass feedstock, cellulosic residues. The objective also included the co-production of chemicals, exemplified by 2,3-Butanediol (2,3-BDO), which can be converted to key chemical intermediates. The team successfully demonstrated that biomass syngas fermentation followed by catalytic conversion is a viable alternative to the Fischer-Tropsch process and produces a fuel with properties comparable to F-T and HEFA SPKs. Plasma gasification and gas fermentation were successfully integrated and demonstrated in continuous fermentations on waste wood, corn stover, and cellulosic bagasse. Gas fermentation was demonstrated to produce ethanol suitable for catalytic upgrading, isolating the upgrading from variations in biomass

  10. Dual Converter Fed Open-End Transformer Topology with Parallel Converters and Integrated Magnetics

    DEFF Research Database (Denmark)

    Gohil, Ghanshyamsinh Vijaysinh; Bede, Lorand; Teodorescu, Remus

    2016-01-01

    converter group comprises of two parallel Voltage Source Converters (VSCs), whose carrier signals are interleaved to improve the harmonic quality of the resultant switched output voltage of that converter group. However, an additional inductive component is required to suppress the circulating current...... that flows between the parallel interleaved VSCs. An integrated inductor is proposed which suppresses the circulating current in both the converter groups. In addition, the functionality of the line filter inductor is also integrated. Flux in various parts of the integrated inductor is analyzed and a design...... procedure is also described. The volume and the losses of the proposed solution are compared with that of the state-of-art solution. The control of the proposed converter system is also discussed. The analysis has been verified by the simulation and experimental results....

  11. Catalytic Upgrading of Thermochemical Intermediates to Hydrocarbons: Conversion of Lignocellulosic Feedstocks to Aromatic Fuels and High Value Chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Cortright, Randy [Virent, Inc., Madison, WI (United States); Rozmiarek, Bob [Virent, Inc., Madison, WI (United States); Van Straten, Matt [Virent, Inc., Madison, WI (United States)

    2017-11-28

    The principal objective of this project was to develop a fully integrated catalytic process that efficiently converts lignocellulosic feedstocks (e.g. bagasse, corn stover, and loblolly pine) into aromatic-rich fuels and chemicals. Virent led this effort with key feedstock support from Iowa State University. Within this project, Virent leveraged knowledge of catalytic processing of sugars and biomass to investigate two liquefaction technologies (Reductive Catalytic Liquefaction (USA Patent No. 9,212,320, 2015) and Solvolysis (USA Patent No. 9,157,030, 2015) (USA Patent No. 9,157,031, 2015)) that take advantage of proprietary catalysts at temperatures less than 300°C in the presence of unique solvent molecules generated in-situ within the liquefaction processes.

  12. Identification of Catalytic Residues Using a Novel Feature that Integrates the Microenvironment and Geometrical Location Properties of Residues

    Science.gov (United States)

    Han, Lei; Zhang, Yong-Jun; Song, Jiangning; Liu, Ming S.; Zhang, Ziding

    2012-01-01

    Enzymes play a fundamental role in almost all biological processes and identification of catalytic residues is a crucial step for deciphering the biological functions and understanding the underlying catalytic mechanisms. In this work, we developed a novel structural feature called MEDscore to identify catalytic residues, which integrated the microenvironment (ME) and geometrical properties of amino acid residues. Firstly, we converted a residue's ME into a series of spatially neighboring residue pairs, whose likelihood of being located in a catalytic ME was deduced from a benchmark enzyme dataset. We then calculated an ME-based score, termed as MEscore, by summing up the likelihood of all residue pairs. Secondly, we defined a parameter called Dscore to measure the relative distance of a residue to the center of the protein, provided that catalytic residues are typically located in the center of the protein structure. Finally, we defined the MEDscore feature based on an effective nonlinear integration of MEscore and Dscore. When evaluated on a well-prepared benchmark dataset using five-fold cross-validation tests, MEDscore achieved a robust performance in identifying catalytic residues with an AUC1.0 of 0.889. At a ≤10% false positive rate control, MEDscore correctly identified approximately 70% of the catalytic residues. Remarkably, MEDscore achieved a competitive performance compared with the residue conservation score (e.g. CONscore), the most informative singular feature predominantly employed to identify catalytic residues. To the best of our knowledge, MEDscore is the first singular structural feature exhibiting such an advantage. More importantly, we found that MEDscore is complementary with CONscore and a significantly improved performance can be achieved by combining CONscore with MEDscore in a linear manner. As an implementation of this work, MEDscore has been made freely accessible at http://protein.cau.edu.cn/mepi/. PMID:22829945

  13. Catalytic processes towards the production of biofuels in a palm oil and oil palm biomass-based biorefinery.

    Science.gov (United States)

    Chew, Thiam Leng; Bhatia, Subhash

    2008-11-01

    In Malaysia, there has been interest in the utilization of palm oil and oil palm biomass for the production of environmental friendly biofuels. A biorefinery based on palm oil and oil palm biomass for the production of biofuels has been proposed. The catalytic technology plays major role in the different processing stages in a biorefinery for the production of liquid as well as gaseous biofuels. There are number of challenges to find suitable catalytic technology to be used in a typical biorefinery. These challenges include (1) economic barriers, (2) catalysts that facilitate highly selective conversion of substrate to desired products and (3) the issues related to design, operation and control of catalytic reactor. Therefore, the catalytic technology is one of the critical factors that control the successful operation of biorefinery. There are number of catalytic processes in a biorefinery which convert the renewable feedstocks into the desired biofuels. These include biodiesel production from palm oil, catalytic cracking of palm oil for the production of biofuels, the production of hydrogen as well as syngas from biomass gasification, Fischer-Tropsch synthesis (FTS) for the conversion of syngas into liquid fuels and upgrading of liquid/gas fuels obtained from liquefaction/pyrolysis of biomass. The selection of catalysts for these processes is essential in determining the product distribution (olefins, paraffins and oxygenated products). The integration of catalytic technology with compatible separation processes is a key challenge for biorefinery operation from the economic point of view. This paper focuses on different types of catalysts and their role in the catalytic processes for the production of biofuels in a typical palm oil and oil palm biomass-based biorefinery.

  14. Entropy production of a steady-growth cell with catalytic reactions

    Science.gov (United States)

    Himeoka, Yusuke; Kaneko, Kunihiko

    2014-10-01

    Cells generally convert external nutrient resources to support metabolism and growth. Understanding the thermodynamic efficiency of this conversion is essential to determine the general characteristics of cellular growth. Using a simple protocell model with catalytic reaction dynamics to synthesize the necessary enzyme and membrane components from nutrients, the entropy production per unit-cell-volume growth is calculated analytically and numerically based on the rate equation for chemical kinetics and linear nonequilibrium thermodynamics. The minimal entropy production per unit-cell growth is found to be achieved at a nonzero nutrient uptake rate rather than at a quasistatic limit as in the standard Carnot engine. This difference appears because the equilibration mediated by the enzyme exists only within cells that grow through enzyme and membrane synthesis. Optimal nutrient uptake is also confirmed by protocell models with many chemical components synthesized through a catalytic reaction network. The possible relevance of the identified optimal uptake to optimal yield for cellular growth is also discussed.

  15. Unification of catalytic water oxidation and oxygen reduction reactions: amorphous beat crystalline cobalt iron oxides.

    Science.gov (United States)

    Indra, Arindam; Menezes, Prashanth W; Sahraie, Nastaran Ranjbar; Bergmann, Arno; Das, Chittaranjan; Tallarida, Massimo; Schmeißer, Dieter; Strasser, Peter; Driess, Matthias

    2014-12-17

    Catalytic water splitting to hydrogen and oxygen is considered as one of the convenient routes for the sustainable energy conversion. Bifunctional catalysts for the electrocatalytic oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) are pivotal for the energy conversion and storage, and alternatively, the photochemical water oxidation in biomimetic fashion is also considered as the most useful way to convert solar energy into chemical energy. Here we present a facile solvothermal route to control the synthesis of amorphous and crystalline cobalt iron oxides by controlling the crystallinity of the materials with changing solvent and reaction time and further utilize these materials as multifunctional catalysts for the unification of photochemical and electrochemical water oxidation as well as for the oxygen reduction reaction. Notably, the amorphous cobalt iron oxide produces superior catalytic activity over the crystalline one under photochemical and electrochemical water oxidation and oxygen reduction conditions.

  16. Hydrogen production via catalytic steam reforming of fast pyrolysis oil fractions

    International Nuclear Information System (INIS)

    Wang, D.; Czernik, S.; Montane, D.; Mann, M.; Chornet, E.

    1997-01-01

    Hydrogen is the prototype of the environmentally cleanest fuel of interest for power generation using fuel cells, and as a co-adjuvant or autonomous transportation fuel in internal combustion engines. The conversion of biomass to hydrogen can be carried out through two distinct thermochemical strategies: (a) gasification followed by shift conversion; (b) catalytic steam reforming and shift conversion of specific fractions derived from fast pyrolysis and aqueous/steam processes of biomass. This paper shows that fast pyrolysis of biomass results in a bio-oil that can be adequately fractionated into valuable co-products leaving as by-product an aqueous fraction containing soluble organics (a mixture of alcohols, aldehydes and acids). This fraction can be converted to hydrogen by catalytic steam reforming followed by a shift conversion step. The methods used, the yields obtained and their economic significance will be discussed. (author)

  17. Catalytic oxidation for treatment of ECLSS and PMMS waste streams. [Process Material Management Systems

    Science.gov (United States)

    Akse, James R.; Thompson, John; Scott, Bryan; Jolly, Clifford; Carter, Donald L.

    1992-01-01

    Catalytic oxidation was added to the baseline multifiltration technology for use on the Space Station Freedom in order to convert low-molecular weight organic waste components such as alcohols, aldehydes, ketones, amides, and thiocarbamides to CO2 at low temperature (121 C), thereby reducing the total organic carbon (TOC) to below 500 ppb. The rate of reaction for the catalytic oxidation of aqueous organics to CO2 and water depends primarily upon the catalyst, temperature, and concentration of reactants. This paper describes a kinetic study conducted to determine the impact of each of these parameters upon the reaction rate. The results indicate that a classic kinetic model, the Langmuir-Hinshelwood rate equation for heterogeneous catalysis, can accurately represent the functional dependencies of this rate.

  18. Selective catalytic reduction of nitrogen oxides from industrial gases by hydrogen or methane

    International Nuclear Information System (INIS)

    Engelmann Pirez, M.

    2004-12-01

    This work deals with the selective catalytic reduction of nitrogen oxides (NO x ), contained in the effluents of industrial plants, by hydrogen or methane. The aim is to replace ammonia, used as reducing agent, in the conventional process. The use of others reducing agents such as hydrogen or methane is interesting for different reasons: practical, economical and ecological. The catalyst has to convert selectively NO into N 2 , in presence of an excess of oxygen, steam and sulfur dioxide. The developed catalyst is constituted by a support such as perovskites, particularly LaCoO 3 , on which are dispersed noble metals (palladium, platinum). The interaction between the noble metal and the support, generated during the activation of the catalyst, allows to minimize the water and sulfur dioxide inhibitor phenomena on the catalytic performances, particularly in the reduction of NO by hydrogen. (O.M.)

  19. Catalytic conversion of light alkanes, Phase 1. Topical report, January 1990--January 1993

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    The authors have found a family of new catalytic materials which, if successfully developed, will be effective in the conversion of light alkanes to alcohols or other oxygenates. Catalysts of this type have the potential to convert natural gas to clean-burning high octane liquid fuels directly without requiring the energy-intensive steam reforming step. In addition they also have the potential to upgrade light hydrocarbons found in natural gas to a variety of high value fuel and chemical products. In order for commercially useful processes to be developed, increases in catalytic life, reaction rate and selectivity are required. Recent progress in the experimental program geared to the further improvement of these catalysts is outlined.

  20. MOBILE COMPLEX FOR CATALYTIC THERMAL WASTE TREATMENT

    Directory of Open Access Journals (Sweden)

    Vedi V.E.

    2012-12-01

    Full Text Available The design and purpose of the basic units of the mobile waste processing complex “MPK” are described. Experimental data of catalytic purification of exhaust gases are presented. Experimental data on catalytic clearing of final gases of a designed mobile incinerator plant are shown. It is defined, that concentrating of parasitic bridging in waste gases of the complex are considerably smaller, rather than allowed by normative documents.

  1. National Ignition Facility frequency converter development

    International Nuclear Information System (INIS)

    Barker, C.E.; Auerbach, J.M.; Adams, C.H.

    1996-01-01

    A preliminary error budget for the third harmonic converter for the National Ignition Facility (NIF) laser driver has been developed using a root-sum-square-accumulation of error sources. Such a budget sets an upper bound on the allowable magnitude of the various effects that reduce conversion efficiency. Development efforts on crystal mounting technology and crystal quality studies are discussed

  2. Analysis of a phase-converter performance

    Energy Technology Data Exchange (ETDEWEB)

    Litchev, A.; Yanev, K. [Botswana Univ., Gaborone (Botswana). Dept. of Electrical Engineering

    2008-07-01

    A theoretical investigation of a phase converter consisting of static reactive elements was presented. The converter was connected to a 3-phase voltage supply and a large single-phase load in order to enable the symmetrical loading of all 3 phases. The parameters of the converter elements were determined in order to ensure that source phase currents functioned as part of a symmetrical system. Inductive and capacitive single-phase loads for the 3-phase system were also modelled. The power factor of the 3-phase source was unity at a purely active single-phase load. The source power factor decreased and remained lower than that of the load at inductive-resistive or capacitive-resistive loads. The source power factor was capacitive at inductive-resistive loads and capacitive-resistive when the source power factor was inductive. The theoretical study was compared with experimental data. Results of the investigation indicated that the static converter can be used to load 3-phase voltage systems with single-phase loads by maintaining supply symmetry. 6 refs., 2 tabs., 5 figs.

  3. Validating converted java code via symbolic execution

    NARCIS (Netherlands)

    Sneed, Harry M.; Verhoef, C.

    2017-01-01

    The testing approach described here has grown out of migration projects aimed at converting procedural programs in COBOL or PL/1 to object-oriented Java code. The code conversion itself is now automated but not completely. The human reengineer still has to make some adjustments to the automatically

  4. Converting skeletal structures to quad dominant meshes

    DEFF Research Database (Denmark)

    Bærentzen, Jakob Andreas; Misztal, Marek Krzysztof; Welnicka, Katarzyna

    2012-01-01

    We propose the Skeleton to Quad-dominant polygonal Mesh algorithm (SQM), which converts skeletal structures to meshes composed entirely of polar and annular regions. Both types of regions have a regular structure where all faces are quads except for a single ring of triangles at the center of eac...

  5. Mathematical modeling of the flash converting process

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, H.Y.; Perez-Tello, M.; Riihilahti, K.M. [Utah Univ., Salt Lake City, UT (United States)

    1996-12-31

    An axisymmetric mathematical model for the Kennecott-Outokumpu flash converting process for converting solid copper matte to copper is presented. The model is an adaptation of the comprehensive mathematical model formerly developed at the University of Utah for the flash smelting of copper concentrates. The model incorporates the transport of momentum, heat, mass, and reaction kinetics between gas and particles in a particle-laden turbulent gas jet. The standard k-{epsilon} model is used to describe gas-phase turbulence in an Eulerian framework. The particle-phase is treated from a Lagrangian viewpoint which is coupled to the gas-phase via the source terms in the Eulerian gas-phase governing equations. Matte particles were represented as Cu{sub 2}S yFeS, and assumed to undergo homogeneous oxidation to Cu{sub 2}O, Fe{sub 3}O{sub 4}, and SO{sub 2}. A reaction kinetics mechanism involving both external mass transfer of oxygen gas to the particle surface and diffusion of oxygen through the porous oxide layer is proposed to estimate the particle oxidation rate Predictions of the mathematical model were compared with the experimental data collected in a bench-scale flash converting facility. Good agreement between the model predictions and the measurements was obtained. The model was used to study the effect of different gas-injection configurations on the overall fluid dynamics in a commercial size flash converting shaft. (author)

  6. Near-Shore Floating Wave Energy Converters

    DEFF Research Database (Denmark)

    Ruol, Piero; Zanuttigh, Barbara; Martinelli, Luca

    2011-01-01

    Aim of this note is to analyse the possible application of a Wave Energy Converter (WEC) as a combined tool to protect the coast and harvest energy. Physical model tests are used to evaluate wave transmission past a near-shore floating WEC of the wave activated body type, named DEXA. Efficiency...

  7. Angiotensin Converting Enzyme Insertion/Deletion Gene ...

    African Journals Online (AJOL)

    Purpose: This study investigated the influence of angiotensin-1 converting enzyme (ACE) insertiondeletion (ID) gene polymorphism on the treatment responses of type 2 diabetic subjects at varying stages of nephropathy to ACE inhibitors (ACEI) with regard to blood pressure (MAP) and renal response (GFR). Methods: The ...

  8. Hybrid switch for resonant power converters

    Science.gov (United States)

    Lai, Jih-Sheng; Yu, Wensong

    2014-09-09

    A hybrid switch comprising two semiconductor switches connected in parallel but having different voltage drop characteristics as a function of current facilitates attainment of zero voltage switching and reduces conduction losses to complement reduction of switching losses achieved through zero voltage switching in power converters such as high-current inverters.

  9. Power electronics converters for wind turbine systems

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Liserre, Marco; Ma, Ke

    2011-01-01

    The steady growth of installed wind power which reached 200 GW capacity in 2010, together with the up-scaling of the single wind turbine power capability - 7 MW’s has been announced by manufacturers - has pushed the research and development of power converters towards full scale power conversion,...

  10. Development of the Wave Energy Converter

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter; Frigaard, Peter; Sørensen, Hans Christian

    2000-01-01

    The development of the wave energy converter Wave Dragon (WD) is presented. The WD is based on the overtopping principle. Initially a description of the WD is given. Then the development over time in terms of the various research and development projects working with the concept is described...

  11. Aquabuoy Wave Energy Converter

    DEFF Research Database (Denmark)

    Vicinanza, Diego; Margheritini, Lucia; Frigaard, Peter

    The work reported here is part of the contract agreement between the Finavera Renewables Ocean Energy Ltd. and the Department of Civil Engineering Hydraulics and Coastal Engineering Laboratory to instrument a model in scale 1:10 to prototype of the AquaBuOY (AB) wave energy converter and to analyse...

  12. Compact HVDC converter station design considerations

    Energy Technology Data Exchange (ETDEWEB)

    Lips, P.

    1976-01-01

    Possible means to reduce HVDC converter station land area requirements are shown. The split-up of real estate between the different kinds of equipment in present-day terminals is analyzed. From this, a priority list for suitable action to be taken is deducted. Three concepts of converter values suitable for compact converter stations are briefly discussed. By example of a 2400 MW terminal it is shown that with air-insulated liquid cooled thyristor valves a land area requirement of 0.8 m/sup 2//MW (8.5 sq. ft./MW) can be achieved, i.e., 1.2 percent of that required by the Pacific Intertie. Alternative solutions with metalclad valves are introduced and it is concluded that for converter stations with high rating in metropolitan areas, air-insulated liquid cooled thyristor valves seem to be the most appropriate choice. Where a low profile station is desirable, dead tank oil-insulated thyristor valves for outdoor mounting could be the optimum solution.

  13. Molecules for Converting Sunlight into Electricity

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 10. Molecules for Converting Sunlight into Electricity - Dye Sensitized Nanocrystalline-TiO2 based Photovoltaics. Ravi Mosurkal. General Article Volume 6 Issue 10 October 2001 pp 76-86 ...

  14. Online Scheduling in Distributed Message Converter Systems

    NARCIS (Netherlands)

    Risse, Thomas; Wombacher, Andreas; Surridge, Mike; Taylor, Steve; Aberer, Karl

    The optimal distribution of jobs among hosts in distributed environments is an important factor to achieve high performance. The optimal strategy depends on the application. In this paper we present a new online scheduling strategy for distributed EDI converter system. The strategy is based on the

  15. multilevel buck converter for automotive electrical load

    African Journals Online (AJOL)

    ... from internal combustion engine (ICE). The mass production of the hybrid electric (HE) and the electric vehicle (EV) is still awaited due to subsystem inefficiencies. Increasing the efficiencies of the power converters within subsystems of these HEVs and EVs will increase the performance of the new transportation vehicles.

  16. Convertible bonds and bank risk-taking

    NARCIS (Netherlands)

    Martynova, N.; Perotti, E.

    2015-01-01

    We study how contingent capital that converts in equity ahead of default affects bankrisk-shifting. Going concern conversion restores equity value in highly levered states,thus reducing heightened risk incentives. In contrast, conversion at default for traditionalbail-inable debt has no effect on

  17. Process Design and Economics for the Conversion of Lignocellulosic Biomass to Hydrocarbons: Dilute-Acid and Enzymatic Deconstruction of Biomass to Sugars and Catalytic Conversion of Sugars to Hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Davis, R. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tao, L. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Scarlata, C. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tan, E. C. D. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ross, J. [Harris Group Inc., New York, NY (United States); Lukas, J. [Harris Group Inc., New York, NY (United States); Sexton, D. [Harris Group Inc., New York, NY (United States)

    2015-03-01

    This report describes one potential conversion process to hydrocarbon products by way of catalytic conversion of lignocellulosic-derived hydrolysate. This model leverages expertise established over time in biomass deconstruction and process integration research at NREL, while adding in new technology areas for sugar purification and catalysis. The overarching process design converts biomass to die die diesel- and naphtha-range fuels using dilute-acid pretreatment, enzymatic saccharification, purifications, and catalytic conversion focused on deoxygenating and oligomerizing biomass hydrolysates.

  18. Bidirectional converter interface for a battery energy storage test bench

    DEFF Research Database (Denmark)

    Trintis, Ionut; Thomas, Stephan; Blank, Tobias

    2011-01-01

    This paper presents the bidirectional converter interface for a 6 kV battery energy storage test bench. The power electronic interface consists a two stage converter topology having a low voltage dc-ac grid connected converter and a new dual active bridge dc-dc converter with high transformation...

  19. Do Convertible Bond Issuers Cater to Investor Demand?

    NARCIS (Netherlands)

    de Jong, Abe; Duca, Eric; Dutordoir, Marie

    2013-01-01

    We examine the impact of fluctuations in investor demand for convertible securities on convertible bond issue volumes, pricing, and design. We find evidence of a positive impact of investor demand proxies on convertible bond issue volumes. We also document significantly lower convertible bond

  20. Methods for Converter Sludge Dehydration Intensification

    Science.gov (United States)

    Vakhromeev, M. I.; Moreva, Y. A.; Starkova, L. G.

    2017-11-01

    The article considers the intensification methods for converter sludge dehydration exemplified by the sludges of the Oxygen Converter Workshop (OCW) of the Open Joint-Stock Company “Magnitogorsk Iron and Steel Works” (MMK, OJSC), one of the largest metallurgical companies in the Southern Urals. Converter sludges can contain up to 45-70% of ferrum [21] which is interesting in terms of their use as an addition to a sinter-feed mixture. Sludge intensifies the sintering process. It positively influences pelletizing and fusion mixture melting dynamics at sintering. Over the period of the converter sludge dehydration complex operation at the OCW, MMK, OJSC, it was revealed that processing results in obtaining of high humidity sludge. It causes sludge freezing during the winter period, thus, its transportation involves extra costs for sludge warming up. To resolve the above-mentioned problem, the following works were performed in 2016: - experimental studies of how the application of the low-molecular anionic flocculate “SEURVEY” FL-3 influences sludge humidity reduction. - experimental studies of how the filtering press process operation parameters influence sludge humidity reduction. The new flocculate application didn't lower the dehydrated sludge humidity (the objective was the humidity of not more than 15%). Basing upon the conducted research results, we can make a conclusion that putting into operation the sewage water reactant treatment technology with the use of “SEURVEY”, FL-3 (H-10) is not recommended. The research of the influence the filtering press process parameters have on the dehydration process intensification demonstrated that reaching of the obtained residue humidity value lower than 15% is possible under the reduction of the filtering press chamber depths to 30 mm and with the application of additional operation “Residue drying” with compressed air. This way of the sludge dehydration problem resolving at filtering presses of the

  1. Bidirectional converter interface for a battery energy storage test bench

    DEFF Research Database (Denmark)

    Trintis, Ionut; Thomas, Stephan; Blank, Tobias

    2011-01-01

    This paper presents the bidirectional converter interface for a 6 kV battery energy storage test bench. The power electronic interface consists a two stage converter topology having a low voltage dc-ac grid connected converter and a new dual active bridge dc-dc converter with high transformation...... ratio. The dc-dc converter controls the battery charge/discharge current while the grid converter controls the common dc-link voltage and the grid current. The applied control structures and the hardware implementation of both converters are presented, together with their interaction. Experimental...

  2. Tunable catalytic properties of bi-functional mixed oxides in ethanol conversion to high value compounds

    Energy Technology Data Exchange (ETDEWEB)

    Ramasamy, Karthikeyan K.; Gray, Michel J.; Job, Heather M.; Smith, Colin D.; Wang, Yong

    2016-04-10

    tA highly versatile ethanol conversion process to selectively generate high value compounds is pre-sented here. By changing the reaction temperature, ethanol can be selectively converted to >C2alcohols/oxygenates or phenolic compounds over hydrotalcite derived bi-functional MgO–Al2O3cata-lyst via complex cascade mechanism. Reaction temperature plays a role in whether aldol condensationor the acetone formation is the path taken in changing the product composition. This article containsthe catalytic activity comparison between the mono-functional and physical mixture counterpart to thehydrotalcite derived mixed oxides and the detailed discussion on the reaction mechanisms.

  3. Catalytic conversion of alcohols having at least three carbon atoms to hydrocarbon blendstock

    Science.gov (United States)

    Narula, Chaitanya K.; Davison, Brian H.

    2015-11-13

    A method for producing a hydrocarbon blendstock, the method comprising contacting at least one saturated acyclic alcohol having at least three and up to ten carbon atoms with a metal-loaded zeolite catalyst at a temperature of at least 100°C and up to 550°C, wherein the metal is a positively-charged metal ion, and the metal-loaded zeolite catalyst is catalytically active for converting the alcohol to the hydrocarbon blendstock, wherein the method directly produces a hydrocarbon blendstock having less than 1 vol % ethylene and at least 35 vol % of hydrocarbon compounds containing at least eight carbon atoms.

  4. Catalytic Hydrodechlorination of Trichlorobenzenes with Pd(PhenCl2 as Catalyst Precursor

    Directory of Open Access Journals (Sweden)

    Guanlin Zhang

    2015-01-01

    Full Text Available We reported the catalytic hydrodechlorination (HDC of trichlorobenzenes by an organometallic compound Pd(PhenCl2 as a catalyst precursor. The catalyst precursor was prepared by chemical coordination reaction and characterized by FTIR and 1H NMR techniques. The HDC performance of Pd(PhenCl2 as catalyst precursor was evaluated on 1,2,3-, 1,2,4-, and 1,3,5-trichlorobenzenes (TCBs. All TCBs could be converted to dechlorination products with high conversion. Products distribution was closely related with the substrate structures and C-Cl bond energies. A reasonable reaction mechanism was also proposed.

  5. Catalytic conversion of alcohols having at least three carbon atoms to hydrocarbon blendstock

    Energy Technology Data Exchange (ETDEWEB)

    Narula, Chaitanya K.; Davison, Brian H.

    2018-04-17

    A method for producing a hydrocarbon blendstock, the method comprising contacting at least one saturated acyclic alcohol having at least three and up to ten carbon atoms with a metal-loaded zeolite catalyst at a temperature of at least 100.degree. C. and up to 550.degree. C., wherein the metal is a positively-charged metal ion, and the metal-loaded zeolite catalyst is catalytically active for converting the alcohol to the hydrocarbon blendstock, wherein the method directly produces a hydrocarbon blendstock having less than 1 vol % ethylene and at least 35 vol % of hydrocarbon compounds containing at least eight carbon atoms.

  6. Adsorbent catalytic nanoparticles and methods of using the same

    Energy Technology Data Exchange (ETDEWEB)

    Slowing, Igor Ivan; Kandel, Kapil

    2017-01-31

    The present invention provides an adsorbent catalytic nanoparticle including a mesoporous silica nanoparticle having at least one adsorbent functional group bound thereto. The adsorbent catalytic nanoparticle also includes at least one catalytic material. In various embodiments, the present invention provides methods of using and making the adsorbent catalytic nanoparticles. In some examples, the adsorbent catalytic nanoparticles can be used to selectively remove fatty acids from feedstocks for biodiesel, and to hydrotreat the separated fatty acids.

  7. Dividend-Protected Convertible Bonds and the Disappearance

    OpenAIRE

    Grundy, Bruce D.; Verwijmeren, Patrick

    2012-01-01

    Firms have not historically called their convertible bonds as soon as they could force conversion. Various explanations for the delay rely on the size of the dividends that bondholders forgo so long as they do not convert. We investigate an important change in convertible security design, namely that more than 95 percent of recent convertible bond issues are dividend-protected. Dividend protection means that the conversion value of the shares into which a bond is convertible is unaffected by ...

  8. Imbalance between pulmonary angiotensin-converting enzyme and angiotensin-converting enzyme 2 activity in acute respiratory distress syndrome

    NARCIS (Netherlands)

    Wosten-van Asperen, Roelie M.; Bos, Albert; Bem, Reinout A.; Dierdorp, Barbara S.; Dekker, Tamara; van Goor, Harry; Kamilic, Jelena; van der Loos, Chris M.; van den Berg, Elske; Bruijn, Martijn; van Woensel, Job B.; Lutter, Rene

    2013-01-01

    Objective: Angiotensin-converting enzyme and its effector peptide angiotensin II have been implicated in the pathogenesis of acute respiratory distress syndrome. Recently, angiotensin-converting enzyme 2 was identified as the counter-regulatory enzyme of angiotensin-converting enzyme that converts

  9. Imbalance between pulmonary angiotensin-converting enzyme and angiotensin-converting enzyme 2 activity in acute respiratory distress syndrome

    NARCIS (Netherlands)

    Wösten-van Asperen, Roelie M.; Bos, Albert P.; Bem, Reinout A.; Dierdorp, Barbara S.; Dekker, Tamara; van Goor, Harry; Kamilic, Jelena; van der Loos, Chris M.; van den Berg, Elske; Bruijn, Martijn; van Woensel, Job B.; Lutter, René

    2013-01-01

    Angiotensin-converting enzyme and its effector peptide angiotensin II have been implicated in the pathogenesis of acute respiratory distress syndrome. Recently, angiotensin-converting enzyme 2 was identified as the counter-regulatory enzyme of angiotensin-converting enzyme that converts angiotensin

  10. Contributions to the theory of catalytic titrations-III Neutralization catalytic titrations.

    Science.gov (United States)

    Gaál, F F; Abramović, B F

    1985-07-01

    Neutralization catalytic titrations of weak monoprotic adds and bases with both volumetric and coulometric addition of the titrant (strong base/acid) have been simulated by taking into account the equilibrium concentration of the catalyst during the titration. The influence of several factors on the shape of the simulated catalytic titration curve has been investigated and is discussed.

  11. Multi-output DC-DC converters based on diode-clamped converters configuration

    DEFF Research Database (Denmark)

    Nami, A.; Zare, F.; Ghosh, A.

    2010-01-01

    for a diode-clamed inverter in the grid connection systems, where boosting low rectified output-voltage and series DC link capacitors is required. To verify the proposed topology, steady-state and dynamic analyses of a MOB converter are examined. A simple control strategy has been proposed to demonstrate......This study presents a new DC DC multi-output boost (MOB) converter which can share its total output between different series of output voltages for low- and high-power applications. This configuration can be utilised instead of several single output power supplies. This is a compatible topology...... the performance of the proposed topology for a double-output boost converter. The topology and its control strategy can easily be extended to offer multiple outputs. Simulation and experimental results are presented to show the validity of the control strategy for the proposed converter....

  12. Analog-digital converters for industrial applications including an introduction to digital-analog converters

    CERN Document Server

    Ohnhäuser, Frank

    2015-01-01

    This book offers students and those new to the topic of analog-to-digital converters (ADCs) a broad introduction, before going into details of the state-of-the-art design techniques for SAR and DS converters, including the latest research topics, which are valuable for IC design engineers as well as users of ADCs in applications. The book then addresses important topics, such as correct connectivity of ADCs in an application, the verification, characterization and testing of ADCs that ensure high-quality end products. Analog-to-digital converters are the central element in any data processing system and regulation loops such as modems or electrical motor drives. They significantly affect the performance and resolution of a system or end product. System development engineers need to be familiar with the performance parameters of the converters and understand the advantages and disadvantages of the various architectures. Integrated circuit development engineers have to overcome the problem of achieving high per...

  13. Atomically Precise Metal Nanoclusters for Catalytic Application

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Rongchao [Carnegie Mellon Univ., Pittsburgh, PA (United States)

    2016-11-18

    The central goal of this project is to explore the catalytic application of atomically precise gold nanoclusters. By solving the total structures of ligand-protected nanoclusters, we aim to correlate the catalytic properties of metal nanoclusters with their atomic/electronic structures. Such correlation unravel some fundamental aspects of nanocatalysis, such as the nature of particle size effect, origin of catalytic selectivity, particle-support interactions, the identification of catalytically active centers, etc. The well-defined nanocluster catalysts mediate the knowledge gap between single crystal model catalysts and real-world conventional nanocatalysts. These nanoclusters also hold great promise in catalyzing certain types of reactions with extraordinarily high selectivity. These aims are in line with the overall goals of the catalytic science and technology of DOE and advance the BES mission “to support fundamental research to understand, predict, and ultimately control matter and energy at the level of electrons, atoms, and molecules”. Our group has successfully prepared different sized, robust gold nanoclusters protected by thiolates, such as Au25(SR)18, Au28(SR)20, Au38(SR)24, Au99(SR)42, Au144(SR)60, etc. Some of these nanoclusters have been crystallographically characterized through X-ray crystallography. These ultrasmall nanoclusters (< 2 nm diameter) exhibit discrete electronic structures due to quantum size effect, as opposed to quasicontinuous band structure of conventional metal nanoparticles or bulk metals. The available atomic structures (metal core plus surface ligands) of nanoclusters serve as the basis for structure-property correlations. We have investigated the unique catalytic properties of nanoclusters (i.e. not observed in conventional nanogold catalysts) and revealed the structure-selectivity relationships. Highlights of our

  14. Strained quantum well photovoltaic energy converter

    Science.gov (United States)

    Freundlich, Alexandre (Inventor); Renaud, Philippe (Inventor); Vilela, Mauro Francisco (Inventor); Bensaoula, Abdelhak (Inventor)

    1998-01-01

    An indium phosphide photovoltaic cell is provided where one or more quantum wells are introduced between the conventional p-conductivity and n-conductivity indium phosphide layer. The approach allows the cell to convert the light over a wider range of wavelengths than a conventional single junction cell and in particular convert efficiently transparency losses of the indium phosphide conventional cell. The approach hence may be used to increase the cell current output. A method of fabrication of photovoltaic devices is provided where ternary InAsP and InGaAs alloys are used as well material in the quantum well region and results in an increase of the cell current output.

  15. Flower-petal mode converter for NLC

    International Nuclear Information System (INIS)

    Hoag, H.A.; Tantawi, S.G.; Callin, R.; Deruyter, H.; Farkas, Z.D.; Ko, K.; Kroll, N.; Lavine, T.L.; Menegat, A.; Vlieks, A.E.

    1993-01-01

    It is important to minimize power loss in the waveguide system connecting klystron, pulse-compressor, and accelerator in an X-Band NLC. However, existing designs of klystron output cavity circuits and accelerator input couplers utilize rectangular waveguide which has relatively high transmission loss. It is therefore necessary to convert to and from the low-loss mode in circulator waveguide at each end of the system. A description is given of development work on high-power, high-vacuum open-quote flower-petal close-quote transducers, which convert the TE 10 mode in rectangular guide to the TE 01 mode in circular guide. A three-port modification of the flower petal device, which can be used as either a power combiner at the klystron or a power divider at the accelerator is also described

  16. Converter topologies for common mode voltage reduction

    Science.gov (United States)

    Rodriguez, Fernando

    2017-11-21

    An inverter includes a three-winding transformer, a DC-AC inverter electrically coupled to the first winding of the transformer, a cycloconverter electrically coupled to the second winding of the transformer, and an active filter electrically coupled to the third winding of the transformer. The DC-AC inverter is adapted to convert the input DC waveform to an AC waveform delivered to the transformer at the first winding. The cycloconverter is adapted to convert an AC waveform received at the second winding of the transformer to the output AC waveform having a grid frequency of the AC grid. The active filter is adapted to sink and source power with one or more energy storage devices based on a mismatch in power between the DC source and the AC grid. At least two of the DC-AC inverter, the cycloconverter, or the active filter are electrically coupled via a common reference electrical interconnect.

  17. Flower-petal mode converter for NLC

    International Nuclear Information System (INIS)

    Hoag, H.A.; Tantawi, S.G.; Callin, R.

    1993-04-01

    It is important to minimize power loss in the waveguide system connecting klystron, pulse-compressor, and accelerator in an X-Band NLC. However, existing designs of klystron output cavity circuits and accelerator input couplers utilize rectangular waveguide which has relatively high transmission loss. It is therefore necessary to convert to and from the low-loss mode in circular waveguide at each end of the system. A description is given of development work on high-power, high-vacuum 'flower-petal' transducers, which convert the TE 10 mode in rectangular guide to the TE 01 mode in circular guide. A three-port modification of the flower petal device, which can be used as either a power combiner at the klystron or a power divider at the accelerator is also described

  18. MAGIC: Model and Graphic Information Converter

    Science.gov (United States)

    Herbert, W. C.

    2009-01-01

    MAGIC is a software tool capable of converting highly detailed 3D models from an open, standard format, VRML 2.0/97, into the proprietary DTS file format used by the Torque Game Engine from GarageGames. MAGIC is used to convert 3D simulations from authoritative sources into the data needed to run the simulations in NASA's Distributed Observer Network. The Distributed Observer Network (DON) is a simulation presentation tool built by NASA to facilitate the simulation sharing requirements of the Data Presentation and Visualization effort within the Constellation Program. DON is built on top of the Torque Game Engine (TGE) and has chosen TGE's Dynamix Three Space (DTS) file format to represent 3D objects within simulations.

  19. MOCCASIN: converting MATLAB ODE models to SBML.

    Science.gov (United States)

    Gómez, Harold F; Hucka, Michael; Keating, Sarah M; Nudelman, German; Iber, Dagmar; Sealfon, Stuart C

    2016-06-15

    MATLAB is popular in biological research for creating and simulating models that use ordinary differential equations (ODEs). However, sharing or using these models outside of MATLAB is often problematic. A community standard such as Systems Biology Markup Language (SBML) can serve as a neutral exchange format, but translating models from MATLAB to SBML can be challenging-especially for legacy models not written with translation in mind. We developed MOCCASIN (Model ODE Converter for Creating Automated SBML INteroperability) to help. MOCCASIN can convert ODE-based MATLAB models of biochemical reaction networks into the SBML format. MOCCASIN is available under the terms of the LGPL 2.1 license (http://www.gnu.org/licenses/lgpl-2.1.html). Source code, binaries and test cases can be freely obtained from https://github.com/sbmlteam/moccasin : mhucka@caltech.edu More information is available at https://github.com/sbmlteam/moccasin. © The Author 2016. Published by Oxford University Press.

  20. Optical analog-to-digital converter

    Science.gov (United States)

    Vawter, G Allen [Corrales, NM; Raring, James [Goleta, CA; Skogen, Erik J [Albuquerque, NM

    2009-07-21

    An optical analog-to-digital converter (ADC) is disclosed which converts an input optical analog signal to an output optical digital signal at a sampling rate defined by a sampling optical signal. Each bit of the digital representation is separately determined using an optical waveguide interferometer and an optical thresholding element. The interferometer uses the optical analog signal and the sampling optical signal to generate a sinusoidally-varying output signal using cross-phase-modulation (XPM) or a photocurrent generated from the optical analog signal. The sinusoidally-varying output signal is then digitized by the thresholding element, which includes a saturable absorber or at least one semiconductor optical amplifier, to form the optical digital signal which can be output either in parallel or serially.

  1. An Evaluation of the Vapor Phase Catalytic Ammonia Removal Process for Use in a Mars Transit Vehicle

    Science.gov (United States)

    Flynn, Michael; Borchers, Bruce

    1998-01-01

    An experimental program has been developed to evaluate the potential of the Vapor Phase Catalytic Ammonia Reduction (VPCAR) technology for use as a Mars Transit Vehicle water purification system. Design modifications which will be required to ensure proper operation of the VPCAR system in reduced gravity are also evaluated. The VPCAR system is an integrated wastewater treatment technology that combines a distillation process with high temperature catalytic oxidation. The distillation portion of the system utilizes a vapor compression distillation process to provide an energy efficient phase change separation. This portion of the system removes any inorganic salts and large molecular weight, organic contaminates, i.e., non-volatile, from the product water stream and concentrates these contaminates into a byproduct stream. To oxidize the volatile organic compounds and ammonia, a vapor phase, high temperature catalytic oxidizer is used. This catalytic system converts these compounds along with the aqueous product into CO2, H2O, and N2O. A secondary catalytic bed can then be used to reduce the N2O to nitrogen and oxygen (although not evaluated in this study). This paper describes the design specification of the VPCAR process, the relative benefits of its utilization in a Mars Transit Vehicle, and the design modification which will be required to ensure its proper operation in reduced gravity. In addition, the results of an experimental evaluation of the processors is presented. This evaluation presents the processors performance based upon product water purity, water recovery rates, and power.

  2. Catalytic Combustor for Fuel-Flexible Turbine

    Energy Technology Data Exchange (ETDEWEB)

    W. R. Laster; E. Anoshkina

    2008-01-31

    Under the sponsorship of the U. S. Department of Energy's National Energy Technology Laboratory, Siemens Westinghouse has conducted a three-year program to develop an ultra low NOx, fuel flexible catalytic combustor for gas turbine application in IGCC. The program is defined in three phases: Phase 1 - Implementation Plan, Phase 2 - Validation Testing and Phase 3 - Field Testing. Both Phase 1 and Phase 2 of the program have been completed. In IGCC power plants, the gas turbine must be capable of operating on syngas as a primary fuel and an available back-up fuel such as natural gas. In this program the Rich Catalytic Lean (RCLTM) technology is being developed as an ultra low NOx combustor. In this concept, ultra low NOx is achieved by stabilizing a lean premix combustion process by using a catalytic reactor to oxidize a portion of the fuel, increasing the temperature of fuel/air mixture prior to the main combustion zone. In Phase 1, the feasibility of the catalytic concept for syngas application has been evaluated and the key technology issues identified. In Phase II the technology necessary for the application of the catalytic concept to IGCC fuels was developed through detailed design and subscale testing. Phase III (currently not funded) will consist of full-scale combustor basket testing on natural gas and syngas.

  3. Catalytic Combustor for Fuel-Flexible Turbine

    Energy Technology Data Exchange (ETDEWEB)

    Laster, W. R.; Anoshkina, E.

    2008-01-31

    Under the sponsorship of the U. S. Department of Energy’s National Energy Technology Laboratory, Siemens Westinghouse has conducted a three-year program to develop an ultra low NOx, fuel flexible catalytic combustor for gas turbine application in IGCC. The program is defined in three phases: Phase 1- Implementation Plan, Phase 2- Validation Testing and Phase 3 – Field Testing. Both Phase 1 and Phase 2 of the program have been completed. In IGCC power plants, the gas turbine must be capable of operating on syngas as a primary fuel and an available back-up fuel such as natural gas. In this program the Rich Catalytic Lean (RCLTM) technology is being developed as an ultra low NOx combustor. In this concept, ultra low NOx is achieved by stabilizing a lean premix combustion process by using a catalytic reactor to oxidize a portion of the fuel, increasing the temperature of fuel/air mixture prior to the main combustion zone. In Phase 1, the feasibility of the catalytic concept for syngas application has been evaluated and the key technology issues identified. In Phase II the technology necessary for the application of the catalytic concept to IGCC fuels was developed through detailed design and subscale testing. Phase III (currently not funded) will consist of full-scale combustor basket testing on natural gas and syngas.

  4. Method for Converter Synchronization with RF Injection

    OpenAIRE

    Joshua P. Bruckmeyer; Ivica Kostanic

    2015-01-01

    This paper presents an injection method for synchronizing analog to digital converters (ADC). This approach can eliminate the need for precision routed discrete synchronization signals of current technologies, such as JESD204. By eliminating the setup and hold time requirements at the conversion (or near conversion) clock rate, higher sample rate systems can be synchronized. Measured data from an existing multiple ADC conversion system was used to evaluate the method. Coherent beams were simu...

  5. Combined analog-to-digital converter

    International Nuclear Information System (INIS)

    Zhukov, A.V.; Rzhendinskaya, S.N.

    1983-01-01

    A 10-bit analog-to-digital converter (ADC) designed for operating in spectrometers with time-dependent filters is described. The ADC operation is based on combining the parallel reading and sequential counting methods. At maximum conversion time of 12 μs, timing series frequency of 25 MHz and foUr reference levels the differential nonlinearity withoUt statistical smoothing (maximum relative channel width deviation from average value) is not more than 4%

  6. Spectral converters and luminescent solar concentrators

    Energy Technology Data Exchange (ETDEWEB)

    Scudo, Petra F.; Abbondanza, Luigi; Fusco, Roberto; Caccianotti, Luciano [Eni S.p.A, Research Center for Non-Conventional Energies - Istituto ENI Donegani, Via G.Fauser 4, 28100 Novara (Italy)

    2010-07-15

    In this paper we present a comprehensive theoretical description of molecular spectral converters in the specific context of luminescent solar concentrators (LSCs). The theoretical model is an extension to a three-level system interacting with a solar radiation bath of the standard quantum theory of atomic radiative processes. We derive the equilibrium equations of the conversion process and provide specific examples of application of this principle to the development of solar concentration devices. (author)

  7. Passive components used in power converters

    OpenAIRE

    Rufer, A; Veestra, M; Barrade, P

    2006-01-01

    In power converters, passive components play an important role, and have in general specific nature and properties. The goal of this tutorial is to give an overview, first on inductive components for power conversion, and second on dedicated power capacitors. In a third part, new components— supercapacitors—will be presented. Generally, inductors for power applications must be custom designed. In this tutorial, the most important effects encountered when realising inductive components will be...

  8. MOCCASIN: converting MATLAB ODE models to SBML

    OpenAIRE

    G?mez, Harold F.; Hucka, Michael; Keating, Sarah M.; Nudelman, German; Iber, Dagmar; Sealfon, Stuart C.

    2016-01-01

    Summary: MATLAB is popular in biological research for creating and simulating models that use ordinary differential equations (ODEs). However, sharing or using these models outside of MATLAB is often problematic. A community standard such as Systems Biology Markup Language (SBML) can serve as a neutral exchange format, but translating models from MATLAB to SBML can be challenging?especially for legacy models not written with translation in mind. We developed MOCCASIN (Model ODE Converter for ...

  9. Generalized modular multilevel converter and modulation

    DEFF Research Database (Denmark)

    Liu, Hui; Loh, Poh Chiang; Blaabjerg, Frede

    2014-01-01

    Modular multilevel converter (MMC) has gained popularity recently with its modulation, capacitor voltage balancing and circulating current issues widely discussed. Contributing to this effort, a study is presented here to show how the MMC topology can be derived from the viewpoint of two series....... For controlling the GMMC, a simple modulation scheme is also presented, where the goal is to achieve the desired performance at a minimized complexity. Simulation results are presented to illustrate the operation of the proposed topology....

  10. Characteristics of image converters and image intensifiers

    International Nuclear Information System (INIS)

    Gurvich, A.M.; Shamanov, A.A.; Rozenberg, A.M.; Fajnberg, V.S.; Kavtorova, V.P.; Salyuk, L.V.; Yakovleva, F.B.

    1978-01-01

    The characteristics of image converters and image intensifiers, which determine the range of the X-radiation dose rates used and the image quality, are considered. The equations for calculating the requirements to be imposed on the separate intensifier elements from known parameters of other elements with an allowance for the nonlinearity of the television system and the role of fluctuation in the space distribution of X-radiation quanta are given

  11. H- ion production from different converter materials

    International Nuclear Information System (INIS)

    Leung, K.N.; Ehlers, K.W.

    1984-10-01

    For heating plasmas and for current drive in some fusion reactors, high energy neutral beams may be required. The high neutralization efficiency of H - or D - ions makes them favorable to form neutral atoms with energies in excess of 160 keV. It has been shown that a steady-state H - ion beam with current greater than 1 A can be generated by a surface conversion type source with Mo being used as the converter material. In order to achieve the proper cesium coverage and thereby increasing the H - ion yield, the application of porous cesium-dispensing converters is being investigated. It is also possible to optimize the H - production by choosing the proper converter material. In this paper, we compare the negative ion yield generated by different materials (such as Mo, Ti, V, Nb, Pt, Pd, Rh, Cu, Ta, Al, Au, LaB 6 and stainless-steel) in the pure hydrogen and cesium-hydrogen modes of operation

  12. Converter fed sub sea motor drives

    Energy Technology Data Exchange (ETDEWEB)

    Raad, R.O.

    1995-09-01

    Minor offshore gas and oil resources located 20-50 km from existing installations may often be commercially exploited only by use of complete sub sea solutions. This thesis deals with analyses of a sub sea adjustable speed electric motor which is fed by a frequency converter via a long cable (up to 50 km) between the converter and the motor. The author develops a general model for analysing such motor drive systems with the objective of verifying the feasibility of specific applications and of specifying the requirements on the system components. The simulation model is used to identify the critical frequency ranges in which the converter must not generate significant harmonics, to verify the start-up strategy chosen, and to verify the stability with potential disturbances applied to the system. Simulation models are developed for both transient and steady state analyses. They are accurate up to 5 kHz and can incorporate the frequency dependency of the motor and cable parameters. Ideal thyristors and diodes are used. The models are implemented in existing simulation tools. Most of the results relate to a base case with a 670 kW squirrel cage motor fed from a 30 km long cable, but cases with 3 MW rating or with 50 km cable have also been analyzed and found to be feasible. Each specific application must be separately studied. Results of simulation calculations are presented and conclusions given. 53 refs., 124 figs., 23 tabs.

  13. Electro Catalytic Oxidation (ECO) Operation

    Energy Technology Data Exchange (ETDEWEB)

    Morgan Jones

    2011-03-31

    The power industry in the United States is faced with meeting many new regulations to reduce a number of air pollutants including sulfur dioxide, nitrogen oxides, fine particulate matter, and mercury. With over 1,000 power plants in the US, this is a daunting task. In some cases, traditional pollution control technologies such as wet scrubbers and SCRs are not feasible. Powerspan's Electro-Catalytic Oxidation, or ECO{reg_sign} process combines four pollution control devices into a single integrated system that can be installed after a power plant's particulate control device. Besides achieving major reductions in emissions of sulfur dioxide (SO{sub 2}), nitrogen oxides (NOx), fine particulate matter (PM2.5) and mercury (Hg), ECO produces a highly marketable fertilizer, which can help offset the operating costs of the process system. Powerspan has been operating a 50-MW ECO commercial demonstration unit (CDU) at FirstEnergy Corp.'s R.E. Burger Plant near Shadyside, Ohio, since February 2004. In addition to the CDU, a test loop has been constructed beside the CDU to demonstrate higher NOx removal rates and test various scrubber packing types and wet ESP configurations. Furthermore, Powerspan has developed the ECO{reg_sign}{sub 2} technology, a regenerative process that uses a proprietary solvent to capture CO{sub 2} from flue gas. The CO{sub 2} capture takes place after the capture of NOx, SO{sub 2}, mercury, and fine particulate matter. Once the CO{sub 2} is captured, the proprietary solution is regenerated to release CO{sub 2} in a form that is ready for geological storage or beneficial use. Pilot scale testing of ECO{sub 2} began in early 2009 at FirstEnergy's Burger Plant. The ECO{sub 2} pilot unit is designed to process a 1-MW flue gas stream and produce 20 tons of CO{sub 2} per day, achieving a 90% CO{sub 2} capture rate. The ECO{sub 2} pilot program provided the opportunity to confirm process design and cost estimates, and prepare for large

  14. Highly Dense Isolated Metal Atom Catalytic Sites

    DEFF Research Database (Denmark)

    Chen, Yaxin; Kasama, Takeshi; Huang, Zhiwei

    2015-01-01

    -ray diffraction. A combination of electron microscopy images with X-ray absorption spectra demonstrated that the silver atoms were anchored on five-fold oxygen-terminated cavities on the surface of the support to form highly dense isolated metal active sites, leading to excellent reactivity in catalytic oxidation......Atomically dispersed noble-metal catalysts with highly dense active sites are promising materials with which to maximise metal efficiency and to enhance catalytic performance; however, their fabrication remains challenging because metal atoms are prone to sintering, especially at a high metal...... loading. A dynamic process of formation of isolated metal atom catalytic sites on the surface of the support, which was achieved starting from silver nanoparticles by using a thermal surface-mediated diffusion method, was observed directly by using in situ electron microscopy and in situ synchrotron X...

  15. Catalytic Organic Transformations Mediated by Actinide Complexes

    Directory of Open Access Journals (Sweden)

    Isabell S. R. Karmel

    2015-10-01

    Full Text Available This review article presents the development of organoactinides and actinide coordination complexes as catalysts for homogeneous organic transformations. This chapter introduces the basic principles of actinide catalysis and deals with the historic development of actinide complexes in catalytic processes. The application of organoactinides in homogeneous catalysis is exemplified in the hydroelementation reactions, such as the hydroamination, hydrosilylation, hydroalkoxylation and hydrothiolation of alkynes. Additionally, the use of actinide coordination complexes for the catalytic polymerization of α-olefins and the ring opening polymerization of cyclic esters is presented. The last part of this review article highlights novel catalytic transformations mediated by actinide compounds and gives an outlook to the further potential of this field.

  16. One-Quadrant Switched-Mode Power Converters

    CERN Document Server

    Petrocelli, R.

    2015-06-15

    This article presents the main topics related to one-quadrant power convert- ers. The basic topologies are analysed and a simple methodology to obtain the steady-state output–input voltage ratio is set out. A short discussion of dif- ferent methods to control one-quadrant power converters is presented. Some of the reported derived topologies of one-quadrant power converters are also considered. Some topics related to one-quadrant power converters such as syn- chronous rectification, hard and soft commutation, and interleaved converters are discussed. Finally, a brief introduction to resonant converters is given.

  17. Toward a catalytic site in DNA

    DEFF Research Database (Denmark)

    Jakobsen, Ulla; Rohr, Katja; Vogel, Stefan

    2007-01-01

    A number of functionalized polyaza crown ether building blocks have been incorporated into DNA-conjugates as catalytic Cu(2+) binding sites. The effect of the DNA-conjugate catalyst on the stereochemical outcome of a Cu(2+)-catalyzed Diels-Alder reaction will be presented.......A number of functionalized polyaza crown ether building blocks have been incorporated into DNA-conjugates as catalytic Cu(2+) binding sites. The effect of the DNA-conjugate catalyst on the stereochemical outcome of a Cu(2+)-catalyzed Diels-Alder reaction will be presented....

  18. Thermal and catalytic pyrolysis of plastic waste

    Directory of Open Access Journals (Sweden)

    Débora Almeida

    2016-02-01

    Full Text Available Abstract The amount of plastic waste is growing every year and with that comes an environmental concern regarding this problem. Pyrolysis as a tertiary recycling process is presented as a solution. Pyrolysis can be thermal or catalytical and can be performed under different experimental conditions. These conditions affect the type and amount of product obtained. With the pyrolysis process, products can be obtained with high added value, such as fuel oils and feedstock for new products. Zeolites can be used as catalysts in catalytic pyrolysis and influence the final products obtained.

  19. Catalytic Wastewater Treatment Using Pillared Clays

    Science.gov (United States)

    Perathoner, Siglinda; Centi, Gabriele

    After introduction on the use of solid catalysts in wastewater treatment technologies, particularly advanced oxidation processes (AOPs), this review discussed the use of pillared clay (PILC) materials in three applications: (i) wet air catalytic oxidation (WACO), (ii) wet hydrogen peroxide catalytic oxidation (WHPCO) on Cu-PILC and Fe-PILC, and (iii) behavior of Ti-PILC and Fe-PILC in the photocatalytic or photo-Fenton conversion of pollutants. Literature data are critically analyzed to evidence the main direction to further investigate, in particularly with reference to the possible practical application of these technologies to treat industrial, municipal, or agro-food production wastewater.

  20. Catalytic gasification of oil-shales

    Energy Technology Data Exchange (ETDEWEB)

    Lapidus, A.; Avakyan, T. [I.M. Gubkin Russian State Univ. of Oil and Gas, Moscow (Russian Federation); Strizhakova, Yu. [Samara State Univ. (Russian Federation)

    2012-07-01

    Nowadays, the problem of complex usage of solid fossil fuels as raw materials for obtaining of motor fuels and chemical products is becoming increasingly important. A one of possible solutions of the problem is their gasification with further processing of gaseous and liquid products. In this work we have investigated the process of thermal and catalytic gasification of Baltic and Kashpir oil-shales. We have shown that, as compared with non-catalytic process, using of nickel catalyst in the reaction increases the yield of gas, as well as hydrogen content in it, and decreases the amount of liquid products. (orig.)

  1. Nanorods of manganese oxides: Synthesis, characterization and catalytic application

    Science.gov (United States)

    Yang, Zeheng; Zhang, Yuancheng; Zhang, Weixin; Wang, Xue; Qian, Yitai; Wen, Xiaogang; Yang, Shihe

    2006-03-01

    Single-crystalline nanorods of β-MnO 2, α-Mn 2O 3 and Mn 3O 4 were successfully synthesized via the heat-treatment of γ-MnOOH nanorods, which were prepared through a hydrothermal method in advance. The calcination process of γ-MnOOH nanorods was studied with the help of Thermogravimetric analysis and X-ray powder diffraction. When the calcinations were conducted in air from 250 to 1050 °C, the precursor γ-MnOOH was first changed to β-MnO 2, then to α-Mn 2O 3 and finally to Mn 3O 4. When calcined in N 2 atmosphere, γ-MnOOH was directly converted into Mn 3O 4 at as low as 500 °C. Transmission electron microscopy (TEM) and high-resolution TEM were also used to characterize the products. The obtained manganese oxides maintain the one-dimensional morphology similar to the precursor γ-MnOOH nanorods. Further experiments show that the as-prepared manganese oxide nanorods have catalytic effect on the oxidation and decomposition of the methylene blue (MB) dye with H 2O 2.

  2. Catalytic oxidation of NO to NO2 on activated carbon

    International Nuclear Information System (INIS)

    Zhancheng Guo; Yusheng Xie

    2001-01-01

    Catalytic oxidation of NO to NO 2 over activated carbons PAN-ACF, pitch-ACF and coconut-AC at room temperature (30 o C) were studied to develop a method based on oxidative removal of NO from flue gases. For a dry gas, under the conditions of a gas space flow rate 1500 h -1 in the presence of oxygen of 2-20% in volume concentration, the activated coconut carbon with a surface area 1200 m 2 /g converted about 81-94% of NO with increasing oxygen concentration, the pitch based activated carbon fiber with a surface area 1000 m 2 /g about 44-75%, and the polyacrylonitrile-based activated carbon fiber with a surface area 1810 m 2 /g about 25-68%. The order of activity of the activated carbons was PAN-ACF c P NO P O2 β (F/W), where β is 0.042, 0.16, 0.31 for the coconut-AC, the pitch-ACF and the PAN-ACF respectively, and k c is 0.94 at 30 o C. (author)

  3. Molecular dynamics characterization of five pathogenic factor X mutants associated with decreased catalytic activity

    KAUST Repository

    Abdel-Azeim, Safwat

    2014-11-11

    Factor X (FX) is one of the major players in the blood coagulation cascade. Upon activation to FXa, it converts prothrombin to thrombin, which in turn converts fibrinogen into fibrin (blood clots). FXa deficiency causes hemostasis defects, such as intracranial bleeding, hemathrosis, and gastrointestinal blood loss. Herein, we have analyzed a pool of pathogenic mutations, located in the FXa catalytic domain and directly associated with defects in enzyme catalytic activity. Using chymotrypsinogen numbering, they correspond to D102N, T135M, V160A, G184S, and G197D. Molecular dynamics simulations were performed for 1.68 μs on the wild-type and mutated forms of FXa. Overall, our analysis shows that four of the five mutants considered, D102N, T135M, V160A, and G184S, have rigidities higher than those of the wild type, in terms of both overall protein motion and, specifically, subpocket S4 flexibility, while S1 is rather insensitive to the mutation. This acquired rigidity can clearly impact the substrate recognition of the mutants.

  4. Heterogeneous Catalytic Oligomerization of Ethylene

    Science.gov (United States)

    Jan, Oliver Dennis

    increased with temperature, with 17 wt.% observed at 190ºC. Higher reaction temperatures led to the formation of odd-numbered oligomers primarily due to acid-catalyzed cracking reactions. In the range of space velocities tested, a moderate WHSV of 2.0 hr-1 resulted in a local maximum of 10.6 wt.% of liquid hydrocarbon yield. A moderate nickel loading of 3.4 wt.% also resulted in the highest liquid yield out of the three loadings tested (10.6 wt.%). The variation in nickel loading revealed the importance of having a synergistic balance of nickel and acid sites on the catalyst to maximize ethylene conversion and maintain high liquid hydrocarbon yield. Lastly, we used supercritical ethylene as both a solvent and as a reactant for ethylene oligomerization over two silica-alumina type catalysts: Ni-Hbeta and Ni-Al-SBA-15. Specifically, the effect of pressure and temperature on the overall conversion and product selectivity were evaluated in the range from 0 to 65 bar and 30 to 120ºC. At subcritical conditions, the ethylene conversion reached a plateau of around 50%. By increasing the pressure past the critical point of ethylene, the conversion drastically increased to 71%. The increased conversion can be attributed to the solubility of certain oligomers, namely butene, in supercritical ethylene that promotes desorption from catalytic active site before further oligomerization. We also tested a mesoporous catalyst, Ni-Al-SBA-15 and observed conversion trends analogous to that of Ni-Hbeta. At supercritical conditions, ethylene oligomerization over Ni-Al-SBA-15 was more selective towards the butene product, with nearly 74 wt.% butenes observed. The catalyst activity increased with temperature from 30ºC to 120ºC. The experiment conducted at 30ºC showed very little activity and ethylene conversion, however it effectively heavy molecular weight species from the catalyst. This condition, albeit being not effective for ethylene oligomerization, could be implemented as an in

  5. EVALUATING CONVERTIBLE, CALLABLE AND REDEEMABLE BONDS

    OpenAIRE

    GIULIANO CARROZZA UZEDA IORIO DE SOUZA

    2006-01-01

    Em artigo publicado em 1986 no Journal of Finance, LYON Taming [35], John McConnell e Eduardo Schwartz desenvolveram um modelo para apreçamento do Liquid Yield Option Notes (LYON), um título que não contempla o pagamento de cupom, em que o investidor possui opção de venda e o direito de convertê-lo em um determinado número de ações do emissor que, por sua vez, possui opção de compra, na qual, assim como no caso da opção de venda, o ativo objeto é o pr...

  6. Layout Optimisation of Wave Energy Converter Arrays

    DEFF Research Database (Denmark)

    Ruiz, Pau Mercadé; Nava, Vincenzo; Topper, Mathew B. R.

    2017-01-01

    This paper proposes an optimisation strategy for the layout design of wave energy converter (WEC) arrays. Optimal layouts are sought so as to maximise the absorbed power given a minimum q-factor, the minimum distance between WECs, and an area of deployment. To guarantee an efficient optimisation......, a four-parameter layout description is proposed. Three different optimisation algorithms are further compared in terms of performance and computational cost. These are the covariance matrix adaptation evolution strategy (CMA), a genetic algorithm (GA) and the glowworm swarm optimisation (GSO) algorithm...

  7. Waste Plastic Converting into Hydrocarbon Fuel Materials

    Energy Technology Data Exchange (ETDEWEB)

    Sarker, Moinuddin; Mamunor Rashid, Mohammad; Molla, Mohammad

    2010-09-15

    The increased demand and high prices for energy sources are driving efforts to convert organic compounds into useful hydrocarbon fuels. Although much of this work has focused on biomass, there are strong benefits to deriving fuels from waste plastic material. Natural State Research Inc. (NSR) has invented a simple and economically viable process to decompose the hydrocarbon polymers of waste plastic into the shorter chain hydrocarbon of liquid fuel (patent pending). The method and principle of the production / process will be discussed. Initial tests with several widely used polymers indicate a high potential for commercialization.

  8. Power converters for medium voltage networks

    CERN Document Server

    Islam, Md Rabiul; Zhu, Jianguo

    2014-01-01

    This book examines a number of topics, mainly in connection with advances in semiconductor devices and magnetic materials and developments in medium and large-scale renewable power plant technologies, grid integration techniques and new converter topologies, including advanced digital control systems for medium-voltage networks. The book's individual chapters provide an extensive compilation of fundamental theories and in-depth information on current research and development trends, while also exploring new approaches to overcoming some critical limitations of conventional grid integration te

  9. Hot carrier metamaterial detectors and energy converters

    Science.gov (United States)

    Krayer, Lisa; Munday, Jeremy N.

    Metamaterials can be used to manipulate the flow of light in ways not typically available with traditional materials. Beyond their optical properties, metamaterials can be used as the basis for optoelectronic devices through the incorporation of a metal-semiconductor interface. The absorbed radiation in the metal can excite surface plasmons, which nonradiatively decay into hot electrons or holes that can be injected into the base semiconductor and contribute to photocurrent generation. In this talk, we will present our latest work on metamaterial photo-detectors and solar energy converters.

  10. Data Converter for Multistandard Mobile Phones

    DEFF Research Database (Denmark)

    Yurttas, Aziz; Bruun, Erik; Jensen, Rasmus Glarborg

    2004-01-01

    This paper describes an analog to digital converter (ADC) for mobile communication systems using a direct down conversion architecture. The ADC can be programmed to meet the requirements of different communication standards, including GSM (Global System for Mobile communication) and WCDMA (Wideband....... The entire ADC consumes about 5.5 mW and occupies an active area of about 0.36 mm(2). A test circuit has been developed and fabricated and measurements show that both the required programmability and the required performance can be obtained using the proposed configurations....

  11. Faults and Diagnosis Systems in Power Converters

    DEFF Research Database (Denmark)

    Lee, Kyo-Beum; Choi, Uimin

    2014-01-01

    efforts have been put into making these systems better in terms of reliability in order to achieve high power source availability, reduce the cost of energy and also increase the reliability of overall systems. Among the components used in power converters, a power device and a capacitor fault occurs most...... frequently. Therefore, it is important to monitor the power device and capacitor fault to increase the reliability of power electronics. In this chapter, the diagnosis methods for power device fault will be discussed by dividing into open- and short-circuit faults. Then, the condition monitoring methods...

  12. A Hybrid Modular Multilevel Converter with Partial Embedded Energy Storage

    Directory of Open Access Journals (Sweden)

    Georgios Konstantinou

    2016-11-01

    Full Text Available Modular and cascaded multilevel converters provide a functional solution for the integration of energy storage systems (ESSs. This paper develops a hybrid multilevel converter based on the modular multilevel converter (MMC that can be functionally extended with partial embedded ESS as a fraction of the overall converter power rating. The configuration, which can operate as a typical DC-AC converter, enables multi-directional power flow between the DC- and AC-side of the converter, as well as the embedded energy storage elements. The use of a three-phase flying-capacitor submodule eliminates the second-order harmonic oscillations present in modular cascaded multilevel converters. Current, voltage and power control are discussed in the paper while simulation results illustrate the operation of the hybrid MMC as a DC-AC converter in a typical inverter application and the additional functions and control of the embedded ESS.

  13. A Review of the Catalytic Mechanism of Human Manganese Superoxide Dismutase

    Directory of Open Access Journals (Sweden)

    Jahaun Azadmanesh

    2018-01-01

    Full Text Available Superoxide dismutases (SODs are necessary antioxidant enzymes that protect cells from reactive oxygen species (ROS. Decreased levels of SODs or mutations that affect their catalytic activity have serious phenotypic consequences. SODs perform their bio-protective role by converting superoxide into oxygen and hydrogen peroxide by cyclic oxidation and reduction reactions with the active site metal. Mutations of SODs can cause cancer of the lung, colon, and lymphatic system, as well as neurodegenerative diseases such as Parkinson’s disease and amyotrophic lateral sclerosis. While SODs have proven to be of significant biological importance since their discovery in 1968, the mechanistic nature of their catalytic function remains elusive. Extensive investigations with a multitude of approaches have tried to unveil the catalytic workings of SODs, but experimental limitations have impeded direct observations of the mechanism. Here, we focus on human MnSOD, the most significant enzyme in protecting against ROS in the human body. Human MnSOD resides in the mitochondrial matrix, the location of up to 90% of cellular ROS generation. We review the current knowledge of the MnSOD enzymatic mechanism and ongoing studies into solving the remaining mysteries.

  14. Synthesis of Bio-aromatics from Black Liquors Using Catalytic Pyrolysis

    Science.gov (United States)

    2018-01-01

    Bio-aromatics (benzene, toluene, xylenes, BTX) were prepared by the catalytic pyrolysis of six different black liquors using both in situ and ex situ approaches. A wide range of catalysts was screened and conditions were optimized in microscale reactors. Up to 7 wt % of BTX, based on the organic fraction of the black liquors, was obtained for both the in situ and ex situ pyrolysis (T = 500–600 °C) using a Ga-modified H-ZSM-5 catalyst. The in situ catalytic pyrolysis of black liquors from hardwood paper mills afforded slightly higher yields of aromatics/BTX than softwood black liquors, a trend that could be confirmed by the results obtained in the ex situ catalytic pyrolysis. An almost full deoxygenation of the lignin and carbohydrate fraction was achieved and both organic fractions were converted to a broad range of (substituted) aromatics. The zeolite catalyst used was remarkably stable and even after 100 experiments in batch mode with intermittent oxidative catalyst regeneration, the yields and selectivity toward BTX remained similar. The ex situ pyrolysis of black liquor has potential for large-scale implementation in a paper mill without disturbing the paper production process. PMID:29607268

  15. Diffuser Optimation at Exhaust System with Catalytic Converter for 110 cc Mopet with Fluid Flow CFD Simulation

    Directory of Open Access Journals (Sweden)

    Tresna Soemardi

    2010-10-01

    Full Text Available CFD simulation used to get behavior of exhaust gas through catalyst, this result will be used to optimize geometry form to perform uniform stream distribution to catalyst, and CFD Simulation will used to analyze backpressure that happened at the model.

  16. Bio-Diesel production and Effect of Catalytic Converter on Emission performance with Bio-Diesel Blends

    OpenAIRE

    R.Murali Manohar; M.Prabhahar; Dr.S.Sendil velan

    2010-01-01

    Bio-Diesel the word itself defines almost all the features of the Bio-Diesel literary. In the Era of this Global Warming where the people are making their living more and more comfortable and they are deteriorating the environment also. The uses of the automobiles with the conventional source of fuel leads to the production of the toxic gaseous substances like carbon monoxide, carbon dioxide, oxides of nitrogen, oxide of sulphur, hydro-carbons etc. The limitation comes with the rise in the pr...

  17. Nitrile-converting enzymes as a tool to improve biocatalysis in organic synthesis: recent insights and promises.

    Science.gov (United States)

    Gong, Jin-Song; Shi, Jin-Song; Lu, Zhen-Ming; Li, Heng; Zhou, Zhe-Min; Xu, Zheng-Hong

    2017-02-01

    Nitrile-converting enzymes, including nitrilase and nitrile hydratase (NHase), have received increasing attention from researchers of industrial biocatalysis because of their critical role as a tool in organic synthesis of carboxylic acids and amides from nitriles. To date, these bioconversion approaches are considered as one of the most potential industrial processes using resting cells or purified enzymes as catalysts for production of food additives, pharmaceutical, and agrochemical precursors. This review focuses on the distribution and catalytic mechanism research of nitrile-converting enzymes in recent years. Molecular biology aspects to improve the biocatalytic performance of microbial nitrilase and NHase are demonstrated. The process developments of microbial nitrilase and NHase for organic synthesis are also discussed.

  18. CATALYTIC SPECTROPHOTOMETRIC DETERMINATION OF Mn(II ...

    African Journals Online (AJOL)

    Preferred Customer

    The aim of the present study was to develop a new precise and accurate catalytic spectrophotometric ... manganese sulfate monohydrate (Merck, Darmstadt, Germany) in water and diluted to 250 mL. The working .... and potassium hydrogen phthalate-HCl buffer solutions, the slope of calibration graph was unsatisfactory.

  19. Catalytic enantioselective conjugate addition with Grignard reagents

    NARCIS (Netherlands)

    Lopez, Fernando; Minnaard, Adriaan J.; Feringa, Ben L.

    In this Account, recent advances in catalytic asymmetric conjugate addition of Grignard reagents are discussed. Synthetic methodology to perform highly enantioselective Cu-catalyzed conjugate addition of Grignard reagents to cyclic enones with ee's up to 96% was reported in 2004 from our

  20. Catalytic models developed through social work

    DEFF Research Database (Denmark)

    Jensen, Mogens

    2015-01-01

    of adolescents placed in out-of-home care and is characterised using three situated cases as empirical data. Afterwards the concept of catalytic processes is briefly presented and then applied in an analysis of pedagogical treatment in the three cases. The result is a different conceptualisation of the social...

  1. Fluid catalytic cracking : Feedstocks and reaction mechanism

    NARCIS (Netherlands)

    Dupain, X.

    2006-01-01

    The Fluid Catalytic Cracking (FCC) process is one of the key units in a modern refinery. Traditionally, its design is primarily aimed for the production of gasoline from heavy oil fractions, but as co-products also diesel blends and valuable gasses (e.g. propene and butenes) are formed in

  2. Catalytic dehydrogenations of ethylbenzene to styrene

    NARCIS (Netherlands)

    Nederlof, C.

    2012-01-01

    This research work on the catalytic dehydrogenation of ethylbenzene (EB) to styrene (ST) had a primary goal of developing improved catalysts for dehydrogenation processes both in CO2 as well as with O2 that can compete with the conventional dehydrogenation process in steam. In order to achieve this

  3. Synthesis, spectroscopic characterization and catalytic oxidation ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 123; Issue 3. Synthesis, spectroscopic characterization and catalytic oxidation properties of ONO/ONS donor Schiff base ruthenium(III) complexes containing PPh3/AsPh3. Priyarega M Muthu Tamizh R Karvembu R Prabhakaran K Natarajan. Volume 123 Issue 3 May ...

  4. DEALUMINATION OF MORDENITE ZEOLITE AND ITS CATALYTIC ...

    African Journals Online (AJOL)

    The xylene mixtures result from the catalytic reforming of petroleum NAFTA and the isomers of xylenes are usually obtained from this mixture by separation. After separation of o-isomers and p-isomers, the remainder richer in m-xylene, needs to be subjected to isomerization [2]. Xylene isomerization has received growing ...

  5. Novel Metal Nanomaterials and Their Catalytic Applications

    Directory of Open Access Journals (Sweden)

    Jiaqing Wang

    2015-09-01

    Full Text Available In the rapidly developing areas of nanotechnology, nano-scale materials as heterogeneous catalysts in the synthesis of organic molecules have gotten more and more attention. In this review, we will summarize the synthesis of several new types of noble metal nanostructures (FePt@Cu nanowires, Pt@Fe2O3 nanowires and bimetallic Pt@Ir nanocomplexes; Pt-Au heterostructures, Au-Pt bimetallic nanocomplexes and Pt/Pd bimetallic nanodendrites; Au nanowires, CuO@Ag nanowires and a series of Pd nanocatalysts and their new catalytic applications in our group, to establish heterogeneous catalytic system in “green” environments. Further study shows that these materials have a higher catalytic activity and selectivity than previously reported nanocrystal catalysts in organic reactions, or show a superior electro-catalytic activity for the oxidation of methanol. The whole process might have a great impact to resolve the energy crisis and the environmental crisis that were caused by traditional chemical engineering. Furthermore, we hope that this article will provide a reference point for the noble metal nanomaterials’ development that leads to new opportunities in nanocatalysis.

  6. Catalytic site interactions in yeast OMP synthase

    DEFF Research Database (Denmark)

    Hansen, Michael Riis; Barr, Eric W.; Jensen, Kaj Frank

    2014-01-01

    45 (2006) 5330-5342]. This behavior was investigated in the yeast enzyme by mutations in the conserved catalytic loop and 5-phosphoribosyl-1-diphosphate (PRPP) binding motif. Although the reaction is mechanistically sequential, the wild-type (WT) enzyme shows parallel lines in double reciprocal...

  7. THEORETICAL STUDY OF CATALYTIC HYDROGENATION OF ...

    African Journals Online (AJOL)

    Preferred Customer

    Catalytic hydrotreating process is a technique of purification of the crude oil with the aim of the improvement of the quality and the stability of fuels and lubricants. This is performed by the destruction of heterocyclic compounds and by the saturation of unsaturated hydrocarbons under the effect of the hydrogen pressure in ...

  8. Electrochemical Promotion of Catalytic Reactions Using

    DEFF Research Database (Denmark)

    Petrushina, Irina; Bjerrum, Niels; Cleemann, Lars Nilausen

    2007-01-01

    This paper presents the results of a study on electrochemical promotion (EP) of catalytic reactions using Pt/C/polybenzimidazole(H3PO4)/Pt/C fuel cell performed by the Energy and Materials Science Group (Technical University of Denmark) during the last 6 years[1-4]. The development of our...

  9. Matrix converter applied to energy saving for street lighting systems

    OpenAIRE

    Román Lumbreras, Manuel; Velasco Quesada, Guillermo; Conesa Roca, Alfons

    2010-01-01

    This work presents a three-phase AC-AC converter, with independent phase control, based on matrix-converter structure. This converter is applied to electrical energy saving on the public lighting systems by means of regulation and control of the voltage applied to the lamps. The developed converter represents a technological improvement with respect to the traditional systems based on an autotransformer: it reduces system cost and volume, and increases lamps lifetime.

  10. A New Modular Multilevel Converter with Integrated Energy Storage

    DEFF Research Database (Denmark)

    Trintis, Ionut; Munk-Nielsen, Stig; Teodorescu, Remus

    2011-01-01

    This paper introduces a new modular converter with integrated energy storage based on the cascaded half-bridge modular multilevel converter with common DC bus. It represents a complete modular solution with power electronics and energy storage building blocks, for medium and high voltage...... in the future HVDC meshed grids. Its functionality and flexibility makes the converter independent on the energy storage unit characteristic. The converter concept with its basic functions and control schemes are described and evaluated in this paper....

  11. Sintering of Catalytic Nanoparticles: Particle Migration or Ostwald Ripening?

    DEFF Research Database (Denmark)

    Hansen, Thomas Willum; DeLaRiva, Andrew T.; Challa, Sivakumar R.

    2013-01-01

    deactivation, is an important mechanism for the loss of catalyst activity. This is especially true for high temperature catalytic processes, such as steam reforming, automotive exhaust treatment, or catalytic combustion. With dwindling supplies of precious metals and increasing demand, fundamental...

  12. New active load voltage clamp for HF-link converters

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper proposes a new active clamp for HF-link converters, which features very high efficiency by returning the clamped energy back to the primary side through a small auxiliary converter. It also increases the reliability of HF-link converters by providing an alternative load current path du...

  13. Sheppard-Taylor Isolated High Boost DC-DC Converter

    DEFF Research Database (Denmark)

    Chub, Andrii; Siwakoti, Yam Prasad; Vinnikov, Dmitri

    2017-01-01

    This paper presents a new galvanically isolated step-up dc-dc converter intended for low-power but high step-up applications. The proposed converter is capable of regulating output voltage within a wide range of the input voltage or load variations. In contrast to competitors, the converter can b...

  14. A nine-level hybrid symmetric cascaded multilevel converter for ...

    Indian Academy of Sciences (India)

    Indrajit Sarkar

    Abstract. A nine-level hybrid symmetric cascaded multilevel converter (MLC) fed induction motor drive is proposed in this paper. The proposed converter is capable of producing nine output voltage levels by using the same number of power cells as that of conventional five-level symmetric cascaded H-bridge converter.

  15. Multistage switched inductor boost converter for renewable energy application

    DEFF Research Database (Denmark)

    Maroti, Pandav Kiran; Padmanaban, Sanjeevikumar; Bhaskar, Mahajan Sagar

    2017-01-01

    In this paper Multistage Switched Inductor Boost Converter (Multistage SIBC) is uttered for renewable energy applications. The projected converter is derived from an amalgamation of the conventional step-up converter and inductor stack. The number of inductor and duty ratio decides the overall...

  16. A nine-level hybrid symmetric cascaded multilevel converter for ...

    Indian Academy of Sciences (India)

    A nine-level hybrid symmetric cascaded multilevel converter (MLC) fed induction motor drive is proposed in this paper. The proposed converter is capable of producing nine output voltage levels by using the same number of power cells as that of conventional five-level symmetric cascaded H-bridge converter. Eachphase in ...

  17. New active load voltage clamp for HF-link converters

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper proposes a new active clamp for HF-link converters, which features very high efficiency by returning the clamped energy back to the primary side through a small auxiliary converter. It also increases the reliability of HF-link converters by providing an alternative load current path...

  18. Fault isolation in parallel coupled wind turbine converters

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Thøgersen, Paul Bach; Stoustrup, Jakob

    2010-01-01

    Parallel converters in wind turbine give a number advantages, such as fault tolerance due to the redundant converters. However, it might be difficult to isolate gain faults in one of the converters if only a combined power measurement is available. In this paper a scheme using orthogonal power re...

  19. Efficiency and reliability improvement in wind turbine converters by grid converter adaptive control

    DEFF Research Database (Denmark)

    Trintis, Ionut; Munk-Nielsen, Stig; Abrahamsen, Flemming

    2013-01-01

    This paper presents a control method that reduces the losses in wind turbine converters adaptively controlling the grid converter. The dc-link voltage adapts its reference based on the system state and therefore reduces the stored energy, and is therefore kept at the minimum necessary for the grid...... and generator side. Operating in this way, the electrical and thermal stress factors are decreased on the power electronic devices, increasing their lifetime. The simulation results using this method show efficiency increase and devices temperature cycles slightly decreased. Experimental results on a wind...

  20. Sulfur dioxide converter and pollution arrester system

    International Nuclear Information System (INIS)

    Montalvo, V.H.

    1983-01-01

    A sulphur dioxide converter and pollution arrester system are disclosed which involves the treatment of smoke and/or contaminated air emanating from a combustion area by passage through a zone achieving turbulence into a water spray contained first treating chamber. The turbulence zone, into which an atomized catalyst is introduced, serves to create a longer path for cooling as well as increased centrifugal motion to the solid particles in the contaminated air and also the formation of sulphur trioxide. In other words, the arrangement is such that pollution arresting action is provided in the form of ''slinging'' resulting from tangential directional movement and, when combining with the water spray in the first treating chamber, the ultimate formation of sulphuric acid. Subsequently, the contaminated air, containing amounts of sulphurous and sulphuric acids, passes through a second treating chamber, where airflow throughout the system is occasioned by action at the outlet end, such as the vacuum created by a flue and not by independent mechanical means. The arrangement serves to a twofold purpose, i.e. to minimize or arrest pollution and to convert sulphur dioxide, a component of high sulphur coal, into commercially valuable sulphuric acid

  1. Converting DYNAMO simulations to Powersim Studio simulations

    Energy Technology Data Exchange (ETDEWEB)

    Walker, La Tonya Nicole; Malczynski, Leonard A.

    2014-02-01

    DYNAMO is a computer program for building and running 'continuous' simulation models. It was developed by the Industrial Dynamics Group at the Massachusetts Institute of Technology for simulating dynamic feedback models of business, economic, and social systems. The history of the system dynamics method since 1957 includes many classic models built in DYANMO. It was not until the late 1980s that software was built to take advantage of the rise of personal computers and graphical user interfaces that DYNAMO was supplanted. There is much learning and insight to be gained from examining the DYANMO models and their accompanying research papers. We believe that it is a worthwhile exercise to convert DYNAMO models to more recent software packages. We have made an attempt to make it easier to turn these models into a more current system dynamics software language, Powersim © Studio produced by Powersim AS2 of Bergen, Norway. This guide shows how to convert DYNAMO syntax into Studio syntax.

  2. Matrix-form radiation image converter

    International Nuclear Information System (INIS)

    Reiss, K.H.

    1975-01-01

    An image converter is used to make visible images produced by gamma rays or similar penetrating rays like X-rays, etc., by transforming the distribution of ray density contained in a bundle of rays carrying the image which is to be made visible, by means of a cathode and an anode spaced from the cathode. The space between the electrodes contains a gas and the electrodes are subjected to a voltage which produces electrical discharges during ray penetration at corresponding locations depending upon the rays. The cathode as well as the anode consists of a plurality of parts having large surfaces which extend at least approximately perpendicularly to the ray incoming surface of the converter, so that the electric field extends parallel to this surface. The invention is particularly characterized in that the gas is under pressure in the range of 10 at., that the applied voltage makes certain the operation in the proportional range and that parts of the anode and of the cathode are combined in rows. Rows of the cathode elements and those of the anode extend at an angle to each other, the rows being connected electrically with a device for forming an electronic intensity center which produces representable local signals for orientation of the discharge bundle striking the anode

  3. Forback DC-to-DC converter

    Science.gov (United States)

    Lukemire, Alan T.

    1995-05-01

    A pulse-width modulated DC-to-DC power converter including a first inductor, i.e. a transformer or an equivalent fixed inductor equal to the inductance of the secondary winding of the transformer, coupled across a source of DC input voltage via a transistor switch which is rendered alternately conductive (ON) and nonconductive (OFF) in accordance with a signal from a feedback control circuit is described. A first capacitor capacitively couples one side of the first inductor to a second inductor which is connected to a second capacitor which is coupled to the other side of the first inductor. A circuit load shunts the second capacitor. A semiconductor diode is additionally coupled from a common circuit connection between the first capacitor and the second inductor to the other side of the first inductor. A current sense transformer generating a current feedback signal for the switch control circuit is directly coupled in series with the other side of the first inductor so that the first capacitor, the second inductor and the current sense transformer are connected in series through the first inductor. The inductance values of the first and second inductors, moreover, are made identical. Such a converter topology results in a simultaneous voltsecond balance in the first inductance and ampere-second balance in the current sense transformer.

  4. Fundamental study on alkali metal thermoelectric converter

    International Nuclear Information System (INIS)

    Masuda, Toshihisa

    1989-01-01

    The alkali metal thermoelectric converter (AMTEC) utilizing the sodium ion conducting β''-alumina is a device to convert heat energy to electric energy directly. In this paper, the results of theoretical and experimental studies on AMTEC power generating characteristics, internal electrical resistances of single cell, and system analysis of AMTEC power generating systems are reported. This paper consists of 5 chapters, which are summarized as follows: In chapter 1, a theoretical explanation of AMTEC, a brief survey of the research and development history of AMTEC and a purpose of this paper are reported. In chapter 2, the properties of β''-alumina, preparations of thin film electrodes, and special attention points to be paid in handling of β''-alumina and film electrodes are reported. The AMTEC power generating characteristics of the tubular cells are also reported. In chapter 3, the experimental results of the disk type cells and the theoretical considerations about internal resistances are reported. The causes of electrode erosion are also reported. In chapter 4, the system analysis on AMTEC steam-turbine combined cycle for a dispersed power station and AMTEC power system for a aerospace power are reported. Chapter 5 summarizes major results achieved in the preceding four chapters as a concluding remark. (J.P.N.) 62 refs

  5. CCLIBS: The CERN Power Converter Control Libraries

    CERN Document Server

    AUTHOR|(SzGeCERN)404953; Lebioda, Krzysztof Tomasz; Magrans De Abril, Marc; Martino, Michele; Murillo Garcia, Raul; Nicoletti, Achille

    2015-01-01

    Accurate control of power converters is a vital activity in large physics projects. Several different control scenarios may coexist, including regulation of a circuit’s voltage, current, or field strength within a magnet. Depending on the type of facility, a circuit’s reference value may be changed asynchronously or synchronously with other circuits. Synchronous changes may be on demand or under the control of a cyclic timing system. In other cases, the reference may be calculated in real-time by an outer regulation loop of some other quantity, such as the tune of the beam in a synchrotron. The power stage may be unipolar or bipolar in voltage and current. If it is unipolar in current, it may be used with a polarity switch. Depending on the design, the power stage may be controlled by a firing angle or PWM duty-cycle reference, or a voltage or current reference. All these cases are supported by the CERN Converter Control Libraries (CCLIBS). These open-source C libraries include advanced reference generati...

  6. Contingent convertible bonds as countercyclical capital measures

    Directory of Open Access Journals (Sweden)

    Francois Liebenberg

    2017-06-01

    Aim: The effectiveness of the CCB during contractions is not obvious. Contingent convertible (CoCo bonds – which are bond-like until triggered by a deterioration of a prescribed capital metric, at which point they convert into a form of equity – are explored as a supplementary countercyclical capital measure for such periods to establish whether or not they function effectively. Setting: The analysis is undertaken using global bank CoCo data, and then applied to South African banks. Methods: The Hodrick Prescott filter was applied to empirical historical data. Results: The CCB functions as a good countercyclical capital measure in times of economic expansion by absorbing losses and stabilising the capital base through equity issuance. Conclusion: The issuance of CoCo bonds – if their trigger mechanisms are designed correctly – may prove helpful to banks and the broader financial sector in times of economic contraction through the countercyclical capital properties that manifest through CoCo bonds under these economic conditions.

  7. Efficient Wide Range Converters (EWiRaC): A new family of high efficient AC-DC Converters

    DEFF Research Database (Denmark)

    Petersen, Lars; Andersen, Michael Andreas E.

    2006-01-01

    The performance in terms of efficiency of the existing power supplies used for PFC is very dependent on the input voltage range. The boost converter is the most commonly used PFC converter because of its simplicity and high efficiency. But, the boost converter as well as other known converters...... suffers a major penalty in efficiency when used at the low end of the voltage range (90VAC) in a universal voltage range application (90-270VAC). This paper addresses this problem by suggesting a new family of converters that effectively reduces the apparent voltage range with a factor of 2 by changing...... the converter topology according to the input voltage. This new converter type has been named: efficient wide range converter (EWiRaC). The performance of the EWiRaC is experimental verified in a universal input range (90-270VAC) application with an output voltage of 185VDC capable of 500W output power. The EWi...

  8. Active Component Migration and Catalytic Properties of Nitrogen Modified Composite Catalytic Materials

    Directory of Open Access Journals (Sweden)

    Miaomiao Li

    2018-03-01

    Full Text Available During the catalytic combustion reaction of methane, the migration of the active species on surface facilitates the catalytic reaction, and the element doping can improve the redox performance of the catalyst. Nitrogen-modified perovskite type composite catalysts were prepared by hydrothermal method and then characterized by X-ray diffractometer (XRD, scanning electron microscopy (SEM, Brunauer-Emmett-Teller (BET, temperature-programmed reductions (TPR, and X-ray photoelectron spectra (XPS. The results revealed that nitrogen sources (urea, biuret, melamine, carbohydrazide, and semicarbazide hydrochloride and nitrogen source addition changed the catalytic performance in physical and chemical properties, the migration of reactive species and the catalytic performance. When the addition amount of semicarbazide hydrochloride was three times that of LaCoO3, the composite catalysts had high Co3+/Co2+ (1.39 and Oads/Olat (15.18 and showed the best catalytic performance: the temperatures that are required for achieving methane conversion of 50% and 90% were 277 and 360 °C, which are more effective than noble metal oxides. Moreover, the in situ diffuse reflectance infrared fourier transform spectroscopy (DRIFTS were applied to elucidate the efficient for CH4 removal and also can further explain the surface reaction mechanism of the composite catalyst during the methane catalytic combustion.

  9. Structural determinants of APOBEC3B non-catalytic domain for molecular assembly and catalytic regulation

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Xiao; Yang, Hanjing; Arutiunian, Vagan; Fang, Yao; Besse, Guillaume; Morimoto, Cherie; Zirkle, Brett; Chen, Xiaojiang S. (USC)

    2017-05-30

    The catalytic activity of human cytidine deaminase APOBEC3B (A3B) has been correlated with kataegic mutational patterns within multiple cancer types. The molecular basis of how the N-terminal non-catalytic CD1 regulates the catalytic activity and consequently, biological function of A3B remains relatively unknown. Here, we report the crystal structure of a soluble human A3B-CD1 variant and delineate several structural elements of CD1 involved in molecular assembly, nucleic acid interactions and catalytic regulation of A3B. We show that (i) A3B expressed in human cells exists in hypoactive high-molecular-weight (HMW) complexes, which can be activated without apparent dissociation into low-molecular-weight (LMW) species after RNase A treatment. (ii) Multiple surface hydrophobic residues of CD1 mediate the HMW complex assembly and affect the catalytic activity, including one tryptophan residue W127 that likely acts through regulating nucleic acid binding. (iii) One of the highly positively charged surfaces on CD1 is involved in RNA-dependent attenuation of A3B catalysis. (iv) Surface hydrophobic residues of CD1 are involved in heterogeneous nuclear ribonucleoproteins (hnRNPs) binding to A3B. The structural and biochemical insights described here suggest that unique structural features on CD1 regulate the molecular assembly and catalytic activity of A3B through distinct mechanisms.

  10. Comparative Analysis of Resonant Converters for Energy Storage Systems

    Directory of Open Access Journals (Sweden)

    Vuchev Stoyan

    2017-01-01

    Full Text Available The following paperwork presents a comparative analysis of multiphase resonant converters for applications in energy storage systems. Models of the examined converters are developed in the software environments of MATLAB and LTspice. Results from the simulation examination of the converters during charging of supercapacitors and rechargeable batteries are presented. These results are compared to results obtained from experimental examination of the converters via a laboratory stand. For the purposes of the experimental examination, a control system is developed on the base of a virtual instrument in LabVIEW. The advantages and disadvantages of the different converters are discussed.

  11. Three new DC-to-DC Single-Switch Converters

    Directory of Open Access Journals (Sweden)

    Barry W. Williams

    2017-06-01

    Full Text Available This paper presents a new family of three previously unidentified dc-to-dc converters, buck, boost, and buck-boost voltage-transfer-function topologies, which offer advantageous transformer coupling features and low capacitor dc voltage stressing. The three single-switch, single-diode, converters offer the same features as basic dc-to-dc converters, such as the buck function with continuous output current and the boost function with continuous input current. Converter time-domain simulations and experimental results (including transformer coupling support and extol the dc-to-dc converter concepts and analysis presented.

  12. Two phase interleaved buck converter for driving high power LEDs

    DEFF Research Database (Denmark)

    Beczkowski, Szymon; Munk-Nielsen, Stig

    2011-01-01

    The goal of this paper is to evaluate an interleaved buck topology for driving high current light-emitting diodes. Low output capacitor value allows the use of non-electrolytic capacitors extending the lifetime of the converter. Converter is operated as a constant, regulated current source which...... increases luminous efficacy of LED compared to PWM dimmed system. Because of the low dynamic resistance of LEDs the duty cycle of the converter does not change greatly with controlled current. By setting the input voltage of the buck converter to around twice the voltage of diode strings, converter can...

  13. Research on Compensating Power Converter used for Artillery

    Directory of Open Access Journals (Sweden)

    Xing Wang

    2014-11-01

    Full Text Available Aiming at the low efficiency shortage of traditional power supply converter used for artillery, a novel compensating power converter used for artillery was proposed, and its work mode was analyzed. The current expression of inductor was given and work statuses under two working modes were analyzed. Finally an experimental prototype based on DSP was built, the results indicate that the compensating power converter own low current and voltage stress and high efficiency because only part of power pass through the converter, thus, the converter own large potential application value.

  14. Three-phase Resonant DC-link Converter

    DEFF Research Database (Denmark)

    Munk-Nielsen, Stig

    The purpose of the project is to develop a three-phase resonant converter suitable for standard speed drives. The motivation for working with resonant converters is found in the problem of the standard converter type used today. In standard converter type Pulse Width Modulated-Voltage Source...... no additional power electric components is eliminating the high voltage peaks associated with the resonant circuit. The resonant link voltage peaks are limited below 2.1 times the DC link voltages. A new principle eliminating former resonant converter stability problems are proposed, implemented and tested...

  15. Catalytic and thermal cracking processes of waste cooking oil for bio-gasoline synthesis

    Science.gov (United States)

    Dewanto, Muhammad Andry Rizki; Januartrika, Aulia Azka; Dewajani, Heny; Budiman, Arief

    2017-03-01

    Non-renewable energy resources such as fossil fuels, and coal were depleted as the increase of global energy demand. Moreover, environmental aspect becomes a major concern which recommends people to utilize bio-based resources. Waste cooking oil is one of the economical sources for biofuel production and become the most used raw material for biodiesel production. However, the products formed during frying, can affect the trans-esterification reaction and the biodiesel properties. Therefore, it needs to convert low-quality cooking oil directly into biofuel by both thermal and catalytic cracking processes. Thermal and catalytic cracking sometimes are regarded as prospective bio-energy conversion processes. This research was carried out in the packed bed reactor equipped with 2 stages preheater with temperature of reactor was variated in the range of 450-550°C. At the same temperature, catalytic cracking had been involved in this experiment, using activated ZSM-5 catalyst with 1 cm in length. The organic liquid product was recovered by three stages of double pipe condensers. The composition of cracking products were analyzed using GC-MS instrument and the caloric contents were analyzed using Bomb calorimeter. The results reveal that ZSM-5 was highly selective toward aromatic and long aliphatic compounds formation. The percentage recovery of organic liquid product from the cracking process varies start from 8.31% and the optimal results was 54.08%. The highest heating value of liquid product was resulted from catalytic cracking process at temperature of 450°C with value of 10880.48 cal/gr and the highest product yield with 54.08% recovery was achieved from thermal cracking process with temperature of 450°C.

  16. Converter applications and their influence on large electrical machines

    CERN Document Server

    Drubel, Oliver

    2013-01-01

    Converter driven applications are applied in more and more processes. Almost any installed wind-farm, ship drives, steel mills, several boiler feed water pumps, extruder and many other applications operate much more efficient and economic in case of variable speed solutions. The boundary conditions for a motor or generator will change, if it is supplied by a converter. An electrical machine, which is operated by a converter, can no longer be regarded as an independent component, but is embedded in a system consisting of converter and machine. This book gives an overview of existing converter designs for large electrical machines. Methods for the appropriate calculation of machine phenomena, which are implied by converters are derived in the power range above 500kVA. It is shown how due to the converter inherent higher voltage harmonics and pulse frequencies special phenomena are caused inside the machine which can be the reason for malfunction. It is demonstrated that additional losses create additional tempe...

  17. Generators for gearless wind energy converters

    Energy Technology Data Exchange (ETDEWEB)

    Grauers, A. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Electric Power Engineering

    1996-12-01

    This paper discusses some design alternatives for directly driven generators, and one specific generator type is investigated for a wide range of rated power. First, the specification for a directly driven generator is presented, then different design alternatives are discussed. A radial-flux permanent magnet generator for frequency converter connection has been chosen for a more detailed investigation. The design, optimization and performance of that generator type are presented. Generators from 30 kW to 3 MW are designed and compared with conventional four-pole generators with gear. It is found that a directly driven generator can be more efficient than a conventional generator and gear and have a rather small diameter and a low active weight. 8 refs, 7 figs, 2 tabs

  18. Mechanical vibration to electrical energy converter

    Science.gov (United States)

    Kellogg, Rick Allen [Tijeras, NM; Brotz, Jay Kristoffer [Albuquerque, NM

    2009-03-03

    Electromechanical devices that generate an electrical signal in response to an external source of mechanical vibrations can operate as a sensor of vibrations and as an energy harvester for converting mechanical vibration to electrical energy. The devices incorporate a magnet that is movable through a gap in a ferromagnetic circuit, wherein a coil is wound around a portion of the ferromagnetic circuit. A flexible coupling is used to attach the magnet to a frame for providing alignment of the magnet as it moves or oscillates through the gap in the ferromagnetic circuit. The motion of the magnet can be constrained to occur within a substantially linear range of magnetostatic force that develops due to the motion of the magnet. The devices can have ferromagnetic circuits with multiple arms, an array of magnets having alternating polarity and, encompass micro-electromechanical (MEM) devices.

  19. Clustering of cycloidal wave energy converters

    Science.gov (United States)

    Siegel, Stefan G.

    2016-03-29

    A wave energy conversion system uses a pair of wave energy converters (WECs) on respective active mountings on a floating platform, so that the separation of the WECs from each other or from a central WEC can be actively adjusted according to the wavelength of incident waves. The adjustable separation facilitates operation of the system to cancel reactive forces, which may be generated during wave energy conversion. Modules on which such pairs of WECs are mounted can be assembled with one or more central WECs to form large clusters in which reactive forces and torques can be made to cancel. WECs of different sizes can be employed to facilitate cancelation of reactive forces and torques.

  20. Modular Multilevel Converters: Control and Applications

    Directory of Open Access Journals (Sweden)

    Fernando Martinez-Rodrigo

    2017-10-01

    Full Text Available This review article is mainly oriented to the control and applications of modular multilevel converters (MMC. The main topologies of the switching modules are presented, for normal operation and for the elimination of DC faults. Methods to keep the capacitor voltage balanced are included. The voltage and current modulators, that are the most internal loops of control, are detailed. Voltage control and current control schemes are included which regulate DC link voltage and reactive power. The cases of unbalanced and distorted networks are analyzed, and schemes are proposed so that MMC contribute to improve the quality of the grid in these situations. The main applications in high voltage direct current (HVDC transmission along with other medium voltage (MV and low voltage (LV applications are included. Finally, the application to offshore wind farms is specifically analyzed.

  1. Layout Optimisation of Wave Energy Converter Arrays

    Directory of Open Access Journals (Sweden)

    Pau Mercadé Ruiz

    2017-08-01

    Full Text Available This paper proposes an optimisation strategy for the layout design of wave energy converter (WEC arrays. Optimal layouts are sought so as to maximise the absorbed power given a minimum q-factor, the minimum distance between WECs, and an area of deployment. To guarantee an efficient optimisation, a four-parameter layout description is proposed. Three different optimisation algorithms are further compared in terms of performance and computational cost. These are the covariance matrix adaptation evolution strategy (CMA, a genetic algorithm (GA and the glowworm swarm optimisation (GSO algorithm. The results show slightly higher performances for the latter two algorithms; however, the first turns out to be significantly less computationally demanding.

  2. Modular Power Converters for PV Applications

    Energy Technology Data Exchange (ETDEWEB)

    Ozpineci, Burak [ORNL; Tolbert, Leon M [ORNL

    2012-05-01

    This report describes technical opportunities to serve as parts of a technological roadmap for Shoals Technologies Group in power electronics for PV applications. There are many different power converter circuits that can be used for solar inverter applications. The present applications do not take advantage of the potential for using common modules. We envision that the development of a power electronics module could enable higher reliability by being durable and flexible. Modules would have fault current limiting features and detection circuits such that they can limit the current through the module from external faults and can identify and isolate internal faults such that the remaining modules can continue to operate with only minimal disturbance to the utility or customer. Development of a reliable, efficient, low-cost, power electronics module will be a key enabling technology for harnessing more power from solar panels and enable plug and play operation. Power electronics for computer power supplies, communication equipment, and transportation have all targeted reliability and modularity as key requirements and have begun concerted efforts to replace monolithic components with collections of common smart modules. This is happening on several levels including (1) device level with intelligent control, (2) functional module level, and (3) system module. This same effort is needed in power electronics for solar applications. Development of modular units will result in standard power electronic converters that will have a lower installed and operating cost for the overall system. These units will lead to increased adaptability and flexibility of solar inverters. Incorporating autonomous fault current limiting and reconfiguration capabilities into the modules and having redundant modules will lead to a durable converter that can withstand the rigors of solar power generation for more than 30 years. Our vision for the technology roadmap is that there is no need

  3. Pseudomonas spp. convert metmyoglobin into deoxymyoglobin.

    Science.gov (United States)

    Motoyama, Michiyo; Kobayashi, Miho; Sasaki, Keisuke; Nomura, Masaru; Mitsumoto, Mitsuru

    2010-01-01

    Meat 'reddening' by bacteria was observed in chilled beef. To identify the reddening bacteria, isolates were inoculated onto beef and the changes in CIE L*a*b* values monitored. As a result, two Pseudomonas spp., including Pseudomonas fragi which is commonly observed in raw meat, were selected and identified as reddening bacteria. The reddening was coincidentally occurred with the appearance of slime, and the increase in thiobarbituric acid-reactive substances (TBARS) was simultaneously suppressed. In myoglobin-containing nutrient broth, it is shown spectroscopically that P. fragi converted metmyoglobin into deoxymyoglobin. It was concluded that the meat reddening was due to the formation of deoxymyoglobin, induced by the very-low-oxygen tension brought about by Pseudomonad's oxygen consumption: This oxygen depletion simultaneously suppressed TBARS increase.

  4. Large-scale digitizer system, analog converters

    International Nuclear Information System (INIS)

    Althaus, R.F.; Lee, K.L.; Kirsten, F.A.; Wagner, L.J.

    1976-10-01

    Analog to digital converter circuits that are based on the sharing of common resources, including those which are critical to the linearity and stability of the individual channels, are described. Simplicity of circuit composition is valued over other more costly approaches. These are intended to be applied in a large-scale processing and digitizing system for use with high-energy physics detectors such as drift-chambers or phototube-scintillator arrays. Signal distribution techniques are of paramount importance in maintaining adequate signal-to-noise ratio. Noise in both amplitude and time-jitter senses is held sufficiently low so that conversions with 10-bit charge resolution and 12-bit time resolution are achieved

  5. Power Generation Using Mechanical Wave Energy Converter

    Directory of Open Access Journals (Sweden)

    Srinivasan Chandrasekaran

    2012-03-01

    Full Text Available Ocean wave energy plays a significant role in meeting the growing demand of electric power. Economic, environmental, and technical advantages of wave energy set it apart from other renewable energy resources. Present study describes a newly proposed Mechanical Wave Energy Converter (MEWC that is employed to harness heave motion of floating buoy to generate power. Focus is on the conceptual development of the device, illustrating details of component level analysis. Employed methodology has many advantages such as i simple and easy fabrication; ii easy to control the operations during rough weather; and iii low failure rate during normal sea conditions. Experimental investigations carried out on the scaled model of MWEC show better performance and its capability to generate power at higher efficiency in regular wave fields. Design Failure Mode and Effect Analysis (FMEA shows rare failure rates for all components except the floating buoy.

  6. Will oscillating wave surge converters survive tsunamis?

    Directory of Open Access Journals (Sweden)

    L. O’Brien

    2015-07-01

    Full Text Available With an increasing emphasis on renewable energy resources, wave power technology is becoming one of the realistic solutions. However, the 2011 tsunami in Japan was a harsh reminder of the ferocity of the ocean. It is known that tsunamis are nearly undetectable in the open ocean but as the wave approaches the shore its energy is compressed, creating large destructive waves. The question posed here is whether an oscillating wave surge converter (OWSC could withstand the force of an incoming tsunami. Several tools are used to provide an answer: an analytical 3D model developed within the framework of linear theory, a numerical model based on the non-linear shallow water equations and empirical formulas. Numerical results show that run-up and draw-down can be amplified under some circumstances, leading to an OWSC lying on dry ground!

  7. Impact of heterotrophically stressed algae for biofuel production via hydrothermal liquefaction and catalytic hydrotreating in continuous-flow reactors

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, Karl O.; Zhu, Yunhua; Schmidt, Andrew J.; Billing, Justin M.; Hart, Todd R.; Jones, Susanne B.; Maupin, Gary; Hallen, Richard; Ahrens, Toby; Anderson, Daniel

    2016-03-01

    Two algal feedstocks were prepared for direct comparison of their properties when converted to liquid hydrocarbon fuel. The first feedstock was prepared by growing an algal strain phototrophically using a bio-film based approach. The second feedstock employed the same algal strain but was stressed heterotrophically to significantly increase the lipid concentration. The algal feedstocks were converted to liquid hydrocarbon fuels. First, the whole algae (i.e. not defatted or lipid extracted) were converted to an intermediate biocrude using continuous hydrothermal liquefaction (HTL) at 350°C and 3000 psig. The biocrudes were subsequently upgraded via catalytic hydrotreating (HT) at 400°C and 1500 psig to remove oxygen and nitrogen as well as increase the hydrogen-to-carbon ratio. The yield and composition of the products from HTL and HT processing of the feedstocks are compared. A techno-economic analysis of the process for converting each feedstock to liquid fuels was also conducted. The capital and operating costs associated with converting the feedstocks to finished transportation fuels are reported. A fuel minimum selling price is presented as a function of the cost of the algal feedstock delivered to the HTL conversion plant.

  8. Catalytic conversion of nonfood woody biomass solids to organic liquids.

    Science.gov (United States)

    Barta, Katalin; Ford, Peter C

    2014-05-20

    This Account outlines recent efforts in our laboratories addressing a fundamental challenge of sustainability chemistry, the effective utilization of biomass for production of chemicals and fuels. Efficient methods for converting renewable biomass solids to chemicals and liquid fuels would reduce society's dependence on nonrenewable petroleum resources while easing the atmospheric carbon dioxide burden. The major nonfood component of biomass is lignocellulose, a matrix of the biopolymers cellulose, hemicellulose, and lignin. New approaches are needed to effect facile conversion of lignocellulose solids to liquid fuels and to other chemical precursors without the formation of intractable side products and with sufficient specificity to give economically sustainable product streams. We have devised a novel catalytic system whereby the renewable feedstocks cellulose, organosolv lignin, and even lignocellulose composites such as sawdust are transformed into organic liquids. The reaction medium is supercritical methanol (sc-MeOH), while the catalyst is a copper-doped porous metal oxide (PMO) prepared from inexpensive, Earth-abundant starting materials. This transformation occurs in a single stage reactor operating at 300-320 °C and 160-220 bar. The reducing equivalents for these transformations are derived by the reforming of MeOH (to H2 and CO), which thereby serves as a "liquid syngas" in the present case. Water generated by deoxygenation processes is quickly removed by the water-gas shift reaction. The Cu-doped PMO serves multiple purposes, catalyzing substrate hydrogenolysis and hydrogenation as well as the methanol reforming and shift reactions. This one-pot "UCSB process" is quantitative, giving little or no biochar residual. Provided is an overview of these catalysis studies beginning with reactions of the model compound dihydrobenzofuran that help define the key processes occurring. The initial step is phenyl-ether bond hydrogenolysis, and this is followed by

  9. Catalysis by Glomerella cingulata cutinase requires conformational cycling between the active and inactive states of its catalytic triad.

    Science.gov (United States)

    Nyon, Mun Peak; Rice, David W; Berrisford, John M; Hounslow, Andrea M; Moir, Arthur J G; Huang, Huazhang; Nathan, Sheila; Mahadi, Nor Muhammad; Bakar, Farah Diba Abu; Craven, C Jeremy

    2009-01-09

    Cutinase belongs to a group of enzymes that catalyze the hydrolysis of esters and triglycerides. Structural studies on the enzyme from Fusarium solani have revealed the presence of a classic catalytic triad that has been implicated in the enzyme's mechanism. We have solved the crystal structure of Glomerella cingulata cutinase in the absence and in the presence of the inhibitors E600 (diethyl p-nitrophenyl phosphate) and PETFP (3-phenethylthio-1,1,1-trifluoropropan-2-one) to resolutions between 2.6 and 1.9 A. Analysis of these structures reveals that the catalytic triad (Ser136, Asp191, and His204) adopts an unusual configuration with the putative essential histidine His204 swung out of the active site into a position where it is unable to participate in catalysis, with the imidazole ring 11 A away from its expected position. Solution-state NMR experiments are consistent with the disrupted configuration of the triad observed crystallographically. H204N, a site-directed mutant, was shown to be catalytically inactive, confirming the importance of this residue in the enzyme mechanism. These findings suggest that, during its catalytic cycle, cutinase undergoes a significant conformational rearrangement converting the loop bearing the histidine from an inactive conformation, in which the histidine of the triad is solvent exposed, to an active conformation, in which the triad assumes a classic configuration.

  10. On the Structural Context and Identification of Enzyme Catalytic Residues

    Science.gov (United States)

    Chien, Yu-Tung; Huang, Shao-Wei

    2013-01-01

    Enzymes play important roles in most of the biological processes. Although only a small fraction of residues are directly involved in catalytic reactions, these catalytic residues are the most crucial parts in enzymes. The study of the fundamental and unique features of catalytic residues benefits the understanding of enzyme functions and catalytic mechanisms. In this work, we analyze the structural context of catalytic residues based on theoretical and experimental structure flexibility. The results show that catalytic residues have distinct structural features and context. Their neighboring residues, whether sequence or structure neighbors within specific range, are usually structurally more rigid than those of noncatalytic residues. The structural context feature is combined with support vector machine to identify catalytic residues from enzyme structure. The prediction results are better or comparable to those of recent structure-based prediction methods. PMID:23484160

  11. Synthesis and catalytic properties of ferrocenophane phosphines

    OpenAIRE

    Škoch, Karel

    2014-01-01

    6 Title: Sythesis and catalytic properties of ferrocenophane phosphines Author: Karel Škoch Institution: Faculty of Science, Charles University in Prague, Department of Inorganic Chemistry Supervisor: prof. RNDr. Petr Štěpnička, Ph.D. Keywords: ferrocene, ferrocenophane, phosphine ligands, palladium, asymetric catalysis, aza- Morita-Baylis-Hillman reaction, asymetric allylic alkylation Abstract: This Thesis describes the preparation of five sterically and electronically different ferrocene ph...

  12. Method to produce catalytically active nanocomposite coatings

    Energy Technology Data Exchange (ETDEWEB)

    Erdemir, Ali; Eryilmaz, Osman Levent; Urgen, Mustafa; Kazmanli, Kursat

    2017-12-19

    A nanocomposite coating and method of making and using the coating. The nanocomposite coating is disposed on a base material, such as a metal or ceramic; and the nanocomposite consists essentially of a matrix of an alloy selected from the group of Cu, Ni, Pd, Pt and Re which are catalytically active for cracking of carbon bonds in oils and greases and a grain structure selected from the group of borides, carbides and nitrides.

  13. Materials for High-Temperature Catalytic Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Ersson, Anders

    2003-04-01

    Catalytic combustion is an environmentally friendly technique to combust fuels in e.g. gas turbines. Introducing a catalyst into the combustion chamber of a gas turbine allows combustion outside the normal flammability limits. Hence, the adiabatic flame temperature may be lowered below the threshold temperature for thermal NO{sub X} formation while maintaining a stable combustion. However, several challenges are connected to the application of catalytic combustion in gas turbines. The first part of this thesis reviews the use of catalytic combustion in gas turbines. The influence of the fuel has been studied and compared over different catalyst materials. The material section is divided into two parts. The first concerns bimetallic palladium catalysts. These catalysts showed a more stable activity compared to their pure palladium counterparts for methane combustion. This was verified both by using an annular reactor at ambient pressure and a pilot-scale reactor at elevated pressures and flows closely resembling the ones found in a gas turbine combustor. The second part concerns high-temperature materials, which may be used either as active or washcoat materials. A novel group of materials for catalysis, i.e. garnets, has been synthesised and tested in combustion of methane, a low-heating value gas and diesel fuel. The garnets showed some interesting abilities especially for combustion of low-heating value, LHV, gas. Two other materials were also studied, i.e. spinels and hexa aluminates, both showed very promising thermal stability and the substituted hexa aluminates also showed a good catalytic activity. Finally, deactivation of the catalyst materials was studied. In this part the sulphur poisoning of palladium, platinum and the above-mentioned complex metal oxides has been studied for combustion of a LHV gas. Platinum and surprisingly the garnet were least deactivated. Palladium was severely affected for methane combustion while the other washcoat materials were

  14. Enantioselective catalytic fluorinative aza-semipinacol rearrangement.

    Science.gov (United States)

    Romanov-Michailidis, Fedor; Pupier, Marion; Besnard, Céline; Bürgi, Thomas; Alexakis, Alexandre

    2014-10-03

    An efficient and highly stereoselective fluorinative aza-semipinacol rearrangement is described. The catalytic reaction requires use of Selectfluor in combination with the chiral, enantiopure phosphate anion derived from acid L3. Under optimized conditions, cyclopropylamines A were transformed into β-fluoro cyclobutylimines B in good yields and high levels of diastereo- and enantiocontrol. Furthermore, the optically active cyclobutylimines were reduced diastereoselectively with L-Selectride in the corresponding fluorinated amines C, compounds of significant interest in the pharmacological industry.

  15. Method to produce catalytically active nanocomposite coatings

    Science.gov (United States)

    Erdemir, Ali; Eryilmaz, Osman Levent; Urgen, Mustafa; Kazmanli, Kursat

    2016-02-09

    A nanocomposite coating and method of making and using the coating. The nanocomposite coating is disposed on a base material, such as a metal or ceramic; and the nanocomposite consists essentially of a matrix of an alloy selected from the group of Cu, Ni, Pd, Pt and Re which are catalytically active for cracking of carbon bonds in oils and greases and a grain structure selected from the group of borides, carbides and nitrides.

  16. Antibody proteases: induction of catalytic response.

    Science.gov (United States)

    Gabibov, A G; Friboulet, A; Thomas, D; Demin, A V; Ponomarenko, N A; Vorobiev, I I; Pillet, D; Paon, M; Alexandrova, E S; Telegin, G B; Reshetnyak, A V; Grigorieva, O V; Gnuchev, N V; Malishkin, K A; Genkin, D D

    2002-10-01

    Most of the data accumulated throughout the years on investigation of catalytic antibodies indicate that their production increases on the background of autoimmune abnormalities. The different approaches to induction of catalytic response toward recombinant gp120 HIV-1 surface protein in mice with various autoimmune pathologies are described. The peptidylphosphonate conjugate containing structural part of gp120 molecule is used for reactive immunization of NZB/NZW F1, MRL, and SJL mice. The specific modification of heavy and light chains of mouse autoantibodies with Val-Ala-Glu-Glu-Glu-Val-PO(OPh)2 reactive peptide was demonstrated. Increased proteolytic activity of polyclonal antibodies in SJL mice encouraged us to investigate the production of antigen-specific catalytic antibodies on the background of induced experimental autoimmune encephalomyelitis (EAE). The immunization of autoimmune-prone mice with the engineered fusions containing the fragments of gp120 and encephalitogenic epitope of myelin basic protein (MBP(89-104)) was made. The proteolytic activity of polyclonal antibodies isolated from the sera of autoimmune mice immunized by the described antigen was shown. Specific immune response of SJL mice to these antigens was characterized. Polyclonal antibodies purified from sera of the immunized animals revealed proteolytic activity. The antiidiotypic approach to raise the specific proteolytic antibody as an "internal image" of protease is described. The "second order" monoclonal antibodies toward subtilisin Carlsberg revealed pronounced proteolytic activity.

  17. Catalytic pyrolysis of olive mill wastewater sludge

    Science.gov (United States)

    Abdellaoui, Hamza

    From 2008 to 2013, an average of 2,821.4 kilotons/year of olive oil were produced around the world. The waste product of the olive mill industry consists of solid residue (pomace) and wastewater (OMW). Annually, around 30 million m3 of OMW are produced in the Mediterranean area, 700,000 m3 year?1 in Tunisia alone. OMW is an aqueous effluent characterized by an offensive smell and high organic matter content, including high molecular weight phenolic compounds and long-chain fatty acids. These compounds are highly toxic to micro-organisms and plants, which makes the OMW a serious threat to the environment if not managed properly. The OMW is disposed of in open air evaporation ponds. After evaporation of most of the water, OMWS is left in the bottom of the ponds. In this thesis, the effort has been made to evaluate the catalytic pyrolysis process as a technology to valorize the OMWS. The first section of this research showed that 41.12 wt. % of the OMWS is mostly lipids, which are a good source of energy. The second section proved that catalytic pyrolysis of the OMWS over red mud and HZSM-5 can produce green diesel, and 450 °C is the optimal reaction temperature to maximize the organic yields. The last section revealed that the HSF was behind the good fuel-like properties of the OMWS catalytic oils, whereas the SR hindered the bio-oil yields and quality.

  18. Catalytic hydrogen recombination for nuclear containments

    International Nuclear Information System (INIS)

    Koroll, G.W.; Lau, D.W.P.; Dewit, W.A.; Graham, W.R.C.

    1994-01-01

    Catalytic recombiners appear to be a credible option for hydrogen mitigation in nuclear containments. The passive operation, versatility and ease of back fitting are appealing for existing stations and new designs. Recently, a generation of wet-proofed catalyst materials have been developed at AECL which are highly specific to H 2 -O 2 , are active at ambient temperatures and are being evaluated for containment applications. Two types of catalytic recombiners were evaluated for hydrogen removal in containments based on the AECL catalyst. The first is a catalytic combustor for application in existing air streams such as provided by fans or ventilation systems. The second is an autocatalytic recombiner which uses the enthalpy of reaction to produce natural convective flow over the catalyst elements. Intermediate-scale results obtained in 6 m 3 and 10 m 3 spherical and cylindrical vessels are given to demonstrate self-starting limits, operating limits, removal capacity, scaling parameters, flow resistance, mixing behaviour in the vicinity of an operating recombiner and sensitivity to poisoning, fouling and radiation. (author). 13 refs., 10 figs

  19. Electrochemical catalytic treatment of phenol wastewater

    International Nuclear Information System (INIS)

    Ma Hongzhu; Zhang Xinhai; Ma Qingliang; Wang Bo

    2009-01-01

    The slurry bed catalytic treatment of contaminated water appears to be a promising alternative for the oxidation of aqueous organic pollutants. In this paper, the electrochemical oxidation of phenol in synthetic wastewater catalyzed by ferric sulfate and potassium permanganate adsorbed onto active bentonite in slurry bed electrolytic reactor with graphite electrode has been investigated. In order to determine the optimum operating condition, the orthogonal experiments were devised and the results revealed that the system of ferric sulfate, potassium permanganate and active bentonite showed a high catalytic efficiency on the process of electrochemical oxidation phenol in initial pH 5. When the initial concentration of phenol was 0.52 g/L (the initial COD 1214 mg/L), up to 99% chemical oxygen demand (COD) removal was obtained in 40 min. According to the experimental results, a possible mechanism of catalytic degradation of phenol was proposed. Environmental estimation was also done and the results showed that the treated wastewater have little impact on plant growth and could totally be applied to irrigation.

  20. Highly efficient conversion of terpenoid biomass to jet-fuel range cycloalkanes in a biphasic tandem catalytic process

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiaokun [Univ. of Nevada, Reno, NV (United States); Li, Teng [Washington State Univ., Pullman, WA (United States); Tang, Kan [Washington State Univ., Pullman, WA (United States); Zhou, Xinpei [Univ. of Nevada, Reno, NV (United States); Lu, Mi [Univ. of Nevada, Reno, NV (United States); Ounkham, Whalmany L. [Univ. of Nevada, Reno, NV (United States); Spain, Stephen M. [Univ. of Nevada, Reno, NV (United States); Frost, Brian J. [Univ. of Nevada, Reno, NV (United States); Lin, Hongfei [Washington State Univ., Pullman, WA (United States)

    2017-06-12

    The demand for bio-jet fuels to reduce carbon emissions is increasing substantially in the aviation sector, while the scarcity of high-density jet fuel components limits the use of bio-jet fuels in high-performance aircrafts compared with conventional jet fuels. In this paper, we report a novel biphasic tandem catalytic process (biTCP) for synthesizing cycloalkanes from renewable terpenoid biomass, such as 1,8-cineole. Multistep tandem reactions, including C–O ring opening by hydrolysis, dehydration, and hydrogenation, were carried out in the “one-pot” biTCP. 1,8-Cineole was efficiently converted to p-menthane at high yields (>99%) in the biTCP under mild reaction conditions. Finally, the catalytic reaction mechanism is discussed.

  1. Mining disease state converters for medical intervention of diseases.

    Science.gov (United States)

    Dong, Guozhu; Duan, Lei; Tang, Changjie

    2010-02-01

    In applications such as gene therapy and drug design, a key goal is to convert the disease state of diseased objects from an undesirable state into a desirable one. Such conversions may be achieved by changing the values of some attributes of the objects. For example, in gene therapy one may convert cancerous cells to normal ones by changing some genes' expression level from low to high or from high to low. In this paper, we define the disease state conversion problem as the discovery of disease state converters; a disease state converter is a small set of attribute value changes that may change an object's disease state from undesirable into desirable. We consider two variants of this problem: personalized disease state converter mining mines disease state converters for a given individual patient with a given disease, and universal disease state converter mining mines disease state converters for all samples with a given disease. We propose a DSCMiner algorithm to discover small and highly effective disease state converters. Since real-life medical experiments on living diseased instances are expensive and time consuming, we use classifiers trained from the datasets of given diseases to evaluate the quality of discovered converter sets. The effectiveness of a disease state converter is measured by the percentage of objects that are successfully converted from undesirable state into desirable state as deemed by state-of-the-art classifiers. We use experiments to evaluate the effectiveness of our algorithm and to show its effectiveness. We also discuss possible research directions for extensions and improvements. We note that the disease state conversion problem also has applications in customer retention, criminal rehabilitation, and company turn-around, where the goal is to convert class membership of objects whose class is an undesirable class.

  2. Methane converted to low emission energy

    International Nuclear Information System (INIS)

    Kelly, Michael; McLennan, Tim

    2006-01-01

    A new project is underway at a major mine site in China to capture and use waste methane gas from coal mines. The three-year joint project will develop and demonstrate an innovative new Australian technology that captures harmful methane gas from coal mine ventilation air and uses it to produce low emission energy. The project will demonstrate that ventilation air from coal mines, which is largely untapped to date, can be safely captured to provide a source of electricity. An additional benefit of using ventilation air methane from coal mines is an increase in mine safety due to the reduced risk of gas explosions. The project is based on ventilation air methane catalytic combustion gas turbine (VAMCAT) technology. The project will fabricate a prototype demonstration unit and demonstrate the technology in a laboratory in Australia. Once tested in the laboratory the operational performance data and experience obtained will be used to design a 1% I methane turbine for demonstration at Huainan Mine, China. This project will develop technology that uses waste coal mine methane currently vented i into the atmosphere to create electricity and by doing so will reduce greenhouse gas emissions and improve mine safety. Development of this prototype will advance Australia's and China's capacity to reduce the potential greenhouse impact of coal through the development and deployment of VAMCAT technology as a practical solution for mitigating and utilising mine methane to generate power. The project will be implemented by the CSIRO with the Australian Government contributing a grant worth $350 000 to this $1.9 million project. Copyright (2006) Reed Business Information

  3. Thermo-Catalytic Reforming of municipal solid waste.

    Science.gov (United States)

    Ouadi, Miloud; Jaeger, Nils; Greenhalf, Charles; Santos, Joao; Conti, Roberto; Hornung, Andreas

    2017-10-01

    Municipal Solid Waste (MSW) refers to a heterogeneous mixture composed of plastics, paper, metal, food and other miscellaneous items. Local authorities commonly dispose of this waste by either landfill or incineration which are both unsustainable practices. Disposing of organic wastes via these routes is also becoming increasingly expensive due to rising landfill taxes and transport costs. The Thermo-Catalytic Reforming (TCR®) process, is a proposed valorisation route to transform organic wastes and residues, such as MSW, into sustainable energy vectors including (H 2 rich synthesis gas, liquid bio-oil and solid char). The aim herein, was to investigate the conversion of the organic fraction of MSW into fuels and chemicals utilising the TCR technology in a 2kg/h continuous pilot scale reactor. Findings show that MSW was successfully processed with the TCR after carrying out a feedstock pre-treatment step. Approximately, 25wt.% of the feedstock was converted into phase separated liquids, composed of 19wt.% aqueous phase and 6wt.% organic phase bio-oil. The analysis of the bio-oil fraction revealed physical and chemical fuel properties, higher heating value (HHV) of 38MJ/kg, oxygen content <7wt.% and water content <4wt.%. Due to the bio-oil's chemical and physical properties, the bio-oil was found to be directly miscible with fossil diesel when blended at a volume ratio of 50:50. The mass balance closure was 44wt.% synthesis gas, with a H 2 content of 36vol% and HHV of 17.23MJ/Nm 3 , and 31 wt.% char with a HHV of 17MJ/kg. The production of high quantities of H 2 gas and highly de-oxygenated organic liquids makes downstream hydrogen separation and subsequent hydro-deoxygenation of the produced bio-oil a promising upgrading step to achieve drop-in transportation fuels from MSW. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Hot char-catalytic reforming of volatiles from MSW pyrolysis

    International Nuclear Information System (INIS)

    Wang, Na; Chen, Dezhen; Arena, Umberto; He, Pinjing

    2017-01-01

    Highlights: • Volatile from MSW pyrolysis is reformed with hot char from the same pyrolysis process. • The yields of syngas increase evidently with H 2 being the main contributor and the major component of the syngas. • Pyrolysis oil becomes light and its composition distribution is narrowed. • The HHV, volatile elements and alkali metals contents in the char decrease. • The emissions including SO 2 , NO, NO 2 and HCN changed after reforming process. - Abstract: Volatile products obtained from pyrolysis of municipal solid waste (MSW), including syngas and pyrolysis oil, were forced to contact the hot char from the same pyrolysis process at 500–600 °C in a fixed bed reactor to be reformed. The yields and properties of syngas, char and pyrolysis liquid were investigated; and the energy re-distribution among the products due to char reforming was quantified. The preliminary investigation at lab scale showed that hot char-catalytic reforming of the volatiles leads to an increase in the dry syngas yield from 0.25 to 0.37 N m 3 kg −1 MSW at 550 °C. Accordingly, the carbon conversion ratio into syngas increases from 29.6% to 35.0%; and the MSW chemical energy transferred into syngas increased from 41.8% to 47.4%. The yield of pyrolysis liquid products, including pyrolysis oil and water, decreased from 27.3 to 16.5 wt%, and the molecular weight of the oil becoming lighter. Approximately 60% of the water vapour contained in the volatiles converted into syngas. After reforming, the concentrations of SO 2 and HCN in the syngas decreases, while those of NO and NO 2 increase. The char concentrations of N, H, C and alkali metal species decreased and its higher heating value decreased too.

  5. Grid Connected Solar PV System with SEPIC Converter Compared with Parallel Boost Converter Based MPPT

    Directory of Open Access Journals (Sweden)

    T. Ajith Bosco Raj

    2014-01-01

    Full Text Available The main objective of this work is to study the behaviour of the solar PV systems and model the efficient Grid-connected solar power system. The DC-DC MPPT circuit using chaotic pulse width modulation has been designed to track maximum power from solar PV module. The conversion efficiency of the proposed MPPT system is increased when CPWM is used as a control scheme. This paper also proposes a simplified multilevel (seven level inverter for a grid-connected photovoltaic system. The primary goal of these systems is to increase the energy injected to the grid by keeping track of the maximum power point of the panel, by reducing the switching frequency, and by providing high reliability. The maximum power has been tracked experimentally. It is compared with parallel boost converter. Also this model is based on mathematical equations and is described through an equivalent circuit including a PV source with MPPT, a diode, a series resistor, a shunt resistor, and dual boost converter with active snubber circuit. This model can extract PV power and boost by using dual boost converter with active snubber. By using this method the overall system efficiency is improved thereby reducing the switching losses and cost.

  6. Development of a test platform for controlling parallel converters

    DEFF Research Database (Denmark)

    Bede, Lorand; Kopacz, Csaba; Kerekes, Tamas

    2014-01-01

    As renewable energy contributes more and more in the power generation, bigger and more efficient power converters are used to integrate these energy sources into the power grid. Paralleling the power converters, is an accepted method to reduce the size of the passive elements and losses. By making...... a proper interleaving angle between the converters the current ripple can be reduced considerably. In order to be able to investigate the performance of these converters a safe and cheap platform is essential. The development of a test platform for such an application is challenging, since a proper...... synchronization has to be established between the converters. In this paper a universal platform is presented, which allows to parallel n converters with arbitrary interleaving angle between each other....

  7. Synchronously Driven Power Converter Controller Solution for MedAustron

    CERN Document Server

    Šepetavc, Luka; Tavčar, Rok; Moser, Roland; Gutleber, Johannes

    2011-01-01

    MedAustron is an ion beam cancer therapy and research centre currently under construction in Wiener Neustadt, Austria. This facility features a synchrotron particle accelerator for light ions. Cosylab is closely working together with MedAustron on the development of a power converter controller (PCC) for the 260 deployed power converters – power supplies. Power converters deliver power to magnets used for focusing and steering particle beams. We have designed and developed software and hardware which allows integration of different types of power converters into MedAustron's control system (MACS). PCC's role is to synchronously control and monitor connected power converters. Custom real-time fibre optics link and modular front end devices have been designed for this purpose. Modular front end devices make it possible to interface with almost any type of power converter – with or without built in regulation logic. We implemented realtime mechanisms and a dedicated real-time fibre link to ...

  8. PV source based high voltage gain current fed converter

    Science.gov (United States)

    Saha, Soumya; Poddar, Sahityika; Chimonyo, Kudzai B.; Arunkumar, G.; Elangovan, D.

    2017-11-01

    This work involves designing and simulation of a PV source based high voltage gain, current fed converter. It deals with an isolated DC-DC converter which utilizes boost converter topology. The proposed converter is capable of high voltage gain and above all have very high efficiency levels as proved by the simulation results. The project intends to produce an output of 800 V dc from a 48 V dc input. The simulation results obtained from PSIM application interface were used to analyze the performance of the proposed converter. Transformer used in the circuit steps up the voltage as well as to provide electrical isolation between the low voltage and high voltage side. Since the converter involves high switching frequency of 100 kHz, ultrafast recovery diodes are employed in the circuitry. The major application of the project is for future modeling of solar powered electric hybrid cars.

  9. Distance relay performance in future converter dominated power systems

    DEFF Research Database (Denmark)

    Sarkar, Moumita; Jia, Jundi; Yang, Guangya

    2017-01-01

    relay is major concern as miscoordination of backup relays in case of cascading faults can lead to severe stress in system, which can develop into blackout. In this paper, response of relays in traditional system is compared with response of relays in low short-circuit-current power systems. Impact...... of converter controls on fault current response of converter-based generations is also investigated. Index Terms—Converter control, distance relays, power system protection, system modelling.......Increasing penetration of converter-based generations in power system has led to new system challenges. Short circuit power response from converter-based generations is different from that of traditional synchronous generators. Power electronic converters can be designed for over-current only up...

  10. Grid Converters for Stationary Battery Energy Storage Systems

    DEFF Research Database (Denmark)

    Trintis, Ionut

    to hours, rated at MW and MWh, battery energy storage systems are suitable and ecient solutions. Grid connection of the storage system can be done at dierent voltage levels, depending on the location and application scenario. For high power and energy ratings, increase in the battery and converter voltage...... was realized for a 100 kW active rectier to be used in a 6 kV battery energy storage test bench. In the second part, dierent solutions for power converters to interface energy storage units to medium voltage grid are given. A new modular multilevel converter concept is introduced, where the energy storage......-voltage 100 kW bidirectional grid converter, to be used in a high voltage battery energy storage test bench. The control structure proved to be stable without damping. The converter was tested in the test bench and the experimental results are presented. Multilevel converters are replacing the classical two...

  11. High Voltage Bi-directional Flyback Converter for Capacitive Actuator

    DEFF Research Database (Denmark)

    Thummala, Prasanth; Zhang, Zhe; Andersen, Michael A. E.

    2013-01-01

    This paper presents a high voltage DC-DC converter topology for bi-directional energy transfer between a low voltage DC source and a high voltage capacitive load. The topology is a bi-directional flyback converter with variable switching frequency control during the charge mode, and constant...... switching frequency control during the discharge mode. The converter is capable of charging the capacitive load from 24 V DC source to 2.5 kV, and discharges it to 0 V. The flyback converter has been analyzed in detail during both charge and discharge modes, by considering all the parasitic elements...... in the converter, including the most dominating parameters of the high voltage transformer viz., self-capacitance and leakage inductance. The specific capacitive load for this converter is a dielectric electro active polymer (DEAP) actuator, which can be used as an effective replacement for conventional actuators...

  12. Serum angiotensin converting enzyme in pemphigus vulgaris

    Directory of Open Access Journals (Sweden)

    Reza M Robati

    2014-01-01

    Full Text Available Background: Pemphigus vulgaris is an autoimmune blistering skin disease with unknown etiology. Drugs such as angiotensin-converting enzyme (ACE inhibitors may contribute in the pathogenesis of pemphigus. Objective: We plan this essay to evaluate the serum ACE level in pemphigus vulgaris patients in comparison with healthy controls to recognize its possible role in disease pathogenesis or activity. Methods: This study was planned and performed in the dermatology clinics of Shahid Beheshti University of MedicalSciences′ Hospitals between July 2010 and June 2011. Patients with new onset of pemphigus vulgaris were enrolled in our study. Control subjects were frequency-matched to cases by sex and age. Serum ACE was determined by the spectrophotometric method. Results: Thirty-four patients with pemphigus vulgaris and 35 healthy individuals were recruited in the study. No statistical significant difference was detected in the mean level of serum ACE of the two groups (t-test, P = 0.11. The mean ACE level was significantly lower in male patients compared with male controls (P = 0.04. Moreover, a significant higher serum ACE level of patients with cutaneous involvement was observed compared to patients with mucosal involvement (P = 0.02. Conclusions: Despite lack of any significant difference of serum ACE level between pemphigus and control group, the serum ACE level was considerably lower in male pemphigus vulgaris patients compared with male controls. Therefore, ACE might have some association with pemphigus vulgaris especially in male patients; however, further studies are required to confirm this association.

  13. Structural Loads Analysis for Wave Energy Converters

    Energy Technology Data Exchange (ETDEWEB)

    van Rij, Jennifer A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Yu, Yi-Hsiang [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Guo, Yi [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-06-03

    This study explores and verifies the generalized body-modes method for evaluating the structural loads on a wave energy converter (WEC). Historically, WEC design methodologies have focused primarily on accurately evaluating hydrodynamic loads, while methodologies for evaluating structural loads have yet to be fully considered and incorporated into the WEC design process. As wave energy technologies continue to advance, however, it has become increasingly evident that an accurate evaluation of the structural loads will enable an optimized structural design, as well as the potential utilization of composites and flexible materials, and hence reduce WEC costs. Although there are many computational fluid dynamics, structural analyses and fluid-structure-interaction (FSI) codes available, the application of these codes is typically too computationally intensive to be practical in the early stages of the WEC design process. The generalized body-modes method, however, is a reduced order, linearized, frequency-domain FSI approach, performed in conjunction with the linear hydrodynamic analysis, with computation times that could realistically be incorporated into the WEC design process.

  14. Image processing to optimize wave energy converters

    Science.gov (United States)

    Bailey, Kyle Marc-Anthony

    The world is turning to renewable energies as a means of ensuring the planet's future and well-being. There have been a few attempts in the past to utilize wave power as a means of generating electricity through the use of Wave Energy Converters (WEC), but only recently are they becoming a focal point in the renewable energy field. Over the past few years there has been a global drive to advance the efficiency of WEC. Placing a mechanical device either onshore or offshore that captures the energy within ocean surface waves to drive a mechanical device is how wave power is produced. This paper seeks to provide a novel and innovative way to estimate ocean wave frequency through the use of image processing. This will be achieved by applying a complex modulated lapped orthogonal transform filter bank to satellite images of ocean waves. The complex modulated lapped orthogonal transform filterbank provides an equal subband decomposition of the Nyquist bounded discrete time Fourier Transform spectrum. The maximum energy of the 2D complex modulated lapped transform subband is used to determine the horizontal and vertical frequency, which subsequently can be used to determine the wave frequency in the direction of the WEC by a simple trigonometric scaling. The robustness of the proposed method is provided by the applications to simulated and real satellite images where the frequency is known.

  15. Do selvagem convertível

    Directory of Open Access Journals (Sweden)

    Andréa Daher

    Full Text Available A atitude de tolerância frente à alteridade indígena e a representação do índio tupinambá docilmente "convertível" contidas no relato do capuchinho Claude d'Abbeville,Histoire de la Mission... en l'isle de Maragnan (1614, são claramente tributárias do livro do huguenote Jean de Léry,Histoire d'un voyage fait en la terre du Brésil (1578. O capuchinho parafraseia o huguenote em várias passagens, mostrando o índio como objeto de análise "etnográfica", sem excluí-lo - como faz Léry - da possibilidade de salvação. Provavelmente, Claude d'Abbeville responde, desta forma, às expectativas do público francês, num contexto de exortação à colonização do Maranhão e de propaganda da obra apostólica da Ordem dos Capuchinhos.

  16. Effect of support on the catalytic activity of manganese oxide catalyts for toluene combustion

    Energy Technology Data Exchange (ETDEWEB)

    Pozan, Gulin Selda, E-mail: gpozan@istanbul.edu.tr [Istanbul University, Faculty of Engineering, Chemical Engineering Department, Avcilar 34320, Istanbul (Turkey)

    2012-06-30

    Highlights: Black-Right-Pointing-Pointer {alpha}-Al{sub 2}O{sub 3}, obtained from Bohmite, as a support for enhancing of the activity. Black-Right-Pointing-Pointer The support material for catalytic oxidation. Black-Right-Pointing-Pointer The manganese state and oxygen species effect on the catalytic combustion reaction. - Abstract: The aim of this work was to study combustion of toluene (1000 ppm) over MnO{sub 2} modified with different supports. {alpha}-Al{sub 2}O{sub 3} and {gamma}-Al{sub 2}O{sub 3} obtained from Boehmite, {gamma}-Al{sub 2}O{sub 3} (commercial), SiO{sub 2}, TiO{sub 2} and ZrO{sub 2} were used as commercial support materials. In view of potential interest of this process, the influence of support material on the catalytic performance was discussed. The deposition of 9.5MnO{sub 2} was performed by impregnation over support. The catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), temperature programmed reduction and oxidation (TPR/TPO) and thermogravimetric analysis (TGA). The catalytic tests were carried out at atmospheric pressure in a fixed-bed flow reactor. 9.5MnO{sub 2}/{alpha}-Al{sub 2}O{sub 3}(B) (synthesized from Boehmite) catalyst exhibits the highest catalytic activity, over which the toluene conversion was up to 90% at a temperature of 289 Degree-Sign C. Considering all the characterization and reaction data reported in this study, it was concluded that the manganese state and oxygen species played an important role in the catalytic activity.

  17. Effect of support on the catalytic activity of manganese oxide catalyts for toluene combustion

    International Nuclear Information System (INIS)

    Pozan, Gulin Selda

    2012-01-01

    Highlights: ► α-Al 2 O 3 , obtained from Bohmite, as a support for enhancing of the activity. ► The support material for catalytic oxidation. ► The manganese state and oxygen species effect on the catalytic combustion reaction. - Abstract: The aim of this work was to study combustion of toluene (1000 ppm) over MnO 2 modified with different supports. α-Al 2 O 3 and γ-Al 2 O 3 obtained from Boehmite, γ-Al 2 O 3 (commercial), SiO 2 , TiO 2 and ZrO 2 were used as commercial support materials. In view of potential interest of this process, the influence of support material on the catalytic performance was discussed. The deposition of 9.5MnO 2 was performed by impregnation over support. The catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), temperature programmed reduction and oxidation (TPR/TPO) and thermogravimetric analysis (TGA). The catalytic tests were carried out at atmospheric pressure in a fixed-bed flow reactor. 9.5MnO 2 /α-Al 2 O 3 (B) (synthesized from Boehmite) catalyst exhibits the highest catalytic activity, over which the toluene conversion was up to 90% at a temperature of 289 °C. Considering all the characterization and reaction data reported in this study, it was concluded that the manganese state and oxygen species played an important role in the catalytic activity.

  18. Power Converters Maximize Outputs Of Solar Cell Strings

    Science.gov (United States)

    Frederick, Martin E.; Jermakian, Joel B.

    1993-01-01

    Microprocessor-controlled dc-to-dc power converters devised to maximize power transferred from solar photovoltaic strings to storage batteries and other electrical loads. Converters help in utilizing large solar photovoltaic arrays most effectively with respect to cost, size, and weight. Main points of invention are: single controller used to control and optimize any number of "dumb" tracker units and strings independently; power maximized out of converters; and controller in system is microprocessor.

  19. Heterogeneous catalytic materials solid state chemistry, surface chemistry and catalytic behaviour

    CERN Document Server

    Busca, Guido

    2014-01-01

    Heterogeneous Catalytic Materials discusses experimental methods and the latest developments in three areas of research: heterogeneous catalysis; surface chemistry; and the chemistry of catalysts. Catalytic materials are those solids that allow the chemical reaction to occur efficiently and cost-effectively. This book provides you with all necessary information to synthesize, characterize, and relate the properties of a catalyst to its behavior, enabling you to select the appropriate catalyst for the process and reactor system. Oxides (used both as catalysts and as supports for cata

  20. A SOFT SWITCHED INTERLEAVED HIGH GAIN DC-DC CONVERTER

    Directory of Open Access Journals (Sweden)

    SHESHIDHAR REDDY ADDULA

    2017-09-01

    Full Text Available In this paper, a novel soft-switched interleaved DC-DC converter which provides a high voltage gain of 12 is proposed. Voltage gain of the basic interleaved boost converter is extended by using diode-capacitor multiplier (DCM cells. The switches are operated at a nominal duty ratio of 0.5. The voltage stress on the power switches and diodes is only a fraction of the output voltage. To enhance the operating power conversion efficiency, the switches are turned ON at zero voltage condition. Experimental results of 18-216V, 100W prototype converter validate the operating principle and the advantageous features of the presented converter.

  1. Analysis and Design of Embedded Controlled Parallel Resonant Converter

    Directory of Open Access Journals (Sweden)

    P. CHANDRASEKHAR

    2009-07-01

    Full Text Available Microcontroller based constant frequency controlled full bridge LC parallel resonant converter is presented in this paper for electrolyser application. An electrolyser is a part of renewable energy system which generates hydrogen from water electrolysis. The DC power required by the electrolyser system is supplied by the DC-DC converter. Owing to operation under constant frequency, the filter designs are simplified and utilization of magnetic components is improved. This converter has advantages like high power density, low EMI and reduced switching stresses. DC-DC converter system is simulated using MATLAB, Simulink. Detailed simulation results are presented. The simulation results are compared with the experimental results.

  2. Number-to-voltage converter on commutated condensers

    International Nuclear Information System (INIS)

    Grekhov, Yu.N.

    1975-01-01

    A code-voltage converter using precision voltage dividers based on commutated capacitors [1] is described which is distinguished by the absence of precision elements. Each digit includes eight field-effect transistors in two 1KT682 microcircuit assemblies and three microcapacitors with a conventional unstable capacitance 6200 pF +- 50%. The converter has a speed of response that is not inferior to that of converters based on R-2R matrices, while in time stability of the characteristics, low interference level, and low output impedance it is superior to such converters

  3. Fast parallel-series analog-to-digital converter

    International Nuclear Information System (INIS)

    Pogosov, A.Yu.

    1987-01-01

    Fast analog-to-digital converters are used in systems for detection of rapid processes, nuclear spectroscopy. A 12-digit analog-to-digital converter with conversion time of 160 ns and conversion frequency of 8.3 MHz is described; a segmented digital-to-analog converter with differential non-linearity of < 0.01% and a differential amplifier-limiter with setting time of 80 ns at the error of 0.2% are utilized in the converter; a control device is based on the chain of flip-flop circuit

  4. High Efficiency Hall Thruster Discharge Power Converter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Busek leveraged previous, internally sponsored, high power, Hall thruster discharge converter development which allowed it to design, build, and test new printed...

  5. A new configuration for multilevel converters with diode clamped topology

    DEFF Research Database (Denmark)

    Nami, A.; Zare, F.; Ledwich, G.

    2008-01-01

    Due to the increased use of renewable energy and power elctronic applications, more multilevel converters (MLC) are developed. A Neutral Point Clamped (NPC) inverter is one of the most used multilevel topologies for wind turbine (WT) and photovoltaic (PV) applications. One of the most crucial...... points in this type of converter is dc-voltage control. In this paper, a novel multi output dc-dc converter connected to a diode clamped topology is presented. This converter, for a given duty cycles, is able to regulate the capacitor voltage to provide an appropriate input voltage for NPC regardless...

  6. Development of a wind converter and investigation of its operational function. Part 1: Technical description of the wind energy converter

    Science.gov (United States)

    Molly, J. P.; Steinheber, R.

    1982-11-01

    A 10 kW wind energy converter was developed by using as far possible standard serial production parts. The design criteria and the description of the essential machinery components of the MODA 10 wind energy converter are discussed. For some special load cases the safety calculation of the important components is shown. The blade control system which qualified for small wind energy converters, is explained. Weight and cost of the MODA 10 are considered.

  7. Protein structure based prediction of catalytic residues

    Science.gov (United States)

    2013-01-01

    Background Worldwide structural genomics projects continue to release new protein structures at an unprecedented pace, so far nearly 6000, but only about 60% of these proteins have any sort of functional annotation. Results We explored a range of features that can be used for the prediction of functional residues given a known three-dimensional structure. These features include various centrality measures of nodes in graphs of interacting residues: closeness, betweenness and page-rank centrality. We also analyzed the distance of functional amino acids to the general center of mass (GCM) of the structure, relative solvent accessibility (RSA), and the use of relative entropy as a measure of sequence conservation. From the selected features, neural networks were trained to identify catalytic residues. We found that using distance to the GCM together with amino acid type provide a good discriminant function, when combined independently with sequence conservation. Using an independent test set of 29 annotated protein structures, the method returned 411 of the initial 9262 residues as the most likely to be involved in function. The output 411 residues contain 70 of the annotated 111 catalytic residues. This represents an approximately 14-fold enrichment of catalytic residues on the entire input set (corresponding to a sensitivity of 63% and a precision of 17%), a performance competitive with that of other state-of-the-art methods. Conclusions We found that several of the graph based measures utilize the same underlying feature of protein structures, which can be simply and more effectively captured with the distance to GCM definition. This also has the added the advantage of simplicity and easy implementation. Meanwhile sequence conservation remains by far the most influential feature in identifying functional residues. We also found that due the rapid changes in size and composition of sequence databases, conservation calculations must be recalibrated for specific

  8. Converting hard copy documents for electronic dissemination

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, F.

    1994-12-31

    Since the advent of computer systems, the goal of a paperless office, and even a paperless society, has been pursued. While the normal paper flow in an organization is far from totally automated, particularly for items requiring signatures or authorizations, electronic information dissemination is becoming an almost simple task. The reasons for providing on-line documents are many and include faster and easier access for everyone, elimination of printing costs, reduction of wasted shelf and desk space, and the security of having a centrally-located, always up-to-date document. New computer software even provides the user with the ability to annotate documents and to have bookmarks so that the old scribbled-in and dog-eared manual can be replaced without loosing this `customizability`. Moreover, new hypermedia capabilities mean that documents can be read in a non-linear fashion and can include color figures and photographs, audio, and even animation sequences, capabilities which exceed those of paper. The proliferation of network-based information servers, coupled with the growth of the Internet, has enticed academic, governmental, and even commercial organizations to provide increasing numbers of documents and data bases in electronic form via the network, not just to internal staff, but to the public as well. Much of this information, which includes everything from mundane company procedures to spiffy marketing brochures, was previously published only in hard copy. Converting existing documents to electronic form and producing only electronic versions of new documents poses some interesting challenges to the maintainer or author.

  9. Catalytic bioscavengers in nerve agent poisoning: A promising approach?

    Science.gov (United States)

    Worek, Franz; Thiermann, Horst; Wille, Timo

    2016-02-26

    The repeated use of the nerve agent sarin against civilians in Syria in 2013 emphasizes the continuing threat by chemical warfare agents. Multiple studies demonstrated a limited efficacy of standard atropine-oxime treatment in nerve agent poisoning and called for the development of alternative and more effective treatment strategies. A novel approach is the use of stoichiometric or catalytic bioscavengers for detoxification of nerve agents in the systemic circulation prior to distribution into target tissues. Recent progress in the design of enzyme mutants with reversed stereo selectivity resulting in improved catalytic activity and their use in in vivo studies supports the concept of catalytic bioscavengers. Yet, further research is necessary to improve the catalytic activity, substrate spectrum and in vivo biological stability of enzyme mutants. The pros and cons of catalytic bioscavengers will be discussed in detail and future requirements for the development of catalytic bioscavengers will be proposed. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  10. Plasma-catalytic reforming of liquid hydrocarbons

    International Nuclear Information System (INIS)

    Nedybaliuk, O.A.; Chernyak, V.Ya; Kolgan, V.V.; Iukhymenko, V.V.; Solomenko, O.V.; Fedirchyk, I.I.; Martysh, E.V.; Demchina, V.P.; Klochok, N.V.; Dragnev, S.V.

    2015-01-01

    The series of experiments studying the plasma-catalytic reforming of liquid hydrocarbons was carried out. The dynamic plasma-liquid system based on a low-power rotating gliding arc with solid electrodes was used for the investigation of liquid hydrocarbons reforming process. Conversion was done via partial oxidation. A part of oxidant flow was activated by the discharge. Synthesis-gas composition was analysed by means of mass-spectrometry and gas-chromatography. A standard boiler, which operates on natural gas and LPG, was used for the burning of synthesis-gas

  11. Catalytic oxidation of soot over alkaline niobates

    International Nuclear Information System (INIS)

    Pecchi, G.; Cabrera, B.; Buljan, A.; Delgado, E.J.; Gordon, A.L.; Jimenez, R.

    2013-01-01

    Highlights: ► No previous reported studies about alkaline niobates as catalysts for soot oxidation. ► NaNbO 3 and KNbO 3 perovskite-type oxides show lower activation energy than other lanthanoid perovskite-type oxides. ► The alkaline niobate does not show deactivation by metal loss. - Abstract: The lack of studies in the current literature about the assessment of alkaline niobates as catalysts for soot oxidation has motivated this research. In this study, the synthesis, characterization and assessment of alkaline metal niobates as catalysts for soot combustion are reported. The solids MNbO 3 (M = Li, Na, K, Rb) are synthesized by a citrate method, calcined at 450 °C, 550 °C, 650 °C, 750 °C, and characterized by AAS, N 2 adsorption, XRD, O 2 -TPD, FTIR and SEM. All the alkaline niobates show catalytic activity for soot combustion, and the activity depends basically on the nature of the alkaline metal and the calcination temperature. The highest catalytic activity, expressed as the temperature at which combustion of carbon black occurs at the maximum rate, is shown by KNbO 3 calcined at 650 °C. At this calcination temperature, the catalytic activity follows an order dependent on the atomic number, namely: KNbO 3 > NaNbO 3 > LiNbO 3 . The RbNbO 3 solid do not follow this trend presumably due to the perovskite structure was not reached. The highest catalytic activity shown by of KNbO 3 , despite the lower apparent activation energy of NaNbO 3 , stress the importance of the metal nature and suggests the hypothesis that K + ions are the active sites for soot combustion. It must be pointed out that alkaline niobate subjected to consecutive soot combustion cycles does not show deactivation by metal loss, due to the stabilization of the alkaline metal inside the perovskite structure.

  12. Catalytic wet oxidation of black liquor

    OpenAIRE

    Viader Riera, Gerard

    2012-01-01

    The major aspects of wet air oxidation and catalytic wet air oxidation have been reviewed in this work paying special attention to the reaction mechanisms, kinetics and the industrial process. In the experimental section a set of heterogeneous catalysts have been tested in the wet oxidation of non-wood black liquor. The oxidation runs were performed batchwise in a laboratory-scale mechanically stirred slurry reactor for 1 h at a temperature of 170°C and total pressure of 12 bar. Pure oxygen w...

  13. Atomic Distribution in Catalytic Amorphous Metals

    Directory of Open Access Journals (Sweden)

    Sanghita Mridha

    2015-01-01

    Full Text Available The atomic distribution in catalytically active metallic glass alloys, Pd43Cu27Ni10P20 and Pt57.5Cu14.7Ni5.3P22.5, was investigated using three-dimensional atom probe microscopy. Atom probe analysis showed uniform distribution of constituent elements for both the starting amorphous alloys, with no phase separation. Both the crystallized alloys showed eutectic microstructure with a very sharp interface (~0.5 nm as determined from atom probe. The atomic distribution in the devitrified state is explained based on the “fragile liquid” behavior for these noble-metal glassy alloys.

  14. Catalytic Synthesis of Nitriles in Continuous Flow

    DEFF Research Database (Denmark)

    Nordvang, Emily Catherine

    , alternative path to acetonitrile from ethanol via the oxidative dehydrogenation of ethylamine. The catalytic activity and product ratios of the batch and continuous flow reactions are compared and the effect of reaction conditions on the reaction is investigated. The effects of ammonia in the reaction...... dehydrogenation of ethylamine and post-reaction purging.Chapter 4 outlines the application of RuO2/Al2O3 catalysts to the oxidative dehydrogenation of benzylamine in air, utilizing a new reaction setup. Again, batch and continuous flow reactions are compared and the effects of reaction conditions, ammonia...

  15. Methane combustion in catalytic premixed burners

    International Nuclear Information System (INIS)

    Cerri, I.; Saracco, G.; Specchia, V.

    1999-01-01

    Catalytic premixed burners for domestic boiler applications were developed with the aim of achieving a power modularity from 10 to 100% and pollutant emissions limited to NO x 2 , where the combustion took place entirely inside the burner heating it to incandescence and allowing a decrease in the flame temperature and NO x emissions. Such results were confirmed through further tests carried out in a commercial industrial-scale boiler equipped with the conical panels. All the results, by varying the excess air and the heat power employed, are presented and discussed [it

  16. Tritium stripping by a catalytic exchange stripper

    International Nuclear Information System (INIS)

    Heung, L.K.; Gibson, G.W.; Ortman, M.S.

    1991-01-01

    A catalytic exchange process for stripping elemental tritium from gas streams has been demonstrated. The process uses a catalyzed isotopic exchange reaction between tritium in the gas phase and protium or deuterium in the solid phase on alumina. The reaction is catalyzed by platinum deposited on the alumina. The process has been tested with both tritium and deuterium. Decontamination factors (ration of inlet and outlet tritium concentrations) as high as 1000 have been achieved, depending on inlet concentration. The test results and some demonstrated applications are presented

  17. Direct catalytic hydrothermal liquefaction of spirulina to biofuels with hydrogen

    Science.gov (United States)

    Zeng, Qin; Liao, Hansheng; Zhou, Shiqin; Li, Qiuping; Wang, Lu; Yu, Zhihao; Jing, Li

    2018-01-01

    We report herein on acquiring biofuels from direct catalytic hydrothermal liquefaction of spirulina. The component of bio-oil from direct catalytic hydrothermal liquefaction was similar to that from two independent processes (including liquefaction and upgrading of biocrude). However, one step process has higher carbon recovery, due to the less loss of carbons. It was demonstrated that the yield and HHV of bio-oil from direct catalytic algae with hydrothermal condition is higher than that from two independent processes.

  18. A study on naphtha catalytic reforming reactor simulation and analysis.

    Science.gov (United States)

    Liang, Ke-min; Guo, Hai-yan; Pan, Shi-wei

    2005-06-01

    A naphtha catalytic reforming unit with four reactors in series is analyzed. A physical model is proposed to describe the catalytic reforming radial flow reactor. Kinetics and thermodynamics equations are selected to describe the naphtha catalytic reforming reactions characteristics based on idealizing the complex naphtha mixture by representing the paraffin, naphthene, and aromatic groups by single compounds. The simulation results based above models agree very well with actual operation unit data.

  19. A study on naphtha catalytic reforming reactor simulation and analysis

    OpenAIRE

    Liang, Ke-min; Guo, Hai-yan; Pan, Shi-wei

    2005-01-01

    A naphtha catalytic reforming unit with four reactors in series is analyzed. A physical model is proposed to describe the catalytic reforming radial flow reactor. Kinetics and thermodynamics equations are selected to describe the naphtha catalytic reforming reactions characteristics based on idealizing the complex naphtha mixture by representing the paraffin, naphthene, and aromatic groups by single compounds. The simulation results based above models agree very well with actual operation uni...

  20. Including lateral interactions into microkinetic models of catalytic reactions

    DEFF Research Database (Denmark)

    Hellman, Anders; Honkala, Johanna Karoliina

    2007-01-01

    In many catalytic reactions lateral interactions between adsorbates are believed to have a strong influence on the reaction rates. We apply a microkinetic model to explore the effect of lateral interactions and how to efficiently take them into account in a simple catalytic reaction. Three differ...... different approximations are investigated: site, mean-field, and quasichemical approximations. The obtained results are compared to accurate Monte Carlo numbers. In the end, we apply the approximations to a real catalytic reaction, namely, ammonia synthesis....

  1. Studies of coupled chemical and catalytic coal conversion methods. Tenth quarterly report, January--March 1990

    Energy Technology Data Exchange (ETDEWEB)

    Stock, L.M.

    1990-12-31

    This report concerns our research on base-catalyzed coal solubilization and a new approach for hydrogen addition. The work on base-catalyzed, chemical solubilization is continuing. this report is focused on the hydrogenation research. Specifically it deals with the use of arene chromium carbonyl complexes as reagents for the addition of dideuterium to coal molecules. In one phase of the work, he has established that the aromatic hydrocarbons in a representative coal liquid can be converted in very good yield to arene chromium carbonyl compounds. In a second phase of the work directly related to our objective of improved methods for catalytic hydrogenation, he has established that the aromatic constituents of the same coal liquid add dideuterium in the presence of added napththalene chromium carbonyl.

  2. Catalytic oxidative conversion of cellulosic biomass to formic acid and acetic acid with exceptionally high yields

    KAUST Repository

    Zhang, Jizhe

    2014-09-01

    Direct conversion of raw biomass materials to fine chemicals is of great significance from both economic and ecological perspectives. In this paper, we report that a Keggin-type vanadium-substituted phosphomolybdic acid catalyst, namely H4PVMo11O40, is capable of converting various biomass-derived substrates to formic acid and acetic acid with high selectivity in a water medium and oxygen atmosphere. Under optimized reaction conditions, H4PVMo11O40 gave an exceptionally high yield of formic acid (67.8%) from cellulose, far exceeding the values achieved in previous catalytic systems. Our study demonstrates that heteropoly acids are generally effective catalysts for biomass conversion due to their strong acidities, whereas the composition of metal addenda atoms in the catalysts has crucial influence on the reaction pathway and the product selectivity. © 2013 Elsevier B.V.

  3. Pyrolysis and catalytic pyrolysis as a recycling method of waste CDs originating from polycarbonate and HIPS.

    Science.gov (United States)

    Antonakou, E V; Kalogiannis, K G; Stephanidis, S D; Triantafyllidis, K S; Lappas, A A; Achilias, D S

    2014-12-01

    Pyrolysis appears to be a promising recycling process since it could convert the disposed polymers to hydrocarbon based fuels or various useful chemicals. In the current study, two model polymers found in WEEEs, namely polycarbonate (PC) and high impact polystyrene (HIPS) and their counterparts found in waste commercial Compact Discs (CDs) were pyrolysed in a bench scale reactor. Both, thermal pyrolysis and pyrolysis in the presence of two catalytic materials (basic MgO and acidic ZSM-5 zeolite) was performed for all four types of polymers. Results have shown significant recovery of the monomers and valuable chemicals (phenols in the case of PC and aromatic hydrocarbons in the case of HIPS), while catalysts seem to decrease the selectivity towards the monomers and enhance the selectivity towards other desirable compounds. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. A Highly Efficient Heterogenized Iridium Complex for the Catalytic Hydrogenation of Carbon Dioxide to Formate.

    Science.gov (United States)

    Park, Kwangho; Gunasekar, Gunniya Hariyanandam; Prakash, Natarajan; Jung, Kwang-Deog; Yoon, Sungho

    2015-10-26

    A heterogenized catalyst on a highly porous covalent triazine framework was synthesized and characterized to have a coordination environment similar to that of its homogeneous counterpart. The catalyst efficiently converted CO2 into formate through hydrogenation with a turnover number of 5000 after 2 h and an initial turnover frequency of up to 5300 h(-1) ; both of these values are the highest reported to date for a heterogeneous catalyst, which makes it attractive toward industrial application. Furthermore, the synthesized catalyst was found to be stable in air and was recycled by simple filtration without significant loss of catalytic activity. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Integration of decentralized torrefaction with centralized catalytic pyrolysis to produce green aromatics from coffee grounds.

    Science.gov (United States)

    Chai, Li; Saffron, Christopher M; Yang, Yi; Zhang, Zhongyu; Munro, Robert W; Kriegel, Robert M

    2016-02-01

    The aim of this work was to integrate decentralized torrefaction with centralized catalytic pyrolysis to convert coffee grounds into the green aromatic precursors of terephthalic acid, namely benzene, toluene, ethylbenzene, and xylenes (BTEX). An economic analysis of this bioproduct system was conducted to examine BTEX yields, biomass costs and their sensitivities. Model predictions were verified experimentally using pyrolysis GC/MS to quantify BTEX yields for raw and torrefied biomass. The production cost was minimized when the torrefier temperature and residence time were 239°C and 34min, respectively. This optimization study found conditions that justify torrefaction as a pretreatment for making BTEX, provided that starting feedstock costs are below $58 per tonne. Copyright © 2015. Published by Elsevier Ltd.

  6. Review of Heterogeneous Catalysts for Catalytically Upgrading Vegetable Oils into Hydrocarbon Biofuels

    Directory of Open Access Journals (Sweden)

    Xianhui Zhao

    2017-03-01

    Full Text Available To address the issues of greenhouse gas emissions associated with fossil fuels, vegetable oilseeds, especially non-food oilseeds, are used as an alternative fuel resource. Vegetable oil derived from these oilseeds can be upgraded into hydrocarbon biofuel. Catalytic cracking and hydroprocessing are two of the most promising pathways for converting vegetable oil to hydrocarbon biofuel. Heterogeneous catalysts play a critical role in those processes. The present review summarizes current progresses and remaining challenges of vegetable oil upgrading to biofuel. The catalyst properties, applications, deactivation, and regeneration are reviewed. A comparison of catalysts used in vegetable oil and bio-oil upgrading is also carried out. Some suggestions for heterogeneous catalysts applied in vegetable oil upgrading to improve the yield and quality of hydrocarbon biofuel are provided for further research in the future.

  7. Nanostructured Catalytic Reactors for Air Purification, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I project proposes the development of lightweight compact nanostructured catalytic reactors for air purification from toxic gaseous organic...

  8. Nanostructured Catalytic Reactors for Air Purification, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase II project proposes the development of lightweight compact nanostructured catalytic reactors for air purification from toxic gaseous organic...

  9. Catalytically favorable surface patterns in Pt-Au nanoclusters

    KAUST Repository

    Mokkath, Junais Habeeb

    2013-01-01

    Motivated by recent experimental demonstrations of novel PtAu nanoparticles with highly enhanced catalytic properties, we present a systematic theoretical study that explores principal catalytic indicators as a function of the particle size and composition. We find that Pt electronic states in the vicinity of the Fermi level combined with a modified electron distribution in the nanoparticle due to Pt-to-Au charge transfer are the origin of the outstanding catalytic properties. From our model we deduce the catalytically favorable surface patterns that induce ensemble and ligand effects. © The Royal Society of Chemistry 2013.

  10. Microwave Catalytic Oxidation of Hydrocarbons in Aqueous Solutions

    National Research Council Canada - National Science Library

    Cha, Chang

    2003-01-01

    .... A sufficient amount of experimental work has been completed evaluating the performance of the microwave catalytic oxidation process and determining the effect of different operating parameters...

  11. Catalytic conversion of methanol to light olefins

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C.S.; Stead, G.E.

    1987-05-12

    A process is described for converting a methanol-containing feed to an olefin-containing hydrocarbon product having a propylene-methylene weight ratio of at least 35.1:6.4. The process comprises contacting the methanol-containing feed in a reaction zone under methanol conversion conditions with a ZSM-12 zeolite catalyst modified by incorporation of a minor amount of a modifier selected from magnesium oxide, manganese oxide and a combination of both magnesium oxide and manganese oxide.

  12. A New Perspective for Modeling Power Electronics Converters : Complementarity Framework

    NARCIS (Netherlands)

    Vasca, Francesco; Iannelli, Luigi; Camlibel, M. Kanat; Frasca, Roberto

    2009-01-01

    The switching behavior of power converters with "ideal" electronic devices (EDs) makes it difficult to define a switched model that describes the dynamics of the converter in all possible operating conditions, i.e., a "complete" model. Indeed, simplifying assumptions on the sequences of modes are

  13. Converting Geometry from Creo Parametric to BRL-CAD

    Science.gov (United States)

    2017-06-28

    ARL-SR-0376 ● JUNE 2017 US Army Research Laboratory Converting Geometry from Creo Parametric to BRL- CAD by Clifford W Yapp...to the originator. ARL-SR-0376 ● JUNE 2017 US Army Research Laboratory Converting Geometry from Creo Parametric to BRL- CAD by...

  14. Development of custom radiation-tolerant DCDC converter ASICs

    CERN Document Server

    Faccio, F; Michelis, S; Saggini, S; Fuentes, C; Ongaro, F; Orlandi, S

    2010-01-01

    Based on a detailed study of the radiation tolerance of high-voltage transistors, 2 commercial CMOS technologies have been selected for the design of synchronous buck DCDC converter ASICs. Three prototype converters have been produced, embedding increasingly sophisticated functions. The electrical and radiation performance of these prototypes is presented.

  15. Digital parallel-to-series pulse-train converter

    Science.gov (United States)

    Hussey, J.

    1971-01-01

    Circuit converts number represented as two level signal on n-bit lines to series of pulses on one of two lines, depending on sign of number. Converter accepts parallel binary input data and produces number of output pulses equal to number represented by input data.

  16. Modeling and simulation of matrix converter for wind power generation

    International Nuclear Information System (INIS)

    Masood, F.; Mahmood, T.; Choudhry, M.A.

    2013-01-01

    In this paper, a matrix converter structure is proposed which is suitable for wind power generation applications. The matrix converter (MC) is the most general converter type in the family of AC-AC converters. It is a single-stage converter which has an array of m x n bidirectional power switches to connect, directly, an m- phase voltage source to an n-Phase load. It does not have any DC-link circuit and does not need any large energy storage elements. The key element in a matrix converter is the fully controlled four quadrant bidirectional switch, which allows highfrequency operation. The proposed converter uses MOSFETs as bidirectional switches. The model has been implemented using MATLAB/SIMULINK. The results obtained are presented. The waveforms for input current and output voltage are sinusoidal with very low total harmonic distortion (THD). Low THD is an indication that the model is suitable for wind power generation applications. The simulation results confirm the reduction of conversion losses by 10% to 12% as compared to conventional two stage converters thereby increasing the overall conversion efficiency. The MOSFETs which have been used as switching devices have four to five times more switching frequency as compared to IGBTs thus improving the resulting wave shapes. (author)

  17. Multifunctional Converter Drive for Automotive Electric Power Steering Systems

    NARCIS (Netherlands)

    Hackner, T.J.

    2013-01-01

    In this thesis it is shown that in the case of an automotive electric power steering system, critical pulse power loads can be decoupled from the power net with a storage element and a multifunctional converter. A multifunctional converter system is proposed because it uses the motor drive system as

  18. Utilization of non-linear converters for audio amplification

    DEFF Research Database (Denmark)

    Iversen, Niels Elkjær; Birch, Thomas; Knott, Arnold

    2012-01-01

    . The introduction of non-linear converters for audio amplification defeats this limitation. A Cuk converter, designed to deliver an AC peak output voltage twice the supply voltage, is presented in this paper. A 3V prototype has been developed to prove the concept. The prototype shows that it is possible to achieve...

  19. Wave Dragon Wave Energy Converters Used as Coastal Protection

    DEFF Research Database (Denmark)

    Nørgaard, Jørgen Harck; Andersen, Thomas Lykke; Kofoed, Jens Peter

    2011-01-01

    This paper deals with wave energy converters used to reduce the wave height along shorelines. For this study the Wave Dragon wave energy converter is chosen. The wave height reduction from a single device has been evaluated from physical model tests in scale 1:51.8 of the 260 x 150 m, 24 kW/m mod...

  20. Converted Firearms: A Transnational Problem with Local Harm

    NARCIS (Netherlands)

    de Vries, Marsha

    2012-01-01

    Over the last decade, the Dutch police as well as police forces in several other Western-European countries were confronted with an increase in the availability and use of converted firearms. Converted firearms were originally blank firing weapons, for example gas and alarm pistols, which are